What does code P1538 mean?

Q: What does code P1538 mean?

Intake Manifold Runner Control Stuck Open. P1538 on Ford vehicles means the powertrain control module (PCM) has commanded the intake manifold runner control (IMRC) to close the runner flaps, but the monitor circuit indicates the flaps remain open. The PCM detects this by comparing the commanded IMRC state to the actual position signal from the IMRC actuator or position sensor, and it sets the code when the open condition persists longer than the calibrated threshold.

DTC codes / Ford codes / P1538

P1538 · FordIntake Manifold Runner Control Stuck Open

P1538 on Ford vehicles means the powertrain control module (PCM) has commanded the intake manifold runner control (IMRC) to close the runner flaps, but the monitor circuit indicates the flaps remain open. The PCM detects this by comparing the commanded IMRC state to the actual position signal from the IMRC actuator or position sensor, and it sets the code when the open condition persists longer than the calibrated threshold.

SystemPowertrain

Code typeFord specific

SeverityMedium

Fix difficultyIntermediate

AreaVehicle speed, idle control and auxiliary inputs

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