The following is a list of Diagnostic Trouble Codes (DTCs) that are associated with the Operator Control Switch (Switch to Ground) circuits of the machine.
Implement ECM (MID 82) | ||
---|---|---|
DTC
(1) |
Code Description | System Response |
490-3 | Implement Lockout Switch: Voltage Above Normal | When this diagnostic code occurs, there is no change in the system operation. The Implement system will remain in the last known state, either "locked" or "unlocked."
This code is triggered when both pins are open. |
490-4 | Implement Lockout Switch: Voltage Below Normal | When this diagnostic code occurs, there is no change in the system operation. The Implement system will remain in the last known state, either "locked" or "unlocked."
This code is triggered when both pins are grounded. |
1325-3 | Autodig Trigger Switch: Voltage Above Normal | Operation of the “Autodig” feature (if installed) will be limited.
This code is triggered when both pins are open. |
1325-4 | Autodig Trigger Switch: Voltage Below Normal | Operation of the “Autodig” feature (if installed) will be limited.
This code is triggered when both pins are grounded. |
1628-3 | Armrest Position Switch: Voltage Above Normal | Diagnostic occurs with Armrest DOWN and steering already enabled: Steering will remain enabled.
Diagnostic occurs with Armrest UP: Steering will not be enabled when Armrest is lowered, unless machine speed is detected. |
1628-4 | Armrest Position Switch: Voltage Below Normal | Diagnostic occurs with Armrest DOWN and steering already enabled: Steering will remain enabled.
Diagnostic occurs with Armrest UP: Steering will not be enabled when Armrest is lowered, unless machine speed is detected. |
2113-3 | Operator In Seat Switch: Voltage Above Normal | The transmission will lock in neutral until a valid neutral switch position is sensed. |
2113-4 | Operator In Seat Switch: Voltage Below Normal | The transmission will lock in neutral until a valid neutral switch position is sensed.. |
2659-2 | Cab Air Temperature Control Switch: Data Erratic, Intermittent, or Incorrect | Air conditioning is disabled.
The Auto Temperature Control feature will not work properly |
(1) | Diagnostic Codes for components that are connected to the Relay Driver Module are communicated to the Implement ECM via CAN Data Link. |
Possible causes for an FMI 2 Diagnostic code are:
- A short circuit exists.
- An open circuit exists.
- The switch has failed.
- The ECM has failed. A failure of the ECM is unlikely.
Possible causes for an FMI 3 Diagnostic code are:
- The ground wire is open.
- A signal is permanently open.
- The switch has failed.
- The ECM has failed. A failure of the ECM is unlikely.
Possible causes for an FMI 4 Diagnostic code are:
- A short to ground.
- The switch has failed.
- The ECM has failed. A failure of the ECM is unlikely.
Use the tables below to aid in the troubleshooting of the suspect faulty switches. The tables display the expected continuity for the switches for the given switch states.
Status of Implement Lockout Switch | ||
---|---|---|
Implement Lockout Switch | Contact J1-33 Wire E917-WH | Contact J1-34 Wire E918-GN |
ON | Closed | Open |
OFF | Open | Closed |
Status of HVAC Switch | ||
---|---|---|
HVAC Switch | Contact J2-60 Wire C539-YL | Contact J2-61 Wire C540-GY |
Manual | Closed | Open |
Auto | Open | Closed |
Off | Open | Open |
Illustration 1 | g03646360 |
Schematic of the Operator Control (Switch to Ground) connections |
Note: The diagram above is a simplified schematic of the connections for the operator control (switch to ground) circuits. The schematic is electrically correct. However, not all of the possible harness connectors are shown. Refer to the latest revision of the Electrical Schematic, UENR3117 for the complete schematic.
The following is a list of Diagnostic Trouble Codes (DTCs) that are associated with the Operator Control Switch (Switch to Ground) circuits of the machine.
Transmission ECM (MID 81) | ||
---|---|---|
DTC | Code Description | System Response |
70-2 | Parking Brake Switch: Data Erratic, Intermittent, Or Incorrect | Parking brake will not disengage when requested. |
668-3 | Transmission Shift Lever: Voltage Above Normal | Transmission ECM shifts to neutral the first time this DTC is active. Transmission ECM ignores the Transmission Shift Lever thereafter. |
668-4 | Transmission Shift Lever: Voltage Below Normal | Transmission ECM shifts to neutral the first time this DTC is active. Transmission ECM ignores the Transmission Shift Lever thereafter. |
702-3 | Transmission Gear Lever Selector Sensor (Switch): Voltage Above Normal | Transmission ECM holds present gear the first time this DTC is active. Transmission ECM ignores the Transmission Shift Lever thereafter. |
702-4 | Transmission Gear Lever Selector Sensor (Switch): Voltage Below Normal | Transmission ECM holds present gear the first time this DTC is active. Transmission ECM ignores the Transmission Shift Lever thereafter. |
1628-3 | Armrest Position Switch: Voltage Above Normal | Diagnostic occurs with Armrest DOWN and steering already enabled: Steering will remain enabled.
