Code 34 - Mass Air Flow (MAF) Sensor
The MAF sensor measures the flow of air entering the engine. This information is used by the ECM for fuel control. Code 34 is set when the engine is running with MAF sensor disconnected or the engine is running faster than 1400 RPM with the TPS signal more than 50% (2.5 volts) and the air flow less than 10 grams per second (low frequency).
NOTE:
The following step numbers refer to the numbers in the accompanying flow chart(s).
- A loose or damaged air duct can set Code 34.
- This test checks if ECM recognizes a problem. "SERVICE ENGINE SOON" light "OFF" indicates an intermittent problem.
- This test checks if 5 volt reference signal from ECM is at MAF sensor harness connector. Less than 1 volt here indicates a faulty circuit 492, wiring connector or ECM.
- This test checks continuity of electrical circuit.
- This test checks for open in ignition circuit.