VOLVO
ECM-288A - Front heated oxygen sensor (HO2S), bank 1. Signal missing
System
Engine Control Module (ECM)
Volvo models this fault code applies to
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?
Although the code is named signal missing, it is set when the front oxygen sensor on bank 1 reacts too slowly when the fuel and air mixture changes. The control module monitors the aging of the sensor, and the cause may be a wiring fault such as a short between the calibration and pump current cables, or an open circuit.
Possible causes
- Calibration and pump current cables shorted to each other
- Open circuit in the signal cable (-)
- Open circuit in the calibration current cable
- Damaged front oxygen sensor
What you can do
- 1Do not use rust solvent or grease on the sensor connector. Check that the connector is secure and free from contact resistance and oxidation
- 2With the car switched off, use a multimeter to check the wires one at a time for an open circuit
- 3Use a multimeter to check that the calibration and pump current wires are not shorted to each other
- 4If the connector and wires are in order but the fault remains, have a workshop fit a new oxygen sensor
Symptoms you may notice1
- Malfunction indicator lamp (MIL) lit
What the fault can affect1
- Catalytic converter diagnostic is switched off
General guidance for car owners. Diagnosis on the car can point to a different cause.