CYL GP- 4869966 - Caterpillar

Table 4
Troubleshooting Test Steps Values Results
1. Identify Active FMI Code Associated With Relay Circuit.
Code is present. FMI 3 diagnostic code, proceed to Test Step 2.
FMI 5 Diagnostic code, proceed to Test Step 4.
FMI 6 diagnostic code, proceed to Test Step 6.
Begin Process For FMI 3 Troubleshooting HERE
2. Check The Relay.
A. Turn the Key Start switch and the disconnect switch to the ON position.
B. Observe the status of the active diagnostic code.
C. Disconnect the relay from the machine harness.
D. Refer to the schematic to identify the points for the coil and measure the resistance with a multimeter.
The coil should measure 27.5 3 Ω at 20° C (68° F).
When the relay is removed from the wiring harness, the active diagnostic code does not change. OK- All of the checks of the relay are the same as the expected results.
Proceed to Test Step 3.
NOT OK- The observed diagnostic code was replaced with an FMI 5 code when the relay was removed from the wiring harness. Also the resistance check does not match the expected results.
Repair- The relay has failed. Replace the faulty relay. After replacing the relay, verify that the new relay has corrected the problem before operating the machine.
STOP
3. Check The Machine Harness For A Short
A. Turn key start switch and disconnect switch to the OFF position.
B. Disconnect harness connection at the relay.
C. If the relay is connected directly to an ECM, disconnect J1 and J2 connectors from ECM.
D. Measure resistance of relay signal contact to all J1 and J2 connectors, if the relay is wired directly to an ECM.
Each reading is greater than 5K Ω. OK - All resistance measurements are greater than 5K Ω.
Proceed to Test Step 9.
NOT OK - One or more readings are less than 5 Ω.
Repair - A short exists between the signal contact and the circuit with the low resistance. Examine all the connectors in the circuits for locations in the machine harness where the circuits could be shorted. Repair or replace the machine harness.
Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose or corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit.
STOP
Begin Process For FMI 5 Troubleshooting HERE
4. Check The Relay.
A. Turn the disconnect switch and the key start switch to the OFF position.
B. Disconnect the relay for the starter motor from the machine harness.
C. At the machine harness connector for the relay, place a jumper wire from contact 2 to contact 3 of the relay. (These pins should correspond with the coil.)
D. Turn the disconnect switch and the key start switch to the START position for a few seconds.
E. Observe the status of the active diagnostic code.
The diagnostic code has changed from an active FMI 5 code to an FMI 6 code. OK- The active code has changed from an FMI 5 to an FMI 6, when the jumper wire is installed. The relay is the cause of the problem.
Repair- The relay has failed. Repeat the