U0122 moderate

Lost Communication With Vehicle Dynamics Control Module

What does U0122 mean?

The U0122 code means the vehicle's onboard diagnostic system has detected: Lost Communication With Vehicle Dynamics Control Module. This is a moderate severity code.

Common Symptoms

  • Traction control and stability control warning lights on
  • ABS warning light illuminated
  • Vehicle stability system disabled
  • Traction control not engaging on slippery surfaces
  • Check Engine Light may also be on

Probable Causes (Ranked by Likelihood)

  • Failed vehicle dynamics control module Very High
  • Damaged CAN bus wiring to the dynamics module High
  • ABS module failure affecting dynamics communication Moderate
  • Faulty wheel speed sensor causing module confusion Moderate
  • Corroded connector at vehicle dynamics module Low

Step-by-Step Diagnostic Procedure

  1. Scan for DTCs in ABS, traction control, and stability control modules

  2. Check CAN bus wiring and connectors at the vehicle dynamics module

  3. Test all four wheel speed sensors for proper output

  4. Verify power supply and ground at the dynamics control module

  5. Inspect the ABS hydraulic unit for leaks or damage

Frequently Asked Questions

Can I drive with code U0122?

You can drive short distances carefully, but your stability control, traction control, and potentially ABS are disabled. Avoid slippery roads and drive cautiously.

What causes U0122?

A failed vehicle dynamics control module or damaged CAN bus wiring are the most common causes. ABS module failure and wheel speed sensor issues can also trigger this code.

Is U0122 expensive to fix?

Repair costs range from $200 for wiring repairs to $1200 for a vehicle dynamics control module replacement. Some vehicles integrate the dynamics module with the ABS unit, increasing cost.

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