VOLVO
ECM-4320 - Leak diagnostic unit, valve. Signal too low
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
7 modelsC30 (2007–2013), C70 (2006–2013), S40 (2004–2013), S60 (2001–2009), S80 (1999–2006), V50 (2004–2013), V70 (2000–2008)
Show models by year and engine (11)
- Volvo C30 (2007–2013)2007–2011Engine B5244S4 only
- Volvo C70 (2006–2013)2006–2011Engine B5244S4 only
- Volvo S40 (2004–2013)2004Engine B5244S4 only
- Volvo S40 (2004–2013)2005–2010Engine B5244S4, B5244S7 only
- Volvo S60 (2001–2009)2003–2006Engine B5244S, B5244S6 only
- Volvo S60 (2001–2009)2007–2009Engine B5244S only
- Volvo S80 (1999–2006)2003–2006Engine B5244S only
- Volvo V50 (2004–2013)2004Engine B5244S4 only
- Volvo V50 (2004–2013)2005–2010Engine B5244S4, B5244S7 only
- Volvo V70 (2000–2008)2003–2006Engine B5244S, B5244S6 only
- Volvo V70 (2000–2008)2007–2008Engine B5244S only
What does this fault code mean?
The engine control module keeps watch on the drive signal for the reset valve inside the leak diagnostic pump. When the signal is too low the fault code is set and the leak diagnosis is interrupted. The fault can be caused by the signal wire being short-circuited to ground or having an open circuit.
Possible causes
- Signal wire short-circuited to ground
- Open circuit in the signal wire
- Signal wire short-circuited to supply voltage, where the signal is too high
- Damaged leak diagnostic pump
What you can do
- 1Have you got a diagnostic tool: switch the valve on with the ignition on and listen for a click; if no click comes, the fault is most likely still active
- 2Check the connectors at the engine control module and the leak diagnostic pump for contact resistance and oxidation
- 3Look for chafed or pinched wiring to the reset valve, especially where the signal wire may have touched ground
- 4Use a multimeter to check that the signal wire has no contact with ground and is not open-circuited
- 5Have a workshop check the engine control module software and clear any faults before the leak troubleshooting continues
- 6Have a workshop replace the leak diagnostic pump if the wiring is intact but the fault remains
Symptoms you may notice1
- Malfunction indicator lamp (MIL) is on
What the fault can affect1
- The leak diagnosis is interrupted
General guidance for car owners. Diagnosis on the car can point to a different cause.