What does code P1503 mean?

Q: What does code P1503 mean?

Load Signal From Generator Range Performance. P1503 on Volkswagen vehicles means the engine control module (ECM) is not receiving a plausible load signal from the generator, so it cannot confirm the alternator is responding correctly to electrical demand. The ECM monitors the generator's load feedback circuit and sets this code when the signal voltage or duty cycle falls outside the expected range for the current operating conditions.

DTC codes / Volkswagen codes / P1503

P1503 · VolkswagenLoad Signal From Generator Range Performance

P1503 on Volkswagen vehicles means the engine control module (ECM) is not receiving a plausible load signal from the generator, so it cannot confirm the alternator is responding correctly to electrical demand. The ECM monitors the generator's load feedback circuit and sets this code when the signal voltage or duty cycle falls outside the expected range for the current operating conditions.

SystemPowertrain

Code typeVolkswagen specific

SeverityMedium

Fix difficultyIntermediate

AreaVehicle speed, idle control and auxiliary inputs

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