906K, 906M, 907K, 907M, 908K and 908M Compact Wheel Loaders Electrohydraulic System Sensor Signal (Analog, Passive)

Sensor Signal (Analog, Passive) - Test

906K, 906M, 907K, 907M, 908K and 908M Compact Wheel Loaders Electrohydraulic System [UENR5036]

906K, 906M, 907K, 907M, 908K and 908M Compact Wheel Loaders Electrohydraulic System Sensor Signal (Analog, Active) - Test

906K, 906M, 907K, 907M, 908K and 908M Compact Wheel Loaders Electrohydraulic System Sensor Signal (PWM) - Test

ELECTRICAL AND STARTING SYSTEM

SENSOR GP

906K, 906M, 907K, 907M, 908K and 908M Compact Wheel Loaders Electrohydraulic System Sensor Signal (Analog, Active) - Test

906K, 906M, 907K, 907M, 908K and 908M Compact Wheel Loaders Electrohydraulic System Sensor Signal (Analog, Passive) - Test

906K, 906M, 907K, 907M, 908K and 908M Compact Wheel Loaders Electrohydraulic System Sensor Signal (PWM) - Test

906K, 906M, 907K, 907M, 908K and 908M Compact Wheel Loaders Electrohydraulic System Speed Sensor - Test

906K, 906M, 907K, 907M, 908K and 908M Compact Wheel Loaders Electrohydraulic System Sensor Supply - Test

906K, 906M, 907K, 907M, 908K and 908M Compact Wheel Loaders Electrohydraulic System Calibration

1.1. Machine ECM

2.1. Diagnostic Trouble Code Procedure

Machine ECM

The following is a list of Diagnostic Trouble Codes (DTCs) that are associated with the passive (analog) circuits of the machine.

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Table 1
Machine ECM (MID 71)
DTC	Code Description	System Response
110-3	Engine Coolant Temperature Sensor: Voltage above normal	The Coolant Temperature gauge on the cluster will show high temperature. Machines with a Demand Fan will run the fan at the max while the temperature sensor is faulted.
110-4	Engine Coolant Temperature Sensor: Voltage below normal	The Coolant Temperature gauge on the cluster will show high temperature. Machines with a Demand Fan will run the fan at the max while the temperature sensor is faulted.
600-3	Hydraulic Oil Temperature Sensor: Voltage above normal	Hydraulic Oil Temperature gauge on the cluster will show hot oil or blink due to error. Machines with a Demand Fan will run the fan at max while the oil temperature sensor is faulted.
600-4	Hydraulic Oil Temperature Sensor: Voltage below normal	Hydraulic Oil Temperature gauge on the cluster will show hot oil or blink due to error. Machines with a Demand Fan will run the fan at max while the oil temperature sensor is faulted.

Possible causes for an FMI 3 diagnostic code are:

The sensor has failed.
The sensor supply or the ground circuit in the machine harness is open.
The signal circuit in the machine harness is shorted to the +battery.
The signal circuit in the machine harness is open or the sensor is disconnected.
The ECM has failed. A failure of the ECM is unlikely.

Possible causes for an FMI 4 diagnostic code are:

The sensor has failed.
The signal circuit in the machine harness is shorted to ground.
The ECM has failed. A failure of the ECM is unlikely.

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Illustration 1	g03714395
Schematic of the Analog Passive Sensors

Note: The diagram above is a simplified schematic of the Machine ECM and the Analog Passive Sensors connections. The schematic is electrically correct. However, not all of the possible harness connectors are shown. Refer to the latest revision of Electrical Schematic, UENR5407 for prefixes: L66, L77, L88, or Electrical Schematic, UENR5408 for prefixes: Z66, Z77, Z88, or Electrical Schematic, UENR5409 for prefixes: H66, H77, H88.

Diagnostic Trouble Code Procedure

Note: Prior to beginning this procedure, inspect the harness connectors that are involved in this circuit. Poor connections can often be the cause of a problem in an electrical circuit. Verify that all connections in the circuit are clean, secure, and in good condition. If a problem with a connection is found, correct the problem and verify that the diagnostic code is active before performing a troubleshooting procedure.

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Table 2
Troubleshooting Test Steps	Values	Results
1. Identify Active FMI Code Associated With Sensor Circuit	Code present.	FMI 3 diagnostic code, proceed to Test Step 2. FMI 4 diagnostic code, proceed to Test Step 2.
Begin Process For FMI 3 and FMI 4 Troubleshooting HERE
2. Check The Resistance Of The Sensor A. Turn the key start switch to OFF. B. Disconnect the harness connectors from the sensor. C. Check the resistance of the sensor by measuring between the positive contact and one of the negative contacts.	The resistance of the sensor is 80 Ω to 200 Ω.	OK - The resistance measures between 80 Ω to 200 Ω. Proceed to Test Step 3. NOT OK- The resistance does not measure between 80 Ω to 200 Ω. The sensor has failed. Repair - In order to confirm that the sensor is causing the problem, the harness connections can be switched. If diagnostic code has been activated, replace the sensor. Proceed to Test Step 5.
3. Check For An Open In The Sensor Circuit A. The sensor remains disconnected from the machine harness. B. Turn the key start switch and the disconnect switch OFF. C. At the harness connector for the sensor, place a jumper wire between the sensor positive and the negative. D. Disconnect the harness connector from the ECM. E. At machine harness connector for sensor, measure the resistance from the signal contact to return contact. F. Gently pull on the wires and move the wires in a circular motion at ECM connector and observe the resistance readings.	The resistance is less than 5 Ω at all times during the manipulation of the harness.	OK - The resistance is less than 5 Ω. The resistance measurements are indicating that there is not an open circuit or a poor connection in any of the sensor circuits. Proceed to Test Step 4. NOT OK- Resistance reading for the signal circuit or the return circuit is greater than 5 Ω. Repair - Repair or replace the wiring harness, circuit wires, or any connectors that are found to be faulty. Proceed to Test Step 5.
4. Check For A Short In The Sensor Circuit A. Turn the key start switch to OFF. B. Disconnect the harness connectors from the sensor. C. Disconnect J1 and J2 harness connector from the ECM. D. Measure the resistance between the sensor positive (+) contact and all of the other circuit contacts that are used in the harness connectors for the ECM. E. Measure the resistance between the sensor return (-) contact and all of the other circuit contacts that are used in the harness connectors for the ECM.	The resistance is greater than 4000 Ω.	OK - Each individual resistance measurement is greater than 4000 Ω. Proceed to Test Step 5. NOT OK- At least one or more of the resistance measures less than 4000 Ω. Repair - Repair or replace the machine harness. Proceed to Test Step 5.
5. Check If The Diagnostic Code Remains A. Inspect the harness connectors and clean the contacts of the harness connectors. B. Reconnect all harness connectors. C. Turn key switch and disconnect switch ON. D. Operate the machine. E. Check if diagnostic code is active.	Diagnostic code is no longer present.	OK - Diagnostic code does not exist at this time. Initial diagnostic code may have been caused by poor electrical connection or short at one of the harness connections. Resume machine operation. STOP NOT OK - Diagnostic trouble code has not been corrected. If the diagnostic code has not been corrected after performing the procedure a second time, the ECM may require replacement. Prior to replacing this component, always contact the Technical Communication at your dealership for possible consultation with AVSpare. This consultation may greatly effect repair time. Follow the steps in Troubleshooting, "Electronic Control Module (ECM) - Replace" if the ECM needs to be replaced. STOP