Ecu question

[Pedalsteel]

Is a 97 b4v ecu a straight direct swap into a 96 b4v? If a 96 b4v is having starting issues how common is it that the ecu is shot?

 

[volksguy]

No 028906021FA had a Different Harnesses took a 180 GP Relay And A Jumper Relay. You can find a 028906021BA cheep with out to much trouble.
And actually i dont know What happens if you Plug in a 028906021FA will it Just Be Trouble Codes? That wont clear? Will the Harnesses Burn up? I hope some one with much more knowledge on this adds to this post

 

[Pedalsteel]

I appreciate the info thank you for the reply

 

[Abacus]

It’s actually the BK ECU, not the BA ECU. The BK is a black plastic case ECU that runs the OBD-D programming at a lower speed than the silver aluminum case ECUs that run the OBD-II programming.

The check engine light will come on if the wrong chips are used, but I forget what codes pop up. It’s easy to swap the chips, however. The GQ and FA ECU’s are the same but the chips in them are different. In rare cases the chips are not socketed but I have never seen one of them in my travels. So to make the 1997 ECU (FA) work in the ‘96 (GQ), all you need to do is find some stock GQ chips and swap them in. The ED (1997 A3 Jetta TDI), the JB (1998/99 A3 Jetta TDI), GQ (1996 B4/B4V) , and FA (1997 B4/B4V) ECU’s are all interchangeable by swapping the chips to the correct model and year.

I use a GQ ECU with FA chips in it to diagnose problems on a '97.

Swapping chips from stock to tuned.

I used to keep different chips around to diagnose issues with TDI's. I found a few errors that were from tuners not setting them up correctly.

The BK inside is an odd duck with its double boards compared to the others with a single board.

 

[volksguy]

Hello so what happens if some one plugs a 028906021FA in to the 1996 O28906021BK Harnesses? No Start ? Fried Harness ? Starts but has error Codes?? I have about 5 028906021GQ ECU 'S RossTeck Vagcom when hood up says there not OBD2 ? And i Have 1 or 2 028906021FA ECU'S And 5 Engine Factory Wiring Harness NOS. For The 028906021FA ECU Those Take the 180 glow plug relay and the Jumper relay

 

[Dave128]

Since you are discussing ECUs, I have a GQ in my 96 B4V with a 1Z. I found a lower mileage AHU that I would like to drop in. What problems should I expect using the GQ?

 

[CasaEd]

You can swap between the black case and silver case ECU's without wiring harness meltdowns, To use different chip's or to tune you need a socketed ECU. The G* onwards ECU's are better to use because you can use different firmware in them, I used JB firmware in a GM ECU, and it would also run the FA firmware too. I swapped a DK (SEAT) ECU into my partners 1z B4 with a MAFless map but that ECU will not accept later firmware, but it will run dual maps with the right modifications and the correct chips. Of course the ECU's over this side of the pond will need an IMMO delete.

 

[volksguy]

So explain what happens if some one plugs in a 028906021FA ECU Iin to a O28906021BK - 028906028GQ Harrness?
Nothing ?Wont Start? or ? Trouble Codes?
They Changed in Harness in 1997 To 3A971072HS To Go Along with the 180 GP Relay And Required Jumper Relay. There is storys of useing a 180 relay in our 1996 Harnesses smoking them.! If i am not misstaken. To add Vagcom dont show The GQ Or BK being OBD 2 When i plug in 6 different GQ all show same. SO The FA is OBD2??? So Some one please Answer What Happens When A FA ECU Is plugged in thank you.
.

 

[CasaEd]

Won't start if it has immo in the ECU, I've changed both mine and my partners B4 passat's (both 94 models) from black case to silver case with no issues, and I've not or heard that story of a 180 GP relay smoking the loom,

 

[volksguy]

So you Pluged in a 028906021FA ? And What happed is the Question That one is the Stock America 1997 Passat ECU With The Changed Wiring harness and Jumper Relay

 

[turbodieseldyke]

I don't think he had an FA, since he's in Europe.

 

[volksguy]

And The information about Using a 180 GP Relay in older cars Smoking Harnesses is from this TDI Club

 

[ToddA1]

And The information about Using a 180 GP Relay in older cars Smoking Harnesses is from this TDI Club

That’s not an ECU swap issue, that’s a GP relay swap issue.

