120M Series 2, 12M Series 2, 140M Series 2 and 160M Series 2 Motor Graders All Wheel Drive Electronic Control System Caterpillar

Illustration 1	g02071833
AWD mode switch schematic

This diagnostic code is associated with the all wheel drive (AWD) mode switch. The AWD mode switch supplies three inputs to the AWD ECM. The AWD ECM expects one of the three switch inputs to be grounded at all times. When the ECM detects that none of the switch inputs is grounded, the ECM will activate an FMI 03 diagnostic code. FMI 03 indicates that the voltage is above normal.

Note: The following test procedure may create other diagnostic codes. Clear the diagnostic codes when the original diagnostic code has been corrected. Ensure that the CID 0517 FMI 03 diagnostic code is active before performing this procedure.

Test Step 1. CHECK THE OPERATION OF THE SWITCH

1. Turn off the disconnect switch.

2. Turn the keyswitch off.

3. Disconnect the harness connector from the AWD mode switch.
   Show/hide table

   Table 1

   Contacts	State of the Switch
   	Off	Manual	"Creep"
   Contacts 1 to 2	Greater than 5000 ohms	Greater than 5000 ohms	Less than 5 ohms
   Contacts 2 to 3	Less than 5 ohms	Greater than 5000 ohms	Greater than 5000 ohms
   Contacts 2 to 4	Greater than 5000 ohms	Less than 5 ohms	Greater than 5000 ohms

4. Measure the resistance between the contact points on the connector as listed in the first column of Table 1. Note the resistance values.

Expected Result:

The measurements agree with the values listed in Table 1.

Results:

• OK - The measurements agree with the values listed in the table. Proceed to Test Step 2.

• NOT OK - The measurements do not agree with the values listed in the table.

  Repair: Replace the switch.

  STOP

Test Step 2. CHECK FOR A SHORTED HARNESS

The AWD mode switch remains disconnected. The disconnect switch and keyswitch remain off.

1. Disconnect the harness connector J1 from the AWD ECM.

2. At the AWD ECM harness connector J1, measure the resistance between the following contacts:
   • J1-13 (wire A201-BK) and all other J1 connector contacts

   • J1-33 (wire F747-OR) and all other J1 connector contacts

   • J1-34 (wire 823-GN) and all other J1 connector contacts

   • J1-40 (wire 718-BU) and all other J1 connector contacts

Expected Result:

The resistance is greater than 5000 ohms.

Results:

• OK - The resistance is greater than 5000 ohms. Proceed to Test Step 3.

• NOT OK - Resistance is less than 5000 ohms.

  Repair: Repair or replace the harness.

  STOP

Test Step 3. CHECK FOR AN OPEN HARNESS

The AWD mode switch remains disconnected. The disconnect switch and keyswitch remain off.

1. At the AWD mode switch harness connector, place a jumper wire between the following contacts:
   • Contact 3 (wire 823-GN) and Contact 2 (wire F747-OR)

   • Contact 3 (wire 823-GN) and contact 4 (wire 718-BU)

2. Verify that the J1 connector is disconnected from the ECM.

3. At the ECM harness connector, measure the resistance between the following contacts:
   • J1-33 (wire F747-OR) and J1-13 (wire A201-BK)

   • J1-34 (wire 823-GN) and J1-13 (wire A201-BK).

   • J1-40 (wire 718-BU) and J1-13 (wire A201-BK).

4. Make a note of the resistance.

Expected Result:

The resistance is less than 5 ohms for all of the measurements.

Results:

• OK - The resistance is less than 5 ohms for all of the measurements. Proceed to Test Step 4.

• NOT OK - Resistance is greater than 5000 ohms for one or more of the measurements.

  Repair: Repair or replace the harness.

  STOP

Test Step 4. CHECK IF THE DIAGNOSTIC CODE IS STILL ACTIVE

1. Perform the following:
   • Visually inspect the contacts of the harness connectors.

   • Clean the contacts of the harness connectors.

2. Reconnect all harness connectors.

3. Turn on the disconnect switch.

4. Turn the keyswitch on.

5. Operate the machine.

6. Determine if CID 0517 FMI 03 is active.

Expected Result:

CID 0517 FMI 03 is no longer active.

Results:

• OK - CID 0517 FMI 03 is not active.

  Repair: The diagnostic code was probably caused by a poor connection or a short at one of the harness connectors that was disconnected and reconnected. Resume normal machine operation.

  STOP

• NOT OK - CID 0517 FMI 03 is active. The ECM may have failed, however, ECM failure is unlikely.

  Repair: Exit this procedure and perform this procedure again. If the cause of the diagnostic code is not found, contact Technical Communicator at your Cat® dealer for possible consultation with Caterpillar®. If ECM replacement is required, see the Testing and Adjusting, "Electronic Control Module (ECM) - Replace" Story in this manual.

  STOP