Audi B6 BHW swap wiring question (one wire left)

Trying to finish up a Audi B6 BHW swap and I'm stuck on the fan control. The Audi used red/white to ECU pin 24. Can't figure out if the BHW ecu has a wire for this. Any help on this would be much appreciated.

I think most people use the mechanical thermostatic fan in their swaps. I'm guessing you are retaining the Audi electric fans? I'm definitely interested in the answer to this question too.

I'm thinking maybe they just aren't compatible because the Passat and A4 use 2 different ways to control the fan. I'm wondering what kind of signal gets sent from the A4 ECU. The BHW ECU might not have that output but if its just specific voltages then maybe there's a way to feed a signal to the existing fan module. I wanted it to be all factory and this is the only thing I'm hung up on.

I was afraid that the BHW ECU didn't have the correct output. Besides maybe a cruise control problem will the BPW ECU should everything else be the same?

Do you think the pin locations are different between the BHW and BPW ECU?

Well my swap is all working except for the fans being on full time.
Looks like the easiest way for me is to use a separate fan controller.
Any idea how many amps these fans draw? I found a controller that can control 2 fans and has an AC input.

Just tried the cruise control, didn't work. The 2 highways I drive everyday are to congested for cruise control so its not a huge deal but it would have been nice for it to be working.

Why don't you just flash your BHW ecu with a BPW file? Isn't it the same thing as using the BPW ecu? Both ECUs are EDC16U31. I have a BPW file if you want to try it.

Sure I'll try the BPW file. Do you think that will also enable the ECU to control my fans? T94/47

I thought Demon Diesel said something about resistors being different in ECU's.

aren't all the EDC16U31s the same with different softwares? I tried the BPW file in my Allroad BHW and the software monitoring version error I had with the BGW flash disappeared but the file needs to be tuned. I will go see a Malone dealer on monday to see what he can do.

when i did my b6 bhw i bought harness and edc15 ecu from europe b6 never had a edc16

QuickTD said:

Did you switch to vacuum EGR and anti shudder valve as well?

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I did pd130 manifold with egr and asv delete

Machineman said:

I did pd130 manifold with egr and asv delete

Click to expand...

Did you have cruise control working with your swap?

Reviving an old thread here, I just bought a 2005 Passat parts car with a BHW in it that I'd like to swap into my 2002 Audi a4 3.0!

I'm doing that exact swap. I bought a BPW controller from Lithuania. I hope i can get it working alright.

There was an EDC16U1 in B6, for 1.9TDI BKE on later 2004 cars with Euro4 without DPF, also with just electric fan like B7 BPW. Take care with the files because the BGW/BHW is EDC16U1 not EDC16U31 like BPW. Also the electronics in the B7 are different, different ABS, Cluster, AIRBAG.
Cruise control is the same between B6 and B7. Usually B7 parts are used for upgrade on B6 for newer MFSW (B7+).
It curious that the BHW can't control the fan because the Passat should have at least one electric fan used for AC.

QuickTD said:

The BHW auxiliary fan is a simple 2 stage thermal switch arrangement, not PWM controlled type like the A4. Passat fan operates independent of the ECU.

For my B6 swap I finally went with EDC15P and used an AWX intake with vacuum EGR and anti-shudder. I was never able to get any EDC16 ECU to integrate with the cars electronics, and I tried several configurations...

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Sorry, I forgot to come look for replies here. I'm just slowly getting ready for the swap, I'm still working on getting the BHW pulled out now.

I don't mind if I have to end up running the clutch fan off the Passat, but cruise would be one thing I would really like to work. Has anyone managed to figure out cruise?

Also will the BHW ecu talk to my 2002 A4 cluster?

Sorry for all the questions! I'm not new to working on vehicles, I have a Compound turbo Cummins that I built up from stock by myself, But I am newer to the VW/Audi world so still trying to learn as much as I can before I dive into the swap.

Thanks!