Iveco 81 – ECAS (Electronically Controlled Air Suspension) Electronic Control Unit: Vehicle speed signal (open or short to + DC)

The control unit is not receiving a valid vehicle speed signal. The system has detected either an open circuit (a broken wire or disconnected plug) or a short circuit to positive DC voltage in the speed signal circuit.

• Iveco Stralis
• Iveco Trakker
• Iveco EuroCargo
• Iveco Daily

1. 1

   Perform an OBD/Diagnostic scan to confirm Code 81 is active and check for any related ABS or transmission speed sensor codes.

2. 2

   Visually inspect the wiring harness running from the vehicle speed sensor (transmission or ABS) to the ECAS ECU for chafed wires, broken lines, or melted insulation.

3. 3

   Disconnect the speed sensor and inspect the connector pins for corrosion, water ingress, or bent pins. Ensure the plug is securely grounded where applicable.

4. 4

   Test the speed sensor with a multimeter to verify proper resistance (inductive Iveco speed sensors should read around 1,150 Ohms) and check for proper voltage/signal output when the wheel or output shaft is rotated.

5. 5

   Test the continuity of the signal wire from the sensor harness connector back to the ECAS ECU pin to isolate whether the fault is in the sensor or the wiring.

1. 1

   Disconnect Power

   Turn off the ignition and disconnect the vehicle's batteries to prevent electrical spikes during repair.

2. 2

   Repair Wiring

   If the diagnostic checks revealed a broken wire or a short to power in the harness, splice and repair the damaged section using weather-sealed heat shrink connectors, or replace the damaged pigtail connector.

3. 3

   Replace the Sensor

   Locate the faulty speed sensor (either on the transmission tail shaft or the wheel hub, depending on which signal the ECAS is losing). Remove the fixing screw/bolt holding the sensor in place. Pull the old sensor out and disconnect it from the wiring harness. Clean the mounting surface and install the new OEM replacement sensor. Torque the mounting bolt to manufacturer specifications.

4. 4

   Reassemble and Clear Codes

   Reconnect the battery and turn on the ignition. Use your diagnostic tool to clear the stored ECAS fault codes.

5. 5

   Test Drive

   Perform a short test drive to ensure the ECAS system registers the vehicle speed, the suspension levels correctly, and the fault code does not return.