VOLVO
ECM-A02B - Communication, control module for anti-lock brakes (ABS). 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:
7 modelsC70 Cabriolet (1998–2005), C70 Coupé (1998–2002), S60 (2001–2009), S70 (1997–2000), S80 (1999–2006), V70 (1997–2000), V70 (2000–2008)
Show models by year and engine (19)
- 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)2001, 2009Engine B5244S, B5244S2 only
- Volvo S60 (2001–2009)2002Engine B5244S, B5244S2, B5244SG, B5244SG2 only
- Volvo S60 (2001–2009)2003–2005Engine 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 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)2001, 2006Engine B5244S, B5244S2, B5244SG only
- Volvo S80 (1999–2006)2002–2005Engine B5244S, B5244S2, B5244SG, B5244SG2 only
- Volvo V70 (1997–2000)1999Engine B5254S DENSO only
- Volvo V70 (1997–2000)2000Engine B5244S, B5244S2, B5244SG, B5244SG2 only
- Volvo V70 (2000–2008)2001, 2007–2008Engine B5244S, B5244S2, B5244SG only
- Volvo V70 (2000–2008)2002Engine B5244S, B5244S2, B5244SG, B5244SG2 only
- Volvo V70 (2000–2008)2003–2005Engine B5244S, B5244S2, B5244S6, B5244SG, B5244SG2 only
- Volvo V70 (2000–2008)2006Engine B5244S, B5244S2, B5244S6, B5244SG only
What does this fault code mean?
The engine control module has registered a fault in its communication with the ABS control module. Communication runs over the CAN network, and the fault may lie in an open CAN wire or in the ABS control module, which may be defective. Anti-spin does not work for as long as the fault is present.
Possible causes
- Open circuit in the CAN wiring
- Defective anti-lock brake (ABS) control module
What you can do
- 1Read the fault codes in the engine control module and in the central electronic module (CEM) and note which are stored
- 2Check that the CAN network connectors are fully seated and free from oxidation, and look for chafing in the wiring harness
- 3Measure with a multimeter that the CAN wires have no open circuit, after disconnecting the battery negative lead
- 4If the fault returns after checking the wiring, have a workshop check the ABS module; anti-spin and ABS belong to the braking system, so do not work on it yourself
Symptoms you may notice1
- Anti-spin does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.