VOLVO
ECM-C073 - Control module, communication fault. Signal missing
System
Engine Control Module (ECM)
Volvo models this fault code applies to
This fault code has different meanings depending on model, model year or engine. Select the meaning that applies to your car.
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
What does this fault code mean?
The code indicates that the engine control module is missing a signal from other control modules. It registers a serious disturbance on the high speed side of the CAN network, and then communication with the module is not possible. The engine control module shuts down and only restarts once the power supply is broken and reconnected.
Possible causes
- Contact resistance or oxidation in the connections
- Open circuit in one of the CAN wires
- Short circuit between the CAN wires
- Internal fault in the engine control module
- Internal fault in another control module on the same section of the CAN network
What you can do
- 1Start by reading the fault codes from the CEM and the other affected modules. Do not erase the engine control module code until the others have been fixed
- 2Check that the battery is connected and that the fuses are intact
- 3Check the connectors at the engine control module and the CEM for corrosion, loose contacts and damage
- 4Look for chafing or pinched sections along the CAN wires
- 5If a control module stays in limp-home mode after the ignition is switched off and on, disconnect and reconnect the battery negative terminal
- 6If the fault remains, have a workshop measure the resistance and traffic load of the CAN network with diagnostic equipment
Symptoms you may notice2
- A warning message or warning symbol appears in the display
- The Check engine warning lamp lights up or behaves abnormally
What the fault can affect2
- The engine control module switches itself off (bus-off)
- The engine control module stays off until the power supply is broken, and tries to communicate again when it is powered
General guidance for car owners. Diagnosis on the car can point to a different cause.