What does code P1399 mean?

Q: What does code P1399 mean?

Wheel Speed Sensor 2 G-Sensor Circuit Intermittent. P1399 on a GM vehicle indicates that the powertrain control module (PCM) has detected an intermittent fault in the circuit for wheel speed sensor 2, which also incorporates a G-sensor (acceleration sensor) signal. The PCM monitors the sensor's output for consistency and continuity, and it sets this code when the signal drops out or becomes erratic for a brief period, often under specific driving conditions.

DTC codes / GM codes / P1399

P1399 · GMWheel Speed Sensor 2 G-Sensor Circuit Intermittent

P1399 on a GM vehicle indicates that the powertrain control module (PCM) has detected an intermittent fault in the circuit for wheel speed sensor 2, which also incorporates a G-sensor (acceleration sensor) signal. The PCM monitors the sensor's output for consistency and continuity, and it sets this code when the signal drops out or becomes erratic for a brief period, often under specific driving conditions.

SystemPowertrain

Code typeGM specific

SeverityMedium

Fix difficultyIntermediate

AreaIgnition system and misfire

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