VOLVO
BCM-U000188 - High Speed CAN Communication Bus. Bus Signal / Message Failures. Bus off
System
Brake Control Module (BCM)
Volvo models this fault code applies to
Applies to the following models:
6 modelsC30 (2007–2013), C70 (2006–2013), S40 (2004–2013), V40 (2013–), V40 Cross Country (2013–), V50 (2004–2013)
Show models by year and engine (7)
- Volvo C30 (2007–2013)2011–2013Engine D4162T, D5204T, D5204T5 only
- Volvo C70 (2006–2013)2011Engine D5204T, D5204T5 only
- Volvo C70 (2006–2013)2012–2013All engines except: B5254T7
- Volvo S40 (2004–2013)2011–2012Engine D4162T, D5204T, D5204T5 only
- Volvo V40 (2013–)2013–2015
- Volvo V40 Cross Country (2013–)2013–2015
- Volvo V50 (2004–2013)2011–2012Engine D4162T, D5204T, D5204T5 only
What does this fault code mean?
The brake control module (BCM) has gone into bus-off on the CAN network, meaning it has lost contact with the other control modules. The fault arises when communication is disturbed by another module or when the brake module's own messages disturb the network. As communication cannot be restored while driving, the code can usually only be read out when the fault is intermittent.
Possible causes
- Short circuit between the CAN wires
- Open circuit in one of the CAN wires
- Internal fault in another module on the same part of the CAN network
- Internal fault in the brake control module
What you can do
- 1Read codes in the central electronic module and in the other modules on the CAN network, and troubleshoot those first
- 2Measure the resistance in the CAN wires against ground and supply voltage and look for shorts and open circuits
- 3Have a workshop identify which module disturbs the network by disconnecting them one at a time, and replace it if it communicates incorrectly
- 4Check that the connectors on the network are secure and that the wiring does not run close to sources of interference
- 5The brake system is safety-critical, so have a workshop carry out all work on the network and the modules
Symptoms you may notice5
- ABS warning lamp lit
- Brake circuit warning lamp lit
- Traction control warning lamp lit
- Stability function does not work
- Traction control does not work
What the fault can affect3
- The brake control module switches itself off and stays off until the power supply is broken and restored
- Stability control and traction control are disabled
- Dynamic stability control (AYC) is disabled
General guidance for car owners. Diagnosis on the car can point to a different cause.