"Stop-Engine Temp" Telltale and Chime
TEST CONDITION(S)
1) Engine is running.
FAILURE CONDITION(S)
1) Engine coolant temperature greater than 125 degrees centigrade.
ACTION TAKEN
1) Light "Stop - Engine Temp" telltale.
DESCRIPTION
The ECM provides and internally monitors voltage to the coolant temperature sensor circuit through pin 3E16. 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 3E16 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 3E16 of the ECM drops low enough), and all other failure conditions are met, the Instrument Panel Cluster (IPC) will light the "Stop - Engine Temp" telltale.
DIAGNOSIS
Refer to engine overheat diagnosis in Cooling Systems. Cooling System