WOMS
P code powertrain Medium severity

P0950 ASM Control Circuit [Up / Down / Auto / etc]

The OBD2 code P0950 indicates a malfunction in the Automatic Shift Module (ASM) control circuit, which affects the operation of the up, down, or automatic shifting functions in the transmission system

Definition

The OBD2 code P0950 indicates a malfunction in the Automatic Shift Module (ASM) control circuit, which affects the operation of the up, down, or automatic shifting functions in the transmission system

Common causes

  • Faulty ASM control module
  • Wiring issues (shorts, opens, or corrosion)
  • Poor connections or damaged connectors
  • Malfunctioning sensors (e.g., position sensors)
  • Failed actuator or motor
  • Software issues or programming errors
  • Low battery voltage or electrical system problems

Common misdiagnoses

  • Faulty transmission control module (TCM)
  • Wiring issues or shorts in the control circuit
  • Defective shift solenoids
  • Malfunctioning transmission sensors
  • Low transmission fluid levels
  • Faulty gear position sensor
  • Issues with the vehicle's battery or charging system
  • Incorrectly diagnosed engine problems
  • Software or programming errors in the TCM
  • Mechanical transmission issues unrelated to the control circuit

Troubleshooting steps

  1. 1. Check for Additional Codes

    Use an OBD-II scanner to check for any other related trouble codes. This can provide more context and help identify if there are multiple issues

  2. 2. Inspect Wiring and Connectors

    Visually inspect the wiring and connectors associated with the ASM control circuit. Look for

  3. 3. Damaged, frayed, or corroded wires

  4. 4. Loose or disconnected connectors

  5. 5. Signs of short circuits or open circuits

  6. 6. Test the ASM Module

    If the wiring and connectors appear to be in good condition, the next step is to test the ASM module itself. This may involve

  7. 7. Checking the module for any visible damage

  8. 8. Testing the module's power and ground connections

  9. 9. Using a multimeter to check for proper voltage and continuity

  10. 10. Check for Ground Issues

    Ensure that the ASM module has a good ground connection. A poor ground can lead to erratic behavior and trigger the P0950 code

  11. 11. Inspect Related Components

    Check other components related to the transmission system, such as

  12. 12. Transmission fluid level and condition

  13. 13. Shift solenoids and sensors

  14. 14. Transmission control module (TCM) for any faults

  15. 15. Perform a Visual Inspection of the Transmission

    Look for any signs of leaks or damage in the transmission itself. Low fluid levels or contamination can affect the operation of the ASM

  16. 16. Clear Codes and Test Drive

    After performing inspections and repairs, clear the trouble codes using the OBD-II scanner. Take the vehicle for a test drive to see if the code returns

  17. 17. Seek Professional Help

    If the issue persists after performing the above steps, it may be necessary to consult a professional mechanic or technician who has experience with transmission systems and OBD-II diagnostics.Additional Tips: - Always ensure safety when working on a vehicle, including disconnecting the battery when inspecting electrical components. - Keep in mind that some vehicles may have specific quirks or common issues related to the P0950 code, so researching forums or technical service bulletins (TSBs) for your specific make and model can be beneficial. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the P0950 code