DTC P0850:00

Neutral switch input circuit problem

DETECTION CONDITION

• The PCM monitors changes in input voltage from the neutral switch. If the PCM does not detect a voltage change while driving the vehicle at a vehicle speed above 30 km/h {19 mph} and the clutch pedal is pressed and released 10 times repeatedly, the PCM determines that the neutral switch circuit has a malfunction.

Diagnostic support note

• This is a continuous monitor (CCM).

• The check engine light illuminates if the 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 the PCM detects the above malfunction condition during first drive cycle.

• FREEZE FRAME DATA (Mode 2)/Snapshot data is available.

• DTC is stored in the PCM memory.

FAIL-SAFE FUNCTION

Not applicable

POSSIBLE CAUSE

• Neutral switch connector or terminals malfunction

• Neutral switch malfunction

• Open circuit in wiring harness between neutral switch terminal B and body ground

• Short to ground in wiring harness between neutral switch terminal A and PCM terminal 1K

• PCM connector or terminals malfunction

• Open circuit in wiring harness between neutral switch terminal A and PCM terminal 1K

• PCM malfunction

STEP

INSPECTION

ACTION

1

• Has the FREEZE FRAME DATA (Mode 2)/snapshot data been recorded?

Yes

Go to the next step.

No

Record the FREEZE FRAME DATA (Mode 2)/snapshot data on the repair order, then go to the next step.

2

• 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

• Switch the ignition 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 connector and/or terminals, then go to Step 9.

No

Go to the next step.

4

• Inspect the neutral switch.

  (See NEUTRAL SWITCH INSPECTION [SKYACTIV-G 2.5].)

• Is there any malfunction?

Yes

Replace the neutral switch, then go to Step 9.

(See NEUTRAL SWITCH REMOVAL/INSTALLATION [C66M-R].)

No

Go to the next step.

5

• Verify that the neutral switch connector is disconnected.

• Inspect for continuity between neutral switch terminal B (wiring harness-side) and body ground.

• Is there continuity?

Yes

Go to the next step.

No

Refer to the wiring diagram and verify whether or not there is a common connector between neutral switch terminal B and body ground.

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Inspect for the following:

• Open circuit between neutral switch and body ground

• Loose or lifting ground point

• Repair or replace the malfunctioning part.

Go to Step 9.

6

• Verify that the neutral switch connector is disconnected.

• Inspect for continuity between neutral switch terminal A (wiring harness-side) and body ground.

• Is there continuity?

Yes

If the short to ground circuit could be detected in the wiring harness:

• Refer to the wiring diagram and verify whether or not there is a common connector between neutral switch terminal A and PCM terminal 1K.

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has a short to ground.

If the short to ground circuit could not be detected in the wiring harness:

• Replace the PCM (short to ground in the PCM internal circuit).

  (See PCM REMOVAL/INSTALLATION [SKYACTIV-G 2.5].)

Go to Step 9.

No

Go to the next step.

7

• Disconnect the PCM connector.

• Inspect for poor connection (such as damaged/pulled-out pins, corrosion).

• Is there any malfunction?

Yes

Repair or replace the connector and/or terminals, then go to Step 9.

No

Go to the next step.

8

• Verify that the neutral switch and PCM connectors are disconnected.

• Inspect for continuity between neutral switch terminal A (wiring harness-side) and PCM terminal 1K (wiring harness-side).

• Is there continuity?

Yes

Go to the next step.

No

Refer to the wiring diagram and verify whether or not there is a common connector between neutral switch terminal A and PCM terminal 1K.

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has an open circuit.

Go to the next step.

9

• Always reconnect all disconnected connectors.

• Clear the DTC from the PCM memory using the M-MDS.

  (See AFTER REPAIR PROCEDURE [SKYACTIV-G 2.5].)

• Drive the vehicle above 30 km/h {19 mph} and stop the vehicle.

• Depress and release the clutch pedal more than 10 times during drive cycle.

• Perform the Pending Trouble Code Access Procedure.

  (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.5].)

• Is the PENDING CODE for this DTC present?

Yes

Repeat the inspection from Step 1.

• If the malfunction recurs, replace the PCM.

  (See PCM REMOVAL/INSTALLATION [SKYACTIV-G 2.5].)

Go to the next step.

No

Go to the next step.

10

• Perform the “AFTER REPAIR PROCEDURE”.

  (See AFTER REPAIR PROCEDURE [SKYACTIV-G 2.5].)

• Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [SKYACTIV-G 2.5].)

No

DTC troubleshooting completed.