P1561
Cruise Vent Solenoid.
- Chevrolet
- Powertrain
- Manufacturer code
- Low severity
How this code is built
- P
- SystemPowertrain
- 1
- Defined byThe manufacturer
- 5
- AreaVehicle speed, idle control and auxiliary inputs
- 61
- FaultThe specific fault in that area
What it means
On Chevrolet, P1561 relates to the cruise control vent solenoid circuit. The vent solenoid releases vacuum to the cruise servo so the throttle returns when cruise is cancelled or the brake is pressed. The control unit set the code because the solenoid circuit or its operation did not match what it commanded, though the exact test logic depends on the model and year.
Symptoms
- Cruise control will not engage or drops out unexpectedly
- Cruise control does not disengage promptly when braking
- Cruise control behaves erratically or surges
- Engine warning light on
- No other noticeable change in everyday driving
Possible causes
- Faulty cruise vent solenoid (open or shorted coil)likely
- Damaged wiring or poor connector contact at the solenoid or servolikely
- Leaking or split vacuum hose or cruise servo diaphragmpossible
- Faulty brake switch or cruise cancel switch giving inconsistent signalspossible
- Blown fuse or fault in the power or earth supply to the cruise circuitpossible
- Fault inside the control module driver circuitrare
How to diagnose
- Read all stored codes and freeze frame data, and note whether other cruise or brake switch codes are present
- Check the relevant fuses and inspect the cruise servo, solenoid, wiring and connectors for damage, corrosion or chafing
- Inspect the vacuum hoses to the servo for splits, kinks or loose fittings, and check the servo holds vacuum
- Check the brake switch and cancel switch operation and their signals on live data, as the layout varies by model
- Measure the solenoid coil resistance and compare it with the manufacturer specification for that model
- Check the solenoid supply voltage and control signal at the connector with the cruise commanded on and off
- Test wiring continuity and for shorts to earth or supply between the solenoid and control module
- Clear the code and road test to confirm whether it returns
How to fix
- Replace the cruise vent solenoid if its resistance or operation is out of specification
- Repair or replace damaged wiring and clean or renew faulty connectors
- Replace split or leaking vacuum hoses or a faulty cruise servo
- Replace a faulty brake or cancel switch
- Restore the fuse and supply or earth fault, finding out why it failed
- Repair or replace the control module only after all other causes have been ruled out
Can I keep driving?
Low severity
The car is normally safe to drive, but the cruise control may not work or release correctly, so avoid using it until it is repaired. Book it in at your convenience.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.