VOLVO
ECM-C326 - Communication control module. Faulty signal
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 (6)
- Volvo C30 (2007–2013)2007–2010Engine D4204T only
- Volvo C70 (2006–2013)2008–2010Engine D4204T only
- Volvo S40 (2004–2013)2004–2006Engine D4204T, D4204T2 only
- Volvo S40 (2004–2013)2007–2010Engine D4204T only
- Volvo V50 (2004–2013)2004–2006Engine D4204T, D4204T2 only
- Volvo V50 (2004–2013)2007–2010Engine D4204T only
Immobilizer Synchronization Volvo (CEM / ECM) available
OBD Tuning repairs and remanufactures the control unit with a 12-month warranty.
What does this fault code mean?
The engine control module watches the CAN link to both the CEM and to the brake control module (BCM). The fault code is set when that communication is wrong. The cause can be faulty software, a missing power supply to the brake control module, or a discharged vehicle battery, and the engine may then not start.
Possible causes
- Faulty software
- Missing supply voltage to the brake control module (BCM)
- Contact resistance, loose contacts or corrosion in the terminals
- Open circuit in the wiring to the CEM or the brake control module on the high speed side
- Internal fault in another control module on the same network section
- The code can also be set if the vehicle battery has become discharged
What you can do
- 1If the software is suspected to be faulty, have a workshop reload the software in the engine control module. If the fault remains after the reload, continue the fault-tracing
- 2Check that the battery is fully charged, since a discharged battery can cause this code
- 3Check that the fuses for the brake control module are intact and that the connectors are firmly seated
- 4Read out the fault codes in the CEM and other control modules, and fix them before erasing anything
- 5The brake control module controls ABS. If the brakes or ABS feel uncertain, do not drive the car; have a workshop check it
- 6Erase the fault code once the faults are fixed, then road test the car to see whether it returns
Symptoms you may notice5
- A text message and warning symbol appear in the display
- The Check engine warning lamp lights up or behaves abnormally
- The engine does not start, the starter motor does not turn and there is no clicking sound at start attempts
- The engine does not start, either all the time or at some times
- The immobilizer warning lamp lights up or behaves abnormally
General guidance for car owners. Diagnosis on the car can point to a different cause.