DTC Data

DTC FREEZE FRAME - RANGE #:
Indicates which DTC this freeze frame information is for. Clearing out DTC's will erase freeze frame information. This information should be recorded or printed before clearing out any DTC's.

AIR FUEL RATIO - RANGE 0:1- 25.5:1:
Indicates the air fuel ratio based on Oxygen Sensor (O2S 1) inputs. The PCM uses fuel trims to adjust fueling to attempt to maintain an air fuel ratio of 14.7:1.

CALCULATED AIR FLOW - RANGE 0-512 GRAMS/SECOND:
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-151°C (-40°F-304°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.

BARO - RANGE 11-105 KPA, 0-5.0 VOLTS:
The Barometric Pressure (BARO) sensor measures the change in the intake manifold pressure which results from altitude changes. This value is updated at ignition ON and also at Wide Open Throttle (WOT).

BASE PWM CYL. 1 - RANGE 0-999.9 MS:
Indicates the base Pulse Width Modulation (PWM) or ON time of the cylinder 1 injector in milliseconds. When the engine load is increased, the injector pulse width will increase.

SHORT TERM FT - RANGE 0-255 (-100% to 100%):
Short Term Fuel Trim (FT) represents a short term correction to fuel delivery by the PCM in response to the amount of time the oxygen sensor voltage spends above or below the 450 mV threshold. If the oxygen sensor has mainly been below 450 mV, indicating a lean air/fuel mixture, short term fuel trim will increase to tell the PCM to add fuel. If the oxygen sensor voltage stays mainly above the threshold, the PCM will reduce fuel delivery to compensate for the indicated rich condition.

LONG TERM FT - RANGE 0-255 (-100% to 100%):
Long Term Fuel Trim (FT) is derived from the short term fuel trim value and is used for long term correction of fuel delivery. A value of 128 counts (0%) indicates that fuel delivery requires no compensation to maintain a 14.7:1 air/fuel ratio. A value below 128 counts means that the fuel system is too rich and fuel delivery is being reduced (decreased injector pulse width). A value above 128 counts indicates that a lean condition exists and the PCM is compensating.

MAP - RANGE 11-105 KPA, 0-5.0 VOLTS:
The Manifold Absolute Pressure (MAP) sensor measures the change in the intake manifold pressure which results from engine load and speed changes. As the intake manifold pressure increases, the air density in the intake also increases and additional fuel is required.

ENGINE SPEED - RANGE 0-16384 RPM:
Engine Speed is computed by the PCM from the fuel control reference input. It should remain close to desired idle under various engine loads with the engine idling. Loop Status - Range Open / Closed: Closed Loop is displayed indicating that the PCM is controlling fuel delivery according to the Oxygen Sensor (O2S 1) voltage as close to an air/fuel ratio of 14.7 to 1 as possible.

VEHICLE SPEED - RANGE 0-255 MPH, 0-255 KM/H:
The vehicle speed sensor signal is converted into MPH/km/h for display. The vehicle speed output from the PCM is 4000 pulses per mile. The scan tool uses the class 2 serial data from the PCM to obtain vehicle speed, while the instrument panel cluster, cruise control module and multi-function alarm module use the 4000 ppm output.

LOAD - RANGE 0100%:
Indicates engine load based on manifold absolute pressure. The higher the percentage, the more load the engine is under.

TP ANGLE - RANGE 0100%:
Throttle Position (TP) angle is computed by the PCM from the TP sensor voltage input. TP angle will auto zero to 0% at idle (TP voltage below .90 volt) and read 100 % at Wide Open throttle (WOT).