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Home >> Mazda >> 2006 >> MX-5 Miata Base >> Repair and Diagnosis >> Engine Performance >> System >> On-Board Diagnostic [Engine Control System] >> DTC P0137 >> Diagnostic Procedure
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Diagnostic Procedure

DTC P0137 DIAGNOSTIC PROCEDURE TABLE

STEP INSPECTION ACTION
1 VERIFY FREEZE FRAME DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED 
  • Have FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS (HO2S related) been recorded?
 Yes Go to next step.
No Record the FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS on the repair order, then go to the next step.
2 VERIFY RELATED REPAIR INFORMATION AVAILABILITY 
  • Verify related Service Bulletins and/or on-line 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 VERIFY RELATED PENDING OR STORED DTCS 
  • Turn the ignition switch off, then to the ON position. (Engine off)
  • Verify pending code or stored DTCs using WDS or equivalent.
  • Is other DTC present?
 Yes Go to the appropriate DTC troubleshooting procedures.
(See DTC TABLE  .)
No Go to the next step.
4 IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA 
  • Is DTC P0137 on FREEZE FRAME DATA?
 Yes Go to the next step.
No Go to troubleshooting procedures for DTC on OBD-II FREEZE FRAME DATA  .
(See DTC TABLE  .)
5 INSPECT REAR HO2S CONNECTOR FOR POOR CONNECTION 
  • Turn the ignition switch off.
  • Disconnect rear HO2S connector.
  • Inspect for poor connection (such as damaged, pulled-out terminals, corrosion).
  • Is there any malfunctions?
 Yes Repair terminal, then go to Step 11.
No Go to the next step.
6 INSPECT PCM CONNECTOR FOR POOR CONNECTION 
  • Disconnect PCM connector.
  • Inspect for poor connection (such as damaged, pulled-out terminals, corrosion).
  • Is there any malfunctions?
 Yes Repair terminal, then go to Step 11.
No Go to the next step.
7 INSPECT REAR HO2S SIGNAL CIRCUIT FOR OPEN 
  • Inspect continuity between rear HO2S terminal A (harness-side) and PCM terminal 2Q (harness-side).
  • Is there any continuity?
 Yes Go to the next step.
No Repair or replace harness for open circuit, then go to Step 11.
8 INSPECT REAR HO2S SIGNAL CIRCUIT FOR SHORT TO GROUND CIRCUIT 
  • Inspect continuity between rear HO2S terminal A (harness-side) and body ground.
  • Is any voltage reading?
 Yes Replace short to power supply circuit, then go to Step 11.
No Go to the next step.
9 INSPECT REAR HO2S GROUND CIRCUIT FOR OPEN 
  • Inspect continuity between rear HO2S terminal B (harness-side) and PCM terminal 2BH (harness-side).
  • Is there any continuity?
 Yes Go to the next step.
No Repair or replace harness for open circuit, then go to Step 11.
10 VERIFY CURRENT INPUT SIGNAL STATUS 
  • Start engine.
  • Access O2S12 PID using WDS or equivalent.
  • Verify PID while racing engine at least 10 times  (in NEUTRAL (MT) or PARK (AT)).
  • Does PID reading stay above 0.45 V  ?
 Yes Repair or replace the rear HO2S, then go to the next step.
(See REAR HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION .)
No Go to the next step.
11 VERIFY TROUBLESHOOTING OF DTC P0137 COMPLETED 
  • Make sure to reconnect all disconnected connectors.
  • Turn the ignition switch off. (Engine OFF).
  • Clear DTC from PCM memory using WDS or equivalent.
  • Perform the KOEO self-test with WDS or equivalent, or "PCM Adaptive Memory Procedure Drive Mode" and "HO2S Heater, HO2S, and TWC Repair Verification Drive Mode".

    (See KOEO/KOER SELF TEST  .)

    (See OBD-II DRIVE MODE  .)

  • Is PENDING CODE of same DTC present?
 Yes Replace the PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION .)
No Go to the next step.
12 VERIFY AFTER REPAIR PROCEDURE  Yes Go to the applicable DTC inspection.
(See DTC TABLE  .)
No Troubleshooting completed.
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