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Home >> Mazda >> 2007 >> 6 Mazdaspeed >> Repair and Diagnosis >> Engine Performance >> System >> On-Board Diagnostic [Engine Control System L3 With TC] >> DTC P0850 >> Diagnostic procedure
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Diagnostic procedure

DTC P0850 DIAGNOSTIC PROCEDURE

STEP INSPECTION ACTION
1 VERIFY FREEZE FRAME DATA HAS BEEN RECORDED 
  • Has the FREEZE FRAME DATA been recorded?
 Yes Go to the next step.
No Record FREEZE FRAME DATA on the repair order, then go to the next step.
2 VERIFY RELATED REPAIR INFORMATION AVAILABILITY 
  • Check for related Service Bulletins and/or online 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.
3 CLASSIFY HIGH INPUT OR LOW INPUT 
  • Connect the WDS or equivalent to the DLC-2.
  • Access the CPP/PNP PID.
  • Verify the CPP/PNP PID when gear is in the neutral position.
  • Is the CPP/PNP PID always off?
 Yes Go to Next step.
No Go to Step 10.
4 INSPECT NEUTRAL SWITCH CONNECTOR FOR POOR CONNECTION 
  • Turn the ignition switch to off.
  • Disconnect the neutral switch 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 14.
No Go to the next step.
5 CLASSIFY NEUTRAL SWITCH OR CIRCUIT 
  • Connect the WDS or equivalent to the DLC-2.
  • Access the CPP/PNP PID.
  • Connect a jumper wire between neutral switch terminal A and B (harness-side).
  • Is the CPP/PNP PID on?
 Yes Go to the next step.
No Go to Step 7.
6 INSPECT NEUTRAL SWITCH 
 Yes Go to Step 14.
No Replace the neutral switch, then go to Step 14.
7 INSPECT NEUTRAL SWITCH GROUND CIRCUIT FOR OPEN CIRCUIT 
  • Inspect for continuity between neutral switch terminal A (harness-side) and body ground.
  • Is there continuity?
 Yes Go to the next step.
No Repair or replace the neutral switch power circuit for an open circuit, then go to Step 14.
8 INSPECT PCM CONNECTOR FOR POOR CONNECTION 
  • Turn the ignition switch to off.
  • 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, then go to Step 14.
No Go to the next step.
9 INSPECT NEUTRAL SWITCH SIGNAL CIRCUIT FOR OPEN CIRCUIT 
  • Inspect for continuity between neutral switch terminal B (harness-side) and PCM terminal 1W (harness-side).
  • Is there continuity?
 Yes Repair or replace wiring harness for an open circuit, then go to Step 14.
No Go to Step 14.
10 INSPECT NEUTRAL SWITCH CONNECTOR FOR POOR CONNECTION 
  • Turn the ignition switch to off.
  • Disconnect neutral switch 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 14.
No Go to the next step.
11 CLASSIFY NEUTRAL SWITCH OR CIRCUIT 
  • Connect the WDS or equivalent to the DLC-2.
  • Access the CPP/PNP PID.
  • Verify that the CPP/PNP PID changes from on to off when the neutral switch connector is disconnected.
  • Does the CPP/PNP PID change from on to off?
 Yes Go to the next step.
No Go to Step 13.
12 INSPECT NEUTRAL SWITCH 
 Yes Go to Step 14.
No Replace the neutral switch, then go to Step 14.
13 INSPECT NEUTRAL SWITCH SIGNAL CIRCUIT FOR SHORT TO GROUND 
  • Inspect for continuity between neutral switch terminal B (harness-side) and body ground.
  • Is there continuity?
 Yes Repair or replace the wiring harness for a short to ground, then go to Step 14.
No Go to the next step.
14 VERIFY TROUBLESHOOTING OF DTC P0850 COMPLETED 
  • Make sure to reconnect all disconnected connectors.
  • Start the engine.
  • Clear the DTC from the PCM memory using the WDS or equivalent.
  • Drive vehicle above 30 km/h {19 mph}  and stop vehicle.
  • Depress and release clutch pedal more than 10 times  during the drive cycle.
  • Is the PENDING CODE for this DTC present?
 Yes Replace PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION ).
No Go to the next step.
15 VERIFY AFTER REPAIR PROCEDURE 
 Yes Go to the applicable DTC inspection.
(See DTC TABLE ).
No Troubleshooting completed.
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