Heated Oxygen Sensor Data

START-UP IAT - Scan Tool Range -40°C to 151°C, (-40°F to 304°F)
Indicates the Intake Air Temperature at the time that the vehicle was started. Used by the Heated Oxygen Sensor (HO2S) diagnostic to determine if the last start-up was a cold start.

START-UP ECT- Scan Tool Range -40°C to 151°C, (-40°F to 304°F)
Indicates the Engine Coolant Temperature at the time that the vehicle was started. Used by the HO2S diagnostic to determine if the last start-up was a cold start.

HEATED OXYGEN SENSORS (HO2S BN1 SEN. 1 and HO2S BN2 SEN. 1) Scan Tool Range 0-1132 mV
Represents the fuel control exhaust oxygen sensor output voltage. Should fluctuate constantly within a range between 10 mV (lean exhaust) and 1000 mV (rich exhaust) while operating in "Closed Loop."

HEATED OXYGEN SENSORS (HO2S BN1 SEN. 2 and HO2S BN2 SEN. 3) Scan Tool Range 0-1132 mV
Represents the catalyst monitor exhaust oxygen sensor output voltage. If the catalyst is operating efficiently, the Bank 1 HO2S 2 signal will be far more active than that produced by the Bank 1 HO2S 3 sensor. If the PCM detects a level of Bank 1 HO2S 3 activity that indicates the catalyst is no longer operating efficiently, DTC P0420 will be set.

HO2S XCOUNTS BN1 / HO2S XCOUNTS BN2 - Scan Tool Range 0-255
Indicates the number of times each HO2S signal has crossed the 450 mV bias voltage during a 1 second interval. A HO2S signal that almost never crosses the bias voltage could indicate a fuel trim problem, a faulty HO2S circuit, or a faulty HO2S.

HO2S WARM UP TIME BN1 SEN. 1 / HO2S WARM UP TIME BN2 SEN. 1 / HO2S WARM UP TIME BN1 SEN. 2 / HO2S WARM UP TIME BN1 SEN. 3 - Scan Tool Range 00:00:00-99:99:99 HRS:MIN:SEC
Indicates time to warm-up for each HO2S. The HO2S warm up time is used for the HO2S heater test. The PCM will run the heater test only after a cold start (determined by engine coolant and intake air temperature at the time of start-up) and only once during an ignition cycle. When the engine is started the PCM will monitor the HO2S voltage. When the HO2S voltage indicates a sufficiently active sensor, the PCM looks at how much time has elapsed since start-up. If the PCM determines that too much time was required for the HO2S to become active, a DTC will set. If the engine was warm when started, "HO2S WARM-UP TIME" will display 00:00:00.

ENGINE SPEED - Scan Tool Range 0-9999 RPM
Engine speed is computed by the PCM from the 3X reference input. It should remain close to desired idle under various engine loads with engine idling.

ECT - Scan Tool Range -40°C to 151°C, (-40°F to 304°F)
The Engine Coolant Temperature (ECT) sensor is mounted in the coolant stream and sends engine temperature information to the PCM. The PCM applies 5 volts to the ECT 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 signal voltage and interprets it 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.

MAF - Scan Tool Range 0.0 to 512 gm/s
Mass Air Flow (MAF) is the MAF Input Frequency converted to grams of air per second. This indicates the amount of air entering the engine.

EVAP PURGE PWM - Scan Tool Range 0% to 100%
Represents the PCM commanded PWM duty cycle of the EVAP Purge Solenoid valve. 0% displayed indicates no purge; 100% displayed indicates full purge.

TP ANGLE - Scan Tool Range 0 to 100%
Throttle Position (TP) Angle is computed by the PCM from the TP sensor voltage. TP Angle should display 0% at idle and 100% at wide open throttle.

IGNITION 1 - Scan Tool Range 0-25.5 Volts
This represents the system voltage measured by the PCM at its ignition feed (CKT 439).