OBD Guide

C00A4

Driveline Control Module Rear Differential Unit B Control Circuit Driver

C00A4 is an OBD-II diagnostic trouble code meaning: Driveline Control Module Rear Differential Unit B Control Circuit Driver. Common causes: open or short circuit in wiring harness, control solenoid malfunction. Estimated repair cost: $56–167.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$56–167 (est.)

Symptoms

  • Unstable operation of the rear differential
  • Check Engine Light Illuminates
  • Reduced efficiency of the all-wheel drive system

Causes

  • Open or short circuit in wiring harness
  • Control solenoid malfunction
  • Problems with the rear differential control module
  • Contact corrosion

How to Fix

  1. Check the wiring harness for opens and shorts
  2. Check control solenoid resistance
  3. Diagnose the rear differential control module
  4. Replace faulty components

Related codes

Error C00A4 by Vehicle Brand

FAQ

What does the C00A4 code mean?

C00A4 is an OBD-II diagnostic trouble code that indicates: Driveline Control Module Rear Differential Unit B Control Circuit Driver

What causes a C00A4 error code?

The most common causes of C00A4 include: Open or short circuit in wiring harness; Control solenoid malfunction; Problems with the rear differential control module; Contact corrosion.

How do I fix a C00A4 diagnostic trouble code?

To fix C00A4: Check the wiring harness for opens and shorts. Check control solenoid resistance. Diagnose the rear differential control module. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with C00A4?

Limited driving only, diagnose soon

How much does it cost to fix C00A4?

The estimated repair cost for C00A4 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat