U0401

Invalid Data Received From ECM/PCM A

Severity

⚠️ Medium

Can you drive?

Yes, but get it checked soon

Approx. repair cost

$56–278 (est.)

Symptoms

Check Engine light comes on
Incorrect operation of the automatic transmission
Disabling stabilization systems
Reduced engine power
Errors in other vehicle systems

Causes

Problems with wiring between modules
ECM/PCM malfunction
Poor contact in connectors
ECM/PCM power supply problems
Software error in ECM/PCM

How to Fix

Check the integrity of the wiring between the modules
Inspect the ECM/PCM connectors for oxidation or damage.
Check ECM/PCM power supply and grounding
Read all error codes and perform a full diagnostic
If necessary, reflash or replace the ECM/PCM

Related codes

U0402 U0121 U0100