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Diagnostic procedure

DTC P0037 [L3] DIAGNOSTIC PROCEDURE

STEP INSPECTION ACTION
1 IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA (MODE 2) 
  • Is DTC P0037 on FREEZE FRAME DATA (Mode 2)?
Yes Go to the next step.
No Go to troubleshooting for DTC on FREEZE FRAME DATA (Mode 2).
(See DTC TABLE .)
2 VERIFY FREEZE FRAME DATA (MODE 12) AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED 
  • Have FREEZE FRAME DATA (Mode 12) and DIAGNOSTIC MONITORING TEST RESULTS (HO2S heater related) been recorded?
Yes Go to the next step.
No Record the FREEZE FRAME DATA (Mode 12) and DIAGNOSTIC MONITORING TEST RESULTS on the repair order, then go to the next step.
3 VERIFY RELATED REPAIR INFORMATION AVAILABILITY 
  • Verify related Service Bulletins and/or on-line repair information availability.
  • Is any related repair information available?
Yes Perform the 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.
4 INSPECT HO2S TERMINAL 
  • Turn the ignition switch off.
  • Disconnect the HO2S connector.
  • Inspect for poor connection (such as damaged/pulled out pins, corrosion).
  • Is there any malfunction?
Yes Repair or replace the terminal, then go to Step 10.
No Go to the next step.
5 INSPECT HO2S HEATER 
Yes Go to the next step.
No Replace the HO2S, then go to Step 10.
6 INSPECT HO2S HEATER POWER CIRCUIT FOR OPEN CIRCUIT OR SHORT TO GROUND 
  • Turn the ignition switch to the ON position. (Engine off).
  • Measure the voltage between HO2S terminal C (wiring-harness-side) and body ground.
  • Is the voltage B+?
Yes Go to the next step.
No If the HO2S heater related fuse.
  • If the fuse is melt:
    • Repair or replace the wiring harness for a possible short to ground.
    • Replace the fuse.
  • If the fuse is deterioration:
    • Replace the fuse.
  • If the fuse is normal:
    • Repair or replace for a possible open circuit.

Then go to Step 10.
7 INSPECT HO2S HEATER CONTROL CIRCUIT FOR SHORT TO GROUND 
  • HO2S connector is disconnected.
  • Turn the ignition switch off.
  • Inspect for continuity between HO2S terminal D (wiring-harness-side) and body ground.
  • Is there continuity?
Yes If the short to ground circuit could be detected:
  • Repair or replace for a possible short to ground.

If the short to ground circuit could not be detected:

Then go to Step 10.
No Go to the next step.
8 INSPECT PCM TERMINAL 
  • Disconnect the PCM connector.
  • Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
  • Is there any malfunction?
Yes Repair the terminal, then go to Step 10.
No Go to the next step.
9 INSPECT HO2S HEATER CONTROL CIRCUIT FOR OPEN CIRCUIT 
  • HO2S and PCM connectors are disconnected.
  • Inspect for continuity between HO2S terminal D (wiring-harness-side) and PCM terminal 2B (wiring-harness-side).
  • Is there continuity?
Yes Go to the next step.
No Repair or replace the wiring harness for open circuit, then go to the next step.
10 VERIFY TROUBLESHOOTING OF DTC P0037 COMPLETED 
  • Make sure to reconnect all disconnected connectors.
  • Clear the DTC from the PCM memory using the M-MDS.
  • Perform the KOEO self-test with M-MDS, or A/F sensor heater, HO2S heater, A/F sensor, HO2S, and TWC Repair Verification Drive Mode. (See KOEO/KOER SELF TEST .) (See OBD-II DRIVE MODE .)
  • Is the PENDING CODE for this DTC present?
Yes Replace the PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION .)
No Go to the next step.
11 VERIFY AFTER REPAIR PROCEDURE 
Yes Go to the applicable DTC troubleshooting.
(See DTC TABLE .)
No Troubleshooting completed.