Porsche 928 Workshop Manual page 262

39
Differential, transaxle system
920
Fault, DTC
Possible causes, remedy, notes
6.
Check wires
from terminal
Ll on
the relay base
to
PIN
24 on the control unit plug and
from L2 to PIN 35 for discontinuity.
Important:
The test from L2 to Pin 35 can be performed only if the
warning contact of the pressure warning switch is closed (see wiring
diagram).
This means that the pump for the lock hydraulics must have opera-
ted beforehand (system pressure greater than 140 bar).
7. Check that the valve relay is energized (voltage present at the so-
lenoid valves).
Connect all plugs and the relay.
Push back protective tube on the transverse lock valve plug (at the
rear
leff in the wheel housing).
Switch the ignition off, then switch it on again.
Battery voltage must be present at the black wire.
If no voltage is present, try replacing the valve relay, or test the relay
with the ABS 2-LED tester in order to detenine whether it is
actually defective.
If the LED of the ABS tester fails
7
to light up steadily in program
switch position 5 with the ignition
switched on, the relay is defective.
LE3 II+-
a
8. If the valve relay is in working order, try replacing the PSD/ABS wn-
trol unit (output stage defecfive).
D39 - 244
a
PSD diagnosis/Troubleshooting
PrInted in Germany - XXXV, ,996