What does code P1423 mean?

Q: What does code P1423 mean?

Intake Air High Pressure Switch Circuit High Voltage. P1423 on a GM vehicle means the powertrain control module (PCM) has detected an abnormally high voltage on the intake air high pressure switch circuit, which is part of the secondary air injection (AIR) system on many GM trucks and SUVs. The PCM expects this switch to report a specific pressure state during the AIR pump's commanded run cycle, and a voltage above the calibrated threshold tells the PCM the circuit is open, shorted to voltage, or the switch has failed internally.

DTC codes / GM codes / P1423

P1423 · GMIntake Air High Pressure Switch Circuit High Voltage

P1423 on a GM vehicle means the powertrain control module (PCM) has detected an abnormally high voltage on the intake air high pressure switch circuit, which is part of the secondary air injection (AIR) system on many GM trucks and SUVs. The PCM expects this switch to report a specific pressure state during the AIR pump's commanded run cycle, and a voltage above the calibrated threshold tells the PCM the circuit is open, shorted to voltage, or the switch has failed internally.

SystemPowertrain

Code typeGM specific

SeverityLow

Fix difficultyIntermediate

AreaAuxiliary emission controls

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