"Mysteries" of the C4 CEL/ Air Bag/Seat Belt warning light panel

[UrS4boy]

None of the 2.2T's had it. I don't know on what and whether it was used at all. Easiest to do on diesel as can reduce fuel injection. On gasoline without a DBW throttle, all you can do is cut fuel sequentially, but it is very rough.

I understood that it was more or less the same as EDL, i.e. use the ABS system to brake the spinning wheel with no traction, not an engine disabling system.

[prj]

I understood that it was more or less the same as EDL, i.e. use the ABS system to brake the spinning wheel with no traction, not an engine disabling system.

No, EDL and ASR are very different things, and ASR always works by reducing torque from the engine.

[A1QSHIP]

ASR is not EDL. ASR is traction control.

ELD, Electronic Differential Lock is an early form of ASR, Automatic Slip Regulation.
"ELD is incorporated in the Bosch 5 ABS (introduced for the MY1996) control unit.
-ELD acts upon all four wheels on a quattro equipped automobile.
-ELD operates up to 40kmh(25mph)."
This is from the factory C4 shop manual. In the electrical wiring part of the wiring schematic there is at least one wire that connects the ABS module to the Engine control module. Maybe to signal timing retardation? That would also act to reduce power output to the wheels.

ABS/ASR has become more sophisticated as electronic throttle, steering angle sensors, body acceleration sensors, suspension travel sensors, front & rear radar sensors, Controller Area Networking, CAN, have been incorporated into automobiles.

HTH, Chris

[prj]

ELD, Electronic Differential Lock is an early form of ASR, Automatic Slip Regulation.
"ELD is incorporated in the Bosch 5 ABS (introduced for the MY1996) control unit.
-ELD acts upon all four wheels on a quattro equipped automobile.
-ELD operates up to 40kmh(25mph)."
This is from the factory C4 shop manual.

The manual is wrong. EDL and ASR have absolutely nothing to do with each other, apart from the fact that both use wheel speed sensors.

In the electrical wiring part of the wiring schematic there is at least one wire that connects the ABS module to the Engine control module. Maybe to signal timing retardation? That would also act to reduce power output to the wheels.

It does not only retard or cut timing as that would blow up the cats very quickly on prolonged use. What it does is sequentially blends out the mixture from different cylinders, uses the semi-electronic throttle on the M5.92 ECU on said unit and so on.

[Zoig]

Dave, Here is the picture of the aux warning lights on my UrS4 gauges, unknown year and not sure if V8 or 2.2T. I'd really like to know what the steering wheel sign was supposed to show. Also the "ASR aus" is on the aux part but on my UrS6 the ASR warning is on the main cluster. Unfortunately the main strip for the warning lights was removed before i got that cluster.

If you need this pic in better quatlity let me know, the mobile camera in these conditions was just nearly useless.

[UrS4boy]

Dave, Here is the picture of the aux warning lights on my UrS4 gauges, unknown year and not sure if V8 or 2.2T. I'd really like to know what the steering wheel sign was supposed to show. Also the "ASR aus" is on the aux part but on my UrS6 the ASR warning is on the main cluster. Unfortunately the main strip for the warning lights was removed before i got that cluster..

Hmm...not seen that before. I will have to see what info I might have on that.

[UrS4boy]

Added this wiring info to the original post: