VOLVO
ECM-6870 - By-pass valve intercooler. Signal too high
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
3 modelsC30 (2007–2013), S40 (2004–2013), V50 (2004–2013)
What does this fault code mean?
The engine control module (ECM) monitors the charge air cooler bypass valve and how it works. If the PWM signal between the module and the bypass valve is too high with the ignition on, the code is set. The cause may be a signal wire shorted to voltage, or a damaged bypass valve.
Possible causes
- Signal wire shorted to voltage
- Damaged bypass valve
What you can do
- 1With the ignition off and the connector disconnected, use a multimeter to check that the signal wire to the bypass valve has no voltage
- 2Check that the wire is intact and not chafed, and that the bypass valve connector is fully engaged and free from oxidation
- 3Read the code, clear it and road test the car to see whether it returns
- 4If no fault is found and the code returns after clearing and a road test, have a workshop replace the bypass valve
Symptoms you may notice1
- Check engine lamp lit or behaving abnormally
General guidance for car owners. Diagnosis on the car can point to a different cause.