U04A0: Invalid Data Received From Engine Coolant Pump Control Module

What it means

A control module received invalid data from the engine coolant pump control module. The code identifies a data validity fault; the specific affected function depends on the vehicle.

At a glance

• Usually lights the warning light of the system that lost communication
• The engine or gearbox may go into limp mode

How it works

The engine coolant pump control module reports pump-related information to other vehicle modules. This code sets when a receiving module judges that information invalid, so it does not alone confirm that the pump has stopped or that the engine is overheating.

Common causes

Most likely first.

1. Fault in the transmitting module
2. Network wiring or connector fault
3. Module power or ground fault
4. Software or configuration mismatch

Symptoms

• Coolant pump operation may be affected
• Engine or cooling-system warning may appear

How to diagnose it

1. Record freeze-frame data and scan all modules for coolant pump, temperature, and network codes to see when invalid pump-module data was reported.
2. Check live coolant temperature and any available pump status data for implausible readings or a mismatch with observed engine warm-up.
3. Inspect the coolant pump control module and pump connectors and harness for corrosion, loose pins, chafing, or heat damage.
4. Check the control module's power and ground, then inspect network wiring and connectors for opens, shorts, or poor connections.
5. If the circuit checks pass, use the manufacturer's procedure to evaluate pump-module data and verify module software and configuration.

Common fixes

• Repair loose, corroded, or damaged pump-module wiring and connectors.
• Restore a faulty power or ground connection to the coolant pump control module.
• Correct a software or configuration mismatch using the manufacturer's procedure.
• Repair or replace the coolant pump control module if it continues to transmit invalid data after circuit checks.

Can I keep driving?

Avoid driving if the engine temperature rises, a cooling warning appears, or the pump is suspected not to be operating, because overheating can cause severe engine damage. If temperature remains normal and there are no warnings, keep any trip short and monitor the temperature closely.