US MK4 Jetta Upgraded to 4Motion

[manicslothpdx]

Ok, cool, thanks. I finally feel like I am getting close and it hasn't always felt that way. VCDS has been invaluable though because I've been able to remove a ton of variables and validate that everything can now talk to everything else.

Even though it's not technically a VCDS issue, I will post here once Malone replies for anyone else who might be doing a similar retrofit. Someone out there bought all those other 4Motion kits from Korwerks

 

[manicslothpdx]

Malone responded to my 4Motion question. They're asking if I know what the coding *should be*. How I might determine this? The popover I see in VCDS doesn't show the numbers for "All Wheel Drive" or "6-Speed Manual Transmission." My Bentley manual doesn't seem to have the programming info for TDI's other than the ALH, even though my copy is from 2005. Is there any other resource I can use? I found one older Ross-Tech thread for a guy in Canada that imported a 4Motion ATD TDI, and his coding was 0000003, but Googling that part number (038906019DD) seems to indicate that it is an EDC15 instead of an EDC16 like mine.

 

[Uwe]

The popover I see in VCDS doesn't show the numbers for "All Wheel Drive" or "6-Speed Manual Transmission."

I suppose that's because BEW was never sold that way. IIRC, they were all FWD, and had either 5MT or slushbox tranmissions.

--Uwe-

 

[manicslothpdx]

I've been doing some digging, and it looks like the EDC16 was used in the 2003-2005 4Motion TDI Passat, not that this really helps me. And, I found some scans in older Ross-Tech threads, but they have the same coding as I do anyway: 0150031. Maybe I am not on the right track after all. Or, maybe I have to keep going deeper and deeper down this rabbit hole and retrofit an EDC15? Or, might there still be a way for a tuner to modify an EDC16? That last question may be a rhetorical one.

 

[Uwe]

it looks like the EDC16 was used in the 2003-2005 4Motion TDI Passat

EDC16 ECUs were used in a plethora of different applications (both engines and cars). But that mean you can just slap any old EDC16 into any application. There are some hardware variations, and there are even more software variations.

-Uwe-

 

[manicslothpdx]

I understand. I guess what I was trying to say is that if I could verify that an EDC16 was used in a 4Motion car, even a different model like a Passat, then maybe that meant it could be tuned to support 4Motion (or, more specifically, this 4Motion ABS module) in a different model like a Jetta. As opposed to finding out that an EDC16 was never used in a 4Motion car at all, and no amount of firmware tuning could make it work. But, maybe I am thinking about this wrong.

 

[manicslothpdx]

Those "binaries" listed in your post may have required loop changes that would be listed in the wiring diagram - sometimes there are 4 or mre different possible combinations.

Have you revisited the wiring of the ABS module plug yet?

There are loop wires between different pins, that have to match the coding.

Often those faults have "mechincal failure" tagged on the end, but maybe not always.

My car has different wire loops for brake size. The car doesn't know it's brake size, but if you code to a model that can ONLY be used with certain sizes, it must match the coding etc.

I may have been going down the wrong rabbit hole after all.

You mentioned this a couple times, and I kept it in the back of my mind but was trying to avoid having to deal with any wiring issues. However, Graeme in Australia found an ancient Vortex thread and sent it me. It sounds exactly like what you're describing. They have the same issue, the same error code, the same coding. It's not exactly the same scenario, but it's close:

ABS (MK60) coding trouble

Hello, My ABS keeps complaining that it's been coded wrong, and not functioning. ABS light is on, some triangle with a round arrow light is on and my handbrake light is flashing. Below are my 'autoscan' results. The coding is 0023049 that should be right for a 2003 R32,(I've seen it in somebody...

www.vwvortex.com

They even mention the exact pins to jump, though I'm not 100% sure it will be the same for my car. Graeme seems to think these pins will work for me because he thinks they're related to a check for how many pressure sensors are located on the master brake cylinder, and that since I am using an ABS module pulled from an R32 (the part number is the same for a 4Motion Bora in PartsLink24,) and because I only have one pressure sensor like that forum user, then the same pins may work for me.

