What does code P1559 mean?

Q: What does code P1559 mean?

Cruise Control Power Management Mode. P1559 on a GM vehicle indicates that the engine control module (ECM) has detected an abnormal condition within the cruise control power management circuit, typically a mismatch between the requested cruise state and the actual voltage or signal on the cruise control power feed. The ECM sets this code when the cruise control system cannot enter or maintain the power management mode it expects, often due to a wiring fault, a failing cruise control switch, or a problem with the throttle actuator control (TAC) system.

DTC codes / GM codes / P1559

P1559 · GMCruise Control Power Management Mode

P1559 on a GM vehicle indicates that the engine control module (ECM) has detected an abnormal condition within the cruise control power management circuit, typically a mismatch between the requested cruise state and the actual voltage or signal on the cruise control power feed. The ECM sets this code when the cruise control system cannot enter or maintain the power management mode it expects, often due to a wiring fault, a failing cruise control switch, or a problem with the throttle actuator control (TAC) system.

SystemPowertrain

Code typeGM specific

SeverityMedium

Fix difficultyIntermediate

AreaVehicle speed, idle control and auxiliary inputs

Guidance is general and written for GM vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.