Revised B4 MFA conversion article

[TDIL3dad]

* Update --- Derek just notified me that he completed my TDI cluster conversion to MFA functionalities, so I should have it in hand soon.
Also, I already have the oil sensor, and I recently bought the below complete harness and stalk from Germany.

* My question --- are there any issues I should watch for in using US cluster and harness plus stalk from German spec B4?

What other parts or wiring or harnesses are needed?
Is this a plug & play installation??

 

[RIP TDI]

Looks complete. Sometimes the ambient temp sensor connector in the interior harness is missing. Not a big deal; the wires are there, but no connector for some reason.

Not an MFA issue, but if you have an early '96 with both oil pressure sensors located in the oil filter adapter, you could take this opportunity to update to the later style, where the blue-bodied sensor is installed in the back of the head and the turbo feed line runs from the filter adapter instead of the back of the head.

 

[TDIL3dad]

Is the cruise control stalk different between VR6 and TDI?

This one appears to be TDI specific:

http://www.ebay.com/itm/281647890634?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT

 

[RIP TDI]

The stalk switch should be the same as VR6, wiring harness is probably different. You should be using your original harness for this anyway.

 

[TDIL3dad]

Today installation was completed on the B4V project of the
MFA cluster with correct cables and sensors and all functions work properly.

Speedeometer at highway speed was within 1-2 miles of GPS.

A public THANK YOU to Derek of Chubbs Auto for his work converting the GLX cluster to TDI configuration, and for Chris Bell who patiently answered my many questions.

Still to do -- sort out non-working cruise control.

 

[G60ING]

You just need to plug the speed sensor, ECU and instrument cluster into the same junction box. They should all have blue single wire plugs with a blue wire with a white stripe iirc.

 

[lisab4]

Just shipped mine off to Derek for conversion

 

[TDIL3dad]

Just completed installation of another Derek modified instrument cluster, this time in my black 96 B4 daily driver.

Driving during daylight hours, one does not notice anything not working.
All the gauges, the speedometer, and the tachometer worked properly.

This evening, drove after dark and noticed that the instrument cluster lights did not work. No lighting for dials, or any of the indicator lights that line the lower edge of the cluster.

Both digital display screens light up and work properly.
The left and right turn indicator lights on the cluster work and flash correctly.

What did I miss?

 

[Digital Corpus]

I've not finished going over these PCBs, but the warning and check engine lights are controlled via a two small clusters of resistors. There is a bit of circuitry between them and their pins. There are also 2 ways to access the 8-pin flash chip and one is removing all LEDs and a injection molded plastic lattice to get to it without some passcode. It's possible the LEDs were soldered back onto the PCB backwards and this would present the same way you described.

 

[RIP TDI]

The 3 2W bayonet bulbs in the top back of the cluster housing produce the frontlighting for the gauges and warning lights.

 

[Steve Addy]

Is the cruise control stalk different between VR6 and TDI?

This one appears to be TDI specific:

http://www.ebay.com/itm/281647890634?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

The stalks should not be specific, in fact the turn sig stalk has a 1H part number which suggests it started usage with Mk3 cars in 1993 (in US).

The wiper stalk (w/o MFA) also has a 1H part number but the MFA function stalk has a 53 part number so that probably came from Corrado, most probably from the Corrado VR6.

At any rate these stalks are shared across a lot of different models. Since no 4 cylinder Mk3 cars in the US got MFA you're not going to find a good one there but the VR6 GLX cars did often get MFA (if not standard) so they're available there too.

Steve

 

[TDIL3dad]

The 3 2W bayonet bulbs in the top back of the cluster housing produce the frontlighting for the gauges and warning lights.

Replaced the two bulbs and bases with new OEM items from local VW dealer and still no lights.

I suspect the problem is caused by my re-using the the TDI wiring harness.
What wires have to be moved to what connectors to get power to the two bulbs and make the back lighting work?

 

[RIP TDI]

Replaced the two bulbs and bases with new OEM items from local VW dealer and still no lights.
I suspect the problem is caused by my re-using the the TDI wiring harness.
What wires have to be moved to what connectors to get power to the two bulbs and make the back lighting work?

You replaced 3 bulbs, not 2, right?

The original TDI cluster harness is fully compatible with the GLX cluster. That is not the issue. If your original cluster lighting worked, so will this one. Swap the original back in to check.

Its not that difficult to trace the lighting circuit on the cluster PCB.

 

[TDIL3dad]

Yes of course 3 bulbs but still "no go".

