A3 Mk1
| Electrical/electronic components and fitting locations |
Note| t | Not included in illustration: traction control system warning lamp -K86- (only for vehicles with TCS). |
| t | Fitting location: in instrument cluster |
| t | Function → Chapter |
| 1 - | Brake master cylinder and brake servo |
| 2 - | Hydraulic control unit |
| q | The hydraulic control unit comprises the ABS hydraulic pump -V64- and the ABS with EDL control unit -J104-. |
| q | Fitting location: in engine compartment (left-side) |
| q | Checked by self-diagnosis |
| q | Only unplug 25-pin connector when the ignition is switched off |
| q | Assignment of 25-pin connector → Anchor |
| q | Removing and installing → Brake system; Rep. Gr.45 |
| q | Perform coding of ABS with EDL control unit -J104- after renewal → Chapter |
| 3 - | Diagnostic connection |
| q | Fitting location up to model year 1999: In centre console |
| q | Fitting location from model year 2000 onwards: In footwell (front left), next to bonnet release lever |
| 4 - | Cover for diagnostic connection |
| 5 - | “Brake warning” symbol |
| q | Lights up in instrument cluster or in display of driver information system |
| q | Function → Chapter |
| 6 - | ABS warning lamp -K47- |
| q | Fitting location: In instrument cluster |
| q | Function → Chapter |
| 7 - | Speed sensor and speed sensor rotor (rear left and rear right) |
| q | Rear left speed sensor -G46- and rear right speed sensor -G44- |
| q | Removing and installing speed sensor, fitting speed sensor wires → Brake system; Rep. Gr.45 |
| q | Checking speed sensor rotor → Brake system; Rep. Gr.45 |
| q | Speed sensor rotor is welded to wheel hub; removing and installing wheel hub → Running gear, front-wheel drive and four-wheel drive; Rep. Gr.42 |
| 8 - | Brake light switch -F- |
| q | Can be checked via reading measured value block → Anchor |
| q | Removing and installing → Brake system; Rep. Gr.45 |
| 9 - | Front left and front right speed sensor and speed sensor rotor |
| q | Front left speed sensor -G47- and front right speed sensor -G45- |
| q | Removing and installing speed sensor, fitting speed sensor wires → Brake system; Rep. Gr.45 |
| q | Checking speed sensor rotor → Brake system; Rep. Gr.45 |
| q | Speed sensor rotor is welded to wheel hub; removing and installing wheel hub → Running gear, front-wheel drive and four-wheel drive; Rep. Gr.40 |
| 10 - | Longitudinal acceleration sender -G251- |
| q | Four-wheel drive vehicles only |
| q | Fitting location: on A-pillar (passenger side) |
| q | Can be checked via reading measured value block → Anchor |
| q | Refer to → Brake system; Rep. Gr.45 for removing and installing, then perform zero compensation in basic setting → Chapter |