I won't be able to re-wire anything for a few more weeks, though. I am also about to upgrade my motor to an ARL bored for 81mm Passat pistons, so I have a few projects happening at once. My concern is what if those pins don't work? It sounds like there might be a few combinations. Even if I used erWin, what diagram would I try to find? Would I look for a 2004 4Motion Bora? Would I have to look for a specific sub-model of a Bora with a specific engine/brake combination?

I guess I will cross that bridge after trying the pins outlined in the Vortex thread.

Thanks again for all the help here.

 

[NZDubNurd]

You can get wiring diagrams from official sources, such as Erwin, yes ;-)

There are other sources such as the ELSAwin PC program too, but some aren't legitimate "legal" sources.

TBH, I'm familiar with MK5 stuff, and not MK4. I suspect it's not so different though.

I'd start with comparing the R32 wiring with the Bora 4-motion version - they may be identical. Also double check all the other wiring variations (like the different date options in that thread) just to make sure you aren't going to let the smoke out (probably unlikely anyway). I guess, your car is more similar to the Bora, so that's probably a safe place to start.

You may end up with esp that isn't EXACTLY as per factory, but will at least function. MK4 R32's used different steering rack ratios, and that rack can cause ESP issues, if everything isn't set up and coded correctly too, so I reckon you're probably right about the Bora wiring/coding.

Usually, the wiring is just a matter of unlocking the connector, extracting the pin and moving it, so can be done pretty easy, assuming the connector is accessible.

 

[manicslothpdx]

I was able to find wiring diagrams and compared them. The ABS module connector is identical on a Jetta and an R32, except for a single jumper wire. On a 4Motion Jetta and the R32, there is a jumper wire between pins 14 and 39. On a front wheel drive Jetta, there is also a jumper wire, but it is between pins 12 and 38. I was worried there would be more differences between the wiring diagrams, but apparently this is the only difference. As mentioned earlier, the ECU performs a check, and if the version of the ABS module (4Motion or FWD) doesn't match the jumper wire, then this error code is triggered.

I won't be 100% sure until I can actually do this in a few weeks, but the solution to this coding error should be just moving the jumper wire.

 

[manicslothpdx]

To close the loop on this, moving the jumper wire fixed the issue! I now have working 4Motion! Thanks for all the help.

 

[manicslothpdx]

Should I get more info when running these output tests for "AWD" then just these two messages separated by a 3-4 minute delay?

I click the start button and it says: "Precharge Pump OFF"
Then, after a few minutes of no other visual changes, it says: "Output Test Sequence Complete"

Where my car is parked has lots of ambient noise, so it's hard to listen to hear if any sounds are coming from the Haldex. I have no error codes but I can post a new log if requested. I can read the Hades oil temperature and voltage in the measuring blocks. I guess my concern is based around some videos I have seen that appear to show more tests being listed after clicking the start button, so I'm not 100% sure what's normal for a MK4 car and the AWD output tests. I haven't been able to take my car somewhere to test whether 4Motion is activating, but it does feel like it drives different ever since we fixed the jumper wire.

 

[NZDubNurd]

It's a sequential manual test. When you click Start/Next the first time, it should display the Pre-Charge Pump Off, then you click again, it powers up the pre-charge pump and says Pre-Charge Pump On, click again and it does the releif valve the depressurises the clutch system, the same as when you brake or apply the handbrake etc.

Both the MK4 and 5 are pretty similar in that regard - they're really basic as far as haldexes go: Precharge pump makes a pressure preload, then mechanical "pump" creates additional pressure from input/output speed differences to lock the clutchpack and the valve dumps the pressure to disengage the system as required.

The haldex pump is pretty quiet - certainly quieter than my fuel pump anyway.

 

[manicslothpdx]

I need to re-test to determine the exact number of clicks, but after reading the previous comment, I think the issue is that the status isn't changing when I click the "Start/Next" button. However, if I click the button enough times, I eventually get to the final "Output Test Sequence Complete" message. But, until I click it enough times to get to the end, all I see is the "Precharge Pump OFF" message. Maybe I am cycling through all the tests, and it's just a visual bug in VCDS? Or, could this be a sign of another issue? Being a retrofit probably makes this harder to diagnose. Either way, I don't have any error codes. Is there another log anywhere that might show the results of the AWD output tests?