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

DTC DETECTING CONDITION:

Two consecutive driving cycles with fault
GENERAL DESCRIPTION < Ref. to DTC P0852 NEUTRAL SWITCH INPUT CIRCUIT HIGH (MT MODEL) , Diagnostic Trouble Code (DTC) Detecting Criteria. >

TROUBLE SYMPTOM:

Erroneous idling

CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode < Ref. to , OPERATION , Clear Memory Mode. > and Inspection Mode < Ref. to , PROCEDURE , Inspection Mode. >.

WIRING DIAGRAM:

Fig 1: DTC P0852 Neutral Switch - Wiring Diagram And Connector Terminal

Courtesy of SUBARU OF AMERICA, INC.

DIAGNOSTIC PROCEDURE DTC P0852

Step	Check	Yes	No
1 CHECK INPUT SIGNAL FOR ECM. Turn ignition switch to ON. Place the shift lever in neutral. Measure the voltage between ECM and chassis ground. Connector & terminal (B137) No. 9 (+) - Chassis ground (-):	Is the voltage more than 10 V?	Go to step 2 .	Go to step 4 .
2 CHECK INPUT SIGNAL FOR ECM. Place the shift lever in a position except for neutral. Measure the voltage between ECM and chassis ground. Connector & terminal (B137) No. 9 (+) - Chassis ground (-):	Is the voltage less than 1 V?	Go to step 3 .	Go to step 5 .
3 CHECK FOR POOR CONTACT. Check for poor contact in ECM connector.	Is there poor contact in ECM connector?	Repair poor contact in ECM connector.	Contact SOA Service Center. NOTE: Inspection by DTM is required, because probable cause is deterioration of multiple parts.
4 CHECK NEUTRAL SWITCH. Place the shift lever in a position except for neutral. Measure the resistance between transmission harness connector terminals. Connector & terminal (T2) No. 1 - No. 2:	Is the resistance more than 1 MΩ?	Go to step 5 .	Repair open circuit in transmission harness or replace neutral switch.
5 CHECK HARNESS BETWEEN ECM AND NEUTRAL SWITCH CONNECTOR. Disconnect the connector from ECM. Measure the resistance of harness between ECM and transmission harness connector. Connector & terminal (B137) No. 9 - (B25) No. 2:	Is the resistance 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 SWITCH CONNECTOR. Measure the resistance of harness between transmission harness connector and engine ground. Connector & terminal (B25) No. 1 - Engine ground:	Is the resistance 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 ground Poor contact in coupling connector
7 CHECK FOR POOR CONTACT. Check for poor contact in transmission harness connector.	Is there a poor contact in the transmission harness connector?	Repair poor contact in transmission harness connector.	Contact SOA Service Center. NOTE: Inspection by DTM is required, because probable cause is deterioration of multiple parts.