VOLVO
ECM-711B - Immobilizer. Signal missing
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
4 modelsC30 (2007–2013), C70 (2006–2013), S40 (2004–2013), V50 (2004–2013)
Show models by year and engine (9)
- Volvo C30 (2007–2013)2007Engine B5254T3 only
- Volvo C30 (2007–2013)2008–2013Engine B5254T7 only
- Volvo C70 (2006–2013)2006–2007Engine B5254T3 only
- Volvo C70 (2006–2013)2008–2013Engine B5254T7 only
- Volvo S40 (2004–2013)2005–2007Engine B5254T3 only
- Volvo S40 (2004–2013)2008Engine B5254T3, B5254T7 only
- Volvo S40 (2004–2013)2009–2012Engine B5254T7 only
- Volvo V50 (2004–2013)2005–2007Engine B5254T3 only
- Volvo V50 (2004–2013)2008–2012Engine B5254T7 only
What does this fault code mean?
The engine control module (ECM) compares the immobilizer code with the central electronic module (CEM), and it also checks that the hardware serial number of the brake control module (BCM) matches over the CAN network. If the communication between the engine control module and the BCM is faulty, the code is set with the ignition on, and the engine does not start. The fault may lie in the BCM or in the CAN wiring between the modules.
Possible causes
- Fault in the brake control module (BCM)
- A break or short in the CAN lines linking the ECM and the BCM
What you can do
- 1Read the codes in the brake control module (BCM) and the central electronic module (CEM) and correct them first; this code should not be cleared until they are gone
- 2With the ignition off and the connectors disconnected, use a multimeter to check that the CAN wires between the engine control module and the BCM are intact and not shorted
- 3Do not work on the brake control module (BCM) yourself; the braking system is safety-critical, so fault tracing of the BCM should be done by a workshop
Symptoms you may notice1
- The engine cranks but will not start
General guidance for car owners. Diagnosis on the car can point to a different cause.