DTC P2198 [AJ (3.0L Duratec)]

DTC P2198	Lack of HO2S-21 switch, sensor indicates rich
DETECTION CONDITION	• The PCM monitors HO2S-21 signal switching during over lean condition at PCM terminal 87. If the PCM no longer detects switching for calibrated amount of time, the PCM determines that HO2S-21 cannot switch from rich to lean.
POSSIBLE CAUSE	• Electrical components malfunction - Short to power supply circuit in wiring between HO2S-21 terminal 4 and PCM terminal 87 - Water in harness connector - Corrosion or poor mating terminals and wiring - Damaged HO2S-21 - Damaged PCM • Fuel system malfunction - Excessive fuel pressure - Leak in fuel injectors - Leaking in fuel pressure regulator - Vapor recovery system • Intake-air system malfunction - Vacuum leaks - PCV system malfunction - Improperly seated engine oil dipstick • EGR system malfunction - Leaking gasket - EGR valve stuck - Vacuum leaking at EGR valve diaphragm or EGR solenoid valve • Base engine malfunction - Oil overfill - Cam timing - Cylinder compression

STEP

INSPECTION

ACTION

1
VERIFY FREEZE FRAME DATA HAS BEEN RECORDED
• Has FREEZE FRAME DATA been recorded?

Yes

Go to the next step.

No

Record the FREEZE FRAME DATA on the repair order, then go to the next step.

2
VERIFY REPAIR INFORMATION AVAILABILITY
• Verify related service repair information availability.

• Is any related repair information available?

Yes

Perform repair or diagnosis according to the available repair information.

If the vehicle is not repaired, go to the next step.

No

Go to the next step.

3
INDETIFY TRIGGER DTC FOR FEEZE FRAME DATA
• Is DTC P2198 on FREEZE FRAME DATA?

Yes

Go to the next step.

No

Go to FREEZE FRAME DATA DTC inspection.

(See DTC TABLE [AJ (3.0L Duratec)].)

4
PERFORM VISUAL INSPECTION

Note

• Address all Continuous Memory Ignition and Misfire DTCs, before KOER DTCs.

• Check visually for following:

- Intake-air for leaks, obstructions and damage.

- Air cleaner element, air cleaner housing for blockage.

- Integrity of the PCV system

- Vacuum leaks

• Were any concerns found during inspection?

Yes

Repair or replace malfunctioning part, then go to Step 41.

No

Go to the next step.

5
CHECK CONDITIONS RELATED TO MAF SENSOR

Note

• Most weather service reports are a local barometric pressure that has been corrected to sea level. However, the BARO PID reports the actual barometric pressure for altitude the vehicle is being diagnosed in Local weather conditions (high or low pressure areas) will change the local barometric pressure by several inches of mercury.

• Connect the WDS or equivalent to DLC.

• Start the engine.

• Access the BARO, LONGFT1, LONGFT2 and MAF V PIDs on fully warmed-up engine.

• Check that the BARO PID is approximately the same as the barometric pressure reading for the location, day and altitude the vehicle is being diagnosed at.

- BARO PID values in PCM memory require updating at high throttle openings. If vehicle is driven down from higher altitudes for diagnosing, complete three or four heavy accelerations at greater than half-throttle to allow BARO PID to update.

- BARO PID must be within +/- 6Hz. (+/- 2 in.Hg.) of the altitude value in Barometric Pressure Reference Chart (at Training Manual).

- Make BARO PID comparisons to Barometric Pressure Reference Chart or diary airport barometric pressure reports, if available.

• Check that the LONGFT1 and LONGFT2 PIDs for all injector banks at idle is not more negative than -12%.

• Check that the MAF V PID at idle and neutral is not greater then 30% of the normal MAF V listed in Section 01-40, Reference values (or not greater than 1.1 V).

• Are two of the above three check okay?

Yes

Go to Step 7.

No

Go to the next step.

6
CHECK TO ISOLATE MAF SENSOR FROM LEAN DELIVEABILITY OCCURRENCE

Note

• Due to increasingly stringent emission/OBD requirements, a fuel system DTC on some vehicles will be generated without a noticeable drivability concern with or without MAF sensor disconnected. Under these conditions, if the BARO_V, LONGFT1, LONGFT2 and MAF PID indicates a MAF sensor concern, replace the MAF sensor.

• Disconnect MAF sensor.

• Start the engine.

• Drive the vehicle.

• Is the lean drivability symptom (lack of power, spark knock/detonation, back/jerk or hesitation/surge on acceleration) gone?

Yes

Replace MAF sensor, then go to Step 41.

No

Go to the next step.

7
PERFORM KOER SELF TEST
• Disconnect fuel vapor hose from intake manifold and plug fitting at intake manifold.

• Connect the WDS or equivalent to DLC.

• Start the engine and run at 2,000 rpm for 5 minutes and return to idle.

• Complete Key On Engine Running (KOER) self test.

• Are DTCs P0040, P1128, P0041, P1129, P1127 or P0402 present?

Yes

Go to the displayed DTC troubleshooting procedure.

No

Go to the next step.

8
HO2S-21 CIRCUIT CHECK (FOR RICH DTCS)
• Disconnect HO2S-21.

• Connect the WDS or equivalent to DLC.

