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| Illustration 1 | g01955976 |
Schematic for the "Edge Cutter" Switch | |
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| Illustration 2 | g01960632 |
Edge Cutter Switch on the RH Console | |
The 8-4 Flash Code is associated with the "Edge Cutter" Switch. The 8-4 flash code means that the "Side Console" ECM has detected a Level 1 fault for the switch. The ECM has determined that both signals from the "Edge Cutter " switch are active at the same time.
Note: Before performing this procedure, inspect the harness connectors that are involved in the circuit. Poor connections can often be the cause of a problem in an electrical circuit. Verify that all connections in the circuit are clean, that all connections are secure and that all connections are in good condition. If a problem with a connection is found, correct the problem and verify that this flash code is active before performing this procedure. Verify that the fuse is not open.
Possible conditions which could occur in this circuit include the following:
- No power supply to the switch
- Short to battery (One or both wires)
- Faulty switch contacts
- Open circuit
- Short to ground (One or both wires)
| SWITCH CONNECTIONS TO TERMINAL 2 | ||
| Switch Position | Terminal 1 | Terminal 3 |
| UP (Momentary) |
Closed | Open |
| CENTER | Open | Open |
| DOWN (Momentary) |
Open | Closed |
Test Step 1. CHECK FOR SUPPLY VOLTAGE AT THE SWITCH
- Turn the main disconnect switch to the OFF position.
- Disconnect the switch from the machine harness.
- Turn the main disconnect switch to the ON position.
- Measure the voltage from pin 1 (wire 123-WH) to ground.
Expected Result:
The measured voltage is battery voltage.
Results:
- OK - Battery voltage is present. Proceed to Test Step 3.
- NOT OK - Battery voltage is NOT present. Proceed to Test Step 2.
Test Step 2. CHECK FOR SUPPLY VOLTAGE AT THE FUSE 2A
- Turn the main disconnect switch to the ON position.
- Measure the voltage between Fuse Panel connection 2A and frame ground.
Expected Result:
The measured voltage is battery voltage.
Results:
- OK - The supply voltage is battery voltage. The supply voltage at the fuse panel is correct. There is a problem in the wiring between the fuse panel and the switch connector. Repair the connectors or wiring and/or replace the connectors or wiring.
Repair: Repair the connectors or wiring and/or replace the connectors or wiring.
STOP
- Not OK - The supply voltage is not battery voltage. The Fuse 2A has failed.
Repair: Replace the fuse.
STOP
Test Step 3. CHECK THE CONTINUITY OF THE SWITCH CONTACTS
- Turn the key start switch to the OFF position.
- Unplug the switch from the wire harness.
- Connect one lead from a multimeter to Switch Terminal 2.
- Connect the other lead of the multimeter to Switch Terminal 1
- Check for continuity from Switch Terminal 2 to Switch Terminal 1 in all switch positions according to Table 1.
- Remove the multimeter lead from Switch Terminal 1 and connect to Switch Terminal 3.
- Check for continuity from Switch Terminal 2 to Switch Terminal 3 in all switch positions according to Table 1.
Expected Result:
Checks for continuity should correspond to Table 1.
Results:
- OK - The checks for continuity correspond to the Table above. Proceed to Test Step 4.
- NOT OK - The checks for continuity do not correspond to the Table above.
Repair: The switch has failed. Replace the switch.
STOP
Test Step 4. CHECK THE HARNESS FOR A SHORT
- The disconnect switch and the key start switch remain in the OFF position.
- The machine harness remains disconnected from the switch.
- Disconnect the machine harness connector from the ECM.
- Measure the resistance from contact 10 (wire C728-YL) of the harness connector of the "Main" ECM to all other contacts that are used in the connector.
- Measure the resistance from contact 12 (wire C855-GY) of the harness connector of the "Main" ECM to all other contacts that are used in the connector.
Expected Result:
Each resistance measurement is greater than 5000 ohms.
Results:
- YES - Each resistance measurement is greater than 5000 ohms. Proceed to Test Step 5.
- NO - One or more of the resistance measurements are less than 5000 ohms. The harness has failed. The short is between 10 (wire C728-YL) and the circuit with the lowest resistance or the short is between 12 (wire C855-GY) and the circuit with the lowest resistance.
Repair: Repair the wiring harness or replace the wiring harness.
STOP
Test Step 5. CHECK THE HARNESS FOR AN OPEN
- The disconnect switch and the key start switch remain in the OFF position.
- The switch remains disconnected from the machine harness.
- Place a jumper from pin 3 (wire C855-GY) to pin 1 (wire C728-YL) of the harness connector for the switch.
- Measure the resistance from pin 10 (wire C728-YL) to pin 12 (wire C855-GY) of the harness connector for the ECM.
Expected Result:
The resistance is less than 5 ohms.
Results:
- OK - The resistance is less than 5 ohms. The ECM may have failed.
Repair: It is unlikely that the ECM has failed. Exit this procedure and perform this procedure again. If the cause of the problem is not found, contact the Technical Communicator for your dealership for possible consultation with Caterpillar. This consultation may greatly reduce repair time. If the ECM requires replacement, see Testing and Adjusting, "Electronic Control Module (ECM) - Replace".
STOP
- NOT OK - The resistance is NOT less than 5 ohms. There is an open in the harness. There is an open in wire (C728-YL) or there is an open in wire (C855-GY). Repair the harness or replace the harness.STOP