Massey Ferguson D197 – Instrument Panel Control Unit and DCC2: Auxiliary Hydraulic Oil Temperature Sensor - Electrical signal too high.

The voltage signal returning from the auxiliary hydraulic oil temperature sensor has exceeded the normal operating parameters. This indicates an open circuit in the sensor wiring or a complete internal failure of the sensor itself.

• MF 8600
• MF 8650
• MF 8660
• MF 8670
• MF 8680
• MF 8690
• MF 8450
• MF 8460
• MF 8470
• MF 8480
• 8600 Series
• 8400 Series
• 7600 Series
• MF 7614 to 7618

1. 1

   Locate Sensor X1 (Auxiliary Hydraulic Oil Temperature Sensor) on the machine.

2. 2

   Check the signal circuit between terminal 67 of the DCC2 (or corresponding ECU pin) and terminal 1 of the X1 sensor for an open circuit or broken wire.

3. 3

   Check the ground circuit between terminal 2 of the X1 sensor and the chassis ground to detect any open circuit.

4. 4

   Test the sensor itself for internal failure if the wiring harness is intact and shows continuity without excessive resistance.

1. 1

   Turn off the tractor and ensure the battery is disconnected before servicing the electrical system.

2. 2

   Locate the auxiliary hydraulic oil temperature sensor (Sensor X1) on the auxiliary hydraulic valve block/reservoir.

3. 3

   Disconnect the wiring harness at the sensor.

   Inspect the connector pins for corrosion, dirt, or pushed-out terminals. Clean if necessary.

4. 4

   Using a multimeter, perform the continuity checks mentioned in the diagnostic steps.

5. 5

   Repair any damaged wiring in the signal or ground circuits.

6. 6

   If the wiring tests good, unthread the old auxiliary hydraulic oil temperature sensor from the hydraulic block.

   Be prepared to catch a small amount of hydraulic fluid.

7. 7

   Install the new sensor and tighten to the manufacturer's torque specification.

8. 8

   Reconnect the X1 wiring harness.

9. 9

   Reconnect the battery, turn the ignition on, and use the Instrument Panel Control Unit to verify that the D197 code has cleared (or changes to an inactive state).