• Turn the ignition switch to ON.

• Access O2S21 PID.

• Is the reading 0.2 V or less?

Yes

Replace HO2S-21, then go to Step 41.

No

Go to the next step.

9
CHECK HO2S-21 CIRCUIT FOR SHORT TO VPWR AND HO2S-11 HEATER GND IN HARNESS
• Disconnect PCM.

• Measure resistance following at PCM harness side connector.

- Between terminal 87 and 71

- Between terminal 87 and 94

• Is each resistance greater than 10,000 ohms?

Yes

Go to the next step.

No

Repair for short circuit, then go to Step 41.

10
CHECK HO2S-21 SIGNAL FOR SHORT TO HO2S-21 HEATER CIRCUIT IN THE SENSOR
• HO2S-21 disconnected.

• Measure resistance between terminal 3 and 4 at HO2S-21 component side connector.

• Is the resistance greater than 10,000 ohms?

Yes

Go to the next step.

No

Replace HO2S-21, then go to Step 41.

11
CHECK FUEL PRESSURE
• Install the fuel pressure gauge.

• Connect the WDS or equivalent to DLC.

• Turn the ignition switch to ON.

• Turn the fuel pump to on using the PID FP on simulation function.

Note

• During simulation function, the fuel pump will stay commanded on for only 5 seconds.

• Is the fuel pressure within with range for the vehicle being diagnosed?

(See FUEL LINE PRESSURE INSPECTION [AJ (3.0L Duratec)].)

Yes

Go to the next step.

No

Go to Step 41.

12
CHECK FUEL SYSTEM FOR PRESSURE STABILITY - FAST LEAKDOWN
• Turn the ignition switch to ON.

• Cycle ignition switch ON and OFF several times to charge fuel system.

• Does the fuel pressure remain within 34 kPa {5 psi} of the highest reading after 10 seconds?

Yes

Go to Step 14.

No

Go to the next step.

13
VERIFY EXTERNAL FUEL LEAK
• Is the external fuel leak detected?

Yes

Go to Step 27.

No

Go to Step 16.

14
CHECK FUEL SYSTEM FOR PRESSURE STABILITY - SLOW LEAKDOWN
• Turn the ignition switch to ON.

• Cycle ignition switch ON and OFF several times to charge fuel system.

• Does the fuel pressure remain within 34 kPa {5 psi} of the highest reading 1 minute?

Yes

Go to the next step.

No

Go to Step 31.

15
DETERMINE DTC BEING DIAGNOSED
• Are any misfire DTCs displayed with the HO2S DTCs?

Yes

Go to Step 17.

No

Go to Step 20.

16
CHECK INIJECTOR FAULT PIDS AND ASSOCIATED DTCS
• Access INJ4F, INJ5F and INJ6F PIDs.

Note

• If misfire DTCs are present, access only injector fault PIDs corresponding to misfire DTCs.

• Is DTC P0204 through P0206 or an injector(s) fault present?

Yes

Go to the next step.

No

Go to Step 20.

17
CHECK FUEL INJECTOR(S) AND HARNESS RESISTANCE
• This causes Continuous Memory DTCs.

• Disconnected PCM.

Note

• Use the fuel injector fault PID to determine the fuel injector circuit(s) requiring testing.

• Measure resistance following for malfunctioning injector in Step 16 at PCM harness side connector.

- Between 100 and 71 (INJ4F, P0204)

- Between 73 and 71 (INJ5F, P0205)

- Between 99 and 71 (INJ6F, P0206)

• Is the resistance between 11.0 -18.0 ohms?

Yes

Replace PCM, then go to Step 41.

No

Go to the next step.

18
CHECK FUEL INJECTOR HARNESS RESISTANCE
• Disconnect the malfunctioning fuel injector in Step 12.

• Measure the resistance for following at harness side connector:

- Between fuel injector No.4 terminal 2 and PCM terminal 71 (INJ4F, P0204)

- Between fuel injector No.4 terminal 1 and PCM terminal 100 (INJ4F, P0204)

- Between fuel injector No.5 terminal 2 and PCM terminal 71 (INJ5F, P0205)

- Between fuel injector No.5 terminal 1 and PCM terminal 73 (INJ5F, P0205)

- Between fuel injector No.6 terminal 2 and PCM terminal 71 (INJ6F, P0206)

- Between fuel injector No.6 terminal 1 and PCM terminal 99 (INJ6F, P0206)

• Is each resistance less than 5.0 ohms?

Yes

Go to the next step.

No

Repair for open circuit, then go to Step 41.

19
CHECK FUEL INJECTOR HARNESS CIRCUIT FOR SHORT TO POWER AND GROUND
• Disconnect PCM.

• Malfunctioning fuel injector in Step 16 disconnected.

• Measure resistance for following at suspected fuel injector harness side connector.

- Terminal 1 and battery positive post (INJ4F, P0204)

- Terminal 1 and battery negative post (INJ4F, P0204)

- Terminal 1 and battery positive post (INJ5F, P0205)

- Terminal 1 and battery negative post (INJ5F, P0205)

- Terminal 1 and battery positive post (INJ6F, P0206)

- Terminal 1 and battery negative post (INJ6F, P0206)

• Is each resistance greater than 10,000 ohms?

