Case IH 1822 – ISM-IDI: ISM-IDI Crank Speed Sensor Low Voltage

The engine control system has detected that the supply or signal voltage for the crankshaft speed/position sensor has dropped below the acceptable operational threshold.

• skid steer
• SSL (Skid Steer Loaders)
• CTL (Compact Track Loaders)

1. 1

   Perform battery and load testing to ensure the battery can maintain stable voltage under a heavy starter load, as a weak battery can cause voltage loss during engine cranking.

2. 2

   Inspect grounding points including the battery negative cable, engine ground strap, and fuse-box grounding to rule out bad grounds corrupting sensor signals.

3. 3

   Check the wiring harness connecting the crank speed sensor to the ISM-IDI module for broken wires, disconnected multiplugs, or circuits shorted to ground.

1. 1

   Locate the Sensor

   The crankshaft position sensor is typically mounted near the flywheel, harmonic balancer, or the top of the bell-housing/gearbox where it can read the engine timing marks.

2. 2

   Clear Access

   Depending on the machine, you may need to remove components like the air box assembly or battery tray to gain clear access to the sensor.

3. 3

   Disconnect

   Unplug the sensor's electrical connector/multiplug from the factory wiring harness.

4. 4

   Remove

   Remove the mounting bolt securing the sensor and pull the old sensor out.

5. 5

   Clean

   Thoroughly clean the sensor mounting area. The sensor uses a magnetic pickup design, and dirt or debris can interfere with its ability to read the crankshaft position.

6. 6

   Install

   Insert the new sensor, secure the mounting bolt, and plug the electrical connector back in.