Case IH t59 – Transmission / EDC (Electronic Draft Control) Controller and Engine ECU: Crankshaft Speed Sensor, Shorted To Low Source

The controller is detecting a short to ground (low voltage) on the circuit for the crankshaft speed/position sensor. When this happens, the module loses the precise rotational timing data of the engine's crankshaft, which can cause erratic RPM readouts, starting hesitation, sudden stalls, or transmission shifting issues.

• MXM
• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190
• Puma Series
• MX / TG Series
• Maxxum
• JXU
• Magnum Series
• Farmlift Telehandlers

1. 1

   Locate the crankshaft speed sensor near the engine flywheel casing or primary timing gear housing and visually inspect the wiring harness for chafing, melted insulation, or pinched wires shorting to the chassis (ground).

2. 2

   Disconnect the 3-pin sealed electrical plug at the sensor and check for moisture, dirt, or corroded pins that could bridge the signal wire to the ground wire.

3. 3

   With a multimeter, check the signal wire from the sensor connector back to the ECU for continuity to ground. If the wire is grounded while disconnected at both ends, the harness must be repaired or replaced.

1. 1

   Power Down

   Turn off the key switch and disconnect the tractor's battery to prevent electrical spikes.

2. 2

   Remove the Sensor

   Unbolt the mounting bracket securing the sensor to the flywheel casing/timing gear housing. Carefully pull the sensor straight out of the bore.

3. 3

   Install the New Sensor

   Clean the mounting surface. Insert the new sensor (it features a double-sealed exterior interface, so ensure it seats properly) and tighten the retaining bolt.

4. 4

   Reconnect

   Plug in the 3-pin electrical connector until it clicks. Reconnect the battery.

5. 5

   Calibration (If Required)

   If the fault caused transmission shift quality to deteriorate or if the non-volatile memory was reset, a Transmission/EDC Calibration is required. Start the engine and hold the High and Low range buttons until 'CAL' appears on the transmission display. Set engine speed to 1200 ERPM (± 100). Follow the on-screen prompts to cycle through the clutch pack calibrations until 'END' is displayed.