ECM-U012002 - Lost Communication with Starter/ Generator Control Module. General Failure Information. General signal failure
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
9 modelsC30 (2007–2013), S40 (2004–2013), S60 (2011–), S80 (2007–), V40 (2013–), V40 Cross Country (2013–), V50 (2004–2013), V60 (2011–), V70 (2008–)
Show models by year and engine (9)
- Volvo C30 (2007–2013)2011–2013Engine D4162T only
- Volvo S40 (2004–2013)2011–2012Engine D4162T only
- Volvo S60 (2011–)2011–2015Engine D4162T only
- Volvo S80 (2007–)2012–2015Engine D4162T only
- Volvo V40 (2013–)2013–2015Engine D4162T only
- Volvo V40 Cross Country (2013–)2013–2015Engine D4162T only
- Volvo V50 (2004–2013)2011–2012Engine D4162T only
- Volvo V60 (2011–)2011–2015Engine D4162T only
- Volvo V70 (2008–)2012–2015Engine D4162T only
What does this fault code mean?
The engine control module (ECM) controls the alternator charging voltage via LIN communication with the alternator control module (ACM), on request from the central electronics control module (CEM). The code is set when the engine control module detects a disturbance in the communication with the alternator control module. Although the code is titled lost communication with the starter/generator control module, the disturbance concerns communication between the engine control module and the alternator control module.
Possible causes
- Internal fault in another control module on the same part of the LIN network
- Faulty alternator control module (ACM), including its charge regulator
- Contact resistance or oxidation in the connectors
- Earth fault between the engine and the body
- Open circuit in the LIN signal wire
What you can do
- 1Check that the fuses are intact and that the battery is well charged with good voltage
- 2Check the connectors at the alternator and at the engine control module for contact resistance and oxidation
- 3Look for chafed or pinched wiring on the LIN signal wire. Use a multimeter to check that it has no break and is not shorted to ground or supply voltage
- 4Check the engine earth points to the body for loose or corroded connections
- 5If you have a diagnostic tool: read the alternator status and charging current in live data with the engine running
- 6If the fault returns: have a workshop with diagnostic equipment check the alternator control module and the alternator, as the fault may be in another control module on the LIN network
Symptoms you may notice4
- The battery is dead or shows low voltage
- Charging warning light comes on or behaves abnormally
- Red warning symbol and text message in the display
- The engine does not start
General guidance for car owners. Diagnosis on the car can point to a different cause.