A0C0
CriticalA0C0 — CAS: Terminal 15 Output Fault (Channel 3)
Description
What the Code Means
Code A0C0 points to a fault in the Terminal 15 Output 3 circuit of the CAS (Car Access System) module. The CAS controls power delivery to onboard systems when the ignition is switched on, and it also handles the start signal and power distribution. The error sets when the start button is pressed but the circuit doesn't activate, which prevents the engine from starting.
Symptoms
Symptoms
- Engine won't start, starter motor doesn't crank
- Warning indicators on the instrument cluster
- Key not recognized or remote functions don't work
- Central locking problems
Causes and fixes
Diagnosis and Repair
Step 1: Diagnosis
Connect ISTA and confirm code A0C0.
Step 2: Check the CAS Module
Inspect the CAS for signs of water intrusion or overvoltage.
Step 3: Repair or Replace
If faulty, replace the CAS with an original module (61356993373). After replacement, program the CAS with ISTA.
Possible secondary damage
Secondary Problems
Ignoring the fault can lead to a complete CAS failure, which makes engine start impossible, disables the anti-theft system, and triggers immobilizer faults. In some cases the DME can be affected by the loss of communication.