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| Illustration 1 | g01995753 |
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Schematic of the Lift Linkage Position Sensor Sales model 994F | |
This diagnostic code is recorded when the implement ECM determines that the voltage for the lift linkage position sensor is below normal. The lift linkage position sensor is a PWM sensor. The signal wire for the lift linkage position sensor connects to connector contact J1-21 (wire 761-GY(Grey)) of the ECM.
The possible causes of this diagnostic code are listed:
- A shorted harness
- An open circuit in the power supply wiring for the lift linkage position sensor
- A failed sensor
- The ECM may have failed. This is unlikely.
Note: Ensure that the diagnostic code is active and that the diagnostic code indicator is active.
Note: The following procedure can create numerous related diagnostic codes. Reconnect all harnesses. Then, the related diagnostic codes will be shown as being NOT active. Complete the following procedure. Then, clear all of the related diagnostic codes.
System Response:
The machine response is listed:
- The lift linkage will not work.
- The tilt linkage will not work.
- The active fault must be removed before the implement features will work properly.
Test Step 1. CHECK THE SENSOR
- Turn the disconnect switch and the key start switch to the ON position.
Expected Result:
The diagnostic code remains active.
Results:
- YES - The diagnostic code remains active. The sensor has not failed. The harness or the ECM may have failed. Proceed to Test Step 2.
- NO - The diagnostic code is not active.
Repair: The harness is correct and the ECM is operating properly. The sensor has failed. Replace the sensor.
STOP
Test Step 2. CHECK THE SIGNAL CIRCUIT FOR A SHORT TO GROUND
- Turn the key start switch and the disconnect switch to the OFF position.
- Disconnect the position sensor from the harness.
- Disconnect the harness connector J1 and J2 from the ECM.
- At the connector for the ECM, measure the resistance between contact J1-21 (wire 761-GY(Grey)) and ground in connector J1 and connector J2. Also, measure the resistance between contact J1-21 and frame ground.
Expected Result:
The resistance should be greater than 5000 ohms.
Results:
- YES - The resistance is greater than 5000 ohms. The harness is correct. Proceed to Test Step 3.
- NO - The resistance is less than 5000 ohms.
Repair: There is a short in the harness. The short is between the signal circuit (761-GY(Grey)) and a ground source. Repair the harness or replace the harness.
STOP
Test Step 3. CHECK FOR +BATTERY
- Do not disconnect the harness connector from the sensor.
- Turn the key start switch and the disconnect switch to the ON position.
- At the harness connector for the sensor, measure the voltage from contact A to contact B. Use the 7X-1710 Multimeter Probes and the 9U-7330 Digital Multimeter.
Expected Result:
The voltage is the system voltage.
Results:
- YES - The voltage is correct. The sensor is getting the proper voltage. Proceed to Test Step 4.
- NO - The + battery circuit has failed.
Repair: Repair the harness or replace the harness.
STOP
Test Step 4. CHECK IF THE DIAGNOSTIC CODE REMAINS
- Clean the contacts of the harness connectors.
- Reconnect all harness connectors.
- Observe the status of the diagnostic code.
- Operate the machine.
- Observe the status of the diagnostic code.
Expected Result:
The diagnostic code is active.
Results:
- YES - The diagnostic code is active.
Repair: The diagnostic code does not exist at this time. The initial diagnostic code was probably caused by a poor electrical connection or a short at one of the harness connectors that was disconnected and then reconnected. Resume normal machine operation.
STOP
- NO - The diagnostic code is not active.
Repair: The diagnostic code has not been corrected. It is unlikely that the ECM has failed. Exit this diagnostic code and perform this procedure again. If the cause of the diagnostic code is not found, then replace the ECM. See Testing and Adjusting, "Module - Replace".
STOP