Yes

Go to the next step.

No

Repair for short circuit, then go to Step 41.

20
INSPECT FUEL INJECTOR(S)
• Inspect fuel injector No.4, No.5 and No.6.

(See FUEL INJECTOR INSPECTION [AJ (3.0L Duratec)].)

• Are fuel injectors okay?

Yes

Go to the next step.

No

Replace suspected fuel injector, then go to Step 41.

21
INSPECT INDUCTION SYSTEM FOR AIR LEAKS
• Inspect the following areas for signs of air leaks:

• Inlet tube(s) from air cleaner to throttle body

• Gaskets which seal the upper and lower intake manifold

• Vacuum hoses and lines for cracks and proper connections.

• Are there any signs of leaks or damaged?

Yes

Repair or replace malfunctioning part, then go to Step 41.

No

Go to the next step.

22
CHECK CYLINDER COMPRESSION
• Check cylinder compression at left bank cylinders.

(See COMPRESSION INSPECTION [AJ (3.0L Duratec)].)

• Are cylinder compression readings within specification?

Yes

Go to the next step.

No

Repair or replace malfunctioning part according inspection results.

Then go to Step 41.

23
ATTEMPT TO GENERATE DTC P1151 OR P2197
• HO2S-21 disconnected.

• Jumper HO2S-21 terminal 3 at component side connector to battery negative post.

• Connect the WDS or equivalent to DLC.

• Start the engine and warm it up normal operating temperature.

• Activate KOER self test.

• Is DTC P1151 or P2197 present?

Yes

Remove the jumper wire.

Go to the next step.

No

Inspect both ends of connector at PCM and HO2S-21 for damaged or pushed out pins, moisture, corrosion, loose pins and repair as necessary.

If okay, replace PCM.

Then go to Step 41.

24
CHECK HO2S-21 VOLTAGE
• HO2S-11 connector disconnected.

• Disconnect the vacuum line to the vacuum tree.

• Run the engine at approx. 2,000 rpm for 30 seconds.

• Measure the voltage between terminal 3 and 4 at the HO2S-21 component side connector.

• Is the voltage below 0.4 V?

Yes

Reconnect all hoses, then go to the next step.

No

Replace HO2S-21, then go to Step 41.

25
PERFORM A THOROUGH WIGGLE TEST ON THE HO2S-21 HARNESS
• Connect HO2S-21 connector.

• Start the engine.

• Warm up the engine to normal operating temperature.

• Access the HO2S21 PID using the WDS or equivalent.

• Wiggle, shake and bend small sections of the wiring harness while working from the sensor to PCM.

• While monitoring the HO2S21 PID, did the HO2S21 PID stop switching?

Yes

Isolate fault and repair or replace as necessary.

Then go to Step 41.

No

Go to the next step.

26
TEST DRIVE WHILE MONITORING O2S11 PID FOR SWITCHING
• Access O2S21 PID for proper operation.

• While observer views PID, test drive vehicle under different road conditions in an attempt to simulate the original fault.

• Does O2S21 switch properly?

Yes

Intermittent concern exists, go to Intermittent Troubleshooting Procedure.

(See INTERMITTENT CONCERN TROUBLESHOOTING [AJ (3.0L Duratec)].)

No

Replace HO2S-21, then go to Step 41.

27
CHECK SYSTEM INTEGRITY
• Visually inspect the following complete fuel delivery system for damage, leaks, looseness, cracks, kinks, pinching, or abrasion caused by a collision or mishandling;

- Fuel line

- Fuel line connection

- Fuel tank

- Fuel pump

- Fuel pressure regulator

- Pulsation damper

- Fuel rail at fuel injectors

- Damaged connector pins

- Electrical connectors not fully damaged

• Verify vehicle has followed maintenance schedule.

• Verify inertia fuel shutoff (IFS) switch is set.

• Verify battery is fully charged (12.5 V or higher).

• Verify electrical/fuse integrity.

• Verify fuel level in the tank is sufficient.

• Are any concerns present?

Yes

Repair or replace malfunctioning part, then go to Step 41.

No

Go to the next step.

28
CHECK FUEL PRESSURE
• Install the fuel pressure gauge.

• Release the fuel pressure.

• Turn the ignition switch to ON.

• Access FP PID.

• Run the fuel pump to obtain maximum fuel pressure using simulation function FP PID.

Note

• During simulation function, the fuel pump will stay commanded on for only 5 seconds.

• Is the fuel pressure within the specified pressure range?

(See FUEL LINE PRESSURE INSPECTION [AJ (3.0L Duratec)], FUEL LINE PRESSURE INSPECTION [AJ (3.0L Duratec)].)

Yes

Go to Step 33.

No

Go to the next step.

29
CHECK FUEL PUMP GROUND CIRCUIT FOR OPEN IN HARNESS
• Disconnect the fuel pump connector.

• Measure the voltage between following the terminals at the harness side connector, referring to the wiring diagram.

- Fuel pump GND and battery positive post.

• Is the voltage above 10 V?

Yes

Go to the next step.

No

Repair open circuit, then go to Step 41.

30
CHECK VOLTAGE AT FUEL PUMP HARNESS CONNECTOR
• Follow the IFS switch reset procedure.

• Connect battery charger.

