VOLVO
ECM-630D - A/C relay. Signal too low. Permanent fault
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:
5 modelsS60 (2001–2009), S80 (1999–2006), V70 (2000–2008), V70 XC / XC70 (2001–2007), XC90 (2003–)
Show models by year and engine (14)
- Volvo S60 (2001–2009)2005–2006Engine B5204T5, B5244T4, B5244T5, B5254T2, B5254T4 only
- Volvo S60 (2001–2009)2007Engine B5204T5, B5244T5, B5254T2, B5254T4 only
- Volvo S60 (2001–2009)2008–2009Engine B5204T5, B5244T5, B5254T2 only
- Volvo S80 (1999–2006)2005–2006Engine B5204T5, B5244T4, B5254T2, B6294S2, B6294T only
- Volvo V70 (2000–2008)2005Engine B5204T5, B5244T4, B5244T5, B5254T2, B5254T4 only
- Volvo V70 (2000–2008)2006–2007Engine B5204T5, B5244T5, B5254T2, B5254T4 only
- Volvo V70 (2000–2008)2008Engine B5254T2 only
- Volvo V70 XC / XC70 (2001–2007)2005All engines except: D5244T
- Volvo V70 XC / XC70 (2001–2007)2006Engine B5244T4, B5254T2 only
- Volvo V70 XC / XC70 (2001–2007)2007Engine B5254T2 only
- Volvo XC90 (2003–)2005–2006Engine B5254T2, B6294T only
- Volvo XC90 (2003–)2007–2012Engine B5254T2 only
- Volvo XC90 (2003–)2013–2014Engine B5254T9 only
- Volvo XC90 (2003–)2015
What does this fault code mean?
The fault is present now: the engine control module (ECM) has registered that the signal to the A/C relay is too low. The fault remains until the cause has been put right, and the A/C system does not work.
Possible causes
- Contact resistance in the connections
- Signal cable short-circuited to ground
- Damaged A/C relay
What you can do
- 1Check that the connections at the A/C relay are clean and firmly fitted
- 2Use a multimeter to check whether the signal cable to the relay touches ground (the body) with the ignition on
- 3Check that the cables to the relay are not chafed
- 4With a diagnostic tool: activate the A/C relay and see whether it responds
- 5If the fault remains after these checks, have a workshop replace the A/C relay
Symptoms you may notice1
- The A/C system does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.