Repair and diagnosis of Audi / Volkswagen ECU 03L906018AB - Errors 0522 and 01314 "No communication with engine computer"
The electronic control unit ECU 03L906018AB is used in a large number of Audi and Volkswagen diesel models.
This module controls the mixture, injections, turbo, sensors, engine protection functions and CAN bus communication.
When the ECU stops communicating, the vehicle can become completely inoperable.
The two most common errors with this module are:
0522 - no communication with motor computer
01314 - motor computer not responding/no communication
Error 0522 - "Motor computer not communicating"
This error means that the external modules (ABS, dashboard, comfort unit, etc.) cannot establish a connection with the ECU.
It occurs in:
diagnostic attempt
engine unresponsiveness
problems in CAN communication
What does the driver feel?
the car does not start
no connection to the tester
multiple control lights on the dashboard
RPM/temperature/engine data missing
communication to other modules is interrupted
Error 01314 - "Motor computer - no communication"
This error is written to other modules when the ECU does not appear in the CAN network.
Signs:
the vehicle enters emergency mode
no power
no signal to the dashboard
the tester does not recognize the ECU
complete blocking of the starting system is possible
What causes these errors?
The reasons can be different, but the most common are:
impaired CAN communication
no stable power supply to the ECU
corrosion in buckets and tables
broken cable
a fault in the controller itself
