Trans Sport V6-191 3.1L VIN D TBI (1995)
Compass: Initial Inspection and Diagnostic Overview
Circuit Operation
COMPASS DISPLAY
The compass display circuitry is entirely contained within the Temperature/Compass Display Module. Initiate compass self-calibrating function or
set the variance.
TEMPERATURE DISPLAY
The Temperature/Compass Display Module applies voltage to the Outside Air Temperature Sensor. The Outside Air Temperature Sensor is a
thermistor, as temperature increases resistance decreases and as temperature decreases resistance increases. As the resistance of the Outside Air
Temperature Sensor increases, the Temperature/Compass Display Module senses a larger voltage drop across the Outside Air Temperature Sensor,
indicating a lower temperature. As the resistance of the Outside Air Temperature Sensor decreases, the Temperature/Compass Display Module
senses a smaller voltage drop across the Outside Air Temperature Sensor, indicating a higher temperature.
The Temperature/Compass Display Module uses the vehicle speed signal, from the Vehicle Speed Sensor Buffer (VIN D) or the Powertrain
Control Module (VIN L), to determine when to update the temperature display with a new outside air temperature reading. The vehicle must be
driven over 30 km/h (18 mph) before the temperature display will be updated.
Troubleshooting Hints
PERFORM BEFORE BEGINNING SYSTEM DIAGNOSIS
1. Check for missing or damaged connector seal at the Outside Air Temperature Sensor.
2. "SC" or "OC" appears in the temperature display during operation, refer to Symptom Table. See: Symptom Related Diagnostic
Procedures/Diagnosis By Symptom
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Check for a broken (or partially broken) wire inside of the insulation which could cause system malfunction but prove "GOOD" in a
continuity/voltage check with a system disconnected. These circuits may be intermittent or resistive when loaded, and if possible, should be
checked by monitoring for a voltage drop with the system operational (under load).
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Check for proper installation of aftermarket electronic equipment which may affect the integrity of other systems (refer to General
Troubleshooting Procedures). See: Diagrams/Diagnostic Aids
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Refer to System Diagnosis. See: Diagnostic Trouble Code Tests and Associated Procedures
