For 1990-2009 cars

The Engine Control Module Scan Tool Data List contains all engine-related parameters that are available on the scan tool. The list is arranged in alphabetical order. A given parameter may appear in any one of the data lists, and in some cases may appear more than once, or in more than one data list in order to group certain related parameters together.

Use the Engine Scan Tool Data List only after the following is determined:

• | The Diagnostic System Check - Vehicle is completed.

• | No diagnostic trouble codes (DTCs)

• | On-board diagnostics are functioning properly

The scan tool values from a properly running engine may be used for comparison with the engine you are diagnosing. The Engine Scan Tool Data List represents values that would be seen on a normally running engine.

Important: A scan tool that displays faulty data should not be used. The scan tool concern should be reported to the manufacturer. Use of a faulty scan tool can result in misdiagnosis and unnecessary parts replacement.

Only the parameters listed below are referenced in this service manual for use in diagnosis. If all values are within the typical range described below, refer to Symptoms - Engine Controls for the 1.8 L engine for diagnosis.

#### Engine Control Module Scan Tool Data Parameters

Parameter | System State | Expected Value | Description
--- | --- | --- | ---
Base Operating Conditions: Engine Idling/Radiator Hose Hot/Closed Throttle/Park or Neutral/Closed Loop/Accessories Off/Brake Pedal Released
A/C Cutoff Mode (Air Conditioning) | -- | OK | This parameter displays whether the engine control module is commanding the A/C compressor clutch relay OFF for max acceleration or pressure issues.
A/C Information Switch (Air Conditioning) | -- | Inactive | The scan tool displays Active or Inactive. Active is displayed when the HVAC control module is requesting A/C operation.
A/C Pressure (Air Conditioning) | -- | 0.7 V | The scan tool displays Active or Inactive. Active is displayed when the system pressure exceeds 3,034 kPa (440 psi).
440 kPa
A/C Relay (Air Conditioning) | -- | Inactive | The scan tool displays Active or Inactive. Active is displayed when the ECM has energized the A/C compressor clutch relay.
Ambient Temperature | -- | 0 degrees | Outside temperature at any given altitude expressed in degrees.
APP at Idle Position (Accelerator Pedal Position) | -- | Active | Indicates that the throttle is active and controlling the engine speed without pedal input.
APP Sensor 1 (Accelerator Pedal Position) | -- | 0.96 V | This parameter displays the voltage signal sent to the control module from APP sensor 1 of the APP sensor assembly. APP sensor 1 is a range of values indicating a low voltage when the accelerator pedal is not depressed to a high voltage when the accelerator pedal is fully depressed.
APP Sensor 2 (Accelerator Pedal Position) | -- | 0.47 V | This parameter displays the voltage signal sent to the control module from APP sensor 2 of the APP sensor assembly. APP sensor 2 is a range of values indicating a low voltage when the accelerator pedal is not depressed to a high voltage when the accelerator pedal is fully depressed.
B1S1 Air/Fuel Ratio (Bank 1 Sensor 1) | -- | Rich | A change made to the fuel delivery will be indicated by the Long and Short Term FT values. The Short Term FT values change rapidly in response to the HO2S signal voltages. These changes fine tune the engine fueling. The Long Term FT values change in response to the trends in the Short Term FT. The Long Term FT makes coarse adjustments to the fueling in order to re-center and restore control to the Short Term FT. The Short Term FT and the Long Term FT can be monitored with a scan tool. A Lean fuel trim value indicates that the ECM is adding fuel in order to compensate for a lean condition. A Rich fuel trim value indicates that the ECM is reducing the amount of fuel in order to compensate for a rich condition.
B1S2 Air/Fuel Ratio (Bank 1 Sensor 2) | -- | Rich | A change made to the fuel delivery will be indicated by the Long and Short Term FT values. The Short Term FT values change rapidly in response to the HO2S signal voltages. These changes fine tune the engine fueling. The Long Term FT values change in response to the trends in the Short Term FT. The Long Term FT makes coarse adjustments to the fueling in order to re-center and restore control to the Short Term FT. The Short Term FT and the Long Term FT can be monitored with a scan tool. A Lean fuel trim value indicates that the ECM is adding fuel in order to compensate for a lean condition. A Rich fuel trim value indicates that the ECM is reducing the amount of fuel in order to compensate for a rich condition.
B1S1 O2 Sensor (Bank 1 Sensor 1) | -- | 58-800 mV | The scan tool displays mV. The scan tool displays a range of 0-1,106 mV. The HO2S bank 1 sensor 1 parameter represents the exhaust oxygen sensor output voltage. The voltage fluctuates constantly within a range between 10-1,000 mV while operating in Closed Loop.
B1S2 O2 Sensor (Bank 1 Sensor 2) | -- | 800 mV | The scan tool displays mV. The scan tool displays a range of 0-1,106 mV. The HO2S bank 1 sensor 2 parameter represents the exhaust oxygen sensor output voltage. The voltage fluctuates constantly within a range between 10-1,000 mV while operating in Closed Loop.
