With Manufacturer's Scan Tool

Vehicle Speed Signal, Checking

Special tools and equipment
- VAG1551 Scan Tool (ST) or VAG1552 mobile scan tool with VAG1551/3 adapter cable
- VAG1598/31 test box
- Multimeter (Fluke 83 or equivalent)
- VW1594 adapter set
- Wiring diagram

Check conditions







- Fuses 5, 10 and 29 OK
- Battery voltage at least 11.5 V
- Speedometer OK

Test sequence


NOTE: To check the speed signal the vehicle must be driven. To do this a second person is necessary.


WARNING!
Secure scan tool to rear seat and operate from this position.


- Connect VAG1551 (VAG1552) Scan Tool (ST).
- Switch ignition on and press buttons -0- and -1- to insert "Engine Electronics" address word 01.

Indicated on display


Rapid data transfer HELP
Select function XX


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

Indicated on display


Read Measuring Value Block
Input display group number XXX


- Press buttons -0-, -0- and -5- to input display group number 5 (005) and press -Q- button to confirm input.

Indicated on display: (1-4 = display fields)


Read Measuring Value Block 5 ->
1 2 3 4


- Carry out road test with 2nd person to observe display.
Observe safety precautions when carrying out road test. Refer under "Fuel Delivery and Air Induction", Service Precautions
- Observe figure displayed in display field 3:
Specified value: approx. driven speed

Display Group 005:

- Press -> button.
- Press buttons -0- and -6- to select "End Output" function 06 and press -Q- button to confirm input.
- Switch ignition off.

Continuation
If no speed is displayed:
- Remove wiper arms and plenum chamber cover.







- Connect VAG1598/31 test box to Engine Control Module (ECM) wiring harness. Engine Control Module (ECM) is not connected by this action.
- Connect multimeter to measure voltage between test box sockets -2- + -54-.
- Switch ignition on.
- Lift vehicle at left-front.
- Rotate front wheel and observe voltage display.
Specified value: between 0 and at least 4 Volts, fluctuating.


NOTE: If necessary, hold the right-front wheel to prevent it from turning.


If the display does not fluctuate:
- Check wiring to speedometer/speedometer sensor.
- Check DTC memory.
- Display readiness code.

If DTC memory has been erased or the Engine Control Module (ECM) was disconnected from permanent battery (B+) voltage, the readiness code must be generated again.