AD30 and AD55 Underground Articulated Trucks Power Train Electronic Control System Caterpillar

MID 027 - CID 0967 - FMI 02

Usage:

AD55 ANW

Conditions Which Generate This Code:

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Illustration 1	g01042490
Schematic of the harness code receptacle for the AD55 machine

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Illustration 2	g01042502
Schematic of the harness code receptacle for the AD30 machine

This diagnostic code is associated with the harness code receptacle. This diagnostic code is recorded when the Power Train/Chassis Electronic Control Module (ECM) receives information from the Caterpillar Monitoring System. The harness code information has changed while the machine is running. This information is not correct.

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Table 1
Troubleshooting Chart for Harness Codes ⁽¹⁾
Connector Contact for the Main Display Module	31	3	12	22	16
Wire Identification	270-BK(Black)	271-BK(Black)	272-BK(Black)	273-BK(Black)	274-BK(Black)	201-BK(Black)
Contacts for the Harness Code Plug ⁽²⁾	1	2	3	4	5	6

Machine Code	Specified Status
(AD55) 40	G⁽³⁾	G	G	O⁽⁴⁾	G	G
(AD30) 41	O	G	G	O	G	G

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⁽¹⁾	The main display module is in the Harness Code Mode (Mode 1).
⁽²⁾	For machines without a harness code plug, permanent harness code connections are in the machine harness.
⁽³⁾	Grounded status
⁽⁴⁾	Open status

Before you perform this procedure, determine the proper machine code. The main display module must have the correct part number for the particular machine. If the machine code is not shown correctly, this procedure determines the component that is malfunctioning. This failure could be caused by a failure in the Caterpillar Monitoring System display, a wrong harness code receptacle or a harness that has failed.

Note: The harness code and the machine code are similar terms. The codes describe the particular machine. The harness code is the status (open or ground) of the six harness code inputs (connector contacts 3, 6, 12, 16, 22 and 31). The Caterpillar Monitoring System ECM assigns a number to a machine. This number is the machine code. The machine code is shown during harness code mode. Each machine model has a specific harness code.

Note: The following procedure checks for incorrect harness codes on the inputs for the Caterpillar Monitoring System ECM. Compare the status of the harness code that is found in the test "Determine the machine code" to the status at the inputs for the Caterpillar Monitoring System display. The table identifies the connector contacts and wire identification of the harness code circuits. Contacts that are specified as grounded contacts should be checked for opens in the harness. Contacts that are specified as open contacts should be checked for shorts in the harness.

System Response:

The identification code from the Caterpillar Monitoring System has changed. This would indicate an impending failure that is related to the harness code inputs for the Caterpillar Monitoring System. If the diagnostic code remains active, cycle the key start switch. This allows the ECM to receive the signal for the identification code from the Caterpillar Monitoring System.

Test Step 1. CHECK FOR OPENS

Turn the battery disconnect switch to the OFF position.
Disconnect the machine harness from the Caterpillar Monitoring System display.
Check for continuity between the connector contacts that are grounded contacts and contact 2 (ground). Check for continuity at the machine harness connector for the Caterpillar Monitoring System display.

Expected Result:

The resistance measures less than 5 ohms.

Results:

YES - The resistance is less than 5 ohms. The circuit for the harness code is not open. No defect was found in the ground circuits for the harness code. Proceed to Test Step 2.
NO - The resistance is greater than 5 ohms. The circuit for the harness code is open. Check the harness code plug on so equipped machines. Record the open contact of the machine harness connector.
Repair: Repair the open circuits for the harness code that is found or replace the machine harness.

If conditions are not resolved, proceed to Test Step 2.

Test Step 2. CHECK FOR SHORTS

The battery disconnect switch remains in the OFF position. The machine harness to the Caterpillar Monitoring System display remains disconnected.
Measure the resistance between the connector contacts that are specified as open contacts and contact 2 (ground). Measure the resistance at the machine harness connector for the Caterpillar Monitoring System display.

Expected Result:

The resistance measures greater than 5 ohms.

Results:

YES - The resistance is greater than 5 ohms. Proceed to Test Step 3.
NO - The resistance is less than 5 ohms. The circuit for the harness code is shorted. Check the harness code receptacle. Record the shorted contact of the machine harness connector.
Repair: Repair the shorted circuits of the harness code that are found or replace the machine harness.

STOP

Test Step 3. CHECK IF THE DIAGNOSTIC CODE REMAINS

Inspect the contacts of the harness connectors and clean the harness connectors.
Reconnect all the harness connectors.
Turn the battery disconnect switch and the key start switch to the ON position.
Operate the machine.
Check the status of the CID 0967 FMI 02.

Expected Result:

The CID 0967 FMI 02 is active.

Results:

YES - The CID 0967 FMI 02 is active. The diagnostic code has not been corrected. The ECM may have failed.
Repair: It is unlikely that the ECM has failed. Exit this procedure and perform this procedure again. If the cause of the diagnostic code is not found, replace the ECM. Refer to Systems operation, Troubleshooting, Testing and Adjusting, "Electronic Control Module (ECM) - Replace" for the machine that is being serviced.

STOP
NO - The CID 0967 FMI 02 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 that was disconnected and reconnected. Resume normal machine operation.

STOP