alpinab7

Is there any way to test the MAF sensor? I don't see any measuring blocks in VAGCOM

Joey T

Checking MAF sensor function

Internal resistance check.

* Disconnect MAF sensor harness connector.
* Switch DVOM to 200 ohm range.
* Connect multimeter (using VW 1594 connector test kit) to MAF sensor terminals 1 and 2.
* Record resistance value.
* Disconnect test leads from MAF sensor, and connect test leads together.
* Display value must equal value recorded previously.

If difference is greater than 0.1 ohm :

* Replace MAF sensor.

Output signal check.

* Re-connect MAF sensor harness connector.

Mass Air Flow Sensor Connection


* Peel back rubber boot on back of harness connector to expose terminals.
* Switch multimeter to 20 Volt range.
* Connect multimeter to (exposed) terminals 1 and 3.
* Switch ignition ON.
* Must be 1.2 - 1.5 Volts .
* Start engine and let idle.
* Must be approx. 2.5 Volts .
* Increase Engine Speed (RPM) briefly.
* Voltage must increase to 3.0 - 5.0 Volts
* All of the specified voltages must be obtained.

If not:

* Replace MAF sensor.

Checking MAF sensor burn-off

Note : The sensing element of the MAF sensor must be clean to function properly. To accomplish this, the element is heated to 100°C (183°F) for one second, each time the ignition is switched OFF.

Burn-off occurs only under the following conditions:

* Engine Coolant Temperature (ECT) above 60°C (140°F) .
* Engine Speed (RPM) has exceeded 2000 rpm for at least 3 seconds .
* MAF sensor wiring is OK.
* Injector valve circuit breaker S72 is OK.
* Disconnect MAF sensor from air cleaner housing and position far enough back so that burn-off process can be observed.

Note : Do not disconnect the intake air hose or the MAF sensor connector.

* Start engine and let idle above 2000 RPM for minimum of 3 seconds .
* Switch ignition OFF.
* Observe burn-off process.
* Heating wire glows for about 1 second.