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Home >> Pontiac >> 1995 >> Sunfire L4-138 2.3L DOHC VIN D MFI >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Testing and Inspection >> Scan Tool Testing and Procedures >> Scan Tool Data Definitions >> DTC Data
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DTC Data

DTC Freeze Frame - Range #
Indicates which DTC this freeze frame information is for. Clearing out DTCs will erase freeze frame information. This information should be recorded or printed before clearing out any DTCs.


Air Fuel Ratio - Range 0:1 - 25.5:1
Indicates the air fuel ratio based on Oxygen Sensor (02S 1) inputs. The PCM uses fuel trims to adjust fueling to attempt to maintain an air fuel ratio of 14.7:1.

Calc. Air Flow - Range 0-512 gm/sec
The calculated air flow is a calculation based on manifold absolute pressure. The calculation is used in several diagnostics to determine when to run.

ECT - Range -40°C - 215°C (-40°F - 419°F)
The Engine Coolant Temperature (ECT) sensor sends engine temperature information to the PCM. The PCM supplies 5 volts to the engine coolant temperature sensor circuit. The sensor is a thermistor which changes internal resistance as temperature changes. When the sensor is cold (internal resistance high), the PCM monitors a high voltage which it interprets as a cold engine. As the sensor warms (internal resistance decreases), the voltage signal will decrease and the PCM will interpret the lower voltage as a warm engine.

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