With Generic Scan Tool

Checking Speed Signal

Recommended special tools and equipment
- VAG1526 multimeter or VAG1715 multimeter
- VAG1594 connector test kit
- Wiring diagram

Test requirements







- The respective fuses of Motronic Engine Control Module (ECM) -J220- must be OK:
- Battery voltage must be at least 11.5 volts.
- Speedometer -G21- must be OK.

Test sequence

NOTE: To test speed signal, vehicle must be driven. Doing this requires a second person.

WARNING: Secure Scan Tool (ST) on the rear seat and have operated from there by second technician.

- Connect diagnostic tester.
Diagnostic Tester, Connecting

- Start engine and let run at idle.
- Under address word 33, select "Diagnostic mode 1: Checking measured values."
- Select the measuring value "PID 13: Vehicle speed".
- Perform a road test, and have the 2nd person observe the indication on the display.
- Check specified value of the vehicle speed:







- End diagnosis and switch ignition off.

If no speed is indicated:
- Connect test box to control module wiring harness, connect test box for wiring test.
Test Box, Connecting For Wiring Test

- To measure voltage, connect multimeter between sockets 2 (Ground -GND-) +54 (speed signal) of test box.
- Raise vehicle at front left.
- Switch ignition on.
- Rotate front wheel, and observe voltage indicated while doing so.
Specified value: 0.0 to at least 4.0 V, fluctuating

NOTE: The right front wheel must not turn during this, hold it steady if necessary.

If indicated voltage does not oscillate:
- Remove instrument cluster:
- Check wire connection from Engine Control Module (ECM) to Speedometer -G21- according to wiring diagram.
- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data.
Diagnostic Mode 4: Reset/Erase Diagnostic Data

- Generate readiness code.
Monitors, Trips, Drive Cycles and Readiness Codes