Cruise Control Installation Problems (Solution)

Hello TDI enthusiasts,

I'm having trouble installing a cruise control system in my 1997 A4 AFN.
Today, I removed the steering column switch again and checked the wiring leading to the control unit.
It is clear that all the pins are connected to the correct terminals on the control unit, or to the ignition power supply.
'However, it's still not working. As soon as I turn on the cruise control, I get this error.'

00671 - cruise control switch
25-10 unknown switch condition - intermittent.

I checked group 6 (everything was in order).

Cruise control disabled: 000000, cruise control present = 0.0

Cruise control enabled: 001011, cruise control present = 1.0.

'Fix': 001111

'+' : 001011, so there's no effect from the shifter?!

Brake: 011011

Clutch: 101011


Could it be that the steering column switch doesn't match my wiring diagram (from 'How it's done'), or that the steering column switch isn't compatible with the vehicle, or...?

Does anyone have any ideas? It would also be great if someone could read out the data for group 6 from their own device!

Thank you in advance.

Regards,
Thomas.

Hi there,

Based on the error message, I believe you may have wired the switch incorrectly.

If the device is already the newer version, it might still require a "security signal" on pin 58. You can simply connect this to pin 66; that's what I did because my switch doesn't have the extra contact (VW bus T3), and it works perfectly.

greetings
dieter

Hello Dieter,

You're right, it does sound like the switch might be wired incorrectly. That's why I completely disassembled everything and measured each wire from the labeled pin on the switch to the engine control unit. It seems to be wired correctly. The safety circuit via pin 58 sounds interesting. Are you referring to the pins on the engine control unit?

Regards,
TWM

Hello,

It seems I'm experiencing the same problem (Passat 35i AFN, manufactured in 10/96).
I've really tried everything, from checking the cables to replacing the switch, but the cruise control still doesn't work. The only thing I've noticed is that the control unit shows 6 pins, while the installation manual says there should only be 5. This somehow supports the theory that it's a newer control unit! In any case, I'm also very interested in finding a solution to this problem.

Best regards,

Albrecht.

Hello everyone,

I looked at the wiring diagram, but pin 58 doesn't exist there. Pin 66 is the output from the control unit to the flow meter in my setup. Could it really be that pin 58 needs the signal from the flow meter? I'm not sure if I should connect those pins.
@dieter: Can you confirm that you connected pin 58 to the quantity setting device?

@albrecht:
'I also have five wires, because pins 4 and 6 of the steering column switch are connected. Four go to the control unit, and one goes to the ignition positive terminal (specifically, terminal 86). By the way, I also suspected that simplifying the connection by taking the ignition positive from terminal 15 would cause some unwanted side effects. I've now connected it to terminal 86 (directly at the brake light switch), but still without success.'

Regards,
TWM

Hi there,

Okay, hopefully we're talking about the same thing. I mean the AFN with the MSA15 control unit and the 68-pin connector. In that case, pin 66 definitely does not go to the quantity control unit.
I have here two wiring diagrams for the A4 and Passat, model year 1997. In both diagrams, pin 58 on the switch is connected.
Please get the correct wiring diagram, for example, here: http://volkswagen.msk.ru/

greetings
dieter

Hello Dieter,

Apparently, I have a different control unit. Mine has significantly more than 68 pins, at least 80. I have a wiring diagram for the 35i with the AFN engine, and it also shows the control unit with 68 pins, and pin 66 also connects to the GRA (glow relay) and provides ignition power.

It would be quite a coincidence if, in my case as well, pin 58 were also the one that needs to be connected to a positive or negative potential. However, the tip about finding circuit diagrams from Eastern Europe is not bad. Maybe it will help me.

Thank you and greetings.
TWM

I just downloaded the wiring diagram (Passat B4 97, page 7, Cruise Control).
Just like with my car, 4 wires run from the switch. One goes to the positive terminal (+), and the other 3 go to the control unit (pins 66, 34, and 35). They have been checked and are in good condition.

@Dieter

I can't find pin 58 on the schematic, and I'm supposed to connect it to pin 66?

Best regards,
Albrecht.

'I had the same problem. In my case, the wiring diagram was incorrect, even though it should definitely have been the right one for my A4 2.5. Apparently, there are many different versions. My mechanic initially thought that someone had tampered with my wiring harness because some of the colors didn't match. It was only after an inquiry to the factory that we discovered the wiring diagram was wrong. Be careful, you could damage a lot of things!'

Hello Albrecht,
I did some digging and found the following:
E45: Switch for GRA.
Position 0 = OFF, locked.
Position 1 = Pressed to OFF.
Position 2 = ON.
Position 3 = RES.

Best regards, Rudi.

Sure, here is the translation of the text from German to English:

'Addendum:'

Applies to AHU and AFN models starting from October 1996.


Best regards, Rudi.

Hello Rudi,

Your wiring diagram doesn't match my car. As I said, mine only has 4 connections/wires on the switch, as shown in the link from the Russian website above. Although it says "year 97" there, it refers to the B4 model. Your wiring diagram is for the 3B or B5 models (strange designations, it's easy to get confused). Mine is a 35 i AFN (which is a B4 model), and I don't think it was available as a 1997 model. Perhaps the Russians made a mistake, but the wiring diagram itself seems correct. I found the idea about a newer ECU version interesting because:

- My car must be one of the last 35i models.
- The pins that are read out using the 1551 device (switch positions, brake, clutch) are one too many (6 instead of 5) according to the installation instructions included with the cruise control kit.

According to the instructions for the ALE, it should be like this, but isn't this a newer model?

Therefore, I'll ask again: Can anyone (besides Dieter) plausibly explain or confirm the connection between the story involving contact numbers 58 and 66?


Best regards,
Albrecht.

Hello everyone, again.

Okay, let's say I have an old switch without the cable for contact 58, but I have a newer control unit that requires this contact (for whatever reason).
Then, considering Rudi's circuit diagram, Dieter's explanation seems quite plausible! Because in positions 2 and 3, a (safety) signal is present at pin 58.
It also triggers the "66" error when the cruise control is activated (with the older switch).
Am I understanding this correctly? I think I'll try a test run this weekend.

Best regards,
Albrecht.

Hello Albrecht,
I found another Passat from 1997 .
Is this one with a different pin assignment?

Best regards, Rudi.

@ Rainer: Please delete it if it could potentially be legally problematic.

Hello Albrecht,

If I understand correctly, you have a list of the 6 bits and their corresponding assignments to the switching functions. That's exactly what I need, because my control unit apparently has one extra line. I would be very grateful if you could provide me with that information.

Regards,
Thomas.

Hello,

@Thomas

The list is basically the installation manual for the cruise control system. However, I don't have the pinout information memorized. I'll check it out tomorrow, but I think it's likely as you described initially. For your car, the wiring diagram that Rudi initially provided should be the correct one.

@Rudi

The second wiring diagram (theoretically) matches my car. As I said, tomorrow I will check my control unit to see if I have contact 58. If I do, I will connect 66 and 58. If not, then it's irrelevant anyway, and the GRA will continue not to work .


I will report!

Best regards,
Albrecht.