DTC P0153[AJ (3.0L Duratec)]

DTC P0153	Front HO2S (LH) sensor circuit slow response
DETECTION CONDITION	• The PCM monitors the input voltage frequency and amplitude from the front HO2S (LH). If during testing the frequency and amplitude were to fall below a calibrated limit, the PCM determines the front HO2S (LH) sensor circuit slow response.
POSSIBLE CAUSE	• Contaminated front HO2S (LH) • Exhaust leaks • Short or open circuit • Improper fueling • Damaged MAF sensor • Deteriorating front HO2S (LH) • Inlet air leaks

DTC P0153

Front HO2S (LH) sensor circuit slow response

DETECTION CONDITION

• The PCM monitors the input voltage frequency and amplitude from the front HO2S (LH). If during testing the frequency and amplitude were to fall below a calibrated limit, the PCM determines the front HO2S (LH) sensor circuit slow response.

POSSIBLE CAUSE

• Contaminated front HO2S (LH)

• Exhaust leaks

• Short or open circuit

• Improper fueling

• Damaged MAF sensor

• Deteriorating front HO2S (LH)

• Inlet air leaks

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 SERVICE INFORMATION AVAILABILITY • Verify related Service Information availability. • Is any related Service Information available?	Yes	Perform repair or diagnosis according to the available Service Information. • If the vehicle is not repaired, go to next step.
No	Go to next step.
3	INDETIFY TRIGGER DTC FOR FEEZE FRAME DATA • Is DTC P0153 on FREEZE FRAME DATA?	Yes	Go to next step.
No	Go to FREEZE FRAME DATA DTC inspection. (See DTC TABLE[AJ (3.0L Duratec)].)
4	FRONT HO2S (LH) RESPONSE TEST • Connect the M-MDS to DLC-2. • Turn the ignition switch to the ON position. • Select Generic OBD Function from the menu and trigger. • Press continue. • Select Diagnostic Monitoring Test Results from menu and press trigger. • Scroll to Test ID: 01 and press trigger. • Turn the ignition switch to off. • Is the indicated value greater than minimum threshold?	Yes	Intermittent malfunction exist, go to Step 11.
No	Go to the next step.
5	CHECK FOR UNMETERED AIR LEAKS Note • Fuel calculations can be affected by unmetered air leaks. • Carefully inspect the following areas for potential air leaks: ― Hoses connecting to MAF/IAT sensor assembly ― Hoses connecting to throttle body ― Intake manifold gaskets leaks ― PCV disconnected ― Vacuum lines disconnected ― Improperly seated engine oil dipstick, tube, and oil fill cap ― Exhaust leaks at flanges and gaskets • Are there any air leaks present?	Yes	Repair or replace for malfunctioning part, then go to Step 11.
No	Go to the next step.
6	CHECK FRONT HO2S (LH) CIRCUIT WIRING Note • Refer to the PCM connector pin number in the beginning of this pinpoint test. • Disconnect front HO2S (LH) connector. • Check for water for contamination. • Jumper front HO2S (LH) signal (pin-B) to VPWR (pin-C) at the front HO2S (LH) harness connector. • Connect the M-MDS to the DLC-2. • Turn the ignition switch to the ON position. • Access the O2S21 PID. • Does the O2S21 PID indicate greater than 1.50 V?	Yes	Replace front HO2S (LH) and oil filter. Then go to Step 11.
No	Go to the next step.
7	CHECK FRONT HO2S (LH) SIGNAL AND SIGNAL RETURN CIRCUITS FOR OPEN IN HARNESS • Measure resistance for following front HO2S (LH) harnesses at harness side connectors: ― Between front HO2S (LH) terminal B and PCM terminal 87 ― Between front HO2S (LH) terminal D and PCM terminal 91 • Is the resistance less than 5.0 ohms?	Yes	Go to the next step.
No	Repair open circuit, then go to Step 11.
8	CHECK FRONT HO2S (RH) CIRCUIT FOR SHORT TO VPWR IN HARNESS • Measure resistance between PCM terminal 87 and 71, 97 at PCM harness connector pin. • Is the resistance greater than 10,000 ohms?	Yes	Go to the next step.
No	Go to Step 10.
9	CHECK FOR SOURCE OF POTENTIAL FRONT HO2S (LH) CONTAMINATION • Investigate the following items as potential sources of front HO2S (LH) contamination. ― Use of unapproved silicon sealers. ― Fuel contaminated by silicon additives. ― Excessive oil burning. (i.e.: rings, valve seals and oil overfill) ― Glycol (antifreeze) leaking internally in the engine. ― Lead contaminated fuel ― Short drive cycles in cold weather ― Use of unapproved cleaning agents • Where any of the above conditions or concerns found during inspection?	Yes	Repair for source of contamination. Replace front HO2S (LH) and oil filter. Then go to Step 11.
No	Replace the PCM, then go to Step 11.
10	VERIFY WIRING IS IN PROPER PIN LOCATION • Measure resistance between PCM terminal 87 and 91 at PCM harness side connector. • Is the resistance less than 5.0 ohms?	Yes	Replace front HO2S (LH), then go to the next step.
No	Intermittent malfunction exist, go to the next step.
11	VERIFY TROUBLESHOOTING OF DTC P0153 COMPLETED • Make sure to reconnect all disconnected connectors. • Clear the DTC from the PCM memory using the M-MDS. • Cruise the vehicle at 64 km/h {40 MPH} for at least 5 min. • Is the PENDING CODE same DTC present?	Yes	Replace PCM, then go to next step. (See PCM REMOVAL/INSTALLATION[AJ (3.0L Duratec)].)
No	Go to the next step.
12	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

VERIFY FREEZE FRAME DATA HAS BEEN RECORDED

• Has FREEZE FRAME DATA been recorded?