Diagnostic occurs with Armrest UP: Steering will not be enabled when Armrest is lowered, unless machine speed is detected. |
1628-4 | Armrest Position Switch: Voltage Below Normal | Diagnostic occurs with Armrest DOWN and steering already enabled: Steering will remain enabled.
Diagnostic occurs with Armrest UP: Steering will not be enabled when Armrest is lowered, unless machine speed is detected. |
Possible causes for an FMI 2 Diagnostic code are:
- A short circuit exists.
- An open circuit exists.
- The switch has failed.
- The ECM has failed. A failure of the Transmission ECM is unlikely.
Possible causes for an FMI 3 Diagnostic code are:
- The ground wire is open.
- A signal is permanently open.
- The switch has failed.
- The ECM has failed. A failure of the ECM is unlikely.
Possible causes for an FMI 4 Diagnostic code are:
- A short to ground.
- The switch has failed.
- The ECM has failed. A failure of the ECM is unlikely.
Use the table below to aid in the troubleshooting of the suspect faulty switches. The tables display the expected continuity for the switches for the given switch states.
Status of the Parking Brake Switch | ||
---|---|---|
Contacts | Switch State | Continuity |
1, 2 | Engaged | No |
1, 2 | Disengaged | Yes |
2, 3 | Engaged | Yes |
2, 3 | Disengaged | No |
4, 5 | Engaged | No |
4, 5 | Disengaged | Yes |
5, 6 | Engaged | Yes |
5, 6 | Disengaged | No |
Status of the FNR Switch | ||
---|---|---|
Switch State | Direction Switch
Switched to Ground (Pin 1, 200-BK) |
Speed Switch
Switched to Ground (Pin 1, 200-BK) |
FWD - 1 | Pin 5 (E946-OR) | Pin 7 (E938-OR) |
FWD - 2 | Pin 5 (E946-OR) | Pin 8 (E939-WH) |
FWD - 3 | Pin 5 (E946-OR) | Pin 9 (E940-BU) |
FWD - D | Pin 5 (E946-OR) | Pin 11 (E941-YL) |
Neutral | Pin 12 (E949-YL) | NA |
REV - 1 | Pin 6 (E947-WH) | Pin 7 (E938-OR) |
REV - 2 | Pin 6 (E947-WH) | Pin 8 (E939-WH) |
REV - 3 | Pin 6 (E947-WH) | Pin 9 (E940-BU) |
REV - D | Pin 6 (E947-WH) | Pin 11 (E941-YL) |
Illustration 2 | g03646363 |
Schematic of the Operator Control (Switch to Ground) connections |
Note: The diagram above is a simplified schematic of the connections for the operator control (switch to ground) circuits. The schematic is electrically correct. However, not all of the possible harness connectors are shown. Refer to the latest revision of the Electrical Schematic, UENR3117 for the complete schematic.
Diagnostic Trouble Code Procedure
Note: 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. If a problem with a connection is found, correct the problem and verify that the diagnostic code is active before performing a troubleshooting procedure. For sensors powered via the fuse panel, check the condition of the appropriate fuse before beginning the troubleshooting procedure.
Troubleshooting Test Steps | Values | Results |
---|---|---|
1. Identify The Active FMI Code Associated With The Sensor Circuit | Code present. |
FMI 2 diagnostic code, proceed to Test Step 2. FMI 3 diagnostic code, proceed to Test Step 4. FMI 4 diagnostic code, proceed to Test Step 9. |
Begin Process For FMI 2 Troubleshooting HERE | ||
2. Check The Circuit For A Short A. Turn the key switch OFF. B. Disconnect the switch from the machine harness. C. Disconnect the J1 and J2 machine harness connections from the ECM. C. At the machine harness connector for the ECM, measure the resistance between each of the signal contacts to every other contact used in the J1 and J2 machine harness connectors. |
The resistance is greater than 5K ohms. |
OK - The resistance is correct. Proceed to Test Step 3. NOT OK - The resistance check is not correct. Repair: There is a short in the signal circuits of the machine harness. Repair or replace the machine harness. STOP |
3. Check the Operation of the Switch. A. The key switch remains OFF. B. Reconnect all harness connectors. C. Check the operation of the switch. Refer to the table for the suspected faulty switch at the beginning of this procedure for switch operation. |
The switch operates correctly. |
OK - The switch is operating correctly. Proceed to Test Step 12. NOT OK - The switch is not operating correctly. The switch has failed. Repair: Replace the switch. STOP |
Begin Process For FMI 3 Troubleshooting HERE | ||
4. Check the Harness For an Open A. Turn key start switch and disconnect switch OFF. B. Disconnect the switch from the machine harness. C. Disconnect the J1 and J2 machine harness connectors at the ECM. D. At the machine harness connector for the switch, place a jumper between the two signal wires at the switch connector. Check for low resistance at the ECM connector E. At the machine harness connect for the ECM, measure the resistance between the signal contact and frame ground. |
The resistance is less than 5 ohms. |
OK - The circuit is correct. Proceed to Test Step 5. NOT OK - The resistance is greater than 5K ohms. The circuit is open. Repair: Repair or replace the machine harness. Note: A resistance that is greater than 5 ohms but less than 5K ohms indicates a loose connection or a corroded connection in the circuit. A resistance measurement that is greater than 5K ohms indicates an open in the circuit. STOP |
5. Check the Harness for a Short A. The key switch remains OFF. B. All harness connectors remain disconnected. C. Remove the jumper wire installed in the previous step. D. At the machine harness connector for the ECM, measure resistance between the signal contacts and all other contacts of the J1 and J2 harness connectors. |
