Skip to content
GTECH Calibration
Portal

P1392

Wheel Speed Sensor 1 G-Sensor Circuit Low Voltage.

  • GM
  • Powertrain
  • Manufacturer code
  • Medium severity

How this code is built

P
SystemPowertrain
1
Defined byThe manufacturer
3
AreaIgnition system or misfire
92
FaultThe specific fault in that area

What it means

On GM vehicles P1392 means the control unit has seen a low voltage in the circuit of the G-sensor (acceleration or lateral force sensor) linked to wheel speed sensor 1. The signal fell below the expected range, which suggests a short to ground, an open circuit, high resistance or a faulty sensor. Exactly which sensor and module are involved depends on the model and year.

Symptoms

  • ABS warning light on
  • Traction control or stability control warning light on
  • Traction or stability control disabled or working erratically
  • ABS or stability control not intervening under braking or on slippery surfaces
  • Other wheel speed or chassis codes stored alongside it

Possible causes

  • Damaged, chafed or corroded wiring to the G-sensor or wheel speed sensor 1 circuit (short to ground or open circuit)likely
  • Corroded, loose or water-damaged connector at the sensor or modulelikely
  • Faulty G-sensor or wheel speed sensor assemblypossible
  • Low supply voltage or poor earth to the sensor or brake control modulepossible
  • Fault inside the brake control modulerare
  • Previous crash or underbody damage affecting the sensor or its harnessrare

How to diagnose

  1. Read all stored codes and freeze frame data, then note any other ABS, traction or wheel speed codes
  2. Check the battery condition and charging voltage, as low voltage can cause false chassis faults
  3. Visually inspect the wiring and connectors for wheel speed sensor 1 and the G-sensor for chafing, corrosion, water ingress and damage
  4. Check the sensor's mounting location and the harness routing for impact or underbody damage
  5. Using the manufacturer's wiring diagram for the model, test the sensor supply, signal and earth circuits for shorts to ground, open circuits and resistance
  6. Wiggle test the harness and connectors with a scan tool live data view to see if the fault appears or the signal drops out
  7. Check the sensor's live data against the expected values for the model, as the sensor location and type vary
  8. Only after the wiring and sensor are proven good, consider testing the brake control module and its earths

How to fix

  • Repair or replace damaged wiring and restore proper insulation and routing
  • Clean or replace corroded or damaged connectors and terminals
  • Replace the faulty G-sensor or wheel speed sensor as specified for the model
  • Repair poor earths or supply voltage faults and correct any battery or charging problem
  • Replace or repair the brake control module only if testing confirms it is faulty, and carry out any required programming or setup
  • Clear the code and road test to confirm it does not return

Can I keep driving?

Medium severity

The car normally remains driveable, but ABS and traction or stability control may not work, so braking in poor grip conditions may be less safe. Drive with extra care and have it checked soon.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.

This code for other makes

Nearby codes