1998 1.8T conversion - MIL/CEL wiring question

[Schimke]

Hi Guys! I'm hoping you can help me here. I'm pulling my hair out trying to find the correct wire(s) for the MIL/CEL (K83) for my '98 Audi AEB swap and it's making me feel like an idiot. I have been through every thread that could find, every FAQ that I could find and all through the Bentley and I still haven't come up with an answer. I looked through the Bentley wiring schematics looking for the 1998 AEB MIL lamp wiring, and this what I have found: The 1997 schematic shows the MIL (K83) wiring coming from pin #17 on ECM. This wire is a ground wire to activate the MIL lamp. The 1998 AEB schematic shows ECM Pin #17 as the Trailer Operation Indicator Light (K18) which appears to be a power wire to activate the lamp (obviously this has nothing to do with the 1998 MIL, but I simply made the connection to show that the 1997 ECM wiring appears to be very different than the 1998/early 1999 wiring). I could not find a MIL (K83) wire in the 1998 schematic at all. The early 1999 schematic is the same as the 1998. The late 1999 schematic has a K149 lamp labeled a "Warning Light for Motor Electronic" (I don't know what that is exactly). However, this wiring track goes nowhere. It does connect to connector T32/13, but that's as far as the information leads. Pin #17 on the late 1999 ECM also goes to the Trailer Operation Indicator Light (K18), so it appears similar to the 1998 wiring. For 2000, the schematic shows the MIL (K83) lamp as ground activated from ECM pin #47. This appears to be a similar layout as the late 1999 described above. The MIL (K83) lamp is shown to be connected via T32a/14 (which happens to be the Fault Light for Power Accelerator Activation lamp connection in the 1999 Schematic). Pin #17, which is used for the Trailer Operation Indicator Light mentioned above, does not appear to be in use with the 2000 wiring, indicating that the 2000 wiring is very different than the others. (Just to be clear, I only mention the ECM Pin#17 and the Trailer Operation Indicator Light as a comparison between the 1997 ECM wiring (which shows ECM pin #17 as the MIL K83) and the other years) So what happened in 1998 and 1999? Does the ECM in those years follow the 1997 (it appears not, but...) or 2000 format or neither? I'm really at a loss here, so if anyone can help me figure what wire is associated with the MIL/CEL (K83), I would REALLY appreciate it.

[morpheousx]

I cant aswer your question but i do have a suggestion.

Register at www.Audiforums.com and post your question in the B5 section,you may get more help there as this forum is good but there isn't a lot of active users with experience on this forum,opposed to audiforums.

Most questions on this forum,go unanswered,i know as i asked a few questions on this forum and they weren't answered but they were on audiforums.com

Good Luck!

[Schimke]

Ah, thank you for the advice, I appreciate it. I will head over there right now.

[Schimke]

For anyone who may be watching this or who happens to look up this information in the future, the answer is that Pin #17 (green/brown wire) from the ECU is what triggers the CEL. If you trace this wire through the Bentley, it shows to connect in the instrument cluster at connector T32/16 (32 pin green connector) which is labeled as K18 (Trailer Operation Indicator Light).