VOLVO
ECM-P040985 - Exhaust Gas Recirculation Sensor A Circuit. Bus Signal / Message Failures. Signal above allowable range
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
5 modelsS80 (2007–), V70 (2008–), XC60 (2009–), XC70 (2008–), XC90 (2003–)
Show models by year and engine (6)
- Volvo S80 (2007–)2007–2009Engine D5244T4, D5244T5 only
- Volvo V70 (2008–)2008–2009Engine D5244T4, D5244T5 only
- Volvo XC60 (2009–)2009All engines except: B6304T2
- Volvo XC70 (2008–)2008All engines except: B6324S
- Volvo XC70 (2008–)2009Engine D5244T4, D5244T5 only
- Volvo XC90 (2003–)2013–2014Engine D5244T18, D5244T5 only
What does this fault code mean?
The fault concerns the signal from the EGR valve position sensor, which is above the permitted limit. The code is named as a bus or message fault, but the condition is an incorrect PWM signal from the sensor.
Possible causes
- Fault codes ECM-P040931 and ECM-P040984 may share the same cause and should be read together
- EGR valve is stuck in the open position
- EGR valve is stuck in the closed position
- Damaged position sensor
- Damaged EGR valve
- Contact resistance, oxidation or an open circuit in the signal cable and connectors
What you can do
- 1Start the engine and read the fault status with a diagnostic tool, if you have one
- 2Check that the EGR valve is not stuck in the open or closed position
- 3Check the connectors to the position sensor and the EGR valve for contact resistance and oxidation
- 4Use a multimeter to check that the signal cable has no open circuit
- 5Clean the EGR valve of dirt and soot if it is clogged
- 6If the fault remains, have a workshop check the position sensor
Symptoms you may notice1
- No noticeable symptoms for the driver
What the fault can affect1
- EGR control is lost
General guidance for car owners. Diagnosis on the car can point to a different cause.