Electronic Speedometer
Testing Electronic Speedometer model 124.034/036A. Testing sensor with multimeter
Static test
- Remove instrument cluster. Service and Repair
- Remove cover (a) on connector housing.
- Check voltage with multimeter (003) between socket 4 (brown wire, ground) and socket 2 (black/violet wire with red dots, terminal 15). For this check turn ignition/starter switch to position 2.
Specified value: Battery voltage: Use electrical connection set 201 589 00 99 00 for testing.
- Measure resistance with multimeter (003) between socket 4 (brown wire, ground) and socket 3 (white wire, sensor lead).
Specified value: 2 k ohms ± 200 ohms. Use electrical connection set 201 589 00 99 00 for testing.
Dynamic test with multimeter
Connect multimeter (003): Red test wire socket 3 (white wire, sensor wire). Black test wire to socket 4 (brown wire, ground) Use electrical connection set 201 589 00 99 00 for testing.
- Switch multimeter (003) on (range: volt)
- Drive vehicle on dynamometer or on road. The voltage should increase continuously at increasing speed up to approx. 40 km/h > 1 V.
- Close cover (a) on connector housing.
B. Testing sensor and speedometer with frequency generator
Static test
- Remove instrument cluster. Service and Repair
- Open cover (a) on connector housing.
- Check voltage with multimeter (003) between socket 4 (brown wire, ground) and socket 2 (black/violet wire with red dots, terminal 15). For this check turn ignition/starter switch to position 2.
Specified value: Battery voltage: Use electrical connection set 201 589 00 99 00 for testing.
- Measure resistance with multimeter (003) between socket 4 (brown wire, ground) and socket 3 (white wire, sensor wire).
Specified value: 2 k ohms +/- 200 ohms. Use electrical connection set 201 589 00 99 00 for testing.
Dynamic test with frequency generator
- Connect frequency generator (032): Red test wire to socket 3 (white wire, sensor wire). Black test wire to socket 4 (brown wire, ground) Use electrical connection set 201 589 00 99 00 for testing.
- Test sensor with (frequency generator in counter mode).
- Drive vehicle on dynamometer or on road. The frequency should increase continuously at increasing speed.
- Turn ignition/starter switch to position 2 (battery voltage).
- Test speedometer with (frequency generator in alternator mode, sine wave function). The speed reading should increase at increasing frequency.
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