VOLVO
ECM-4030 - Leak diagnostic unit, preheating. Signal missing
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:
2 modelsS40 (2004–2013), V50 (2004–2013)
Show models by year and engine (2)
What does this fault code mean?
The engine control module monitors the drive signal of the heater element inside the leak diagnostic unit. If the signal is above or below the expected range, or absent, the fault code is set, and it is only tested when the leak diagnosis runs. The fault normally gives no noticeable symptoms and no other effect on the car.
Possible causes
- Signal wire short-circuited to ground
- Damaged leak diagnostic pump
- Signal wire short-circuited to supply voltage
- Open circuit in the signal wire
What you can do
- 1Clear the fault code and let the car run a new leak diagnostic to see if it returns
- 2Check the wiring to the heater element of the leak diagnostic unit for chafing, pinching and loose connectors
- 3Check the connector to the leak diagnostic unit for contact resistance and oxidation
- 4Use a multimeter to check that the signal wire has no contact with ground or positive and is not open-circuited
- 5Have you got a diagnostic tool: activate the leak diagnostic heater and check in live data that the control signal follows the activation
- 6Have a workshop check the leak diagnostic unit if the fault returns after the wiring check
Symptoms you may notice1
- No noticeable symptoms for the driver
General guidance for car owners. Diagnosis on the car can point to a different cause.