RESERVOIR 8D9761 - Caterpillar

Table 1
Symptom:
Hydraulic oil bypassing status not operating correctly 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.
Illustration 1 g03478338Note: The diagram above is a simplified schematic of the monitor switch connections. The schematic is electrically correct, however, not all of the possible harness connectors are shown. Refer to the latest revision of Electrical Schematic, UENR3118 for the complete schematic.
Table 2
Troubleshooting Test Steps Values Results
1. 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 connector.
D. At the machine harness connector for the switch, place a jumper wire between the signal contact and frame ground.
E. At the machine harness connect for the monitor, measure the resistance between the signal contact and frame ground.
The resistance is less than 5 Ω.
OK - The circuit is correct.
Proceed to Test Step 2.
NOT OK - The resistance is greater than 5K Ω. The circuit is open.
Repair: Repair or replace the machine harness.
Note: A resistance that is greater than 5 Ω but less than 5K Ω indicates a loose connection or a corroded connection in the circuit. A resistance measurement that is greater than 5 K Ω indicates an open in the circuit.
STOP
2. Check The Circuit For A Short
A. At the machine harness connector for the monitor, one at a time, measure the resistance between the signal contacts to every other contact used in the J1 and J2 machine harness connectors.
The resistance is greater than 5K Ω.
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 Ground Source
A. The keyswitch remains OFF.
B. Remove the jumper wire installed in the previous step.
C. At the machine harness connector for the switch, measure resistance between the ground contact and frame ground.
The resistance is less than 5 Ω.
OK - The resistance is less than 5 Ω. The ground circuit is good.
Proceed to Test Step 4.
NOT OK- The resistance greater than 5K Ω.
Repair: The ground source is not good. Repair or replace the machine harness for the ground.
Note: A resistance that is greater than 5 Ω but less than 5K Ω would indicate a loose connection or a corroded connection in the circuit. A resistance measurement that is greater than 5K Ω would indicate an open in the circuit.
STOP
4. Check the Switch.
A. Turn the keyswitch ON.
B. Connect the J1 and J2 machine harness connectors to the monitor.
C. Monitor the