Is the MAF sensor on my Volvo 850 corroded?
MVS Forums member VolvoFreak’s Volvo 850 has been running pretty rough for the past two weeks so he called his mechanic. He said to make sure that the contacts for the MAF aren’t corroded. Here’s where it went:
Why do you need a mass flow sensor?
A mass (air) flow sensor (MAF) is used to find out the mass flowrate of air entering a fuel-injected internal combustion engine. The air mass information is necessary for the engine control unit (ECU) to balance and deliver the correct fuel mass to the engine. Air changes its density as it expands and contracts with temperature and pressure.
How does the MAF and oxygen sensor work?
The MAF sensor provides the open-loop controller predicted air flow information (the measured air flow) to the ECU, and the oxygen sensor provides closed-loop feedback in order to make minor corrections to the predicted air mass. Also see MAP sensor.
Can a dirty MAF sensor cause a check engine light?
There is a way to clean the MAF sensor. A dirty MAF sensor can cause rough running and even a check engine light on some cars. They become dirty over time and/or coated with oil residue, especially if you use an air filter with an oiled filter media.
How to test for a fault in a Volvo 850?
CODE TESTING for fault code diagnosis. 1) Disconnect diagnostic unit “A”. Turn ignition on. Check for voltage at diagnostic connector terminal No. 4. If voltage is not present, check fuse and wiring. If voltage is present, turn ignition off. No. 8 and ground. Ohmmeter should indicate approximately zero ohms.
Where is the ohmmeter on a Volvo 850?
Connect an ohmmeter between socket No. 2 (fuel injection system) or No. 6 (ignition system) and measuring unit terminal No. 35. If continuity is present, repeat test using a known good ECU. 1) Turn ignition on.
Can you drive with a bad mass air flow sensor?
You can drive with a bad mass airflow sensor, but you shouldn’t as it can lead to the damage of other engine components and your vehicle will use a lot more fuel than it should, especially at higher speeds.
What are the symptoms of a bad air flow sensor?
The symptoms of a bad mass air flow sensor include low engine power, poor fuel economy, an engine that won’t start, a check engine light on the dash and a gas smell from the exhaust fumes. A bad mass air flow sensor is often the likely culprit if your car isn’t running as it should.
What are error codes for mass air flow sensor?
For doing so you only need to connect your code reader and turn the ignition key on (engine off), a state usually known as KOEO. Common error codes include P0299 (if turbocharger is fitted), P0300, P0101, P0102 and P0171.