VOLVO
ECM-000B - Mass air flow sensor. Power supply too low. Intermittent fault.
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
4 modelsS70 (1997–2000), S80 (1999–2006), V70 (1997–2000), V70 (2000–2008)
What does this fault code mean?
The mass air flow sensor receives too low a supply voltage. The fault is intermittent, meaning it comes and goes, and may not be present right now. The sensor measures how much air flows into the engine. While the fault is active, the engine control module uses a substitute value for the air mass and limits boost pressure.
Possible causes
- The supply wire is shorted to earth
- Break in the signal or supply wire
- Contact resistance in the connections
- Faulty mass air flow sensor
What you can do
- 1Check the wires and connectors to the mass air flow sensor for chafing and pinch damage, and that the connector is fully seated
- 2Because the fault is intermittent, note when the engine feels sluggish, and whether this happens at certain engine speeds or when the engine is warm
- 3Measure with a multimeter that the supply wire to the sensor has no break or short circuit to earth
- 4Clear the fault code and road test the car. If it returns, have a workshop with diagnostic equipment investigate the mass air flow sensor and the wiring
- 5If you have a diagnostic tool, read the air mass in live data at idle and with a little throttle. The value should rise as the throttle opens
Symptoms you may notice3
- Poor acceleration and a sluggish engine
- The exhaust smokes
- Exhaust gas recirculation (EGR) does not work
What the fault can affect3
- The engine control module uses a substitute value for the air mass
- Boost pressure is limited to the basic level
- Exhaust gas recirculation (EGR) is switched off
General guidance for car owners. Diagnosis on the car can point to a different cause.