TK711, TK721, TK722, TK732, TK741, TK751 and TK752 Track Feller Bunchers IQAN MDM Monitor Fault ; Event Codes Caterpillar

Illustration 1	g01304283
Supply voltage connections for the IQAN XT2 A0 module

This diagnostic code is associated with the power signal that is supplied to the IQAN XT2 A0 module at pin 15 and pin 28 of the IQAN XT2 A0 module. The "HIGH SUPPLY VOLTAGE" code means that the voltage supply to the module is greater than 32 VDC.

The possible causes of this diagnostic code are listed below:

• The power supply is delivering excessive system voltage.

• The energize circuit of the module is open in the harness.

• The module has failed. This is unlikely.

Test Step 1. CHECK THE POWER SUPPLY FOR THE MODULE

1. Turn the disconnect switch and the key start switch to the ON position.

2. Check the voltage at the mating connector pins on the IQAN XT2 A0 module from contact 15 (wire 200-BK) to contact 28 (wire 142-PK).

Expected Result:

The voltage measurement is approximately 24 VDC.

Results:

• YES - The voltage measurement is approximately 24 VDC. The module power supply is correct. Proceed to Test Step 2.

• NO - The voltage measurement is not approximately 24 VDC. There is a problem with the voltage supply for the module.

  Repair: The voltage supply circuit (wire 142-PK) for the module is open in the machine harness. Ensure that the IQAN XT2 A0 fuse is not open. Refer to the complete machine Electrical System Schematic. Examine all of the connections that are in the supply circuit between the fuse and the module. Ensure that the connections are clean, secure and in good condition. Repair the machine harness or replace the machine harness.

  STOP

Test Step 2. CHECK THE STATUS OF THE DIAGNOSTIC CODE

1. Inspect the harness connectors and clean the contacts of the harness connectors and check the wires for damage to the insulation that is caused by excessive heat, battery acid, or chafing.

2. Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit.

3. Reconnect all harness connectors making sure that the connectors are fully seated and the clips for each connector are completely fastened.

4. Turn the disconnect switch and the key start switch to the ON position.

5. Operate the machine.

6. Check the status of the "HIGH SUPPLY VOLTAGE" code.

Expected Result:

The "HIGH SUPPLY VOLTAGE" code is active.

Results:

• YES - The "HIGH SUPPLY VOLTAGE" code is active. The diagnostic code has not been corrected.

  Repair: If the diagnostic code is still active, the module may be faulty.Prior to replacing a module, always contact your dealership's Technical Communicator for possible consultation with Caterpillar. This consultation may greatly reduce repair time. If the cause of the diagnostic code is not found, replace the module.

  STOP

• NO - The "HIGH SUPPLY VOLTAGE" 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 at one of the harness connectors that was disconnected and reconnected. Resume normal machine operation.

  STOP