Speed Signal, Checking

Speed Signal, Checking

Recommended special tools and equipment
- VA.G 1526 multimeter or V.A.G 1715 multimeter
- V.A.G 1594 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.

Function test

NOTE: To check the speed signal, vehicle must be driven at a speed above 5 km/h.

Observe the safety precautions that apply to road tests.
- Connect diagnostic tester. Diagnostic Tester, Connecting
- Start engine and let run at idle.
- Under address word 33, select "Diagnostic mode 1: Check measured values."
- Select the measuring value "PID 13: Vehicle speed".
- Perform a road test at a speed above 5 km/h while a 2nd person observes the indication on the display.
- Check specified value of the vehicle speed:







NOTE: Vehicle speed must not drop to below 5 km/h during test.

- End diagnosis and switch ignition off.

If no speed is indicated:
- Check wires to control module according to wiring diagram.

Check wires to control module
- Connect test box to control module wiring harness. connect test box for wiring test. Test Box, Connecting For Wiring Test
- Remove instrument cluster.
- Check wire connection from Motronic Engine Control Module (ECM) -J220- 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