VOLVO
ECM-1500 - FR alternator. Faulty signal
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
2 modelsS40 (1996–2004), V40 (1996–2004)
Show models by year and engine (2)
What does this fault code mean?
The engine control module (ECM) uses the signal from the alternator FR connection to judge how hard the alternator is loaded. If the pulse signal is outside the expected range while the engine is running, fault code ECM-1500 is set.
Possible causes
- Contact resistance in the connectors at the alternator or the control module
- Open circuit in the alternator signal wire
- Signal wire short-circuited to ground or supply voltage
What you can do
- 1Switch off the ignition and check the connectors at the alternator and the control module for play and oxidation, then reconnect them firmly
- 2Check the alternator signal wire for chafing and breaks
- 3With a multimeter, check that the signal wire has no contact with ground (the body) or battery voltage, and that it is not broken
- 4With a diagnostic tool, check in live data that the alternator load signal changes when the headlights and heated rear window are switched on
- 5If the fault remains, have a workshop check the alternator and how the control module handles the signal
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.