The resistances are greater than 5K ohms. |
OK - The resistance is greater than 5K ohms. The harness circuit is correct. Proceed to Test Step 6. NOT OK- The resistance less than 5 ohms. Repair: A short exists in the harness between the signal circuit and the wire with the low resistance reading. Repair or replace the machine harness. Note: A resistance that is greater than 5 ohms but less than 5K ohms would indicate a loose connection or a corroded connection in the circuit. A resistance measurement that is greater than 5K ohms would indicate an open in the circuit. STOP |
6. Check the Ground Source for the Switch. A. The key switch remains OFF. B. All harness connectors remain disconnected. C. At the switch, measure resistance between the ground contact and frame ground. |
The resistance is less than 5 ohms. |
OK - The resistance is less than 5 ohms. Proceed to Test Step 7. NOT OK - The resistance is greater than 5K ohms. Repair: The switch does not have a good ground source. Replace the harness between the switch and the ground source. Note: A resistance that is greater than 5 ohms but less than 5K ohms indicates a loose connection or a corroded connection in the circuit. A resistance measurement that is greater than 5K ohms indicates an open in the circuit. STOP |
7. Check the Operation of the ECM. A. The key switch remains OFF. B. Reconnect all harness connections. C. Using a wire removal tool, remove the signal wires and socket from the machine harness connector to the switch. D. Turn the key switch ON. E. Use a multimeter probe to contact both signal wire pins through the empty space in the harness connector. F. Ground the other end of the multimeter probe to frame ground. G. Observe the status of the diagnostic code. |
The FMI 3 changes to an FMI 4. |
OK - The ECM is operating correctly. Proceed to Test Step 8. NOT OK - The FMI 3 remains active. The ECM may have failed. Prior to replacing the 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, see Troubleshooting, "ECM - Replace" STOP |
8. Check the Operation of the Switch. A. Turn the key switch OFF. B. Reinstall the signal wire removed in the previous step. C. Check the operation of the switch. Refer to the table for the suspected faulty switch at the beginning of this procedure for switch operation. |
The switch operates correctly. |
OK - The switch is operating correctly. Proceed to Test Step 12. NOT OK - The switch is not operating correctly. The switch has failed Repair: Replace the switch. STOP |
Begin Process For FMI 4 Troubleshooting HERE | ||
9. Check The Switch A. Turn the key switch and disconnect switch OFF. B. Unplug the switch from the machine harness. C. Turn the key switch and disconnect switch ON. D. Observe the status of the diagnostic code. |
The FMI 4 diagnostic code remains active. |
OK - The FMI 4 diagnostic code remains active. Proceed to Test Step 10. NOT OK - The FMI 4 changes to an FMI 3. The switch has failed. Repair: Replace the switch. Verity that the new switch corrects the diagnostic code. STOP |
10. Check the Harness for a Short A. The turn the key start switch and disconnect switch OFF. B. Unplug the J1 and J2 machine harness connectors from the ECM. D. At the machine harness connector for the ECM, measure resistance between the signal contact and all other contacts of the J1 and J2 harness connectors. |
The resistances are greater than 5K ohms. |
OK - The resistance is greater than 5K ohms. The harness circuit is correct. Proceed to Test Step 11. NOT OK- The resistance less than 5 ohms. Repair: A short exists in the harness between the signal circuit and the wire with the low resistance reading. Repair or replace the machine harness. Note: A resistance that is greater than 5 ohms but less than 5K ohms would indicate a loose connection or a corroded connection in the circuit. A resistance measurement that is greater than 5K ohms would indicate an open in the circuit. STOP |
11. Check the Operation of the Switch. A. The key start switch and disconnect switch remain OFF. B. Check the operation of the switch. Refer to the table for the suspected faulty switch at the beginning of this procedure for switch operation. |
The switch operates correctly. |
OK - The switch is operating correctly. Proceed to Test Step 12. NOT OK - The switch is not operating correctly. The switch has failed. Repair: Replace the switch. STOP |
12. Check If The Diagnostic Code Remains A. Inspect the harness connectors and clean the contacts of the harness connectors. B. Perform a C. Reconnect all harness connectors. D. Turn key start switch and disconnect switch ON. E. Operate the machine. F. Check the status of the diagnostic code. |
The diagnostic code is not active. |
OK - The diagnostic code is still active. Repair: Check the status of the diagnostic code. If the cause of the problem is not found, the ECM may require replacement. Prior to replacing the 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, see Troubleshooting, "ECM - Replace". STOP NOT OK - The continuity check is not correct. Repair: There is an open in the signal circuits of the machine harness. Repair or replace the machine harness. STOP |