Case IH 5 – Digital Instrument Cluster (EIC - Electronic Instrument Cluster) / Instrumentation Controller: Wheel speed sender short circuit

The control module has detected a short to ground or a shorted internal circuit within the wheel speed sensor itself or its associated wiring harness.

• MXM
• Case IH MXM Series
• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190

1. 1

   Turn off the tractor and disconnect the processor connectors (C128 and C127 at the instrument cluster/controller).

2. 2

   Disconnect the electrical connector at the wheel speed sender.

3. 3

   Test the wiring harness between the processor (specifically pin C127–6) and the wheel speed sender connector for a short circuit to ground.

4. 4

   With the sender installed, use a multimeter to check for a short to earth on each sender terminal.

5. 5

   If the wiring harness shows a short, trace and repair the wiring. If the sender itself is shorted, the sender must be replaced. (Note: If neither the wiring nor the sender is shorted, the processor itself may be at fault).

1. 1

   Locate the Sensor

   Locate the wheel speed sender, which is typically mounted on the transmission or rear axle housing where it reads a toothed pole wheel.

2. 2

   Disconnect

   Unplug the electrical harness connector from the faulty wheel speed sender.

3. 3

   Remove

   Unscrew and remove the old wheel speed sender from the housing.

4. 4

   Install

   Thread the new wheel speed sensor into the housing. (If the sensor is adjustable, ensure it is set to the correct depth/air gap according to the specific model's service manual to avoid crushing the sensor tip).

5. 5

   Reconnect

   Plug the electrical harness back into the new sensor.

6. 6

   Test

   Turn the key to the 'RUN' position, clear the stored fault codes from the instrument cluster, and test drive the tractor to verify that the speedometer registers correctly and Fault Code 5 does not return.