What does code P1504 mean?

Q: What does code P1504 mean?

Vehicle Speed Output Circuit. P1504 on a GM vehicle means the powertrain control module (PCM) has detected a problem with the vehicle speed output circuit, which is the signal the PCM sends to other modules such as the instrument cluster, cruise control, and radio. The PCM monitors this output circuit and sets the code when the voltage or signal behavior falls outside the expected range, often due to a wiring fault, a failed output driver inside the PCM, or a problem with a module on the receiving end.

DTC codes / GM codes / P1504

P1504 · GMVehicle Speed Output Circuit

P1504 on a GM vehicle means the powertrain control module (PCM) has detected a problem with the vehicle speed output circuit, which is the signal the PCM sends to other modules such as the instrument cluster, cruise control, and radio. The PCM monitors this output circuit and sets the code when the voltage or signal behavior falls outside the expected range, often due to a wiring fault, a failed output driver inside the PCM, or a problem with a module on the receiving end.

SystemPowertrain

Code typeGM specific

SeverityMedium

Fix difficultyProfessional

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.