Transmission

P0815 — Upshift Switch Circuit Malfunction

Severity: low Safe to drive

What P0815 means

P0815 means the transmission control module (TCM or PCM) sees an invalid signal from the upshift switch used in manual shift mode. The switch may be a steering wheel paddle, a selector lever contact or a button. When pressed it tells the module to shift up, and the code sets if the signal is missing, shorted or stuck.

Symptoms

  • Check Engine or transmission warning light on
  • Upshift paddle or button does not work
  • Transmission stuck in manual mode
  • Gear does not go up on driver command
  • Manual mode unavailable altogether

Possible causes

  1. Failed upshift switch (paddle or button)
  2. Faulty clock spring in the steering column
  3. Open or shorted wiring in the steering column or harness
  4. Corroded or loose connector
  5. Failed TCM or PCM (rare)

How to diagnose

  1. Scan for codes and note any other transmission or steering-related DTCs
  2. Watch the switch status in scan tool data while pressing the paddle
  3. Inspect the connectors and wiring in the steering column for damage and corrosion
  4. Test switch circuit continuity and resistance with a multimeter per the service manual
  5. Check the clock spring for broken traces
  6. Verify power and ground to the circuit and wire continuity to the module
  7. Clear the code and confirm it does not return

Common fixes

  • Replace the upshift switch or paddle
  • Replace the clock spring
  • Repair wiring or connectors and clean contacts
  • Replace or reprogram the control module if confirmed faulty

Questions and answers

What does P0815 mean?

It indicates a fault in the upshift switch circuit used for manual shifting. The control module is getting an incorrect signal from the paddle or button.

Can I drive with P0815?

Usually yes, because automatic mode generally still works. If the transmission is stuck in manual mode, get it checked soon.

What most often causes P0815?

A worn clock spring or a faulty switch is common. Wiring and connector problems in the steering column are also worth checking.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.