DTC P2270[AJ (3.0L Duratec)]

id0102a4827200

DTC P2270

Lack of rear HO2S (RH) switch, sensor indicates lean
DETECTION CONDITION
•  The PCM monitors rear HO2S (RH) signal switching during forced rich at PCM terminal 35. If the PCM does not detect signal input from rear HO2S (RH) for calibrated amount of time, the PCM determines that rear HO2S (RH) cannot switch to rich.
POSSIBLE CAUSE
•  Pinched, shorted, and corroded wiring and pins
•  Crossed sensor wires
•  Exhaust leaks
•  Contaminated or damaged rear HO2S (RH)

Diagnostic procedure

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 the next step.
No
Go to the next step.
3
INDETIFY TRIGGER DTC FOR FEEZE FRAME DATA
•  Is DTC P2270 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
VISUALLY INSPECT FOR REAR HO2S (RH)
Note
•  Address all Continuous Memory Ignition and Misfire DTCs, before any KOER rear HO2S (RH)
•  Visually inspect for rear HO2S (RH) followings:
―  Pinched, shorted and corroded wiring and pins
―  Crossed sensor wires
―  Oil or water contamination
―  Contaminated or damaged sensor
•  Were any concerns found during inspection?
Yes
Repair or replace for malfunctioning part, then go to Step 12.
No
Go to the next step.
5
CHECK FOR KOER DTCS
•  Start the engine.
•  Run the engine at approx. 2,000 rpm and maintain engine speed for 3 minutes.
•  Perform KOER self-test.
•  Are DTCs P1137, P2270, P1157, P2272, P1138, P2271, P1158 or P2273 present?
Yes
Go to the next step.
No
Intermittent concerns exist, then go to the next step.
6
CHECK REAR HO2S (RH) SIGNAL LEVEL TOO HIGH
Note
•  Fuel calculations can be affected by abnormal 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 gasket leaks.
―  PCV disconnected.
―  The vacuum lines are disconnected.
―  Improperly seated engine oil dipstick, tube or oil fill cap.
―  Exhaust gas leaks at flanges and gaskets.
•  Raise the vehicle on a hoist and make sure the vehicle is level.
•  Visually inspect for the following:
―  Exhaust leaks at flanges and gaskets.
―  Rear HO2S (RH) not torqued to specification.
―  Physical exhaust system concerns.
―  Aftermarket exhaust.
―  Punctures or cracks in the catalyst.
•  Where any of the above conditions or concerns found during inspection?
Yes
Repair or replace malfunctioning part, then go to Step 12.
No
Go to the next step.
7
CHECK REAR HO2S (RH) CIRCUIT FOR SHORT TO VPWR AND GROND IN HARNESS
•  Disconnect PCM and rear HO2S (RH).
•  Measure the resistance between following terminals at PCM harness side connector.
―  Between terminal 35 and battery negative post
―  Between terminal 35 and 91, 95
•  Is the resistance greater than 10,000 ohms?
Yes
Go to the next step.
No
Repair for short to ground circuit, then go to Step 12.
8
CHECK REAR HO2S (RH) SIGNAL CIRCUIT AND REAR HO2S (RH) SIGNAL RETURN CIRCUITS FOR OPEN IN HARNESS
•  Measure resistance following at harness side connector.
―  Between rear HO2S (RH) terminal A and PCM terminal 95
―  Between rear HO2S (RH) terminal D and PCM terminal 91
―  Between rear HO2S (RH) terminal B and PCM terminal 35
―  Between rear HO2S (RH) terminal C and main relay
•  Is the resistance less than 5.0 ohms?
Yes
Go to the next step.
No
Repair for open circuit, then go to Step 12.
9
CHECK REAR HO2S (RH) CIRCUIT VOLTAGE
•  Connect PCM and rear HO2S (RH).
•  Connect the M-MDS to DLC-2.
•  Start the engine.
•  Access the O2S12 PID.
•  Is the voltage greater than 1.5 V?
Yes
Go to Step 11.
No
Go to the next step.
10
REAR HO2S (RH) CIRCUIT CHECK
•  Connect PCM.
•  Rear HO2S (RH) disconnected.
•  Jumper terminal C and B at rear HO2S (RH) harness side connector.
•  Turn the ignition switch to the ON position.
•  Access the O2S12 PID.
•  Is the O2S12 PID value greater than 1.5 V?
Yes
Replace rear HO2S (RH), then go to Step 12.
No
Replace PCM, then go to Step 12.
11
CHECK FOR OVER VOLTAGE ON REAR HO2S (RH) CIRCUIT IN PCM
•  Turn the ignition switch to the ON position.
•  Rear HO2S (RH) disconnected.
•  Measure voltage for following:
―  Between terminal D at rear HO2S (RH) harness side connector and battery negative post.
―  Between terminal B at rear HO2S (RH) harness side connector and battery negative post.
•  Is the voltage greater than 1.5 V?
Yes
Replace PCM, then go to the next step.
No
Replace rear HO2S (RH), then go to the next step.
12
VERIFY TROUBLESHOOTING OF DTC P2270 COMPLETED
•  Make sure to reconnect all disconnected connectors.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Perform KOER self test.
Is the PENDING CODE same DTC present?
•  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.
13
VERIFY AFTER REPAIR PROCEDURE
•  Perform “AFTER REPAIR PROCEDURE”.
•  Is there any DTC present?
Yes
Go to applicable DTC inspection.
(See DTC TABLE[AJ (3.0L Duratec)].)
No
Troubleshooting completed.