ENGINE (DIAGNOSTICS)(H4DOTC) > Diagnostic Procedure with Diagnostic Trouble Code (DTC)

DTC P0852 PARK/NEUTRAL SWITCH INPUT CIRCUIT HIGH (AT MODEL)

DTC DETECTING CONDITION:

Detected when two consecutive driving cycles with fault occur.

TROUBLE SYMPTOM:

Improper idling

CAUTION:

After repairing or replacing the defective part, perform the Clear Memory Mode and Inspection Mode .

WIRING DIAGRAM:

STEPCHECKYESNO

1.CHECK SELECT CABLE.

Is there any fault in the select cable?

Repair or adjust the select cable.

2.CHECK INPUT SIGNAL OF ECM.

1) Turn the ignition switch to ON.

2) Measure the voltage between ECM and chassis ground with select lever at “N” and “P” range.

Connector & terminal

(B136) No. 31 (+) — Chassis ground (−):

Is the voltage less than 1 V?

3.CHECK INPUT SIGNAL OF ECM.

Measure the voltage between ECM and chassis ground with select lever at other than “N” and “P” range.

Connector & terminal

(B136) No. 31 (+) — Chassis ground (−):

Is the voltage 4.5 — 5.5 V?

4.CHECK POOR CONTACT.

Check poor contact of ECM connector.

Is there poor contact in ECM connector?

Repair the poor contact of ECM connector.

Contact with SUBARU distributor service.

5.CHECK INPUT SIGNAL OF ECM.

Measure the voltage between ECM and chassis ground.

Connector & terminal

(B136) No. 31 (+) — Chassis ground (−):

Is the voltage 10 V or more?

Repair the battery short circuit of harness between ECM and inhibitor switch connector.

6.CHECK HARNESS BETWEEN ECM AND INHIBITOR SWITCH CONNECTOR.

1) Turn the ignition switch to OFF.

2) Disconnect the connectors from ECM and inhibitor switch.

3) Measure the resistance of harness between ECM and inhibitor switch connector.

Connector & terminal

(B136) No. 31 — (T7) No. 12:

Is the resistance less than 1 Ω?

Repair the harness and connector.

NOTE:

In this case, repair the following item:

• Open circuit in harness between ECM and inhibitor switch connector

• Poor contact of coupling connector

• Poor contact of inhibitor switch connector

• Poor contact in ECM connector

7.CHECK INHIBITOR SWITCH GROUND LINE.

Measure the resistance of harness between inhibitor switch connector and engine ground.

Connector & terminal

(T7) No. 12 — Engine ground:

Is the resistance less than 5 Ω?

Repair open circuit of harness between inhibitor switch connector and starter motor ground line.

NOTE:

In this case, repair the following item:

• Open circuit in harness between inhibitor switch connector and starter motor ground line

• Poor contact in starter motor connector

• Poor contact in starter motor ground

• Starter motor

8.CHECK INHIBITOR SWITCH.

Measure the resistance between inhibitor switch connector receptacle’s terminals with select lever at “N” and “P” range.

Terminals

No. 7 — No. 12:

Is the resistance less than 1 Ω?

Contact with SUBARU distributor service.

Replace the inhibitor switch.