swededA4

What’s up everyone. I have a 02 1.8t Quattro. It was a 5 speed and now it’s a 6 speed. I got all the parts from a 04 1.8t Quattro. Transmission, driveshaft, rear diff and axles. Tapped abs module to cluster for 04 6 speed sensor. Since it doesn’t read from the transmission anymore. Also changed the coding from 5speed to 6speed. Have it working except I’m having 80mph dropout issues. So then I got a 04 ecu. Same result. So I thought I needed a newer abs module, same result. Then tried wheel speed sensors replaced all four. Which sucked by the way. Same result.


So to clarify 80 mph dropout I’m referring to being on the high going 80 mph and my speedometer will just drop to zero if I turn the car off and turn it back on it goes back to whatever mph I was going and if I go 80 again it’ll drop right back out. So I’m at a complete loss and I’m tired of just throwing parts at it and I want to figure out what it is

p0507 - powertrain idle control system rpm higher than expected

p0507 - idle control system higher than expected 16891

This is the code that I get thank you for your help in advance

junkyard

It sounds like ABS module is losing communication or getting unexpected signals. With everything else you tried, and assuming ABS module coded properly too if not throwing "Incorrectly coded", I'd suspect something with how you tapped into ABS module for vehicle speed. Not familiar with the swap, but this says you need to install a new wire/terminal in pin 33 of ABS module harness to get vehicle speed. I'd still verify coding is all correct on ECU, ABS, and maybe even instrument cluster. 02 ECUs supposedly couldn't be recoded to 6-speed, but the 04 you should be able to.
https://www.audizine.com/forum/showt...4-VSS-from-ABS

When it drops out, do any of the ABS related lights come on? I've only seen this happen with faulty ABS modules or cheap HID kits that share a ground in right headlight harness with ABS module.

swededA4

thank you very much for replying. I will go through the coding again just to verify everything. The ABS light doesn't come on. Just the check engine light after restart

I did run a new wire from the ABS module to the cluster with the initial swap. I have checked and reran that wire

swededA4

Is there a write up showing what all needs to be recoded? maybe I missed something

junkyard

Definitely ECU and ABS module. Some threads mention instrument cluster too. Usually in VCDS when you go to code anything it will show a coding table with the available options/values. You could try checking the existing coding on each module and see if it matches what the correct coding should be. Just make sure to do an auto-scan and save log or copy existing coding values somewhere before changing values so that you can easily change them back if needed.

The last time I had to code an ABS module it took a few tries before the new coding actually saved, but I also kept getting an incorrectly coded message when scanning and new value was never saving. I believe there is a limited timeout for the ABS module to login and change it and you'll have to start over if you don't do it quick enough and possibly need to cycle ignition or disconnect the battery in order to login again. Not sure if other modules act like that too.

swededA4