906K, 906M, 907K, 907M, 908K and 908M Compact Wheel Loaders Electrohydraulic System CAN Data Link

CAN Data Link - 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 General Information

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

ELECTRICAL AND STARTING SYSTEM

WIRING GP

910K and 914K Compact Wheel Loaders Electrohydraulic System Wiring Harness (Short Circuit) - Test

910K and 914K Compact Wheel Loaders Electrohydraulic System Electrical Connector - Inspect

906K, 906M, 907K, 907M, 908K and 908M Compact Wheel Loaders Electrohydraulic System Electronic Control Module

906K, 906M, 907K, 907M, 908K and 908M Compact Wheel Loaders Electrohydraulic System CAN Data Link - Test

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 CAN data link of the machine.

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Table 1
Machine ECM (MID 71)
DTC	Code Description	System Response
590-9	Engine Control Module: Abnormal update rate	The engine is at low idle, machine is inoperable.
811-9	Gauge Cluster #1: Abnormal update rate	Some service features in ET will not display correctly.
967-9	Machine Application: Abnormal update rate	Program Product ID into the ECM via Cat ET
967-14	Machine Application: Special Instruction	The wrong Product ID is programmed into the ECM.
2300-9	Switch Panel: Abnormal update rate	Some features associated with the keypad are disabled.
3514-9	Engine Throttle Actuator: Abnormal Update Rate	Only applicable to LRC engines. Engine speed command will be disabled. Machine drive will be disabled.
4404-9	Left Joystick: Abnormal update rate	There is a Datalink communication issue between the joystick and the machine ECM. The implements are disabled. Also the transmission direction may be disabled.
4404-11	Left Joystick: Failure mode not identifiable	There is an internal component fault on the joystick. Switches or thumbrollers may be disabled.
4405-9	Right Joystick: Abnormal update rate	There is a Datalink communication issue between the joystick and the machine ECM. The auxiliary implements are disabled.
4405-11	Right Joystick: Failure mode not identifiable	There is an internal component fault on the joystick. Certain joystick functions may be disabled while others remain operational.

Possible causes for an FMI 9 diagnostic code are:

An ECM software problem.
A short circuit to ground or to another circuit.
An open or a poor connection in the Can Data Link circuits near the ECM.
One of the ECMs or smart devices has failed. This condition is unlikely.

Possible causes for an FMI 11 diagnostic code are:

There may be an internal faulted component on the joystick.
An open circuit.
A short circuit to ground or to another circuit.
The ECM has failed.

Possible causes for an FMI 14 diagnostic code are:

The ECM is configured with the incorrect product ID.

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Illustration 1	g03713072
Schematic of the CAN Data Link

Note: The diagram above is a simplified schematic of the Machine ECM and the CAN Data Link 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. Check the wiring for pinch points or abrasions. Look for and repair areas that indicate wires are exposed. If a problem with a connection is found, correct the problem and verify that this diagnostic code is active before performing a troubleshooting procedure.

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Table 2
Troubleshooting Test Steps	Values	Results
1. Identify The Active FMI Code Associated With The CAN Data Link	Code present.	FMI 9 diagnostic code, proceed to Test Step 2. FMI 11 diagnostic code, proceed to Test Step 5. FMI 14 diagnostic code, proceed to Test Step 6.
Begin Process For FMI 9 Troubleshooting HERE
2. Check The Data Link For An Open A. Turn the key switch and the battery disconnect switch to the OFF position. B. Disconnect the machine harness connector from the ECM. C. At the disconnected connector for the ECM, connect a jumper wire between CAN positive contact and CAN negative contact. D. Measure the resistance from the ECM.	The resistance measure less than 5 Ω.	OK - The resistance is less than 5 Ω. Proceed to Test Step 3. NOT OK -The resistance measurement is greater than 5 Ω. Repair: Repair or replace the machine harness. Proceed to Test Step 6.
3. Check The Resistance Of The Data Link A. Turn key start switch and disconnect switch OFF. B. Disconnect the machine harness connector from the ECM. C. At the disconnected harness connector of the ECM, measure the resistance between CAN positive contact and CAN negative contact.	The resistance measurement is approximately 60 Ω.	OK - The resistance measurement is approximately 60 Ω. Proceed to Test Step 4. NOT OK - The resistance measurement is not approximately 60 Ω. Repair: Replace the resisters. Proceed to Test Step 6.
4. Check The Data Link For A Short A. Turn key start switch and disconnect switch OFF. B. Disconnect all harnesses from the ECM. C. At the ECM, measure the resistance between CAN positive contact and a ground point. D. Measure the resistance between CAN positive contact and all of the other circuits that are used.	The resistance is greater than 4k Ω.	OK - The resistance is greater than 4k Ω. Proceed to Test Step 6. NOT OK - One or more of the resistance measurements is less than 4kΩ. Repair: Find the short circuit in the data link circuits in order to resolve this problem. Proceed to Test Step 6.
Begin Process For FMI 11 Troubleshooting HERE
5. Verify the function of everything on the joystick. Note: There may be a Diff Lock button on the joystick but no Diff Lock on the axle. This does not constitute a failure of the joystick.	The function on the joystick is operational.	OK - The function on the joystick is operational. Proceed to Test Step 7. NOT OK -The function on the joystick is non-operational. Repair:If the harness is OK, replace the joystick. Proceed to Test Step 7.
Begin Process For FMI 14 Troubleshooting HERE
6. Check The ECM For The Proper Software Version A. Use AVSpare Electronic Technician (Cat ET) in order to verify that the correct version of software is installed.	The correct version of software is installed on the ECM.	OK - The correct version of software is installed. Proceed to Test Step 7. NOT OK -The correct software is not installed. Repair: Flash the correct software to the appropriate ECM. Cycle the keyswitch in order to initialize the new software. Ensure that the diagnostic code is no longer active. Proceed to Test Step 7.
7. Check If The Diagnostic Code Remains A. Inspect the contacts of the harness connectors and clean the contacts. B. Reconnect all harness connectors. C. Turn the disconnect switch and the key start switch to the ON position. D. Operate the machine. E. Check if diagnostic code is active.	Diagnostic code is no longer present.	OK - The diagnostic code is no longer active. Repair: The initial diagnostic code could have been caused by a poor electrical connection or a short at one of the harness connectors. Resume normal machine operation. STOP NOT OK - The diagnostic code is active. Repair: A failure of the Machine ECM is unlikely. If the cause of the diagnostic code is not found, the ECM may have failed. Prior to replacing an ECM, always contact the Technical Communicator for your dealership for possible consultation with AVSpare. This consultation may effect repair time. If the ECM requires replacement, see the Troubleshooting, "ECM - Replace" section of this manual for additional information. STOP