I have 12 volts entering the cluster on the terminal 58 circuit, t28 pin 12, when the lights are switched on but no voltage on either of the metal strips that connect to the 3 back lighting bulbs on the outside of the cluster, both show ground. When the high beams are switched on I get 12 volts on BOTH metal strips for the back lighting on the outside of the cluster, but no lights illuminate.

If I manually apply power to EITHER of the metal strips for the back lighting bulbs they do not light but the high beam indicator bulb does light up. This leads me to believe there is a short between the back lighting circuit and the high beam indicator circuit somewhere on the board. Both functions work correctly with another cluster installed.

 

[Digital Corpus]

Solder bridge somewhere and man that'll be a fun one to track down. There are 3 places I'd check the front/back of the board. When oriented as if you were driving and it were your cluster, the top right, the resistors & caps on the left 28-pin terminal, and the top left.

 

[TDIL3dad]

Ended up sending back to Derek and he corrected and sent back.
Both my daily driver black B4 and blue B4V project have MFA clusters by Derek and both work flawlessly with all functions.

Again, a public THANK YOU to Derek for flawless service.

 

[martiis]

if some one still insetting got full set, send pm

 

[ChubsAuto]

Adding this to the sticky thread so it wont get lost. Here is a link to a TDI non MFA cluster dump, I have highlighted what I remember and put an explanation with them. In the event I find my info I will update you guys, Hopefully a member will take over where I left off and keep these cars supported for years to come!
https://docs.google.com/document/d/1FNHHTHhgjE9wyXlWVT404OeE39uEqc6c-PqhrxIVOtc/edit?usp=sharing


A list of tools I use for cluster repair as well
https://docs.google.com/document/d/1VnL9hvWN-G6BU-DNYaSuuiwm5K_QJUVc-kq4IMpdF-k/edit?usp=sharing[/QUOTE]

 

[lisab4]

Anyone know what type these (marked 162) are and where I can buy them?

 

[Windex]

Those are surface mount resistors - newegg or digikey would have them. Why do you think they are faulty?

 

[roadrunner89]

Hi Guys,

taking Derek's great work as a starting point, I've further investigated the cluster's eeprom, because the cluster type has also been used in the VW Eurovan in Germany from 96-98


My findings are documented on the German Eurovan-Wiki

I'll try giving a short translation of the most important facts

eeprom overview:

Start End Description
0x00 0x1F Mileage
0xC8 0xC8 Tach transmission ratio for diesel engines without ECU
0xC9 0xC9 Numbber of clinders for tach for engines with ECU
0xD8 0xD8 End value of Speedo-Gauge
0xD9 0xD9 End value of Tach-Gauge
0xDB 0xDB Variant
0xDC 0xDD K-Value



Note: Values, which are stored in more than one byte need to be flipped before being converted to the decimal system
Example: ABCD becomes CDAB

Tach transmission ratio for diesel engines without ECU
If the tach signal is taken from the generator, this value describes the the frequency of the signal which leads to a tach read of 1000rpm

Numbber of clinders for tach for engines with ECU
Contains the number of cylinders, if the tach signal is taken from the ECU

End-values of gauges
Contains the end values of the gauges
50 for example stands for 5000rpm end value
16 for example stands for 160mph end value

Variant
Value Description
0x01 Passat with digital clock
0x02 Passat with MFA
0x08 Eurovan with analog clock
0x09 Eurovan with digital clock
0x0A Eurovan with MFA

K-Value
Contains the K-Value which can be adapted for different tire dimensions


The article will be added with information, if there are any news

If you have any suggestions or questions, please contact me


Best regards from the north of Germany

Alex

 

[lisab4]

Hi Alex, Do you repair faulty clusters?

 

[roadrunner89]

Hi Lisa,
what's wrong with your cluster?

Please write me a message


Best regards from snowy northern Germany

Alex

 

[lisab4]

Alex, PM sent

 

[lisab4]

I sent my cluster to Alex (riese). He found the problem and very quickly fixed it. Now I finally have a working MFA! I can definitely recommend Alex and the great work he has done! Thanks!

 

[roadrunner89]

Hi,
the Problem was quite easy to find.
Next to pin 20 of the black connector a 1,6 kiloohms pullup resistior was missing.

This resistor is responsible for keeping the LED off, thus it's driven to ground by the ECU to activate it.
On the other hand, the ECU can recognize by the resistor, if a cluster is connected.

Thanks to @lisab4 for the trust

Best regards

Alex