Fault Description: BMW CAS3 ECU Communication Failure
Fault Codes: The following fault codes may be logged in the ECU:
1. A116 – CAS Supply Voltage Terminal 30 (Voltage Too Low)
2. A0B0 – Engine Start Starter Operation (Terminal 50 On)
3. A0B4 – Engine Start Starter Operation (Terminal 50 Off)
4. A0B5 – Engine Start Starter Operation (Terminal 50, Terminal 50E Off)
5. A0C1 – CAS Control Module (Internal Fault)
Affected Vehicles and Production Years: The CAS3 ECU is commonly fitted to various BMW models, including, but not limited to:
1. BMW 1 Series (E81, E82, E87, E88) – Production years: 2007-2011
2. BMW 3 Series (E90, E91, E92, E93) – Production years: 2005-2013
3. BMW 5 Series (E60, E61) – Production years: 2003-2010
4. BMW 6 Series (E63, E64) – Production years: 2004-2011
5. BMW X1 (E84) – Production years: 2009-2015
6. BMW X3 (E83) – Production years: 2004-2010
7. BMW X5 (E70) – Production years: 2006-2013
8. BMW Z4 (E89) – Production years: 2009-2016
Description:
The CAS3 (Car Access System 3) ECU is an essential component in modern BMW vehicles that provides access control and anti-theft functionality. It communicates with various systems within the vehicle, including the engine control unit (ECU) and the starter system, to ensure proper operation during engine start and keyless entry.
One common fault that can occur with the CAS3 ECU is a communication failure. This fault can lead to a variety of symptoms, including intermittent starting issues, failure to start the engine, or problems with keyless entry. When the CAS3 ECU detects a communication fault, it may log one or more of the above-mentioned fault codes to indicate the specific issue.
The fault codes mentioned above provide information about the potential causes of the communication failure. They could indicate problems with the CAS3 power supply, starter operation, or internal module issues.
Part numbers of affected CAS modules include:
61359395657 / 61359226238 / 61359217853 / 61359147226 / 61359147221 / 61359147191 / 61359147195 / 61359147184 / 61356943834 / 61356943822 / 61356943814