A DTC P0957 means that the ECU has detected an abnormally low voltage signal from the automatic transmission manual shift mode circuit (this includes the automatic shift switch/transmission shift switch, a mode actuator, and the associated wires/connectors).
How severe is the code?
Having a diagnostic code P0957 is not the end of the world. However, it means you will not be able to manually shift between gears of your automatic transmission.
Symptoms
Symptoms of a P0957 include:
- Manual shifting function is disabled
Causes
- Damaged connectors and/or wiring
- Failure of the Autostick transmission shift switch
How to diagnose the code?
Surprisingly, the most common cause of a P0957 OBDII fault code is water damage from spilling a drink on the shift lever or from water dripping onto it from the sunroof. Therefore, the diagnostic process for this OBD2 code should start by inspecting the autostick switch and wiring/connectors for signs of corrosion and other damage. The switch itself should also be tested to ensure it is functioning properly.
What repairs will fix P0957?
- Repair or replace damaged wiring and connectors
- Replace the Autostick transmission shift switch