What does it mean?
P1525 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Cruise Control Switch Circuit Malfunction .
Symptoms
- Check engine light on and the cruise control indicator will not come on
- Cruise control refuses to set, or cancels itself shortly after being engaged
- Buttons respond only in certain positions or need to be pressed hard
- Speed control cancels when the steering wheel is turned in some cases
- Other steering wheel controls such as the horn or audio buttons behave oddly
- Normal engine performance apart from the missing cruise function
Likely causes
- Worn or dirty contacts inside the cruise control stalk or the steering wheel buttons
- Broken conductors in the clock spring behind the steering wheel
- Corroded or loose connector in the steering column harness
- Chafed wire where the column harness moves with the tilt or reach adjustment
- Brake or clutch switch out of adjustment, sending a conflicting cancel signal
- Water ingress into the switch assembly after a leak around the windscreen or door seal
- Module input circuit failure as the last suspect
How to fix it
- Monitor the cruise control switch states in live data while pressing every button in turn
- Inspect the clock spring and the column harness for broken wires and heat or wear damage
- Check the connector terminals for corrosion and looseness, and reseat them
- Measure the switch resistance in each position and compare with the specified values
- Verify the brake and clutch switch adjustment and their signals in live data
- Replace the cruise control switch or the clock spring depending on which fails the tests
- Repair the harness, then confirm cruise control sets, holds and cancels correctly on a road test