VOLVO
ECM-0028 - System relay. Signal faulty. Intermittent fault.
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
3 modelsS70 (1997–2000), V70 (1997–2000), V70 (2000–2008)
What does this fault code mean?
The engine control module has recorded a fault in the system relay, which switches off the main relay after the ignition is turned off. The fault is intermittent, meaning it comes and goes, and may not be present right now. The code normally causes no noticeable symptoms for the driver.
Possible causes
- The main relay is faulty
- The signal wire is shorted to earth
What you can do
- 1Check the wires and connectors to the system relay for play, chafing and corrosion
- 2Listen when the ignition is switched off: the main relay should switch off at the right time. If you hear nothing or notice anything unusual, make a note of it
- 3Measure with a multimeter that the signal wire to the relay is not shorted to earth
- 4Clear the fault code and road test the car. If it returns, have a workshop investigate the system relay and the main relay
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.