Vw Golf Immobliser (mk 3)

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Sat 8 Apr 2006 17:00
Vw Golf Immobliser (mk 3) - peejay1959
just put an ahu (tdi ) in my 1974 golf, to replace a failed aaz (td). have sorted loads of issues and I'm now at the stage (home straight hopefully) where I get

Control Module Part Number: 028 906 021 BF
Component and/or Version: 1.9l R4 EDC 00SG 0804
Software Coding: 00002
Work Shop Code: WSC 01268 Faults Found:
17978 - Engine Start Blocked by Immobilizer
P1570 - 35-10 - - - Intermittent
00522 - Engine Coolant Temperature Sensor (G62)
30-10 - Open or Short to B+ - Intermittent

Coolant obvious I've put none in yet!!! But I haven't got an immobilizer, nor do I want one!! It starts for about 1 sec then dies. Also it has blanked out the fuel gauge, clock and mileage on two different instrument clusters. Can I default something in the engine ECU, as thats all I've got, to get me going? A scan does not pick up any other modules, eg Instruments or immobiliser. There must be either A pin I can short out or the software equivelant of, to 'fool the ecu that all is well and allow the car to sart and the instruments to start working again.

Cheers Pete
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Sat 8 Apr 2006 18:15
Vw Golf Immobliser (mk 3) - Screwloose
Pete

You've walked into a bit of a nightmare here. The engine ECU is matched with an immobilizer box which itself is matched to a chipped key. Without the correct code being sent by the [missing] immobilizer to the ECU at key-on, then it will indeed only run for a couple of seconds.

How much of the AHU's wiring loom did you fit? You've obviously now got a diag socket; have you still got the immob unit plug on it as well? It may be possible to have the requirement for a security code removed from the ECU by a reconditioner [ECU virginizing] but it won't be a cheap process.

There is a possibility that 1Z/AHU ECUs built before August 94 don't have this immobilizer system; but you'll have to check that out for yourself.
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