VOLVO
ECM-A03B - Communication, Central electronic module. Faulty signal
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:
9 modelsC70 Cabriolet (1998–2005), C70 Coupé (1998–2002), S60 (2001–2009), S70 (1997–2000), S80 (1999–2006), V70 (1997–2000), V70 (2000–2008), V70 XC / XC70 (2001–2007), XC90 (2003–)
Show models by year and engine (31)
- Volvo C70 Cabriolet (1998–2005)2000Engine B5244S only
- Volvo C70 Coupé (1998–2002)1999Engine B5254S DENSO only
- Volvo C70 Coupé (1998–2002)2000Engine B5244S only
- Volvo S60 (2001–2009)2001Engine B5244S, B5244S2, D5244T only
- Volvo S60 (2001–2009)2002All engines except: B5204T5, B5234T3, B5234T7, B5244T3
- Volvo S60 (2001–2009)2003All engines except: B5204T5, B5234T3, B5234T7, B5244T3, B5254T2
- Volvo S60 (2001–2009)2004All engines except: B5204T5, B5234T3, B5234T7, B5254T2, B5254T4
- Volvo S60 (2001–2009)2005Engine B5244S, B5244S2, B5244S6, B5244SG, B5244SG2 only
- Volvo S60 (2001–2009)2006Engine B5244S, B5244S2, B5244S6, B5244SG only
- Volvo S60 (2001–2009)2007–2008Engine B5244S, B5244S2, B5244SG only
- Volvo S60 (2001–2009)2009Engine B5244S, B5244S2 only
- Volvo S70 (1997–2000)1999Engine B5254S DENSO only
- Volvo S70 (1997–2000)2000Engine B5244S, B5244S2, B5244SG, B5244SG2 only
- Volvo S80 (1999–2006)1999–2000Engine B5244S, B5244S2 only
- Volvo S80 (1999–2006)2001Engine B5244S, B5244S2, B5244SG, D5244T only
- Volvo S80 (1999–2006)2002All engines except: B5204T5, B5234T7, B5244T3, B6294S2, B6294T
- Volvo S80 (1999–2006)2003Engine B5244S, B5244S2, B5244SG, B5244SG2, D5244T, D5244T2 only
- Volvo S80 (1999–2006)2004All engines except: B5204T5, B5234T7, B5254T2, B6294S2, B6294T
- Volvo S80 (1999–2006)2005Engine B5244S, B5244S2, B5244SG, B5244SG2 only
- Volvo S80 (1999–2006)2006Engine B5244S, B5244S2, B5244SG only
- Volvo V70 (1997–2000)1999Engine B5254S DENSO only
- Volvo V70 (1997–2000)2000Engine B5244S, B5244S2, B5244SG, B5244SG2 only
- Volvo V70 (2000–2008)2001Engine B5244S, B5244S2, B5244SG, D5244T only
- Volvo V70 (2000–2008)2002All engines except: B5204T5, B5234T3, B5234T7, B5244T3
- Volvo V70 (2000–2008)2003All engines except: B5204T5, B5234T3, B5234T7, B5244T3, B5254T2
- Volvo V70 (2000–2008)2004All engines except: B5204T5, B5234T3, B5234T7, B5254T2, B5254T4
- Volvo V70 (2000–2008)2005Engine B5244S, B5244S2, B5244S6, B5244SG, B5244SG2 only
- Volvo V70 (2000–2008)2006Engine B5244S, B5244S2, B5244S6, B5244SG only
- Volvo V70 (2000–2008)2007–2008Engine B5244S, B5244S2, B5244SG only
- Volvo V70 XC / XC70 (2001–2007)2003–2004Engine D5244T only
- Volvo XC90 (2003–)2003–2004Engine D5244T only
What does this fault code mean?
The engine control module has registered a communication failure with the CEM over the CAN network. It may be caused by a CAN communication problem, such as an open circuit in the wiring, or by an internal fault in the CEM, which may be damaged. Switching over to gas power is then not possible.
Possible causes
- Open circuit in the CAN wiring
- Damaged central electronic module (CEM)
What you can do
- 1Read the fault codes in the central electronic module (CEM) and deal with them first, since they may be the cause
- 2Check the connectors and wiring of the CAN network between the engine control module and the CEM for open circuits and chafing
- 3Disconnect the battery negative lead and use a multimeter to check that the CAN wires have no open circuit or short to ground or supply voltage
- 4If the fault remains and no wires are damaged, the CEM may be damaged and need replacing; leave this to a workshop
Symptoms you may notice1
- Switching over to gas power is not possible
General guidance for car owners. Diagnosis on the car can point to a different cause.