Conditions Which Generate This Code:
The ECM detects the following conditions:
• The engine coolant temperature is greater than 109 C (228.2 F) for more than ten seconds.
• The engine has been running for at least 30 seconds.
System Response:
“DIAG” will be displayed next to the status for “Engine Coolant Temperature” on the Caterpillar
Electronic Technician (Cat ET). The check engine lamp and the warning lamp will illuminate.
Note: If a high coolant temperature lamp is installed, the high coolant temperature lamp will turn on
instead of the warning lamp.
Customer passwords are required to clear this diagnostic code.
Possible Performance Effect:
The engine will be derated. The engine power and the vehicle speed will be limited. The amount of derate depends on the engine coolant temperature.
Note: If the “Engine Monitoring” parameter is programmed to “Warning”, the engine power is not affected.
Troubleshooting:
Check the Cooling System Refer to Testing and Adjusting, “Cooling System – Check”.
Results:
• OK – STOP.
