Tech Tip: BMW no start, bad CAS module

Sept. 8, 2017

Vehicle: 2008 BMW 335xi, AWD (E90), L6-3.0L Turbo (N54), Automatic Transmission

Mileage: 118,669

Problem: When trying to start the engine, the starter momentarily engaged then stopped.

Details: The tech found that, while attempting to crank/start the engine, the starter solenoid was only powered for a split second. He connected a scan tool and retrieved an A0C1 (Output Terminal 50) diagnostic trouble code.

The ALLDATA Tech-Assist consultant suggested he open the Car Access System (CAS) module to inspect for signs of burned spots on the circuit board.

Confirmed Repair: When the tech opened the CAS module, he found several burned circuits. He replaced the CAS module. After the repair, the engine started and ran normally.

Information provided by: ALLDATA