120M Series 2, 12M Series 2, 140M Series 2 and 160M Series 2 Motor Graders Power Train Electronic Control System Caterpillar

Illustration 1	g02102234
Schematic of the "Battery Cable Shield Monitor" Circuit

This diagnostic code is associated with the "Battery Cable Shield Monitor" Circuit of the "Transmission/Chassis ECM".

Note: The circuit for the "Battery Cable Shield Monitor" is designed to indicate to the machine operator that the shield of the cable has been damaged. The damage could be the result of chaffing over a long period. The damage could also be the result of a nick in the shielding of the harness due to an impact.

The CID 3035 FMI 03 diagnostic code is activated when the ECM detects that the voltage of the "Battery Cable Shield Monitor" Circuit is above normal.

The following conditions could cause this diagnostic code:

• The "Battery Cable Shield Monitor" Circuit is shorted to a higher voltage source.

• One of the resistors in the circuit is outside of the tolerance range.

• A resistor with an incorrect part number has been installed in the circuit.

• The ECM has failed. A failure of the Transmission.Chassis ECM is unlikely.

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

Note: The following test procedure may cause other diagnostic codes to be activated. Ignore these created diagnostic codes and clear the diagnostic codes when the problem has been corrected.

Test Step 1. INSPECT THE HARNESS CONNECTIONS.

1. Turn the disconnect switch to the OFF position.

2. Inspect all harness connections that are related to the Battery Cable Shield Monitor. Make sure that the connectors are clean and that the connections are tight.

3. Check the connectors for proper mating. Ensure that all the seals are present and in place.

4. Check the harness for signs of damage or signs of abrasion.

5. 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.

6. Check the exposed wires at the connectors for nicks or signs of abrasion.

7. Check for moisture inside the connector.

8. Check the connectors for dirty contacts or corroded contacts.

9. 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.

Expected Result:

The machine harness connectors are tight and free of corrosion.

Results:

• OK - The machine harness connectors are tight and free of corrosion. Proceed to Test Step 2.

• NOT OK - The machine harness connectors are in need of repair.

  Repair: Repair the machine harness or replace the machine harness.

  STOP

Test Step 2. CHECK THE POWER SUPPLY AT THE ECM

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

2. At the connector of the "Transmission/Chassis ECM" J1, use a 151-6320 Removal Tool to remove the wire and the socket at contact J1-30 (wire P835-GY). The machine harness connector J1 remains connected to the ECM.

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

4. Use the multimeter probes in order to make contact on the connector pins of the ECM. Measure the voltage at the ECM pins between the contact of the power supply J1-30 and a clean ground connection on the chassis of the machine.

Expected Result:

The voltage measurement is 1.88 ± 0.2 VDC.

Results:

• OK - The voltage measurement is 1.88 ± 0.2 VDC. The voltage is correct. The circuit for the "Battery Cable Shield Monitor" is correct. Install the wires and sockets that were removed from the J1 connector back into the original locations. Proceed to Test Step 6.

• NOT OK - The voltage measurement is greater than 1.88 ± 0.2 VDC. The circuit for the "Battery Cable Shield" is not correct. Proceed to Test Step 3.

Test Step 3. CHECK FOR A SHORT CIRCUIT IN THE MACHINE HARNESS

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

2. Disconnect the machine harness connectors J1 and J2 from the "Transmission/Chassis ECM".

3. At the harness connector J1 for the "Transmission/Chassis ECM", check the resistance from contact J1-30 (wire P835-GY) to all of the other ECM +battery (wire 126-RD) contacts that are connected to the ECM. The contacts are J1-31, J1-38, J1-39, J1-46 and J1-47.

4. At the harness connector J1 for the "Transmission/Chassis ECM", check the resistance from contact J1-30 (wire P835-GY) to all of the other contacts that are used in connectors J1 and J2 for the "Transmission/Chassis ECM".

Expected Result:

Each resistance measurement is greater than 5000 ohms.

Results:

• OK - Each resistance measurement is greater than 5000 ohms. The supply circuit is not shorted to another circuit in the machine harness. Proceed to Test Step 4.

• NOT OK - One or more of the resistance measurements is less than 5000 ohms. There is a short in the machine harness.

  Repair: The power supply circuit is shorted to another circuit in the machine harness. Refer to the complete Electrical System Schematic of the machine. Examine the supply circuit in order to determine the location of the problem.For information on testing for short circuits and finding short circuits, refer to Testing and Adjusting, "Wiring Harness (Short Circuit) - Test". Repair the machine harness or replace the machine harness.

  Proceed to Test Step 4.

Test Step 4. CHECK THE PART NUMBER OF THE RESISTORS IN THE CIRCUIT

1. Locate each of the resistors that are associated with the circuit for the "Battery Cable Shield Monitor".

2. Check the part number that is located on each resistor.

3. Compare the part number for the resistors of the "Battery Cable Shield Monitor".

   Note: Refer to the complete Electrical System Schematic for the machine.

Expected Result:

Each of the part numbers are correct.

Results:

• OK - Each of the part numbers are correct. Proceed to Test Step 5.

• NOT OK - One (or more) of the resistors do not have the correct part number.

  Repair: Replace the faulty resistor(s). Identify the correct resistor(s) from the complete Electrical System Schematic for the machine.

  STOP

Test Step 5. CHECK THE RESISTANCE VALUE OF THE RESISTORS IN THE CIRCUIT

1. Remove one of the resistors from the circuit of the "Battery Cable Shield Monitor".

2. Set the voltmeter to read resistance.

3. Read the resistance across pin 1 and pin 2 of the resistor.

4. Repeat the process for each of the resistors in the circuit. (Refer to the schematic at the beginning of this procedure.)

Expected Result:

The resistance reading for each of the resistors is 1500 ohms ± 15 ohms.

Results:

• OK - Each of the resistors are within the tolerance that is specified. Proceed to Test Step 6.

• NOT OK -

  Repair: One or more of the resistors in the circuit is not within the specified tolerance. Replace the faulty resistors with new resistors that meet the tolerance that is specified.

  Proceed to Test Step 6.

Test Step 6. CHECK THE STATUS OF THE DIAGNOSTIC CODE

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

2. Reconnect all harness connectors. Make sure that the connectors are fully seated. Observe that the clips for each connector are fastened securely.

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

4. Operate the machine.

5. Determine if the CID 3035 FMI 03 diagnostic code is active.

Expected Result:

The CID 3035 FMI 03 diagnostic code is no longer active.

Results:

• YES - The CID 3035 FMI 03 diagnostic code is not active. The problem 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

• NO - The CID 3035 FMI 03 diagnostic code is active. The problem has not been corrected.

  Repair: Check the circuit again. Use the Caterpillar Electronic Technician (ET) service tool, if available, in order to perform a wiggle test on the machine wiring harness. The wiggle test can detect momentary or intermittent shorts or opens in the machine wiring harness.If the cause of the problem is not found, the ECM may be activating the diagnostic code incorrectly. The ECM may have failed. Prior to replacing an ECM, always contact the Technical Communicator at your dealership for possible consultation with Caterpillar. This consultation may greatly reduce repair time. If the ECM requires replacement, refer to Testing and Adjusting, "Electronic Control Module (ECM) - Replace".

  STOP