WOMS
P code powertrain Medium severity

P0957 ASM Mode Circuit Low

The OBD2 code P0957 indicates a low voltage or malfunction in the Automatic Shift Mode (ASM) circuit, which affects the transmission's ability to operate in the correct mode

Definition

The OBD2 code P0957 indicates a low voltage or malfunction in the Automatic Shift Mode (ASM) circuit, which affects the transmission's ability to operate in the correct mode

Common causes

  • Faulty transmission control module (TCM)
  • Wiring issues or damaged connectors
  • Faulty ASM (Automated Shift Module) sensor
  • Low transmission fluid level
  • Transmission fluid contamination
  • Malfunctioning transmission solenoids
  • Software issues or programming errors in the TCM
  • Grounding issues in the circuit

Common misdiagnoses

  • Transmission Control Module (TCM) failure
  • Faulty wiring or connectors
  • Transmission fluid issues
  • Shift solenoid problems
  • Engine control module (ECM) issues
  • Incorrectly calibrated transmission
  • Mechanical transmission problems
  • Sensor malfunctions
  • Battery or charging system issues
  • Grounding problems

Troubleshooting steps

  1. 1. Check for Additional Codes

    Use an OBD-II scanner to check for any other trouble codes that may be present. This can provide more context and help identify related issues

  2. 2. Inspect Wiring and Connectors

  3. 3. Visually inspect the wiring and connectors associated with the transmission control module and the ASM (Automatic Shift Mode) circuit

  4. 4. Look for signs of damage, corrosion, loose connections, or frayed wires

  5. 5. Check the Transmission Control Module (TCM)

  6. 6. Ensure that the TCM is functioning properly. If you have access to a scan tool, you can check for any communication issues with the TCM

  7. 7. If necessary, reprogram or replace the TCM if it is found to be faulty

  8. 8. Test the ASM Circuit

  9. 9. Use a multimeter to test the voltage and ground signals in the ASM circuit. Compare the readings to the specifications in the vehicle’s service manual

  10. 10. Check for continuity in the circuit to ensure there are no breaks

  11. 11. Inspect the Shift Selector

  12. 12. Ensure that the shift selector is functioning correctly and is not stuck or malfunctioning. A faulty shift selector can cause issues with the ASM mode

  13. 13. Check for Fluid Issues

  14. 14. Inspect the transmission fluid level and condition. Low or contaminated fluid can affect transmission performance and may trigger codes

  15. 15. If the fluid is low, top it off with the correct type of transmission fluid. If it is dirty, consider a transmission fluid change

  16. 16. Look for Mechanical Issues

  17. 17. Check for any mechanical issues within the transmission that could affect the ASM mode, such as worn components or internal failures

  18. 18. Clear the Code and Test Drive

  19. 19. After performing the above checks and repairs, clear the trouble code using the OBD-II scanner

  20. 20. Take the vehicle for a test drive to see if the code returns. Monitor the transmission performance during the drive

  21. 21. Consult a Professional

  22. 22. If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or a transmission specialist for further diagnosis. Always refer to the specific service manual for your vehicle for detailed procedures and specifications, as the exact steps may vary depending on the make and model