What does code P1508 mean?

Q: What does code P1508 mean?

Idle System Learned Value Upper Limit Attained. P1508 on Volkswagen vehicles means the engine control module (ECM) has learned an idle air/fuel correction that has reached its upper limit, so the engine is running leaner than expected at idle and the ECM can no longer compensate. The ECM monitors idle speed and mixture adaptation and sets this code when the long-term idle learned value stays pegged at the rich end of its adjustment range.

DTC codes / Volkswagen codes / P1508

P1508 · VolkswagenIdle System Learned Value Upper Limit Attained

P1508 on Volkswagen vehicles means the engine control module (ECM) has learned an idle air/fuel correction that has reached its upper limit, so the engine is running leaner than expected at idle and the ECM can no longer compensate. The ECM monitors idle speed and mixture adaptation and sets this code when the long-term idle learned value stays pegged at the rich end of its adjustment range.

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.