AWD Red Warning - Code 00526

[Pistou]

Hello,

I have a frightening warning on the LCD:


AWD is said non functionnal and after using VCDS, I get the code 00526 (brake switch already replaced, still the same code) in 22 - AWD.
Does this warning come from the colorMFA and/or is associated to something else ?


Thanks a lot

[autopilot]

Do you still have a diagnostic error? Did you clear it using the VCDS or the ColorMFA?

If you have diagnostic errors in the all-wheel drive control unit, it's understandable why the ColorMFA is displaying a malfunction message.
The ColorMFA itself doesn't display any messages. Only if there's a malfunction come from CAN bus or connected ColorMFA wires.

[Pistou]

Thanks Autopilot !

I have used both tools to erase and there is nothing in ABS, only in AWD. it may be a speed sensor on 1 of the wheels ? VCDS can measure it ?

PS: so far if I do remember I got this brake light issue since years but never seen this logo on ColorMFA, could this be triggered without getting a specific code but a flag on the canbus ?

[autopilot]

I have used both tools to erase and there is nothing in ABS, only in AWD. it may be a speed sensor on 1 of the wheels ? VCDS can measure it ?

00526 is a "Brake Light Switch-F" error. Not speed sensor error.
Wire from brake light switch F is also directly connected to AWD control unit. May be problem in wires or AWD control unit connector.

so far if I do remember I got this brake light issue since years but never seen this logo on ColorMFA, could this be triggered without getting a specific code but a flag on the canbus ?

ColorMFA does not check diagnostics for display messages about any problems. Used only CAN-bus flags or wires what directly connected to ColorMFA.
Haldex-related errors have been added to the b44 firmware. In earlier firmware versions, the ColorMFA does not display Haldex-related errors.
Although the brake light switch error was present a long time ago, it may not have affected the Haldex's operation or was intermittent. Now it's permanent and affects the Haldex's operation. Therefore, a fault signal appeared on the CAN bus and you received an error message.

[Pistou]

Oh this is why I did not see previously the error... Thx! and I may have lost the AWD years ago without noticing !

I cleaned the rear connector to the haldex; perhaps it's coming from the wires... I'd need an oscilloscope to trig both signals in the brake switch.

Btw I have no warning on the dashboard hence AWD may be functional, I will check the advance measurements of the AWD.

[autopilot]

Oh this is why I did not see previously the error... Thx! and I may have lost the AWD years ago without noticing !

In ColorMFA, this is an additional warning. This warning is absent from the original cluster.