DTC P0852 - Neutral Switch Input Circuit High (At Model) -

DTC DETECTING CONDITION:
- Two consecutive driving cycles with malfunction
TROUBLE SYMPTOM:
- Erroneous idling
CAUTION: After repair or replacement of malfunctioning parts, conduct Clear Memory Mode < Ref. to OPERATION , CLEAR MEMORY MODE > and INSPECTION MODE < Ref. to OPERATION , INSPECTION MODE. >
WIRING DIAGRAM:

Fig 1: Neutral Switch Input Wiring Diagram
Courtesy of SUBARU OF AMERICA, INC.

DIAGNOSTIC PROCEDURE

Step	Check	Yes	No
1 CHECK ANY OTHER DTC ON DISPLAY.	Is any other DTC displayed?	Inspect the relevant DTC using "List of Diagnostics Trouble Code (DTC)". < Ref. to LIST OF DIAGNOSTIC TROUBLE CODE (DTC) . >	Go to step 2.
2 CHECK INPUT SIGNAL FOR ECM. Turn ignition switch to ON. Measure voltage between ECM and chassis ground in select level "N" and "P" positions. Connector & terminal (B136) No. 21 (+) - Chassis ground	Is the measured value less than 1 V?	Go to step 3.	Go to step 5.
3 CHECK INPUT SIGNAL FOR ECM. Measure voltage between ECM and chassis ground in select level "N" and "P" positions. Connector & terminal (B136) No. 21 (+) - Chassis ground	Is the measured value within 4.5 to 5.5 V?	Go to step 4.	Go to step 5.
4 CHECK POOR CONTACT. Check poor contact in ECM connector.	Is there poor contact in ECM connector.	Repair poor contact in ECM connector.	Contact with SOA service center. NOTE: Inspection by DTM is required, because probable cause is deterioration of multiple parts.
5 CHECK HARNESS BETWEEN ECM AND INHIBITOR SWITCH CONNECTOR. Turn ignition switch to OFF. Disconnect connector from ECM and inhibitor switch. Measure resistance of harness between ECM and inhibitor switch connector. Connector & terminal (B136) No. 21 - (T7) No. 12:	Is the measured value less than 1 Ω?	Go to step 6.	Repair harness and connector. NOTE: In this case, repair the following: Open circuit in harness between ECM and inhibitor switch connector Poor contact in coupling connector Poor contact in inhibitor switch connector Poor contact in ECM connector
6 CHECK INHIBITOR SWITCH GROUND LINE. Measure resistance of harness between inhibitor switch connector and engine ground. Connector & terminal (T7) No. 7-Engine ground:	Is the measured value less than 5 Ω?	Go to step 7.	Repair open circuit in harness between inhibitor switch connector and starter motor ground line. NOTE: In this case, repair the following: Open circuit in harness between inhibitor switch connector and starter motor grond line Poor contact in satrter motor connector Poor contact in starter motor ground Starter motor
7 CHECK INHIBITOR SWITCH. Measure resistance between inhibitor switch connector terminals in select level "N" and "P" positions. Terminal No.7 - No.12:	Is the measured value less than 1 Ω?	Go to step 8.	Replace inhibitor switch. < Ref. to INHIBITOR SWITCH . >
8 CHECK SELECTOR CABLE CONNECTION.	Is there any malfunction in selector cable connection to inhibitor switch?	Repair selector cable connection. < Ref. to SELECT CABLE . >	Contact with SOA service center. NOTE: Inspection by DTM is required, because probable cause is deterioration of multiple parts.