General information about PD testing for troubleshooting idle problems... (Articles)

To check the PD unit values using VCDS in the engine control unit:

- Read error codes, and if necessary, clear or address them.
- MWB 001 Field 2 (Target: 3.0 - 9.0 mg/h) - TURN OFF AIR CONDITIONING !!
- MWB 004 Field 4 (-3 to +3 kW - allowable fluctuation of 0.5 kW)
- Check MWB 007 temperature readings for accuracy (cold vehicle with outside temperature).
- MWB 013 values fluctuating between -3.0 and +3.0 mg/H.
(if one or more fixed MWB 1 devices are present, with a flow rate less than 3 mg/h)
MWB 023 -100 is +100 (note that values from -60 or +60 should be considered).
(If values are greater than -60, suspect a fuel supply problem.)
(Values > +60 indicate poor fuel quality or a stuck injector.)

Furthermore, you should examine the values of the idle speed control in the measurement data.