DTC P0851: Park/Neutral Switch Input Circuit Low: Notes
1. -
DTC detecting condition:
Detected when two consecutive driving cycles with fault occur.
Trouble symptom:
Improper idling
Wiring diagram:
Engine Electrical System Refer to WIRING SYSTEM>ENGINE ELECTRICAL SYSTEM .
CAUTION:
Use the check board when measuring the ECM terminal voltage and resistance. Refer to ENGINE (DIAGNOSTICS) (H4DOTC)>GENERAL DESCRIPTION>PREPARATION TOOL>HOW TO USE CHECK BOARD
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NOTE:
After the faulty parts are repaired or replaced, perform the final check in Basic Diagnostic Procedure. Refer to ENGINE (Diagnostics) (H4DOTC)>Basic Diagnostic Procedure>PROCEDURE
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- CHECK SELECT CABLE
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Check the select cable.
Is there any fault in select cable?
Yes : Repair or adjust the select cable. Refer to CONTROL SYSTEMS>SELECT CABLE .
No : Go to 2.
- CHECK INPUT SIGNAL OF ECM
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- Turn the ignition switch to ON.
- Place the select lever in other than "P" range and "N" range.
- Measure the voltage between ECM connector and chassis ground.
Connector & terminal
(E51) No. 17 - Engine ground:
Is the voltage 10 V or more?
Yes : Repair the poor contact of ECM connector.
No : Go to 3.
- CHECK HARNESS BETWEEN ECM AND TRANSMISSION HARNESS CONNECTOR (SHORT TO GROUND)
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- Turn the ignition switch to OFF.
- Disconnect the connector from ECM.
- Disconnect the connector from inhibitor switch.
- Measure the resistance between ECM connector and chassis ground.
Connector & terminal
(E51) No. 17 - Engine ground:
Is the resistance 1 MΩ or more?
Yes : Replace the inhibitor switch. Refer to CONTINUOUSLY VARIABLE TRANSMISSION (TR690)>INHIBITOR SWITCH .
No : Repair the following item.
- Short circuit to ground in harness between ECM connector and inhibitor switch connector
- Poor contact of coupling connector