Fault code 0532: Diagnosis/troubleshooting

NOTE: Visual inspection: In the next troubleshooting section, please check first that the affected 'pin' of the transfer box control unit plug connection and the 'pin' of the plug connections are neither damaged nor corroded. Remove any soiling or corrosion/oxidation. Replace damaged parts/wires.

NOTE: Control unit replacement: Before replacing the 'transfer box control unit', the ground connections, power supply and plug connections on the control unit must be checked as OK. After the test drive, read out the fault memory with the 9588 Porsche System Tester II again. Additional causes of faults that could damage the 'transfer box control unit' should be detected and remedied.

Before carrying out the work instruction, check fuse '57', voltage supply terminal 30 for the transfer box control unit, in the fuse carrier to the right of the dashboard and replace if necessary. After replacing the fuse, determine and remedy the cause of the fault in accordance with the work instruction below!

DIAGNOSIS TROUBLESHOOTING PROCEDURE

Work instruction			Display OK	If not OK
1	Check battery voltage/current and charge voltage/current on three-phase generator:	Engine speed > 2,000 rpm. Measure charge voltage/current of generator.	11.4 to 14.5 V Go to Step 2	Charge battery if necessary, replace if faulty. Wiring/regulator or diodes faulty. Repair wiring or generator. After carrying out repairs, erase the fault memory and then read out the fault memory again while observing the diagnostic conditions. If no fault stored, then: → End If fault reappears, then: Go to Step 2
2	Check terminal 30 voltage supply and ground supply line to transfer box control unit:	Measurement '2a': Ignition off Pull plug off the transfer box control unit Measure voltage between 'pin 46' and ground on transfer box control unit plug.	10.5 to 14.5 V continue with measurement '2b'	Check fuse '57' in fuse carrier at right of dashboard (resistance measurement). Check voltage supply line for short circuit to ground: Go to Step 3
2		Measurement '2b': Measure voltage between 'pin 47' and battery terminal 30 on transfer box control unit plug.	10.5 to 14.5 V Go to Step 3	Check ground supply line for short circuit to B+: Go to Step 3
3	Check power supply line for short circuit to ground:	Measurement '3a': Measure voltage between 'pin 46 and battery positive' on transfer box control unit plug.	< 0.3 V Measurement '3b'	Short circuit to ground between transfer box control unit plug leads 'pin 46 and fuse 57' in fuse carrier at right of dashboard. Repair wiring and replace faulty fuse. → End
3	Check ground supply line for short circuit to B+:	Measurement '3b': Measure voltage between 'pin 47' and ground on transfer box control unit plug.	< 0.3 V Go to Step 4	Short circuit to B+ between transfer box control unit plug leads 'pin 47' and ground pin MB26. Repair wiring and replace faulty fuse(s). → End
4	Check for open circuit of terminal 30 voltage supply line and ground supply line for ground pin MB26:	Measure resistance on transfer box control unit plug between 'pin 46 and fuse 57' in fuse carrier at right of dashboard. Measure resistance between 'pin 47' and ground pin MB26 on transfer box control unit plug.	< 0.5 Ω Go to Step 5	Open circuit in wire to fuse carrier at right of dashboard. Open circuit in wire to ground pin MB26. Repair wire(s). Also check fuse. → End
5	Check terminal 30 power supply at fuse:	Measure voltage between fuse plug '57 and body ground' in fuse carrier at right of dashboard.	10.5 V to 14.5 V Go to Step 6	Short circuit/contact resistance/corroded or loose connections near or in fuse carrier. Repair if possible, otherwise replace fuse carrier at right of dashboard. → End
6	Replace transfer box control module		See note on replacing control units! → End