Markc80Audi

thank You for your advice !!!

Hello everyone, I have a puzzling issue with my 2010 Audi A3 1.6 auto sport 8P. When I turn the ignition to the "on" position, most accessory systems like HVAC and lighting work fine. However, all four electric windows don't work, and the instrument cluster doesn't respond. I can only get a response from the cluster by pressing and holding the left button, which shows the time, date, and mileage, but no other info. At first, I thought the instrument cluster was faulty, so I sent it to ECU testing in Derbyshire and paid £180 for a check and rebuild, but the problem persists. The cluster remains unresponsive (no dashboard lights, etc.). When I try to start the car's engine, it briefly starts and then stops—seems like the immobilizer is preventing further operation. Another issue is that I can't communicate with most modules using OBDeleven VAG pro. An autoscan shows issues with 2 modules: Car: Audi A3 Year: 2010 Body type: Sportback Engine: BSE Engine Control Unit (01): Active faults: 6 U0164 - Lost Communication With HVAC Control Module U0146 - Lost Communication With Serial Data Gateway Module "A" U0155 - Lost Communication With Instrument Panel Cluster (IPC) Control Module U0447 - Invalid Data Received From Serial Data Gateway Module "A" P0513 - Incorrect Immobilizer Key P1652 - Read DTC memory of transmission CM Transmission Control Unit (02): Active faults: 8 P1867 - Databus drivetrain missing message of steering columns electron. P1880 - Data bus missing message from Diagnostic Interface CM P1862 - Databus drivetrain missing message from instrument cluster P1880 - Data bus missing message from Diagnostic Interface CM P1850 - Databus drivetrain Missing Message from Engine CM U0235 - Lost Communication With Cruise Control Front Distance Range Sensor P1852 - Databus drivetrain Implausible Message from Engine CM U0103 - Lost Communication with Gear Shift Module To troubleshoot, I'll try replacing the gateway with a second-hand unit with the same part and hardware numbers. If that doesn't work, I might have to send the engine ECU for a pricy check/rebuild at £240. I've checked wires, fuses, and relays, and everything seems fine. I'm reaching out to see if anyone has insights or suggestions. I'm especially interested in testing the CAN-bus network more comprehensively. Thanks for your help.