Porsche 928 Workshop Manual page 261

928 Differential, transaxle system
39
a
Fault, DTC
Possible causes, remedy, notes
Re transverse lock valve + wiring:
Separate plug connection at the transverse lock valve (arrow).
Measure internal resistance of the solenoid valve.
Nominal value 2...4 n
If an incorrect value is obtained: Reolace transverse lock valve
3. Pull off valve relay (i'-pole) at hydraulic unit. Measure at control unit
plug PIN 17 in order to determine whether there is a short circuit to
plus or to ground.
If necessary, interrupt the circuit at the hydraulic unit plug (12-pole)
and localize the fault by reference to the wiring diagram.
4. Check whether voftage is present at terminal 87 of the relay base
when the valve relay is pulled off. Required display: approx. 12 Volt
(battery voltage).
5. Measure resistance between terminal 87 a on the relay base and
the ground wire at the pump motor.
Nominal value a 2...4 R. The prerequisite is here is that the ground
wire and the gmund point are in working order.
If necessary, replace the hydraulic unif (resistance in relay base has
increased in value).
a
PSD diagnosis/Troubleshooting
Printed in '3em"ny -XXX", 1996
D39 - 243