VOLVO
ECM-1123 - Fuel temperature sensor. Signal too low. Intermittent fault
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 has intermittently received a signal from the fuel temperature sensor that is too low, or has found a fault on its wiring. Engine management can then use a fixed value instead of the real fuel temperature. The fault is intermittent and may not be present right now.
Possible causes
- Signal wire short-circuited to ground
- Signal wire short-circuited to supply voltage
- Open circuit in the signal wire
- Fault in the injection pump
What you can do
- 1Read and note the code, clear it and road test to see whether it returns
- 2Check the fuel temperature sensor connector for play, contact resistance and oxidation
- 3Use a multimeter to check that the signal wire is not broken and has no contact with ground or voltage
- 4If the fault remains, have a workshop with diagnostic equipment check the sensor and the injection pump
Symptoms you may notice1
- The malfunction indicator lamp comes on
What the fault can affect1
- The engine control module uses a fixed value for the fuel temperature
General guidance for car owners. Diagnosis on the car can point to a different cause.