Vision V6-3.5L VIN F (1997)
Temperature Gauge: Description and Operation
At idle the temperature gauge could rise slowly to about 1/2 gauge travel. The fan will come on and the gauge could drop to about 1/3 gauge travel, this
is normal.
CIRCUIT OPERATION
The engine coolant temperature gauge receives its information across the CCD Bus from the Body Control Module (BCM). The engine coolant
temperature sensor uses a variable resistor to send a signal to the Powertrain Control Module (PCM) indicating coolant temperature. The PCM
then sends this information to the BCM across the CCD Bus.
The BCM calculates the position of the engine coolant temperature gauge and based on the information received from the PCM it adjusts the
position of the gauge pointer. This signal is sent over the CCD Bus to the instrument cluster.
The engine coolant temperature lamp is used to alert the operator that the coolant temperature has risen above the normal operating range. When
the Powertrain Control Module (PCM) determines a problem, a message is sent across the CCD Bus to the Body Control Module (BCM).
The PCM receives coolant temperature information from the engine coolant temperature sensor. This sensor uses a variable resistor to send a
signal to the PCM indicating engine coolant temperature.
The BCM processes this message and sends a signal on the CCD Bus to the instrument cluster for lamp illumination. This lamp also is illuminated,
for a few seconds, when the ignition switch is moved from the OFF to the RUN position as a bulb check.
