A P0957 DTC means that the ECU has detected an unusually low voltage signal coming from the auto shift manual mode circuit (this includes the auto stick shift switch/transmission shift switch, a mode actuator, and the associated wires/connectors).
How Serious is the Code?
Having a P0957 diagnostic trouble code is not the end of the world. It does mean however, you won’t be able to manually row through the gears of your automatic transmission.
Symptoms of a P0957 include:
- Manual shifting function is disabled
- Damaged connectors and/or wiring
- Failed Autostick transmission shift switch
How to Diagnose the Code?
Surprisingly enough, the most common cause of a P0957 OBDII trouble code is water damage due to a drink being spilled on the shifter, or water dripping down onto it from the sunroof. So the process of diagnosing this OBD2 code should begin with inspecting the autostick switch and wiring/connectors for signs of corrosion and other damage. The switch itself should also be tested to ensure that it works properly.
What Repairs Will Fix P0957?
- Repair or replace damaged wiring and connectors
- Replace Autostick transmission shift switch