DTC P0850 [L3]

BME010200800201

DTC P0850

Neutral switch circuit malfunction

DETECTION CONDITION

• The PCM monitors changes in input voltage from neutral switch. If the PCM does not detect PCM terminal 1W voltage changes while running vehicle with vehicle speed above 30 km/h {19 mph} and clutch pedal turns press and depress 10 times repeatedly, the PCM determines that the neutral switch circuit has malfunction.
Diagnostic support note
• This is a continuous monitor (CCM).
• 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 during first drive cycle.
• FREEZE FRAME DATA is available.
• DTC is stored in PCM memory.

POSSIBLE CAUSE

• Neutral switch malfunction
• Poor connection of neutral switch connector or PCM connector
• Short to ground between neutral switch terminal A and PCM connector terminal 1W
• Open harness between neutral switch terminal A and PCM connector terminal 1W
• Open harness between ground and brake switch terminal B
• PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION

1
VERIFY FREEZE FRAME DATA HAS BEEN RECORDED
• Has FREEZE FRAME DATA been recorded?
Yes
Go to the next step.
No
Record FREEZE FRAME DATA on repair order, then go to the next step.
2
VERIFY RELATED SERVICE INFORMATION AVAILABILITY
• Check for related Service Information availability.
• Is any related Service Information available?
Yes
Perform repair or diagnosis according to available Service Information.
• If vehicle is not repaired, go to the next step.
No
Go to the next step.
3
CLASSIFY HIGH INPUT OR LOW INPUT
• Connect WDS or equivalent to DLC-2.
• Access CPP/PNP PID.
• Verify CPP/PNP PID when gear is in neutral position.
• Is 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 off.
• Disconnect the neutral switch connector.
• Inspect for poor connection (such as damaged/pulled-out terminals, 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 CPP/PNP PID.
• Connect a jumper wire between neutral switch terminal A and B.
• Is CPP/PNP PID on?
Yes
Go to the next step.
No
Go to Step 7.
6
INSPECT NEUTRAL SWITCH
• Perform neutral switch inspection.
• Is the neutral switch normal?
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 B and ground.
• Is there continuity?
Yes
Go to the next step.
No
Repair or replace the neutral switch power circuit for 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 terminals, corrosion).
• Is there any malfunction?
Yes
Repair or replace 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 A and PCM terminal 1W.
• Is there continuity?
Yes
Repair or replace the wiring harness for open circuit, then go to Step 14.
No
Go to Step 14.
10
INSPECT NEUTRAL SWITCH CONNECTOR FOR POOR CONNECTION
• Turn the ignition switch off.
• Disconnect the neutral switch connector.
• Inspect for poor connection (such as damaged/pulled-out terminals, 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 CPP/PNP PID.
• Verify that CPP/PNP PID changes from ON to OFF when the neutral switch connector is disconnected.
• Does CPP/PNP PID change from ON to OFF?
Yes
Go to the next step.
No
Go to Step 13.
12
INSPECT NEUTRAL SWITCH
• Perform neutral switch inspection.
• Is the neutral switch normal?
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 A and ground.
• Is there continuity?
Yes
Repair or replace the wiring harness for short to ground, then go to the next step.
No
Go to 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 drive cycle.
• Is the same DTC present?
Yes
Replace the PCM, then go to the next step.
No
Go to the next step.
15
VERIFY AFTER REPAIR PROCEDURE
• Perform "After Repair Procedure".
• Is there any DTC present?
Yes
Go to the applicable DTC inspection.
No
Troubleshooting completed.