-Todd

 

[volksguy]

Read Were CasaEd posted he never Heard of smoking a wire Harnesses .
So Why Still No Answer on What Happens if you Plug in a 028906021FA were a 02890602GQ was ?
No One Knows ???

 

[ToddA1]

Ummmmm…. I did read his comment. Maybe he’s never heard of the issue… ever think that’s a possibility even though it’s documented?

Why not plug your FA in and see? You can be the pioneer.

-Todd

 

[volksguy]

His comments are in this Thread Sir!

 

[volksguy]

And Thank You For Saying (YOU Dont Know) I Dont Know !!! Is Why I Asked In the First Place Maybe some one knows

 

[ToddA1]

His comments are in this Thread Sir!

I saw that…

And Thank You For Saying (YOU Dont Know) I Dont Know !!! Is Why I Asked In the First Place Maybe some one knows

I don’t need to say that. If I knew and wanted to post the answer, I would. I’m taking my knowledge to the grave and not sharing!!!

Keep harping on the subject. These cars get older by the second. The car numbers are diminishing. The ownership circle follows….

Someone will eventually reply….maybe. YOU need to keep this thread alive!!!

-Todd

 

[Lug_Nut]

To the original post: No. The 1997 B4 TDI ECU can not be swapped into a 1996 engine harness B4 TDI. The 1996 and 1997 US market B4 TDI use different engine harnesses with different pin-outs. 1997 chips to not activate correct circuit wires when connected to a 1996 harness, The glow plug relay circuit is just one difference.
The 1997 ECU can be made compatible by using chips that are compatible with the 1996 engine wiring harness. At that point the 1997 ECU becomes a 1996 ECU.

1996 B4 TDI: GQ chips only
1997 B4 TDI: FA chips only

 

[volksguy]

Yes correct older every Day Correct Sir So i am Buying up all Radiator Hoses. Got 12 of The Upper And Lower Ones.
4 oem New Clusters 2 Oem European ones 1 Even Shows Miles instead of K.
5 orm Engine Wireing Harnesses Mad

 

[CasaEd]

To the original post: No. The 1997 B4 TDI ECU can not be swapped into a 1996 engine harness B4 TDI. The 1996 and 1997 US market B4 TDI use different engine harnesses with different pin-outs. 1997 chips to not activate correct circuit wires when connected to a 1996 harness, The glow plug relay circuit is just one difference.
The 1997 ECU can be made compatible by using chips that are compatible with the 1996 engine wiring harness. At that point the 1997 ECU becomes a 1996 ECU.

1996 B4 TDI: GQ chips only
1997 B4 TDI: FA chips only

Interesting to read your post, but if the 97 passat use's a different pin-out to the 96 passat, how by just changing the chips to 96 spec chips doe's it make it compatible ? because the plcc32 chips are the same in each ecu, the difference is only in the software. Unfortunately I don't have an FA 68 pin ecu or software because I would try it in my 94 passat. I know JB works in a GM ecu because that's what I'm using now without issue's and obviously GM software works too.

 

[Lug_Nut]

The 1996 chips (BK and GQ) are expecting an input signal from the catalyst temperature sensor 1 through pin #10 of the 68 pins in the connector.
The 1997 chips (FA) do not use pin #10.
Similarly the 1996 chips are looking for an input from cat temp sensor 2 through pin #56 of 68. The 1997 chips do not.
The 1996 BK chips send an output through pin #27 (based on the inputs through #10 and #56). The 1996 GQ chips only monitor the circuit for presence through pin #27, but do not send any output. The 1997 chips do not use pin #27 at all.

And here's the glow plug issue:
The 1996 chips use ECU pin #30 for the quantity adjuster. The 1997 chips use pin #30 for the glow plug relay.

 

[Steve Addy]

Yes correct older every Day Correct Sir So i am Buying up all Radiator Hoses. Got 12 of The Upper And Lower Ones.
4 oem New Clusters 2 Oem European ones 1 Even Shows Miles instead of K.
5 orm Engine Wireing Harnesses Mad

I'm not following what this is about or has to do with the confusion about ecu interchange or engine interchange...but curious about what you've posted above?

Steve