Yes

Go to the next step.

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

VERIFY SERVICE INFORMATION AVAILABILITY

• Verify related Service Information availability.

• Is any related Service Information available?

Yes

Perform repair or diagnosis according to the available Service Information.

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

Go to next step.

INDETIFY TRIGGER DTC FOR FEEZE FRAME DATA

• Is DTC P0153 on FREEZE FRAME DATA?

Yes

Go to next step.

Go to FREEZE FRAME DATA DTC inspection.

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

FRONT HO2S (LH) RESPONSE TEST

• Connect the M-MDS to DLC-2.

• Turn the ignition switch to the ON position.

• Select Generic OBD Function from the menu and trigger.

• Press continue.

• Select Diagnostic Monitoring Test Results from menu and press trigger.

• Scroll to Test ID: 01 and press trigger.

• Turn the ignition switch to off.

• Is the indicated value greater than minimum threshold?

Yes

Intermittent malfunction exist, go to Step 11.

Go to the next step.

CHECK FOR UNMETERED AIR LEAKS

Note

• Fuel calculations can be affected by unmetered air leaks.

• Carefully inspect the following areas for potential air leaks:

― Hoses connecting to MAF/IAT sensor assembly

― Hoses connecting to throttle body

― Intake manifold gaskets leaks

― PCV disconnected

― Vacuum lines disconnected

― Improperly seated engine oil dipstick, tube, and oil fill cap

― Exhaust leaks at flanges and gaskets

• Are there any air leaks present?

Yes

Repair or replace for malfunctioning part, then go to Step 11.

Go to the next step.

CHECK FRONT HO2S (LH) CIRCUIT WIRING

Note

• Refer to the PCM connector pin number in the beginning of this pinpoint test.

• Disconnect front HO2S (LH) connector.

• Check for water for contamination.

• Jumper front HO2S (LH) signal (pin-B) to VPWR (pin-C) at the front HO2S (LH) harness connector.

• Connect the M-MDS to the DLC-2.

• Turn the ignition switch to the ON position.

• Access the O2S21 PID.

• Does the O2S21 PID indicate greater than 1.50 V?

Yes

Replace front HO2S (LH) and oil filter.

Then go to Step 11.

Go to the next step.

CHECK FRONT HO2S (LH) SIGNAL AND SIGNAL RETURN CIRCUITS FOR OPEN IN HARNESS

• Measure resistance for following front HO2S (LH) harnesses at harness side connectors:

― Between front HO2S (LH) terminal B and PCM terminal 87

― Between front HO2S (LH) terminal D and PCM terminal 91

• Is the resistance less than 5.0 ohms?

Yes

Go to the next step.

Repair open circuit, then go to Step 11.

CHECK FRONT HO2S (RH) CIRCUIT FOR SHORT TO VPWR IN HARNESS

• Measure resistance between PCM terminal 87 and 71, 97 at PCM harness connector pin.

• Is the resistance greater than 10,000 ohms?

Yes

Go to the next step.

Go to Step 10.

CHECK FOR SOURCE OF POTENTIAL FRONT HO2S (LH) CONTAMINATION

• Investigate the following items as potential sources of front HO2S (LH) contamination.

― Use of unapproved silicon sealers.

― Fuel contaminated by silicon additives.

― Excessive oil burning. (i.e.: rings, valve seals and oil overfill)

― Glycol (antifreeze) leaking internally in the engine.

― Lead contaminated fuel

― Short drive cycles in cold weather

― Use of unapproved cleaning agents

• Where any of the above conditions or concerns found during inspection?

Yes

Repair for source of contamination.

Replace front HO2S (LH) and oil filter.

Then go to Step 11.

Replace the PCM, then go to Step 11.

VERIFY WIRING IS IN PROPER PIN LOCATION

• Measure resistance between PCM terminal 87 and 91 at PCM harness side connector.

• Is the resistance less than 5.0 ohms?

Yes

Replace front HO2S (LH), then go to the next step.

Intermittent malfunction exist, go to the next step.

VERIFY TROUBLESHOOTING OF DTC P0153 COMPLETED

• Make sure to reconnect all disconnected connectors.

• Clear the DTC from the PCM memory using the M-MDS.

• Cruise the vehicle at 64 km/h {40 MPH} for at least 5 min.

• Is the PENDING CODE same DTC present?

Yes

Replace PCM, then go to next step.

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

Go to the next step.

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)].)

Troubleshooting completed.