for Dozing, Gen 3.0 Remote Control Operator Console with RFID Caterpillar

Feedback Line - Test

Usage:

D11T AMA

Remote Control Module (RCM)

The following is a list of Diagnostic Trouble Codes (DTCs) that are associated with the relays of the machine.

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Table 1
Remote Control Module (RCM)- MID 126
DTC	Code Description	System Response
4586 - 03	Implement Remote Control Enable Feedback Line - Voltage Above Normal	The Feedback line from the Implement ECM for the mode select circuit is open when should be in RC Mode (grounded). RC is Disabled
4586 - 04	Implement Remote Control Enable Feedback Line - Voltage Below Normal	The Feedback line from the Implement ECM for the mode select circuit is grounded when it should be in RC Override Mode (open). RC is Disabled
4587 - 03	Power train Remote Control Enable Feedback Line - Voltage Above Normal	The Feedback line from the power train ECM for the mode select circuit is open when should be in RC Mode (grounded). RC is Disabled
4587 - 04	Power train Remote Control Enable Feedback Line - Voltage Below Normal	The Feedback line from the power train ECM for the mode select circuit is grounded when it should be in RC Override Mode (open). RC is Disabled

These diagnostics related to the Machine ECM Feedback lines. The ECM Feedback lines help the ECM determine if it should be in RC mode. When a diagnostic FMI 3 or 4 occurs, a mismatch has been detected between the CAN message (on Machine CAN) between the Machine ECM feedback and the Switch to Ground. Proper Operation will ground the feedback line (P991) from the RC override Switch and ECM at the Mode select relay. When the machine is in Remote Control Mode, grounding will occur through the Mode Select (Remote Control Mode Relay) and will be detected at the ECM. When the Mode Select relay is energized, P991 is grounded and the expected state is RC Enable. When the Mode Select Relay is not energized P991 is open and the expected state is RC Override/RC disabled.

Possible causes for an FMI 03 diagnostic code are:

The mode select circuit from Ground to ECM is open (RC Override/Disabled) when the CAN message is reporting as RC Enable
The mode select circuit has high voltage from another source

Possible causes for an FMI 04 diagnostic code are:

The mode select circuit from Ground to ECM Short to ground when the CAN message is reporting as RC Override

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Illustration 1	g06306004
RC feedback enable mini schematic

Note: The diagram above is a simplified schematic of the RC Feedback Enable wires. The schematic is electrically correct. However, not all the possible harness connectors are shown. Refer to the latest revision of the Electrical Schematic, UENR8288 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.

Identify the active FMI code associated with the components.
Determine which code is present and use the list below to determine which procedure to follow.

FMI 03 diagnostic code, proceed to Table 2.
FMI 04 diagnostic code, proceed to Table 3.

