Speed Signal, Checking

Speed signal, checking

Recommended special tools and equipment
- V.A.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.

Test sequence

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

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

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






- End diagnosis and switch ignition off.

If no speed is indicated:
- Connect test box to control module wiring harness.

Vehicles > 07.99

- To measure voltage, connect multimeter between sockets 56 (Ground -GND-) +65 (speed signal) of test box.

Vehicles 08.99 >
- To measure voltage, connect multimeter between sockets 2 (Ground -GND-) +20 (speed signal) of test box.

Continued for all vehicles
- Raise left front wheel.
- 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- or to Speedometer Vehicle Speed Sensor (VSS) -G22- according to wiring diagram:
- Erase DTC memory of Engine Control Module (ECM).
- Generate readiness code.