My home brew cruise control has stopped working since changing to a new 16bit ecu. Even though cruise control has been activated on the new ecu through vcds. Strangely, the clutch switch is no longer recognised. And I can confirm it is not the switch either. I have taken a video of the conditions shown on vcds in case someone spots an obvious problem I cant see. Any one have any ideas as to what's happened? The only fault code is 00671 Cruise control switch E45 10-25 undefined switch implausable. Vid to follow.
Once you are logged into vag com then into the engine block. Instead of going to measuring blocks click on the box called Coding-07. Then in there there are boxes you want to change the top box called software coding like this http://www.ross-tech.com/vcds/tour/recode_screen.html Change that to 00002. Then click do it.
Did not work. Value was already 00002. Tried to re enter it. Did not work. Still not recognising clutch switch or cruise control. Same fault code.
You lose the on signal with everything but the brake pedal pressed? Time to check wiring diagrams to compare 8 and 16bit differences
M1ke, do you know what car the ecu i sent you may have come from? I cant remember the ecu number either.
Right, my old ecu is 028906021AF and my new ecu is 028906021GG From what I can make out, the new ecu is from an AHU engine code. Anyone have pinouts for either?
Im still stumped by this, the ecu is listed in etka as a good replacment for my ecu and should in theory have the same pin outs. I cant understand why I have no clutch pedal signal when i check vcds, when i put the old ecu back in, everything works as it should, cruise works fine as does the clutch pedal switch. Really starting to bug me now, im gutted iv lost cruise control anyone have any more suggestions?
if it works on the old ecu then i cant see how wiring will be a problem, see my sig for ahu wiring diagram though. its more likely there is somethign else you need to do in vag-com to make it work, maybe look on the vortex they have a lot more cars with cruise over there so more likely someone has had this problem before actually, im sure i found 2 numbers for the clutch switch. i thought the difference was just the plug, but maybe its down to the ecu as well. whats the number of your old switch?
The switch works fine, and if i bridge the connector it still wont read out to vcit turns out my ecu is 028906021gm not 'gg' like i thought. This is an audi a4 tdi 1z/ahu ecu. switch I have traced the wires from the ecu connector back to my switches for cruise and ecu, and all tests are fine. So it must be the actual ecu pins being in a different order, like the clutch switch pin is in a different place. Its just strange that if you watch the vid i made, the signal goes to the cruise on, when you press resume or set, what could that mean?
i just mean maybe later switch works differently? looking at elsa the clutch switch wiring is the same on the mk3 tdi on the post-96 audi a4 tdi, the earlier one doesnt appear to even have a clutch switch?
oh i see. well i think im getting closer now, i have found pin outs for fitting cruise control to an a4 with the same ecu, turns out the cruise on signal wire is on a different pin, so i have swapped that in the ecu plug. now the cruise stays on with each button press. but still the same fault code, and still no cluctch switch signal. i wonder if the code is related to having no clutch signal?
is the ecu definitly in manual mode, maybe its in auto mode or something. though you would think that it wouldnt say clutch switch issue but rather auto ecu signal error. much oddness