• Verify IFS switch state.

• Connect the WDS or equivalent to DLC.

• Disconnect the fuel pump harness connector at the fuel pump.

• Turn the ignition switch to ON.

• Access FP PID.

• Measure voltage during fuel pump operates using simulation function FP PID at following terminal referring to wiring diagram.

- Between fuel pump harness side connector terminal FPPWR and battery negative post.

• Is the voltage greater than 12.5 V?

Yes

Go to Step 33.

No

Repair for open circuit, then go to Step 41.

31
CHECK PRESSURE REGULATOR AND PULSATION DAMPER DIAPHAGM
• Fuel pressure gauge installed.

• Start the engine and run it for 10 seconds.

• Stop the engine and wait 10 seconds.

• Start the engine and run it for 10seconds.

• Stop the engine and remove the vacuum hose from pulsation damper port.

• Inspect for fuel in the vacuum hose or pulsation damper.

• Is fuel present in the vacuum hose or pulse damper?

Yes

Replace the pulsation damper, then go to Step 41.

No

Go to the next step.

32
CHECK FUEL SUPPLY LINE FOR RESTRICTION
• Disconnect fuel supply line at the fuel rail.

• Disconnect fuel supply line at the fuel pump.

• Check the fuel supply line for restrictions due to blockage, kinking or pinching.

• Apply 21 to 34 kPa regulated shop air pressure to the fuel supply line.

• Does air flow freely through the line?

Yes

Replace the fuel pump unit, then go to Step 41.

No

Repair or replace for fuel line, then go to Step 41.

33
CHECK FUEL INJECTOR
• Perform the FUEL INJECTOR INSPECTION for left bank cylinder.

(See FUEL INJECTOR INSPECTION [AJ (3.0L Duratec)].)

• Are fuel injectors okay?

Yes

Intermittent malfunction exist, go to Step 41.

No

Replace malfunctioning fuel injector, then go to Step 41.

34
CHECK DAMPER AND PULLEY ASSEMBLY

Note

• This step is for engines that have damper mounted pulse rings. Remove the front cover if necessary to observe the crank pulley.

• Observe the crank pulley for wobble.

• Examine the EI pulse ring fastened to the harmonic dampener.

• Does the crank pulley wobble or is the pulse ring loose or damaged?

Yes

Disconnect the battery for 5 minutes to allow the PCM to learn the new profile.

Replace the pulley or damper assembly.

Then go to Step 41.

No

Go to the next step.

35
CHECK THE EVAPORATIVE EMISSION SYSTEM
• Check the EVAP canister for fuel saturation.

• Is there an excess amount of liquid fuel present in the canister?

Yes

Replace the EVAP canister.

Then go to Step 41.

No

Go to the next step.

36
PRESSURE TEST EVAPORATIVE EMISSION SYSTEM
• Install a Rotunda Evaporative Emission System Tester 134-00056 or equivalent first at the EVAP service port, if equipped, then at the fuel filler cap.

• Follow the test instructions from the tester kit.

• Is the evaporative emission system holding pressure?

Yes

Go to the next step.

No

Repair or replace for malfunctioning part, then go to Step 41.

37
CHECK VACUUM IN EVAPORATIVE EMISSION SYSTEM
• Check the vacuum system between the engine vacuum port and EVAP canister.

• Check the EVAP system lines/hoses (check for proper connections, damage or blockage).

• Check for blockage in the fuel tank vent system.

• Is there any malfunction?

Yes

Replace damaged vacuum hoses, or remove blockage/restrictions.

Then go to Step 41.

No

Go to the next step.

38
CHECK PURGE SOLENOID VALVE HOUSING LEAKS
• Remove the purge solenoid valve together with the electrical connector.

• Install a hand vacuum pump to the fuel vapor port from the EVAP canister on the purge solenoid valve at line.

• Apply 53 kPa {16 inHg} of vacuum with the vacuum pump.

• Does the purge solenoid valve hold vacuum at room temperature?

Yes

Go to the next step.

No

Remove the vacuum pump.

Replace purge solenoid valve, then go to Step 41.

39
CHECK FOR FILTER CONTAMINATION ON PURGE SOLENOID VALVE
• Vacuum line from input vacuum port to intake manifold on the purge solenoid valve is removed.

• Install a hand vacuum pump to the open vacuum port on the purge solenoid valve.

• Apply 48-52 kPa {10-15 inHg} of vacuum to the purge solenoid valve.

• Does the purge solenoid valve hold vacuum to atmosphere?

Yes

Repair purge solenoid valve filter.

If unable to clean filter or remove blockage to filter, replace purge solenoid valve.

Then go to Step 41.

No

Go to the next step.

40
CHECK FOR BASE ENGINE CONCERNS

Note

• This step will determine if there are any base engine concerns that any have caused the misfire DTC or drive concern.

• Engine temperature may affect results.

• Perform the following tests in order to evaluate base engine integrity:

• Engine compression and leakdown test

• Valve train analysis.

• Check PCV system

• Check positive leakage points

• Is any service required?

Yes

Repair or replace malfunctioning part, then go to the next step.

No

Intermittent concerns exist, then go to the next step.

