WOMS
P code powertrain Medium severity

P0828 Up and Down Switch Input Circuit High

The OBD2 code P0828 indicates a problem with the up and down switch input circuit, specifically that the circuit is reading a high voltage signal when it should not be

Definition

The OBD2 code P0828 indicates a problem with the up and down switch input circuit, specifically that the circuit is reading a high voltage signal when it should not be

Common causes

  • Faulty up/down switch
  • Short circuit in the wiring
  • Open circuit in the wiring
  • Corroded or damaged connectors
  • Faulty transmission control module (TCM)
  • Malfunctioning body control module (BCM)
  • Poor ground connection
  • Electrical interference or noise

Common misdiagnoses

  • Faulty transmission control module (TCM)
  • Malfunctioning shift lever assembly
  • Defective wiring or connectors
  • Faulty transmission range sensor
  • Incorrectly installed or damaged transmission
  • Issues with the vehicle's body control module (BCM)
  • Problems with the powertrain control module (PCM)

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 the Wiring and Connectors

    Visually inspect the wiring and connectors associated with the up and down shift switches. Look for signs of damage, corrosion, or loose connections

  3. 3. Pay special attention to the wiring harness that connects to the transmission control module (TCM) and the shift switches

  4. 4. Test the Shift Switches

    Use a multimeter to test the up and down shift switches for proper operation. Check for continuity when the switches are activated

  5. 5. If the switches are faulty, they may need to be replaced

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

    Inspect the TCM for any signs of damage or corrosion. Ensure that it is securely connected and that there are no issues with the pins or connectors

  7. 7. If necessary, test the TCM for proper operation. This may require specialized diagnostic equipment

  8. 8. Inspect the Ground Connections

    Ensure that all ground connections related to the transmission and TCM are clean and secure. Poor grounding can lead to erratic behavior and false codes

  9. 9. Check for Short Circuits

    Use a multimeter to check for short circuits in the wiring harness. A short to power or ground can cause the circuit to read high

  10. 10. Clear the Codes and Test Drive

    After performing the above checks and repairs, clear the trouble codes using the OBD-II scanner

  11. 11. Take the vehicle for a test drive to see if the code returns. Monitor the transmission operation to ensure it is functioning correctly

  12. 12. Consult Technical Service Bulletins (TSBs)

    Check for any TSBs related to the P0828 code for your specific vehicle make and model. Manufacturers may have issued guidance or fixes for known issues

  13. 13. 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 can perform more in-depth diagnostics. By following these troubleshooting steps, you should be able to identify and resolve the issue associated with the P0828 code