Install Cruise Control: Retrofit Guide

Hi everyone, I have a question. Has anyone here ever retrofitted a cruise control system to an Audi A6 C4 with the AEL engine? If so, please let me know how much work it involves, what parts are needed, and whether the functionality is already present in the engine control unit (ECU). Do I need to activate the function in the ECU afterwards? Thanks in advance for your help, Jürgen.

Quoted from Mecki's FAQ:
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'I now have it in writing. For every C4 with the engine code AEL and for every AAT with the third version of the engine control unit, the GRA (presumably a specific component or system) consists only of a switch, a cable, and the diesel control unit, which is already installed in the vehicle (for engine management).'

Unfortunately, the wiring to the control unit is missing. These wires need to be connected from the switch. There is no pre-made wiring harness available!


Contact 1 on the GRA (Gear Range Adapter) terminal is connected to pin 30 on the control unit.
Contact 2 on the GRA (Grounding Relay Assembly) terminal is connected to pin 45 on the control unit.
Contact 3 on the GRA (Grounding Relay Assembly) terminal block is connected to pin 48 on the control unit.
Contact 4 on the GRA switch is connected to pin 24 on the control unit.
Contact 5 on the GRA terminal block is connected to fuse 64 (switching mechanism).
Contact 5 on the GRA terminal block is connected to the transmission control unit (automatic transmission).
Contact 6 on the GRA switch is connected to pin 24 on the control unit.

Then, unlock it using code 11463.

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'The quick brown fox jumps over the lazy dog.'
I think that should answer everything for you.

All information is provided to the best of my knowledge, but I assume no responsibility or liability.

Thank you for the quick response. By any chance, do you also have the circuit diagram for that? Best regards, Jürgen.

No, sorry, but just ask your next dealer.
He should be able to copy that for you.

Hello.
Try searching on eBay for 'GRA cable A6'. You might find what you're looking for. Perhaps they have the right cable in stock, or they can make it for you.
Best regards,
Michael.

Hello.

'What's the point of a wiring diagram? If you have the steering column switch, just wire it up as described and activate the GRA (Gear Range Adaption) function in the control unit. I did it myself, and it works great. You can easily find the matching connectors at a junkyard.'
By the way, don't look for fuse 64 for Kontakt 5; many people have already been frustrated trying to find it. Just use a positive wire that is switched by the ignition.

Does that also apply to the A6 2.5 TDI model manufactured in 1998?