41
VERIFY TROUBLESHOOTING OF DTC P2198 COMPLETED
• Make sure to reconnect all disconnected connectors.

• Clear the DTC from the PCM memory using the WDS or equivalent.

• Perform KOER self test.

(See KOEO/KOER SELF-TEST [AJ (3.0L Duratec)].)

• Is the PENDING CODE same DTC present?

Yes

Replace PCM, then go to the next step.

(See PCM REMOVAL/INSTALLATION [AJ (3.0L Duratec)].)

No

Go to the next step.

42
VERIFY AFTER REPAIR PROCEDURE
• Perform "AFTER REPAIR PROCEDURE".

(See AFTER REPAIR PROCEDURE [AJ (3.0L Duratec)].)

• Is there any DTC present?

Yes

Go to applicable DTC inspection.

(See DTC TABLE [AJ (3.0L Duratec)].)

No

Troubleshooting completed.

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA HAS BEEN RECORDED • Has FREEZE FRAME DATA been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA on the repair order, then go to the next step.
2	VERIFY REPAIR INFORMATION AVAILABILITY • Verify related service repair information availability. • Is any related repair information available?	Yes	Perform repair or diagnosis according to the available repair information. If the vehicle is not repaired, go to the next step.
2		No	Go to the next step.
3	INDETIFY TRIGGER DTC FOR FEEZE FRAME DATA • Is DTC P2198 on FREEZE FRAME DATA?	Yes	Go to the next step.
3		No	Go to FREEZE FRAME DATA DTC inspection. (See DTC TABLE [AJ (3.0L Duratec)].)
4	PERFORM VISUAL INSPECTION Note • Address all Continuous Memory Ignition and Misfire DTCs, before KOER DTCs. • Check visually for following: - Intake-air for leaks, obstructions and damage. - Air cleaner element, air cleaner housing for blockage. - Integrity of the PCV system - Vacuum leaks • Were any concerns found during inspection?	Yes	Repair or replace malfunctioning part, then go to Step 41.
4		No	Go to the next step.
5	CHECK CONDITIONS RELATED TO MAF SENSOR Note • Most weather service reports are a local barometric pressure that has been corrected to sea level. However, the BARO PID reports the actual barometric pressure for altitude the vehicle is being diagnosed in Local weather conditions (high or low pressure areas) will change the local barometric pressure by several inches of mercury. • Connect the WDS or equivalent to DLC. • Start the engine. • Access the BARO, LONGFT1, LONGFT2 and MAF V PIDs on fully warmed-up engine. • Check that the BARO PID is approximately the same as the barometric pressure reading for the location, day and altitude the vehicle is being diagnosed at. - BARO PID values in PCM memory require updating at high throttle openings. If vehicle is driven down from higher altitudes for diagnosing, complete three or four heavy accelerations at greater than half-throttle to allow BARO PID to update. - BARO PID must be within +/- 6Hz. (+/- 2 in.Hg.) of the altitude value in Barometric Pressure Reference Chart (at Training Manual). - Make BARO PID comparisons to Barometric Pressure Reference Chart or diary airport barometric pressure reports, if available. • Check that the LONGFT1 and LONGFT2 PIDs for all injector banks at idle is not more negative than -12%. • Check that the MAF V PID at idle and neutral is not greater then 30% of the normal MAF V listed in Section 01-40, Reference values (or not greater than 1.1 V). • Are two of the above three check okay?	Yes	Go to Step 7.
5		No	Go to the next step.
6	CHECK TO ISOLATE MAF SENSOR FROM LEAN DELIVEABILITY OCCURRENCE Note • Due to increasingly stringent emission/OBD requirements, a fuel system DTC on some vehicles will be generated without a noticeable drivability concern with or without MAF sensor disconnected. Under these conditions, if the BARO_V, LONGFT1, LONGFT2 and MAF PID indicates a MAF sensor concern, replace the MAF sensor. • Disconnect MAF sensor. • Start the engine. • Drive the vehicle. • Is the lean drivability symptom (lack of power, spark knock/detonation, back/jerk or hesitation/surge on acceleration) gone?	Yes	Replace MAF sensor, then go to Step 41.
6		No	Go to the next step.
7	PERFORM KOER SELF TEST • Disconnect fuel vapor hose from intake manifold and plug fitting at intake manifold. • Connect the WDS or equivalent to DLC. • Start the engine and run at 2,000 rpm for 5 minutes and return to idle. • Complete Key On Engine Running (KOER) self test. • Are DTCs P0040, P1128, P0041, P1129, P1127 or P0402 present?	Yes	Go to the displayed DTC troubleshooting procedure.
7		No	Go to the next step.
8	HO2S-21 CIRCUIT CHECK (FOR RICH DTCS) • Disconnect HO2S-21. • Connect the WDS or equivalent to DLC. • Turn the ignition switch to ON. • Access O2S21 PID. • Is the reading 0.2 V or less?	Yes	Replace HO2S-21, then go to Step 41.
8		No	Go to the next step.
