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

WARNING: This page is about a different variant/trim than selected.

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 INPUT SIGNAL FOR ECM. Turn ignition switch to ON. Place the shift lever in neutral position. Measure voltage between ECM and chassis ground. Connector & terminal (B136) No. 21 (+) - Chassis ground (-):	Is the measured value less than 1 V?	Go to step 2.	Go to step 4.
2 CHECK INPUT SIGNAL FOR ECM. Place the shift lever in any other than neutral position. Measure voltage between ECM and chassis ground. Connector & terminal (B136) No. 21 (+) - Chassis ground (-):	Is the measured value more than 5 V?	Go to step 3.	Go to step 5.
3 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.
4 CHECK NEUTRAL POSITION SWITCH. Place the shift lever in any other than neutral position. Measure resistance between transmission harness connector terminals. Connector & terminal (T2) No. 1 - No. 2:	Is the measured value 1 MΩ or more?	Go to step 5.	Repair short circuit in transmission harness or replace neutral position switch.
5 CHECK HARNESS BETWEEN ECM AND NEUTRAL POSITION SWITCH CONNECTOR. Disconnect connector from ECM. Measure resistance of harness between ECM and transmission harness connector. Connector & terminal (B136) No. 21 - (B25) No. 1:	Is the measured value less than 1 Ω?	Go to step 6.	Repair open circuit in harness between ECM and transmission harness connector.
6 CHECK HARNESS BETWEEN ECM AND NEUTRAL POSITION SWITCH CONNECTOR. Measure resistance of harness between transmission harness connector and engine ground. Connector & terminal (B25) No. 2 - Engine ground:	Is the measured value less than 5 Ω?	Go to step 7.	Repair harness and connector. NOTE: In this case, repair the following: Open circuit in harness between transmission harness connector and engine grounding terminal Poor contact in coupling connector
7 CHECK POOR CONTACT. Check poor contact in transmission harness connector.	Is there poor contact in transmission harness connector?	Repair poor contact in transmission harness connector.	Contact with SOA (distributor) service. NOTE: Inspection by DTM is required, because probable cause is deterioration of multiple parts.