AL4 Transmission output speed sensor fault

Created: 23. 09. 2005
Updated: --. --. ----

206, 306, 307, 406 with AL4 automatic transmission.

With an output speed sensor malfunction the following symptoms can be experienced.

  • "S" and "W" light flashing,
    or "Automatic Transmission Fault" on display.
  • Untimely gearshifts.
  • Harsh up and down shifts.
  • Hanging in gear.
  • Thumping after stopping.

Check sensor connections. If connections OK, replace the sensor.

General sensor information
The output speed sensor is mounted below the 33 way grey connector at the back of the transmission case. It is bolted to the housing from the outside and reaches through an opening in close proximity of the output shaft.

The output speed sensor is of the inductive type. It generates an AC signal and does not require a power supply. The sensor is triggered by the rotation of the transmission's output shaft. The signal is sent to pin 47 and 48 of the transmission ECU connector. Depending on the model, the sensor can be connected to the transmission with the black 2 way connector or through the grey 33 way connector -E1 and E2- (blue block). The sensor resistance should be between 1000Ω and 1400Ω.

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