9	CHECK HO2S-21 CIRCUIT FOR SHORT TO VPWR AND HO2S-11 HEATER GND IN HARNESS • Disconnect PCM. • Measure resistance following at PCM harness side connector. - Between terminal 87 and 71 - Between terminal 87 and 94 • Is each resistance greater than 10,000 ohms?	Yes	Go to the next step.
9		No	Repair for short circuit, then go to Step 41.
10	CHECK HO2S-21 SIGNAL FOR SHORT TO HO2S-21 HEATER CIRCUIT IN THE SENSOR • HO2S-21 disconnected. • Measure resistance between terminal 3 and 4 at HO2S-21 component side connector. • Is the resistance greater than 10,000 ohms?	Yes	Go to the next step.
10		No	Replace HO2S-21, then go to Step 41.
11	CHECK FUEL PRESSURE • Install the fuel pressure gauge. • Connect the WDS or equivalent to DLC. • Turn the ignition switch to ON. • Turn the fuel pump to on using the PID FP on simulation function. Note • During simulation function, the fuel pump will stay commanded on for only 5 seconds. • Is the fuel pressure within with range for the vehicle being diagnosed? (See FUEL LINE PRESSURE INSPECTION [AJ (3.0L Duratec)].)	Yes	Go to the next step.
11		No	Go to Step 41.
12	CHECK FUEL SYSTEM FOR PRESSURE STABILITY - FAST LEAKDOWN • Turn the ignition switch to ON. • Cycle ignition switch ON and OFF several times to charge fuel system. • Does the fuel pressure remain within 34 kPa {5 psi} of the highest reading after 10 seconds?	Yes	Go to Step 14.
12		No	Go to the next step.
13	VERIFY EXTERNAL FUEL LEAK • Is the external fuel leak detected?	Yes	Go to Step 27.
13		No	Go to Step 16.
14	CHECK FUEL SYSTEM FOR PRESSURE STABILITY - SLOW LEAKDOWN • Turn the ignition switch to ON. • Cycle ignition switch ON and OFF several times to charge fuel system. • Does the fuel pressure remain within 34 kPa {5 psi} of the highest reading 1 minute?	Yes	Go to the next step.
14		No	Go to Step 31.
15	DETERMINE DTC BEING DIAGNOSED • Are any misfire DTCs displayed with the HO2S DTCs?	Yes	Go to Step 17.
15		No	Go to Step 20.
16	CHECK INIJECTOR FAULT PIDS AND ASSOCIATED DTCS • Access INJ4F, INJ5F and INJ6F PIDs. Note • If misfire DTCs are present, access only injector fault PIDs corresponding to misfire DTCs. • Is DTC P0204 through P0206 or an injector(s) fault present?	Yes	Go to the next step.
16		No	Go to Step 20.
17	CHECK FUEL INJECTOR(S) AND HARNESS RESISTANCE • This causes Continuous Memory DTCs. • Disconnected PCM. Note • Use the fuel injector fault PID to determine the fuel injector circuit(s) requiring testing. • Measure resistance following for malfunctioning injector in Step 16 at PCM harness side connector. - Between 100 and 71 (INJ4F, P0204) - Between 73 and 71 (INJ5F, P0205) - Between 99 and 71 (INJ6F, P0206) • Is the resistance between 11.0 -18.0 ohms?	Yes	Replace PCM, then go to Step 41.
17		No	Go to the next step.
18	CHECK FUEL INJECTOR HARNESS RESISTANCE • Disconnect the malfunctioning fuel injector in Step 12. • Measure the resistance for following at harness side connector: - Between fuel injector No.4 terminal 2 and PCM terminal 71 (INJ4F, P0204) - Between fuel injector No.4 terminal 1 and PCM terminal 100 (INJ4F, P0204) - Between fuel injector No.5 terminal 2 and PCM terminal 71 (INJ5F, P0205) - Between fuel injector No.5 terminal 1 and PCM terminal 73 (INJ5F, P0205) - Between fuel injector No.6 terminal 2 and PCM terminal 71 (INJ6F, P0206) - Between fuel injector No.6 terminal 1 and PCM terminal 99 (INJ6F, P0206) • Is each resistance less than 5.0 ohms?	Yes	Go to the next step.
18		No	Repair for open circuit, then go to Step 41.
19	CHECK FUEL INJECTOR HARNESS CIRCUIT FOR SHORT TO POWER AND GROUND • Disconnect PCM. • Malfunctioning fuel injector in Step 16 disconnected. • Measure resistance for following at suspected fuel injector harness side connector. - Terminal 1 and battery positive post (INJ4F, P0204) - Terminal 1 and battery negative post (INJ4F, P0204) - Terminal 1 and battery positive post (INJ5F, P0205) - Terminal 1 and battery negative post (INJ5F, P0205) - Terminal 1 and battery positive post (INJ6F, P0206) - Terminal 1 and battery negative post (INJ6F, P0206) • Is each resistance greater than 10,000 ohms?	Yes	Go to the next step.
19		No	Repair for short circuit, then go to Step 41.
20	INSPECT FUEL INJECTOR(S) • Inspect fuel injector No.4, No.5 and No.6. (See FUEL INJECTOR INSPECTION [AJ (3.0L Duratec)].) • Are fuel injectors okay?	Yes	Go to the next step.
20		No	Replace suspected fuel injector, then go to Step 41.
21	INSPECT INDUCTION SYSTEM FOR AIR LEAKS • Inspect the following areas for signs of air leaks: • Inlet tube(s) from air cleaner to throttle body • Gaskets which seal the upper and lower intake manifold • Vacuum hoses and lines for cracks and proper connections. • Are there any signs of leaks or damaged?	Yes	Repair or replace malfunctioning part, then go to Step 41.
