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Home >> Mazda >> 2012 >> 6 i Touring >> Repair and Diagnosis >> External Pages >> Different car >> Section 637 (On-Board Diagnostic (Engine Control System L5) (5 Of 5)) >> DTC P2251:00 [L5] >> Diagnostic procedure

Diagnostic procedure

WARNING: This page is about a different car, the 2009 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.
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 (A/F sensor, HO2S related) been recorded?
Yes Go to the next step
No Record FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS on 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 AND STORED DTC 
  • Switch the ignition to off, then to ON (engine off)
  • Verify pending and stored DTCs using the M-MDS.
  • Is the DTC P0030-00, P0031-00 or P0032-00 also present?
Yes Go to the applicable DTC inspection.
(See DTC P0030:00 [L5] .)
(See DTC P0031:00 [L5] .)
(See DTC P0032:00 [L5] .)
No Go to the next step.
4 IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA 
  • Is the DTC P2251:00 on FREEZE FRAME DATA?
Yes Go to the next step.
No Go to troubleshooting procedures for DTC on FREEZE FRAME DATA. (See DTC TABLE [L5] .)
5 INSPECT A/F SENSOR CONNECTOR CONDITION 
  • Switch the ignition to off.
  • Disconnect the A/F sensor connector.
  • Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
  • Is there any malfunction?
Yes Repair or replace the terminal and/or connector, then go to Step 9.
No Go to the next step.
6 INSPECT PCM CONNECTOR CONDITION 
  • Disconnect the PCM connector
  • Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
  • Is there any malfunction?
Yes Repair or replace the terminal and/or connector, then go to Step 9.
No Go to the next step.
7 INSPECT A/F SENSOR 
Yes Replace the A/F sensor, then go to Step 9.
(See AIR FUEL RATIO (A/F) SENSOR REMOVAL/INSTALLATION [L5] .)
No Go to the next step.
8 INSPECT A/F SENSOR NEGATIVE CURRENT CONTROL CIRCUIT FOR OPEN CIRCUIT 
  • Inspect for continuity between A/F sensor terminal D (wiring harness-side) and PCM terminal 2AC (wiring harness-side)
  • Is there continuity?
Yes Go to the next step.
No Repair or replace the wiring harness for a possible open circuit, then go to the next step.
9 VERIFY DTC TROUBLESHOOTING COMPLETED 
  • Make sure to reconnect all disconnected connectors
  • Clear the DTC from the PCM memory using the M-MDS
  • Perform the KOEO/KOER self test (See KOEO/KOER SELF TEST [L5] .)
  • Is the PENDING CODE for this DTC present?
Yes Replace the PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION [L5] .)
No Go to the next step.
10 VERIFY AFTER REPAIR PROCEDURE 
Yes Go to the applicable DTC inspection. (See DTC TABLE [L5] .)
No DTC troubleshooting completed.