With Manufacturer's Scan Tool

Signal From Brake Light Switch And Brake Pedal Switch, Checking

Special tools equipment
- V.A.G 1551 Scan Tool or vehicle system tester V.A.G 1552 with cable V.A.G 1551/3
- Test box V.A.G 1598/31
- Hand multimeter V.A.G 1526 or multimeter V.A.G 1715
- Adapter set V.A.G 1594
- Wiring diagram

Check conditions







- All fuses must be OK.
- Battery voltage must be at least 11.5 V.
- All electrical consumers, e.g. lights and rear window defroster must be switched off

Test sequence
- Connect V.A.G 1551 Scan Tool (V.A.G 1552). Switch ignition on and select engine control module with "Address word" 01. (Connecting scan tool and selecting engine control module. [1][2][3]Connecting VAG 1551 Scan Tool)

Indicated on display

Rapid data transfer HELP
Select function XX

- Press keys 0 and 8 for function "Read measured value block" and confirm entry with Q key.

Indicated on display

Read measured value block HELP
Input display group number XXX

- Press keys 0, 6 and 6 for "display group 66" and confirm with Q key.

Indicated on display

Read measured value block 66
1 2 3 4

Only engine code AWP
- Observe display in display zone 2: (1st and 2nd positions from right)
Specification: x x x x x x 0 0
- Depress brake pedal fully and observe display in display zone 2.
- Specification: x x x x x x 1 1

Only engine code AWW
- Observe display in display zone 2: (3rd and 4th positions from left).
Specification: x x 0 0
- Depress brake pedal fully and observe display in display zone 2.
Specification: x x 1 1

Continuation for all engines
- Press -> key.
- Press keys 0 and 6 for "End output" function and confirm input with Q key.
- Switch ignition off.

If the specification is not obtained:
- Remove shelf on driver's side:
- Disconnect connector from brake light/brake pedal switch.







- Connect multimeter to measure resistance between contacts 1 and 4.
Specification: Infinite Ohms (no continuity)
- Depress brake pedal.
Specification: approx. 0 Ohms
- Connect multimeter to measure resistance between contacts 2 and 3.
Specification: approx. 0 Ohms
- Depress brake pedal.
Specification: Infinite Ohms (no continuity)

If the specifications are not attained:
- Replace brake light/brake pedal switch.
- Check DTC memory, if necessary, repair any malfunctions and then erase DTC memory.
- Read readiness code. If DTC memory has been erased or engine control module was disconnected from permanent positive, readiness code must be generated again. Monitors, Trips, Drive Cycles and Readiness Codes

If the specifications are obtained:







- Connect multimeter to measure voltage between contact 1 and Ground.
Specification: at least 11.5 V
- Switch ignition on.
- Connect multimeter to measure voltage between contact 2 and Ground.
Specification: at least 11.5 V

If the specifications are not obtained:
- Check wire between 4-pin connector contact 1 and main fuse/contact 2 and central electrics using wiring diagram.

If the specification is obtained:







- Connect test box V.A.G 1598/31 to control module wiring harness. Engine control module remains disconnected.







- Check wiring for open circuit between test box and 4-pin connector using wiring diagram.
Contact 3 + socket 55
Contact 4 + socket 56
Wire resistance: Max. 1.5 Ohms

- Check wires for short to one another.
- Check wiring for short to battery positive or Ground.

If no malfunction is detected in the wiring:
- Replace engine control module.