Operation CHARM: Car repair manuals for everyone.

With Manufacturer's Scan Tool




Vehicle speed signal, checking

Special tools, workshop equipment, testers, measuring instruments and auxiliary items required
- VAG 1551/1552 Scan Tool using VAG 1551/3 Adaptor cable
- VAG 1598/22 Test Box
- Fluke 83 multimeter
- VW 1594 Adaptor kit
- Wiring diagram

Requirements
- Battery Voltage must be 11.5 Volts minimum.
- Speedometer must be OK

Test sequence
- Connect VAG 1551/1552 Scan Tool. Refer to "Scan Tool Testing/Scan Tool Connecting and Initial Checks", Testing and Inspection
- Start engine and let idle
- Press 0 and 1 buttons to select "Engine Electronics" address word 01.

Indicated on display (example only)


06A906018AB Motronic M5.9.2 HS V06 ->
Coding 00000 WSC 00000



- Press -> button.

Indicated on display


Rapid data transfer HELP
Select function XX



- Press 0 and 8 buttons to select "Read Measuring Value Block" function 08.
- Press Q button to enter input.

Indicated on display


Read measuring value block
Input Display group number XXX



- Press 0, 0 and 5 buttons to select "Display group 5."
- Press Q button to enter input.

Indicated on display (1 to 4 = Display fields)


Read measuring value block 5 ->
1 2 3 4



- Take test drive with 2nd technician to observe display.
Observe the appropriate safety precautions during road test.

- Observe value in Display field 3
- Specification: approx. driven speed shown on speedometer







If specification obtained
- Press -> button.
- Press 0, 6 and 0 buttons to select "Display group 60"
- Press Q button to enter input.
- Switch OFF ignition.

If no speed is indicated or the display values reduce when driving slowly:







- Connect VAG 1598/22 Test Box to Control Module wiring harness.
- Switch Fluke 83 multimeter to Voltage range
- Connect multimeter between Test Box sockets 2 + 20.
- Switch ON ignition.
- Lift vehicle at front left.
- Rotate front wheel and observe Voltage display.
- Specification: between 0 and 4 Volts minimum (fluctuating)

If display does not fluctuate
- Check wiring to speedometer/speedometer sensor.