C0565: ABS Control Module System Voltage High

What it means

The ABS control module monitors its system voltage. It sets this code when voltage rises above the module’s expected operating range.

At a glance

• Usually lights the ABS or stability-control warning light
• The engine or gearbox may go into limp mode

How it works

The ABS control module relies on supply voltage within its operating range to manage anti-lock braking and related stability functions. This code sets when voltage at the module rises above that range, often pointing to a charging-system or connection problem.

Common causes

Most likely first.

1. Charging system overvoltage
2. Faulty alternator voltage regulator
3. Poor battery connection or ground
4. Wiring fault

Symptoms

• ABS warning light
• ABS may be unavailable or limited
• Stability-control functions may be limited

How to diagnose it

1. Read ABS freeze-frame data to see whether the high-voltage event coincided with engine operation or a charging-system change.
2. Inspect the battery terminals, ABS module connections, and grounds for looseness, corrosion, or poor contact.
3. Measure charging-system voltage under the manufacturer's specified conditions to check for overcharging.
4. Inspect alternator wiring and regulator connections for damage or poor contact that could raise system voltage.
5. If charging output is normal, test the ABS module power and ground circuits for wiring faults against the manufacturer's specification.

Common fixes

• Clean and tighten loose battery, module, or ground connections.
• Repair damaged alternator or ABS module wiring and connector terminals.
• Repair or replace the charging-system voltage regulator or alternator if tests confirm overcharging.
• Repair a module circuit fault only after power and ground tests isolate it.

Can I keep driving?

ABS or stability assistance may be limited while this fault is active. Avoid relying on those systems, and have the overvoltage checked soon because excessive charging voltage can damage electronic modules and the battery.