21		No	Go to the next step.
22	CHECK CYLINDER COMPRESSION • Check cylinder compression at left bank cylinders. (See COMPRESSION INSPECTION [AJ (3.0L Duratec)].) • Are cylinder compression readings within specification?	Yes	Go to the next step.
22		No	Repair or replace malfunctioning part according inspection results. Then go to Step 41.
23	ATTEMPT TO GENERATE DTC P1151 OR P2197 • HO2S-21 disconnected. • Jumper HO2S-21 terminal 3 at component side connector to battery negative post. • Connect the WDS or equivalent to DLC. • Start the engine and warm it up normal operating temperature. • Activate KOER self test. • Is DTC P1151 or P2197 present?	Yes	Remove the jumper wire. Go to the next step.
23		No	Inspect both ends of connector at PCM and HO2S-21 for damaged or pushed out pins, moisture, corrosion, loose pins and repair as necessary. If okay, replace PCM. Then go to Step 41.
24	CHECK HO2S-21 VOLTAGE • HO2S-11 connector disconnected. • Disconnect the vacuum line to the vacuum tree. • Run the engine at approx. 2,000 rpm for 30 seconds. • Measure the voltage between terminal 3 and 4 at the HO2S-21 component side connector. • Is the voltage below 0.4 V?	Yes	Reconnect all hoses, then go to the next step.
24		No	Replace HO2S-21, then go to Step 41.
25	PERFORM A THOROUGH WIGGLE TEST ON THE HO2S-21 HARNESS • Connect HO2S-21 connector. • Start the engine. • Warm up the engine to normal operating temperature. • Access the HO2S21 PID using the WDS or equivalent. • Wiggle, shake and bend small sections of the wiring harness while working from the sensor to PCM. • While monitoring the HO2S21 PID, did the HO2S21 PID stop switching?	Yes	Isolate fault and repair or replace as necessary. Then go to Step 41.
25		No	Go to the next step.
26	TEST DRIVE WHILE MONITORING O2S11 PID FOR SWITCHING • Access O2S21 PID for proper operation. • While observer views PID, test drive vehicle under different road conditions in an attempt to simulate the original fault. • Does O2S21 switch properly?	Yes	Intermittent concern exists, go to Intermittent Troubleshooting Procedure. (See INTERMITTENT CONCERN TROUBLESHOOTING [AJ (3.0L Duratec)].)
26		No	Replace HO2S-21, then go to Step 41.
27	CHECK SYSTEM INTEGRITY • Visually inspect the following complete fuel delivery system for damage, leaks, looseness, cracks, kinks, pinching, or abrasion caused by a collision or mishandling; - Fuel line - Fuel line connection - Fuel tank - Fuel pump - Fuel pressure regulator - Pulsation damper - Fuel rail at fuel injectors - Damaged connector pins - Electrical connectors not fully damaged • Verify vehicle has followed maintenance schedule. • Verify inertia fuel shutoff (IFS) switch is set. • Verify battery is fully charged (12.5 V or higher). • Verify electrical/fuse integrity. • Verify fuel level in the tank is sufficient. • Are any concerns present?	Yes	Repair or replace malfunctioning part, then go to Step 41.
27		No	Go to the next step.
28	CHECK FUEL PRESSURE • Install the fuel pressure gauge. • Release the fuel pressure. • Turn the ignition switch to ON. • Access FP PID. • Run the fuel pump to obtain maximum fuel pressure using simulation function FP PID. Note • During simulation function, the fuel pump will stay commanded on for only 5 seconds. • Is the fuel pressure within the specified pressure range? (See FUEL LINE PRESSURE INSPECTION [AJ (3.0L Duratec)], FUEL LINE PRESSURE INSPECTION [AJ (3.0L Duratec)].)	Yes	Go to Step 33.
28		No	Go to the next step.
29	CHECK FUEL PUMP GROUND CIRCUIT FOR OPEN IN HARNESS • Disconnect the fuel pump connector. • Measure the voltage between following the terminals at the harness side connector, referring to the wiring diagram. - Fuel pump GND and battery positive post. • Is the voltage above 10 V?	Yes	Go to the next step.
29		No	Repair open circuit, then go to Step 41.
30	CHECK VOLTAGE AT FUEL PUMP HARNESS CONNECTOR • Follow the IFS switch reset procedure. • Connect battery charger. • Verify IFS switch state. • Connect the WDS or equivalent to DLC. • Disconnect the fuel pump harness connector at the fuel pump. • Turn the ignition switch to ON. • Access FP PID. • Measure voltage during fuel pump operates using simulation function FP PID at following terminal referring to wiring diagram. - Between fuel pump harness side connector terminal FPPWR and battery negative post. • Is the voltage greater than 12.5 V?	Yes	Go to Step 33.
30		No	Repair for open circuit, then go to Step 41.
31	CHECK PRESSURE REGULATOR AND PULSATION DAMPER DIAPHAGM • Fuel pressure gauge installed. • Start the engine and run it for 10 seconds. • Stop the engine and wait 10 seconds. • Start the engine and run it for 10seconds. • Stop the engine and remove the vacuum hose from pulsation damper port. • Inspect for fuel in the vacuum hose or pulsation damper. • Is fuel present in the vacuum hose or pulse damper?	Yes	Replace the pulsation damper, then go to Step 41.
