VOLVO
ECM-1515 - Brake vacuum sensor. 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) reads the signal from the brake vacuum sensor, which measures the vacuum in the brake booster. If the signal is too high or too low for a certain time, fault code ECM-1515 is set.
Possible causes
- Contact resistance in the connectors at the brake vacuum sensor or the control module
- Open circuit or short circuit in the signal wire to voltage or ground
- Open circuit in the ground wire or short circuit to voltage
- Open circuit in the supply wire to the sensor
- Defective brake vacuum sensor
What you can do
- 1Switch off the ignition and check the connector at the brake vacuum sensor and the control module for contact resistance and oxidation
- 2With a multimeter, check that the signal wire is not broken and has no contact with ground or battery voltage
- 3Check that the ground wire and the supply wire to the sensor are intact and firmly attached
- 4If you have a diagnostic tool: read the brake vacuum sensor value in live data with the engine idling and check that it looks reasonable
- 5If no fault is found in the wiring but the fault remains, the sensor may be faulty and need replacing. Have a workshop do this
- 6If braking feels reduced, do not drive the car until a workshop has checked the brakes
Symptoms you may notice1
- The malfunction indicator light comes on
What the fault can affect1
- The engine does not run in ultra-lean combustion mode
General guidance for car owners. Diagnosis on the car can point to a different cause.