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DTC codes / C06xx · Brakes, steering and suspension / C0680

C0680Electric Park Brake Module Internal Fault

C0680 indicates that the Electric Park Brake (EPB) module has detected an internal fault within its own circuitry or software, rather than a problem with the brake calipers, wiring, or switches. The module's self-test has failed, and it may disable the electric park brake function or set the warning light until the internal issue is resolved.

SystemChassis
Code typeGeneric (all makes)
SeverityMedium
Fix difficultyProfessional
AreaBrakes, steering and suspension

Symptoms you may notice

  • The parking brake warning light or brake system warning light stays illuminated on the dashboard.
  • The electric parking brake may not engage or release when the switch is operated.
  • A message such as 'Parking Brake Fault' or 'Service Parking Brake' appears in the driver information center.
  • The parking brake may engage automatically but fail to release, or vice versa.
  • Often no symptoms besides the warning light, with the brake continuing to function normally.
  • Other driver assistance features that rely on the EPB, such as hill hold or auto hold, may become unavailable.

Common causes, most likely first

  1. Internal failure of the EPB module's electronic circuit board or microprocessor.
  2. Corrupted or outdated software/firmware within the EPB module.
  3. Low system voltage or a weak battery causing the module to set an internal fault during self-test.
  4. Water intrusion or corrosion inside the EPB module connector or housing.
  5. A faulty ground connection to the EPB module, leading to intermittent internal errors.
  6. Damage to the EPB module from a voltage spike or jump-starting.
  7. Rarely, a manufacturing defect in the module itself.

How to diagnose and fix it

  1. Verify battery voltage and condition; charge or replace the battery if it is below 12.4 volts at rest.
  2. Inspect the EPB module connector and wiring for corrosion, water intrusion, or loose pins; clean and dry as needed.
  3. Check and clean the EPB module ground connection to ensure a solid, low-resistance path to the chassis.
  4. Use a scan tool to read all EPB module codes and freeze-frame data, then clear codes and retest to see if C0680 returns.
  5. Check for and install any available software updates or recalibration procedures for the EPB module as specified by the manufacturer.
  6. If the code persists after basic checks, perform a pinpoint test of the module's power, ground, and communication lines according to the service information.
  7. Replace and reprogram the EPB module only after all external causes have been ruled out.

What the EPB module self-test reveals

  • C0680 is often set by a momentary voltage drop during engine cranking, so a battery that passes a basic load test can still be the culprit if its reserve capacity is low.
  • The EPB module may store C0680 alongside communication codes like U0128 or U3000, but those codes do not confirm the module is bad; they can be secondary to the same power or ground issue.
  • A common misdiagnosis is replacing the EPB module when the real problem is water intrusion into the connector behind a wheel well liner, which corrupts the internal logic temporarily.
  • Some vehicles require a scan tool to put the EPB into service mode before any brake work; failing to do so can set C0680 and other codes.
  • The code does not always mean the module is permanently damaged; clearing it after fixing a low-voltage event often restores normal operation.

Can I keep driving with C0680?

If the parking brake still engages and releases normally and the only symptom is the warning light, you can drive the car, but avoid relying on the electric park brake for parking until the fault is repaired. If the brake will not release or the vehicle reports a critical brake fault, do not drive and have it towed.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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