VOLVO
ECM-P1A0800 - Generator Mode Signal. General Failure Information. No sub type information
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) takes in the desired charge voltage from the central electronic module (CEM) and controls the alternator through the alternator control module (ACM) using LIN communication. The ECM also checks that communication with the ACM is working. The code is set when communication with the ACM is lost, and
Possible causes
- Contact resistance and oxidation in connections
- Short circuit between the LIN wires
- Open circuit in one of the LIN wires
- Internal fault in another control module on the same part of the LIN network
- Damaged alternator control module (ACM), the charge regulator
- Fitting an alternator whose charge regulator is not designed for LIN can also set this code
What you can do
- 1Check that the fuses are intact and that the battery terminals and earth connections are secure
- 2Check the connector at the alternator control module for contact resistance and oxidation
- 3With a multimeter you can check that the signal cable between the control modules has no open circuit and no short to ground or voltage
- 4Use a multimeter to check that the engine and the body have the same potential at the earth points between them
- 5If the fault remains, have a workshop check the alternator control module and the LIN communication
Symptoms you may notice4
- Battery is dead or has too low a voltage
- Charge warning lamp lights or behaves abnormally
- Red warning symbol and text message shown in the driver information display
- Engine is hard to start or does not start
What the fault can affect1
- The charge regulator charges at a fixed voltage
General guidance for car owners. Diagnosis on the car can point to a different cause.