966H, 972H and 980H Wheel Loaders Power Train Electronic Control System Caterpillar

ECM Location Code - Test

Usage:

966H BJ6

The following is a list of codes that are associated with the ECM location code of the machine.

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Table 1
Transmission ECM (MID 81)
DTC	Code Description	System Response
1326-2	ECM Location Code: Data erratic, intermittent, or incorrect	The transmission control may be unable to communicate with other modules.

The ECM location code is defined by wires going from the ECM location code pins on the ECM to ground. The combination of wires connected to ground corresponds with the software on the ECM. If the incorrect wires are connected to ground, or the incorrect version of the ECM software is installed a 1326-2 diagnostic code will occur.

Possible Causes for a DTC 1326-2 Diagnostic Trouble Code Are:

The wires for the location code are open or the wires are shorted.
The wrong software is installed on an ECM.

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Illustration 1	g03376262
ECM Location Code

TROUBLESHOOTING PROCEDURE

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
Begin Process For DTC 1326-2 Troubleshooting HERE
1. Verify The Hardware And The Software Part Numbers ⁽¹⁾ A. Using "WinFlash" check that the latest software for each ECM corresponds with the correct location code. Check with your dealer for the latest software part numbers. B. The part number of the flash software for the Transmission ECM. C. The part number of the Switch Panel. D. The part number of the Transmission ECM.	All part numbers are correct.	OK - All part numbers are correct, proceed to test Step 2. NOT OK - No ECM shows any of the location codes listed. There is a problem with the machine harness. Repair: Repair the machine harness or replace the machine harness. NOT OK - All part numbers are NOT correct. The installed ECM has the wrong part number or incorrect configuration software is installed. Repair: Flash the correct configuration software on the ECM with the displayed location code. Refer to Troubleshooting, "Electronic Control Module (ECM) - Flash Program". Prior to replacing an ECM, contact the Technical Communicator for your dealership for possible consultation with Caterpillar. This consultation may greatly reduce repair time. STOP
2. Inspect The Harness Connections Refer to Figure 1 for wire connections associated with this circuit. A. Turn the disconnect switch to the OFF position. B. Inspect all harness connections that are related to the location codes. Make sure that the connectors are clean and tight. C. Check the connectors for proper mating. Ensure that all the seals are present and in place. D. Check the harness for signs of damage or abrasion. E. Check the wires at the connector. Ensure that the wires are secured tightly into the connector. Take care not to pull the wire out of the connector. F. Check the exposed wires at the connectors for nicks or signs of abrasion. G. Check for moisture inside the connector. H. Check the connectors for dirty contacts or corroded contacts. I. Check each pin and each socket of the machine harness connectors. Ensure that the contacts are properly installed. The contacts should mate correctly when the two pieces of the connector are placed together.	The machine harness connectors are tight and free of corrosion.	OK - The machine harness connectors are tight and free of corrosion. Proceed to Test Step 3. NOT OK - The machine harness connectors are in need of repair. Repair: Repair or replace the machine harness. STOP
3. Check For Shorts to ground A. The disconnect switch remains in the OFF position. B. Disconnect the machine harness connectors from the Implement ECM. C. At the machine harness for the Implement ECM, measure the resistance between the location code contacts and the frame ground.	Reading less than 5 Ω.	OK - Each of the resistance measurements are less than 5 Ω. Proceed to Test Step 4. NOT OK - One of the resistance measurements is greater than 5 Ω. The machine harness has failed. Repair: Repair the machine harness or replace the machine harness.. STOP
4. Check For Shorts to the +Battery Circuit A. The disconnect switch remains in the OFF position. B. The machine harness remains disconnected from the Implement ECM. C. At the machine harness for the Implement ECM, measure the resistance between the location code contacts and all possible sources of the +battery circuit.	Reading greater than 5K Ω.	OK - Each of the resistance measurements are greater than 5K Ω. Proceed to Test Step 5. NOT OK - One of the resistance measurements is less than 5K Ω. The machine harness has failed. Repair: Repair the machine harness or replace the machine harness.. STOP
5. Check If The Diagnostic Code Remains Note: There is a 2 minute interval time on this code A. Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit. B. Reconnect all harness connectors. Verity that the connectors are fully seated and clips are fastened. C. Turn the disconnect switch and the key start switch to the ON position. D. Operate the machine. E. Check the status of the DTC 1326-2 diagnostic code.	The DTC 1326-2 diagnostic code is not active.	OK - The DTC 1326-2 diagnostic code is not active. The diagnostic code does not exist at this time. Repair: The initial diagnostic code was probably caused by a poor electrical connection or a short at one of the harness connectors. Resume normal machine operation. STOP NOT OK - The DTC 1326-2 diagnostic code is active. The diagnostic code has not been corrected. The Implement ECM may have failed. Repair: A failure of the Implement 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 Caterpillar. This consultation may greatly reduce repair time. If the ECM requires replacement, see the Troubleshooting, "ECM - Replace" section of this manual for additional information. STOP