Audi S3 2002 cruise control retrofit problems
Discussion
I'm helping a friend out with cruise control on his S3 8L currently. It's a 2002 car with the BAM engine.
In short, someone previously installed the stalk and wiring on it, but it has never worked. I plugged my VCDS cable in, and under Engine there is one code stored, namely:
17977 - Cruise Control Switch (E45): P1569 Implausible Signal.
But... I can open the appropriate measuring block in VCDS and see the various binary numbers changing from a 0 to a 1 when I press any of the stalk switches - so it is seeing all the stalk buttons. But of course I didn't note what those numbers/changes were, so that I could compare to the pictures below which I found later.
Cruise is coded correctly with VCDS,
When I switch cruise off, the code disappears - but of course comes back when I switch it on.
So my thoughts are that the ECU wiring for the cruise stalk is wrong. However, I can't find any wiring diagrams for the BAM engined cars specifically. The instructions from Teeside VW (found at vwgolfr32.co.uk/ccs.pdf) suggest the following wiring for all 1.8T engines, implying they all have the 121 pin connector:
T121/75 Blue/Grey
T121/57 Red/Yellow
T121/38 Black/White
T121/76 White
So I will need to check that those colours correspond to those pins.
Next, the instructions talk about connecting the CCS loom to Fuse 5 in the dash-end fusebox... can anyone enlighten me about this, i.e. does power go from fuse 5 to the cruise switches, then on - through the bulkhead connector - to the ECU pins mentioned above? If so, I should be able to detect voltage at those pins depending on what button is pressed - correct?
Lastly, and this is mostly for my benefit, this is what VCDS should see when various buttons are pressed on the stalk. I will compare these to what I'm seeing, but I think any anomaly should back up the theory that the wiring isn't correct.
Switches on stalk:
Pedals:
All input welcome!
In short, someone previously installed the stalk and wiring on it, but it has never worked. I plugged my VCDS cable in, and under Engine there is one code stored, namely:
17977 - Cruise Control Switch (E45): P1569 Implausible Signal.
But... I can open the appropriate measuring block in VCDS and see the various binary numbers changing from a 0 to a 1 when I press any of the stalk switches - so it is seeing all the stalk buttons. But of course I didn't note what those numbers/changes were, so that I could compare to the pictures below which I found later.
Cruise is coded correctly with VCDS,
When I switch cruise off, the code disappears - but of course comes back when I switch it on.
So my thoughts are that the ECU wiring for the cruise stalk is wrong. However, I can't find any wiring diagrams for the BAM engined cars specifically. The instructions from Teeside VW (found at vwgolfr32.co.uk/ccs.pdf) suggest the following wiring for all 1.8T engines, implying they all have the 121 pin connector:
T121/75 Blue/Grey
T121/57 Red/Yellow
T121/38 Black/White
T121/76 White
So I will need to check that those colours correspond to those pins.
Next, the instructions talk about connecting the CCS loom to Fuse 5 in the dash-end fusebox... can anyone enlighten me about this, i.e. does power go from fuse 5 to the cruise switches, then on - through the bulkhead connector - to the ECU pins mentioned above? If so, I should be able to detect voltage at those pins depending on what button is pressed - correct?
Lastly, and this is mostly for my benefit, this is what VCDS should see when various buttons are pressed on the stalk. I will compare these to what I'm seeing, but I think any anomaly should back up the theory that the wiring isn't correct.
Switches on stalk:
Pedals:
All input welcome!
Edited by BFleming on Thursday 22 April 16:29
Rather than messing with VCDS, physically check the connections. There aren't many, and odds are that one or more are wrong.
The wiring varies between engine codes, look at page 12 and there are subtle differences between engine codes, even on the 121-pin ecu connector.
This https://www.seatcupra.net/forums/threads/cruise-co... suggests following the AUQ layout, so check that whoever installed it followed the AUQ pattern throughout.
eta - the other non-obvious problem used to be the brake and clutch switches, check those, but I don't think that's the issue here.
The wiring varies between engine codes, look at page 12 and there are subtle differences between engine codes, even on the 121-pin ecu connector.
This https://www.seatcupra.net/forums/threads/cruise-co... suggests following the AUQ layout, so check that whoever installed it followed the AUQ pattern throughout.
eta - the other non-obvious problem used to be the brake and clutch switches, check those, but I don't think that's the issue here.
Edited by shtu on Friday 23 April 17:03
OK mystery solved... the owner had installed the old stalk (8L0 953 513j) with the single button at the end, but should have installed the one with the 2 buttons (1J0 953 513 01C).
So the car was just throwing a plausibility error as it wasn't seeing the right things happen when cruise was switched on. The new switch is ordered and I'm 99.9999% sure it'll fix the issue.
So the car was just throwing a plausibility error as it wasn't seeing the right things happen when cruise was switched on. The new switch is ordered and I'm 99.9999% sure it'll fix the issue.
Edited by BFleming on Monday 26th April 11:00
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