31		No	Go to the next step.
32	CHECK FUEL SUPPLY LINE FOR RESTRICTION • Disconnect fuel supply line at the fuel rail. • Disconnect fuel supply line at the fuel pump. • Check the fuel supply line for restrictions due to blockage, kinking or pinching. • Apply 21 to 34 kPa regulated shop air pressure to the fuel supply line. • Does air flow freely through the line?	Yes	Replace the fuel pump unit, then go to Step 41.
32		No	Repair or replace for fuel line, then go to Step 41.
33	CHECK FUEL INJECTOR • Perform the FUEL INJECTOR INSPECTION for left bank cylinder. (See FUEL INJECTOR INSPECTION [AJ (3.0L Duratec)].) • Are fuel injectors okay?	Yes	Intermittent malfunction exist, go to Step 41.
33		No	Replace malfunctioning fuel injector, then go to Step 41.
34	CHECK DAMPER AND PULLEY ASSEMBLY Note • This step is for engines that have damper mounted pulse rings. Remove the front cover if necessary to observe the crank pulley. • Observe the crank pulley for wobble. • Examine the EI pulse ring fastened to the harmonic dampener. • Does the crank pulley wobble or is the pulse ring loose or damaged?	Yes	Disconnect the battery for 5 minutes to allow the PCM to learn the new profile. Replace the pulley or damper assembly. Then go to Step 41.
34		No	Go to the next step.
35	CHECK THE EVAPORATIVE EMISSION SYSTEM • Check the EVAP canister for fuel saturation. • Is there an excess amount of liquid fuel present in the canister?	Yes	Replace the EVAP canister. Then go to Step 41.
35		No	Go to the next step.
36	PRESSURE TEST EVAPORATIVE EMISSION SYSTEM • Install a Rotunda Evaporative Emission System Tester 134-00056 or equivalent first at the EVAP service port, if equipped, then at the fuel filler cap. • Follow the test instructions from the tester kit. • Is the evaporative emission system holding pressure?	Yes	Go to the next step.
36		No	Repair or replace for malfunctioning part, then go to Step 41.
37	CHECK VACUUM IN EVAPORATIVE EMISSION SYSTEM • Check the vacuum system between the engine vacuum port and EVAP canister. • Check the EVAP system lines/hoses (check for proper connections, damage or blockage). • Check for blockage in the fuel tank vent system. • Is there any malfunction?	Yes	Replace damaged vacuum hoses, or remove blockage/restrictions. Then go to Step 41.
37		No	Go to the next step.
38	CHECK PURGE SOLENOID VALVE HOUSING LEAKS • Remove the purge solenoid valve together with the electrical connector. • Install a hand vacuum pump to the fuel vapor port from the EVAP canister on the purge solenoid valve at line. • Apply 53 kPa {16 inHg} of vacuum with the vacuum pump. • Does the purge solenoid valve hold vacuum at room temperature?	Yes	Go to the next step.
38		No	Remove the vacuum pump. Replace purge solenoid valve, then go to Step 41.
39	CHECK FOR FILTER CONTAMINATION ON PURGE SOLENOID VALVE • Vacuum line from input vacuum port to intake manifold on the purge solenoid valve is removed. • Install a hand vacuum pump to the open vacuum port on the purge solenoid valve. • Apply 48-52 kPa {10-15 inHg} of vacuum to the purge solenoid valve. • Does the purge solenoid valve hold vacuum to atmosphere?	Yes	Repair purge solenoid valve filter. If unable to clean filter or remove blockage to filter, replace purge solenoid valve. Then go to Step 41.
39		No	Go to the next step.
40	CHECK FOR BASE ENGINE CONCERNS Note • This step will determine if there are any base engine concerns that any have caused the misfire DTC or drive concern. • Engine temperature may affect results. • Perform the following tests in order to evaluate base engine integrity: • Engine compression and leakdown test • Valve train analysis. • Check PCV system • Check positive leakage points • Is any service required?	Yes	Repair or replace malfunctioning part, then go to the next step.
40		No	Intermittent concerns exist, then go to the next step.
41	VERIFY TROUBLESHOOTING OF DTC P2198 COMPLETED • Make sure to reconnect all disconnected connectors. • Clear the DTC from the PCM memory using the WDS or equivalent. • Perform KOER self test. (See KOEO/KOER SELF-TEST [AJ (3.0L Duratec)].) • Is the PENDING CODE same DTC present?	Yes	Replace PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [AJ (3.0L Duratec)].)
41		No	Go to the next step.
42	VERIFY AFTER REPAIR PROCEDURE • Perform "AFTER REPAIR PROCEDURE". (See AFTER REPAIR PROCEDURE [AJ (3.0L Duratec)].) • Is there any DTC present?	Yes	Go to applicable DTC inspection. (See DTC TABLE [AJ (3.0L Duratec)].)
42		No	Troubleshooting completed.