Air Flow Meter (HLM)

Check HLM signal:
[D] 200 - The load signal provides an indication of the measured air flow rate in the HLM. The value should be 2.0 ms ± 10 % when idling.

Check burn-off function:
Increase engine speed once above 2000 rpm (engine temperature > 60 °C), after stopping the engine, a voltage increase of approx. 3.5 V can be measured at the HLM between Pin 1 (+) arid Pin 5 (-).