What does it mean?
P1561 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Cruise Vent Solenoid Circuit Malfunction .
Symptoms
- Cruise control will not engage at all, or engages and then cancels immediately
- Set speed creeps up, or the system is slow to release when the brake is applied
- Cruise indicator lamp flashes or stays off
- Check engine light on with the fault stored
- No other change in engine performance when the cruise system is not in use
Likely causes
- Open or short circuited vent solenoid winding
- Corroded or loose connector at the cruise servo solenoid pack
- Chafed or broken control wire between the cruise module and the vent solenoid
- Blown fuse or a missing ignition supply to the solenoid pack
- Poor ground on the solenoid or on the cruise control module
- Cracked or collapsed vacuum hose to the servo, which makes the vent function behave abnormally
- Failed solenoid driver inside the cruise or engine control module
How to fix it
- Confirm that the brake switch and the cruise main switch operate correctly before touching the servo
- Inspect the solenoid connector for corrosion, moisture and backed-out terminals
- Measure the vent solenoid winding resistance and compare it against specification
- Check for supply voltage at the solenoid with the ignition on and confirm a clean ground path
- Where the scan tool supports it, command the solenoid on and off and listen for it clicking
- Inspect the vacuum hoses and the servo diaphragm for leaks and hardened rubber
- Replace the solenoid or the servo assembly when the winding is out of specification, then retest on the road