DTC P0038 [L3]

BME010201084204

DTC P0038

Rear HO2S heater circuit high input

DETECTION CONDITION

• The PCM monitors the rear HO2S heater control signal at PCM terminal 4D. If the PCM turns the rear HO2S heater on but the rear HO2S heater circuit has high voltage, the PCM determines that the rear HO2S heater circuit has malfunction.
Diagnostic support note
• This is an intermittent monitor (O2 sensor heater).
• MIL illuminates if PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM.
• PENDING CODE is available if PCM detects the above malfunction condition.
• FREEZE FRAME DATA is available.
• DTC is stored in PCM memory.

POSSIBLE CAUSE

• Short to power circuit between rear HO2S terminal D and PCM terminal 4D
• Rear HO2S or PCM terminal is shorted
• PCM malfunction
• Rear HO2S malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION

1
PERFORM DTC CONFIRMATION PROCEDURE
• Perform DTC CONFIRMATION PROCEDURE.
• Is the same DTC present?
Yes
Go to the next step.
No
Intermittent concern exists. Go to INTERMITTENT CONCERN TROUBLESHOOTING procedure.
2
INSPECT REAR HO2S TERMINAL
• Turn the ignition switch off.
• Disconnect the rear HO2S connector.
• Inspect the bent terminals.
• Is there any malfunction?
Yes
Repair or replace the terminal, then go to Step 6.
No
Go to the next step.
3
INSPECT REAR HO2S HEATER
• Inspect the rear HO2S heater.
• Is the rear HO2S heater normal?
Yes
Go to the next step.
No
Replace the rear HO2S, then go to Step 6.
4
INSPECT PCM TERMINAL
• Disconnect the PCM connector.
• Inspect the bent terminals.
• Is there any malfunction?
Yes
Repair the terminal, then go to Step 6.
No
Go to the next step.
5
INSPECT REAR HO2S HEATER CONTROL CIRCUIT FOR SHORT TO POWER
• Turn the ignition switch to the ON position (Engine off).
• Measure the voltage between rear HO2S terminal D (wiring harness-side) and body ground.
• Is the voltage B+?
Yes
Repair or replace the wiring harness for short to power supply, then go to the next step.
No
Go to the next step.
6
VERIFY TROUBLESHOOTING OF DTC P0038 COMPLETED
• Make sure to reconnect all disconnected connectors.
• Clear the DTC from the PCM memory using the WDS or equivalent.
• Perform KOEO/KOER self-test.
• Is the same DTC present?
Yes
Replace the PCM, then go to the next step.
No
Go to the next step.
7
VERIFY AFTER REPAIR PROCEDURE
• Perform "After Repair Procedure".
• Is there any DTC present?
Yes
Go to the applicable DTC inspection.
No
Troubleshooting completed.