P1399 - FAULT CODE - OBD2

P1399 BUICK, CADILLAC, CHEVROLET, GMC: INTERMITTENT WHEEL SPEED SENSOR CIRCUIT 2 - G - SENSOR

When the crankshaft speed experiences some changes from the ECM (Engine Control Module), these variations are monitored to check and identify various misfires. However, the crankshaft speed changes are not only caused by these failures, as uneven road conditions also cause them.

The ABS (Anti-lock Braking System) uses the data provided by the Wheel Speed Sensors based on the acceleration/deceleration function, which allows identifying uneven road conditions. Once this data is collected, it is sent to the ECM to determine if the speed variations are the result of an engine failure or road conditions.

Setting the fault code P1399 OBDII means that a fault has been detected in the Wheel Speed Sensor 2 or G – Sensor, in which its circuit experiences intermittent voltages.

• Check Engine light on.
• The Anti-Lock Brake System warning light is illuminated on the dashboard.
• Irregular operation by the

The reasons for setting the diagnostic code P1399 OBD2 are

• The electrical components of the Wheel Speed Sensor 2 or even the sensor itself may be in poor condition.
• A component of the ignition system may be damaged.
• ABS may be deficient.

To solve the DTC code P1399 OBDII, you must do the following:

• Check out the TSB.
• The code P1399 is usually set as an additional code. The reason is that the ABS does not send the correct information to the EBCM or ECM. With this in mind, diagnose codes that signal anti-lock brake system problems first.
• Verify that the Wheel Speed Sensor 2 has no wiring damage and that the voltages in this circuit match those specified in the service manual. If any inconsistencies are found, make the necessary corrections.