Stop-Engine Temp Telltale and Chime

Stop Engine Temp Circuit:

TEST CONDITION:

1. Engine is running.
2. Coolant temperature not failed.

FAILURE CONDITION:

Engine coolant temperature greater than 126 degrees centigrade.

ACTION TAKEN:

Light "Stop - Engine Temp" telltale. The ECM provides and internally monitors voltage to the coolant temperature sensor circuit through pin C1O. As the coolant temperature goes from cold to hot, the sensor's resistance goes from high to low, and the voltage level the ECM detects at pin C10 goes from high to low. Every 1 second, the BCM checks the ECM for the coolant temperature. If the calculated coolant temperature reaches 126 degrees centigrade (i.e., the voltage at pin C1O of the ECM drops low enough), and all other failure conditions are met, the IPC will light the "Stop - Engine Temp" telltale.