What it means
The upshift switch signal jumps or drops out intermittently. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
At a glance
- Usually lights the check-engine light
How it works
The upshift switch sends a higher-gear request, often through steering-wheel controls, to the transmission controller. The controller monitors the signal for dropouts or sudden changes while the control is in use. This code sets when the signal becomes intermittent or erratic, which may be caused by a loose steering-wheel connector, worn clock-spring contacts, or a connection that fails with vibration.
Common causes
Most likely first.
- Steering wheel connector loose
- Wear in steering wheel clock spring contacts
- Connector with intermittent contact under vibration
Symptoms
- Check engine or transmission warning light may be on
- Upshift response may come and go
- Manual shift mode may behave unpredictably
How to diagnose it
- Save freeze-frame data and review related transmission codes and available upshift-switch status.
- With the vehicle safely parked, operate the upshift switch repeatedly while watching live data for missed or fluctuating requests.
- Inspect accessible switch and steering-wheel harness connectors for looseness, damage, or corrosion without disturbing airbag components.
- If the fault can be reproduced safely, gently move accessible wiring while watching the switch signal for dropouts.
- If the wiring checks out, test the upshift switch and clock-spring circuit according to the manufacturer’s procedure.
Common fixes
- Secure a loose steering-wheel or upshift-switch connector.
- Repair damaged wiring or terminals in the upshift signal circuit.
- Replace a worn upshift switch if its contacts drop out during testing.
- Replace the clock spring if its contacts cause intermittent upshift signals.
Can I keep driving?
Use automatic mode and do not rely on manual upshift requests while the signal comes and goes. If the transmission shifts unexpectedly or enters limp mode, stop when safe; steering-wheel wiring may be near airbag components, so avoid probing those circuits.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.