HomeTrouble CodesU0124

U0124 — Lost Communication Lateral Acceleration Sensor Module

Generic OBD-II · all makesNetwork / communication

U0124 indicates that the vehicle's CAN network has detected a loss of communication from the lateral acceleration sensor module. This sensor supplies side‑grip data used by stability and traction control systems.

Symptoms

What causes it — most likely first

1. Faulty lateral acceleration sensor module

The sensor may have failed internally, ceasing to transmit data on the CAN bus.

2. Damaged wiring or connector

Corroded, broken, or loose wiring and connector pins can interrupt the sensor's signal.

3. CAN bus communication fault

A short, open, or electromagnetic interference on the CAN bus affecting the sensor's data line can cause loss of communication.

4. Faulty receiving control module

A malfunctioning body control or gateway module that processes the sensor data may drop the message.

5. PCM/ECM software glitch

A rare software issue in the power‑train control module can trigger the code, but this is uncommon.

How it's diagnosed

  1. Verify the U0124 code with a scan tool and clear it to confirm if it returns.
  2. Inspect the lateral acceleration sensor's wiring harness and connector for corrosion, damage, or loose pins.
  3. Measure the sensor's resistance and signal voltage according to the vehicle service manual.
  4. Check CAN bus voltage and continuity on the sensor's CAN lines using a multimeter or oscilloscope.
  5. Test operation of related modules (e.g., ABS/EBD control unit) that may affect sensor communication.

Code facts & related codes

SystemNetwork / communication
StandardizationSAE generic — identical on every make

Frequently asked

Do I need to replace the PCM when I see U0124?

No. Replacing the power‑train control module is rarely required; most often the issue is the sensor, its wiring, or a CAN bus problem.

Can a simple wiring repair clear the code?

Yes. Repairing or resealing a damaged connector or wire often resolves the communication loss without needing component replacement.

Is the lateral acceleration sensor part of the airbag system?

No. It is primarily used by stability and traction control systems, not by the airbag system.

How long does a CAN bus diagnostic usually take?

It typically takes 30–60 minutes to verify bus voltages, check for shorts, and confirm proper communication with all modules.