PLATE 7N1199 - Caterpillar

Table 1
J1939 Code and Description Conditions which Generate this Code System Response
678-03 ECU 8 Volts DC Supply : Voltage Above Normal The 8 VDC supply to the sensor has been lost. The code is active and the code is logged.
All sensors are set to default values.
678-04 ECU 8 Volts DC Supply : Voltage Below Normal The 8 VDC supply to the sensor has been lost. The code is active and the code is logged.
All sensors are set to default values.
3509-00 5 Volt Open Circuit The 5 VDC supply to the sensor has been lost. The code is active and the code is logged.
All sensors are set to default values.
3509-01 5 Volt Short Circuit The 5 VDC supply to the sensor has been lost. The code is active and the code is logged.
All sensors are set to default values.
3510-00 5 Volt Open Circuit The 5 VDC supply to the sensor has been lost. The code is active and the code is logged.
All sensors are set to default values.
3510-01 5 Volt Short Circuit The 5 VDC supply to the sensor has been lost. The code is active and the code is logged.
All sensors are set to default values.
Illustration 1 g03845071
Table 2
Troubleshooting Test Steps Value Results
1. Inspect the Electrical Connectors and the Wiring.
A. Remove electrical power from the ECM.
B. Thoroughly inspect the customer connector J17/P17. Inspect the ECM connector J2/P2. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
C. Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit for the coolant level sensor.
D. Check the allen head screw on the ECM connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Electrical connectors and w
Result : The electrical connectors and wiring are OK.
Proceed to Test Step 2.
Result : The electrical connectors and wiring are NOT OK.
Repair : Repair the wiring and connectors or replace the wiring or the connectors. Ensure that all of the seals are properly connected. Verify that the repair eliminates the problem.
If the problem is not resolved, proceed to Test Step 2.
2. Check Sensor Supply Voltages at the ECM.
A. Reconnect all connectors.
B. Turn the engine control switch to the ON position.
C. Measure the voltage between P2-17 and P2-10.
D. Measure the voltage between P2-18 and P2-10.
The voltage measures 5.0 0.25 VDC between P2-17 and P2-10. The voltage measures 8.0 0.4 VDC between P2-18 and P2-10.
Sensor supply voltage
Result : The sensor supply voltage is OK.
Proceed to Test Step 3.
Result : The 5V sensor supply voltage is NOT OK.
Repair : Check the supply voltage to the ECM. Refer to Troubleshooting, "Electrical Power Supply - Test".
If the voltage is correct, proceed to Test Step 5.
Result : The 8V sensor supply voltage is NOT OK.
Repair : Check the supply voltage to the ECM. Refer to Troubleshooting, "Electrical Power Supply - Test".
If the voltage is correct, proceed to Test Step 4.
3. Check Sensor Supply Voltage at the 5 V Sensors.
A. Turn the engine control switch to the