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Table 2
FMI 03 Troubleshooting
Troubleshooting Test Steps	Values	Results
1. Check The Machine Harness For A Open A. Turn the key start switch and disconnect switch OFF. B. Disconnect the machine harness connector from the RC Override Switch. C. Remove the P991 wire from harness connectors from the Remote Control, Implement, and power train ECM. D. Disconnect the Mode Select Relay. E. Measure the resistance across P991 from the ECM and to the position for Relay contact 87.	Each resistance measurement is less than 10Ω.	OK - All resistance measurements are less than 10 Ω. Proceed to Test Step 2. NOT OK - One or more readings are greater than 10 Ω. There is high resistance in the P991 circuit. Repair: Repair or replace the machine harness. Proceed to Test Step 6.
2. Check the Relay for Failure A. Turn the key start switch and disconnect switch OFF. B. Reconnect the Manual Override Switch and P991 wire to each ECM, Insert the Mode Select relay. C. Remove the Mode Select Relay. D. Check Resistance of the coil of the relay. E. Check the Resistance of the normally closed Contacts of the relay.	The resistance measurements from relay contact 85 to 86 is between 200-300 Ω. The resistance measurements from relay contact 30 to 87A are between 200-300 Ω.	OK - The measurements are correct. Proceed to Test Step 3. NOT OK - The resistance measurements from relay contact 85 to 86 86 is between 200-300 Ω. Repair: Replace the Relay. Proceed to Test Step 6.
3. Check for a failed Relay Contact A. The Key Switch and RC Enable switch Off position and the disconnect switch to the On position. B. Disconnect H816 from the Remote Control ECM and apply 24V to the H816 circuit of the relay. C. Check resistance from Relay Position 87 to 30.	The resistance measurements from relay contact 87 to 30 (when energized) are lower than 10 Ω.	OK - The measurements are correct. Proceed to Test Step 4. NOT OK - The resistance measurements from relay contact 87 to 30 (when energized) are greater than 10 Ω . Repair: Replace the Relay. Proceed to Test Step 6.
4. Check the circuit to energize the relay coil for an Open A. Disconnect the H816 from the ECM or Power Source. B. Remove the Mode Select Relay. C. Check Resistance Across the H816 Wire from the ECM to the Relay Panel.	The resistance measurements from ECM to Relay are lower than 10 Ω.	OK - The measurements are correct. Proceed to Test Step 5. NOT OK - The resistance measurements from the ECM to Relay are greater than 10 Ω . Repair: Repair or replace the machine harness. Proceed to Test Step 6.
5. Check the circuit to energize the relay coil for a Short A. Disconnect the H816 from the ECM or Power Source. B. Remove the Mode Select Relay. C. Check Resistance Across the H816 Wire from the ECM and Relay Panel To all other circuits.	The resistance measurements from H816 to all other circuits are OL Ω.	OK - The measurements are correct. Proceed to Test Step 6. NOT OK - The resistance does not read OL. Repair: Repair or replace the machine harness. Proceed to Test Step 6.
6. Check If The Diagnostic Code Remains A. Reconnect all harness connectors. Return machine to normal operating condition. B. Turn the key start switch and the disconnect switch ON. C. Clear all diagnostic codes. D. Operate the machine. E. Stop the machine and engage the safety lock lever. F. Check if the diagnostic code is active.	The diagnostic code is no longer present.	OK - The diagnostic code does not exist currently. The initial diagnostic code may have been caused by poor electrical connection or short at one of the harness connections. Resume machine operation. STOP. NOT OK - The diagnostic trouble code has not been corrected. If the diagnostic code has not been corrected after performing the procedure a second time, 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 effect repair time. Follow the steps in Troubleshooting, "ECM - Replace" if the ECM needs to be replaced. STOP.

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Table 3
FMI 04 Troubleshooting
Troubleshooting Test Steps	Values	Results
1. Check The Harness For A Short A. Turn key start switch and disconnect switch OFF. B. Disconnect the machine harness connectors from the RC Override Switch. C. Remove the P991 wire from harness connectors from the Remote Control, Implement, and power train ECM. D. Disconnect the Mode Select Relay. E. Measure the resistance at the ECM across P991 and all other circuits in the harness.	The resistance measurements from P991 to all other circuits are OL Ω.	OK - The measurements are correct. Proceed to Test Step 2. NOT OK - The resistance measured between P991 and all other circuits is not OL. Repair: Troubleshoot the poor connection, Repair, or replace the machine harness. Proceed to Test Step 4.
2. Check The Relay A. The P991 wire is disconnected. B. The Remote Control switch and the battery disconnect switch remain in the Off position. C. Insert the Mode Select Relay. D. Measure the Resistance between P991 and Ground .	The resistance measurements from P991 to ground are OL Ω.	OK - The measurements are correct. Proceed to Test Step 3. NOT OK - The measurement was incorrect. Repair: Replace the relay or determine if or why the relay is energized. Proceed to Test Step 4.
3. Check the Remote Control Override Switch A. Disconnect the Remote Control Override Switch B. Perform resistance checks on the switch.	Only contact 10 has resistance to contact 8. Contact 8 is not shorted to any other contact.	OK - The measurements are correct. Proceed to Test Step 4. NOT OK - The measurement was incorrect. Repair: Replace the RC override switch. Proceed to Test Step 4.
4. Check If The Diagnostic Code Remains A. Reconnect all harness connectors. Return machine to normal operating condition. B. Turn the key start switch and the disconnect switch ON. C. Clear all diagnostic codes. D. Operate the machine. E. Stop the machine and engage the safety lock lever. F. Check if the diagnostic code is active.	The diagnostic code is no longer present.	OK - The diagnostic code does not exist currently. The initial diagnostic code may have been caused by poor electrical connection or short at one of the harness connections. Resume machine operation. STOP. NOT OK - The diagnostic trouble code has not been corrected. If the diagnostic code has not been corrected after performing the procedure a second time, 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 effect repair time. Follow the steps in Troubleshooting, "ECM - Replace" if the ECM needs to be replaced. STOP.