Diagnostic procedures for P0851/P0852 – 2005-2008 Subaru
The purpose of this bulletin is to assist when diagnosing P0851 (Neutral Switch Input Circuit Low) and P0852 (Neutral Switch Input Circuit High). If you encounter a vehicle with P0851 and/or P0852, use the following repair procedure.
REPAIR PROCEDURE/INFORMATION
Using the Subaru Select Monitor, check for diagnostic trouble codes stored in memory. If P0851 and/or P0852 are stored in memory, adjust the inhibitor switch and select cable.
Note: Refer to the applicable Subaru Service Manual found on the STIS web-site for component removal to gain access to the inhibitor switch and select cable. It is critical that the following adjustments are performed correctly.
Adjustment for inhibitor switch
- Set the select lever to “N” range.
- Loosen the three inhibitor switch securing bolts.
- Insert ST (special tool) 499267300 Stopper Pin as vertical as possible into the holes in the inhibitor switch lever and switch body.
- Tighten the three inhibitor switch securing bolts then remove special tool.
Tightening torque: 3.4 N-m (0.35 kgf-m, 2.5 ft-lb)
Adjustment for select cable
(A) Adjusting Nut A
(B) Adjusting Nut B
(A) Adjusting Nut A
(B) Adjusting Nut B
(C) Connector
Tightening torque: 7.5 N-m (0.76 kgf-m, 5.5 ft-lb)
(A) Adjusting Nut A
(B) Adjusting Nut B
- After the completion of adjustment, confirm that the select lever operates normally
at all ranges:- Move the select lever from “P” to “D” range. Check that the detents could be felt in each range. If the detents cannot be felt or the position pointer (dash indicator) is improperly aligned, re-adjust the cable.
- Check if the starter motor rotates when the select lever is set to “P” range.
- Check the back-up light illumination when the select lever is in “R” range.
- Check the parking lock operation when the select lever is in “P” range.
- Using the Subaru Select Monitor, clear the diagnostic trouble codes stored in memory.
If the codes return after the correct adjustments, refer to the diagnostic procedure found in the applicable SubaruService Manual.
WARRANTY/CLAIM INFORMATION
For vehicles within the Basic New Car Limited Warranty period, refer to the Subaru Warranty Wizard for claim submission information.