ASR error message on A4 AFB

Hello everyone,

My A4 TDI with the AFB engine is probably showing an error.


1. A beeping sound, followed by the ASR light and the middle red light flashing. Lamp?



What is he trying to tell me?


Regards,
Sepp.

Reading error codes...

harj wrote:

Hello everyone. My A4 TDI with the AFB engine is probably showing an error. 1. A beeping sound, followed by the ASR light and the middle red light flashing. Lamp? What is he trying to tell me? Regards, Sepp

Does this happen when the vehicle is stationary, or when you start moving?

Were the brakes worked on?

"The red light doesn't tell me anything. Perhaps you could check the operating manual beforehand, or tell me what kind of light it is." Then perhaps some information about other aspects (starting behavior/braking behavior/power loss).

In my case, the ASR (Anti-Slip Regulation) or ESP (Electronic Stability Program) light illuminated and beeped when the MAF sensor (Mass Air Flow sensor) was not connected. Something like a "missing load signal" was present in the ABS control unit.

There definitely needs to be something stored in memory. So, all that's left is to guess.

When working on the brakes, this error would likely have been caused by a faulty sensor (or a disconnected connector). It was dirty on my car after working on the brakes, which caused the ABS to activate at low speeds, but without displaying any error messages.

Hello everyone...


I finally managed to borrow a laptop and read the error codes.

Does the message indicate a CAN bus signal error?


Regards,
Sepp.


Thank you very much for your previous suggestions!!!

EDIT MODE: One image is enough .
EDIT MOD2: Now both images are gone.
@MOD: Thanks for the well-intentioned correction!

Yes, he does.

You will encounter a physical problem with the CAN bus related to the ASR control unit.

A broken cable or a loose connection, which is why there's no massage function on the bus.

Okay, let's physically check the CAN bus.

Best regards, Jochen.

Where is the ESP control unit located? Is it possibly integrated into the engine control unit?


Are there any wiring diagrams available for it?

The ABS control unit is likely located directly on the ABS module on the left front side of the engine compartment.


I hope you can provide me with more details.

Regards,

Sepp.

Hello everyone,


Yesterday, I checked the CAN bus lines from the ABS control unit to the engine control unit for continuity, but I couldn't find any breaks.

The cable is routed in the engine compartment. How precisely is it connected to the engine control unit?


Could the error message have other causes? For example, lack of care?

This morning, the ABS system failed during an emergency braking situation. A brief error message appeared while braking, and the ASR light illuminated dimly for a period.


Regards,

Sepp.

Yesterday, I checked the CAN bus lines from the ABS control unit to the engine control unit for continuity, but I couldn't find any breaks.


How did you measure it?

CAN-L connected through, and CAN-H connected through?

If you are working on the AI system, you can check the entire drive CAN by performing a resistance measurement between CAN-L and CAN-H with the ignition turned off }.
You should measure 60 ohms here.
It's important to do this with the MSG connected, as the star point resistor is located within the MSG.

Does the error occur sporadically or permanently? If it's happening sporadically, I still suspect a bad connection.

Best regards, Jochen.

Hello Jochen,

I disconnected the STG (Steuergerät - control unit) connectors and checked the wiring for continuity, and also wiggled the cables.

Sorry for the silly question, where is the Kİ located, or where are the cables accessible?

The error is intermittent, and it seems to be better after my weekend troubleshooting.
I sprayed the contacts with K60, but I couldn't detect any contamination.

Regards,

Sepp.



Yesterday, I checked the CAN bus lines from the ABS control unit to the engine control unit for continuity, but I couldn't find any breaks.


How did you measure it?

CAN-L connected through, and CAN-H connected through?

If you are working on the AI system, you can check the entire drive CAN by performing a resistance measurement between CAN-L and CAN-H with the ignition turned off }.
You should measure 60 ohms here.
It's important to do this with the MSG connected, as the star point resistor is located within the MSG.

Does the error occur sporadically or permanently? If it's happening sporadically, I still suspect a bad connection.

Hi Jochen

KI stands for Kombiinstrument, which is the instrument cluster containing the speedometer, tachometer, and the illuminated warning lights. Behind it are connectors, the pin assignments of which can certainly be found in wiring diagrams. Unfortunately, I can't tell you how easy (or difficult) the disassembly process is in an A4.

Since I'm also having a problem with ABS/ESP/ASR (on my A4), I wanted to ask if anyone could tell me where I can find the ESP control unit. ABS/ASR is the component on the hydroelectric generator, but where is the ESP control unit located?

Thank you very much.

Front passenger footwell, under the carpet.

Hello everyone.


Just today, I was trying to troubleshoot my ABS problem by disconnecting the connector at the control unit and wiggling it while the ignition was on, hoping to trigger a fault code. javascript:emoticon('')
Embarrassed.

And then, a clicking sound from the control unit, and the error message beeping in the vehicle...


I haven't been able to pinpoint the exact cause of the error yet, whether it's the connector, the cable, or the connection to the circuit board...


Can the circuit board be removed without removing the control unit?
Has such an error occurred before?




Regards,

Sepp.

I've experienced something similar before... but I ended up installing a new unit.

Hello everyone.


Since some providers offer ABS control unit repairs (around €200) for units with communication errors, and as an electronics technician, I thought it was worth a try.

Okay, I've removed the ABS control unit and tried to repair it, but unfortunately, the essential part seems to be well-encapsulated within the housing, so I've reinstalled the unit.

There probably won't be an alternative to a new electronic component...javascript:emoticon('')
Crying or Very sad: 500€ (unless you know where to apply the Proxxon tool...).


Here are a few more pictures...

Best regards.

Sepp.