HOUSING 5T6299 - Caterpillar

Illustration 1 g03524778
Schematic of the Electrical Power Supply
Note: The diagram above is a simplified schematic of the Transmission ECM and the Electrical Power Supply connections. The schematic is electrically correct. However, not all of the possible harness connectors are shown. Refer to the latest revision for the complete schematic.Implement ECM
The following is a list of Diagnostic Trouble Codes (DTCs) that are associated with the system voltage of the machine.
Table 2
Implement ECM (MID 82)
DTC Code Description System Response
168-3 Electrical System Voltage: Voltage above normal The supply voltage to the ECM is out of range. This can affect ECM performance.
168-4 Electrical System Voltage: Voltage below normal The supply voltage to the ECM is out of range. This can affect ECM performance. Possible causes for an FMI 3 diagnostic code are:
The sensor supply or the ground circuit in the machine harness is open.
The signal circuit in the machine harness is shorted to another circuit.
The signal circuit in the machine harness is open or the sensor is disconnected.
The sensor has failed.
The ECM has failed. An ECM failure is unlikely.Possible causes for an FMI 4 diagnostic code are:
The signal circuit in the machine harness is shorted to ground.
The sensor has failed.
The ECM has failed. An ECM failure is unlikely.
Illustration 2 g03524781
Schematic of the Electrical Power Supply
Note: The diagram above is a simplified schematic of the Implement ECM and the Electrical Power Supply connections. The schematic is electrically correct. However, not all of the possible harness connectors are shown. Refer to the latest revision 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. Check the wiring for pinch points or abrasions. Look for and repair areas that indicate wires are exposed. If a problem with a connection is found, correct the problem and verify that this diagnostic code is active before performing a troubleshooting procedure.
Table 3
Troubleshooting Test Steps Values Results
1. Identify Active FMI Code Associated With The Electrical Power Supply
Code present. FMI 3 diagnostic code, proceed to Test Step 2.
FMI 4 diagnostic code, proceed to Test Step 4.
Begin Process For FMI 3 Troubleshooting HERE
2. Check The System Voltage At The ECM
A. Turn key start switch and disconnect switch OFF.
B. At the harness connector for the ECM, use the 7X-1710 Multimeter Probes to measure the supply voltage.
C. Insert the probe along the positive power supply circuit wires at the contact point indicated on one of the illustrations above.
D. Insert the negative probe along the supply return circuit wires.
E. Start the engine and run the engine at high idle while monitoring the voltage.
The measured voltage is in the range of 18 VDC to 32 VDC. OK - The voltage measurement of the ECM power supply is in the range of 18 VDC to 32 VDC. The system voltage is correct. The result from this test would