B1S1 O2 Sensor Heater (Bank 1 Sensor 1) | -- | Active | This parameter displays the commanded state of the heater control circuit for oxygen bank 1 sensor 1. The oxygen sensor heater should be ON when the scan tool indicates the HO2S Heater Command is Active. The oxygen sensor heater should be OFF when the scan tool indicates the HO2S Heater Command is Inactive.
B1S2 O2 Sensor Heater (Bank 1 Sensor 2) | -- | Active | This parameter displays the commanded state of the heater control circuit for oxygen bank 1 sensor 2. The oxygen sensor heater should be ON when the scan tool indicates the HO2S Heater Command is Active. The oxygen sensor heater should be OFF when the scan tool indicates the HO2S Heater Command is Inactive.
B1 O2 Sensor Loop (Bank 1) | -- | Closed | Closed Loop indicates that the ECM is controlling fuel delivery according to oxygen sensor voltage. In Open Loop, the ECM ignores the oxygen sensor voltage and bases the amount of fuel to be delivered on throttle position (TP) sensor, ECT, and MAF sensor inputs only.
B1 Short Term Fuel Trim (Bank 1) | -- | 0 % | The short term FT values change rapidly in response to the HO2S signal voltages. These changes fine tune the engine fueling. The long term FT values change in response to the trends in the short term FT. The long term FT makes coarse adjustments to the fueling in order to re-center and restore control to the short term FT. The short term FT and the long term FT can be monitored with a scan tool. A positive fuel trim value indicates that the ECM is adding fuel in order to compensate for a lean condition. A negative fuel trim value indicates that the ECM is reducing the amount of fuel in order to compensate for a rich condition.
Battery Voltage | -- | 14.2 V | This parameter displays the voltage measured at the ignition 1 circuit of the control module. Voltage is applied to the control module when the ignition switch is in the ignition 1 position.
Brake Switch 1 | -- | Inactive | This parameter displays the state of the brake pedal position switch as determined by the brake pedal switch. The scan tool will display Active when the brake pedal is depressed, and Inactive when the brake pedal is not depressed.
Brake Switch 2 | -- | Inactive | This parameter displays the state of the brake pedal position switch as determined by the brake pedal switch. The scan tool will display Active when the brake pedal is depressed, and Inactive when the brake pedal is not depressed.
Calculated Pedal Position | -- | 0 % | This parameter displays the average of the accelerator pedal position (APP) sensors. The APP average is a range of values indicating a low number when the accelerator pedal is not depressed to a high number when the accelerator pedal is fully depressed. This value is listed in percent.
Calculated Throttle Position | -- | 13 % | This parameter displays the angle of the TP sensor 2 in percent. This information is calculated by the control module using the signal from the throttle position sensor 2. The scan tool will display a low percentage when the throttle plates are closed. The scan tool will display a high percentage when the throttle plates are fully open.
Catalyst Protection Enrichment (Bank 1) | -- | Inactive | This parameter displays the state of the Catalytic Converter Protection mode.
Clutch Switch | -- | Inactive | This parameter displays the current state of the clutch pedal as determined by the control module.
Coolant Temperature | -- | 1.74 V | The control module supplies 5 volts to the IAT sensor. This parameter shows that voltage supplied.
Coolant Temperature | -- | 61°C / 141.8°F | This parameter displays the temperature of the engine coolant based on the input from the engine coolant temperature sensor. When the coolant temperature is low, the scan tool will display a low temperature. When the coolant temperature is high, the scan tool will display a high temperature.
Cruise Control | -- | Inactive | This parameter displays the status of the cruise control system as determined by the engine control module. The scan tool will display Yes when the cruise control system is in control of vehicle speed. The scan tool will display No when the cruise control system is not operating.
Cruise Control Tip Switch | -- | OFF | This parameter displays the status of the cruise control switch.
Deceleration Fuel Cutoff | -- | Inactive | This parameter displays the status of the operating mode used to turn OFF the fuel injectors during certain deceleration conditions. When the scan tool displays Active, the control module has turned OFF the fuel injectors. When the scan tool displays Inactive, the fuel system is operating normally.
Desired Engine Idle Speed | -- | 775 RPM | This parameter displays the engine idle speed in RPM commanded by the control module. The control module compensates for various engine loads in order to maintain the desired engine RPM at idle. This parameter is not valid unless the engine is running.
Engine Oil Level Status | -- | OK | This parameter displays if the level of the engine oil is within range as determined by the engine control module from information received from the engine oil level switch.
Engine Speed | -- | 780 RPM | This parameter displays the speed of the crankshaft as determined by the control module using an input from the crankshaft position (CKP) sensor. The scan tool will display a high value at high engine speeds and a low value at low engine speeds.
ETC Limp Home Mode | -- | Inactive | The scan tool displays Active or Inactive. The scan tool displays Active when the ECM receives a signal from the TAC module that a throttle actuator control system fault is occurring. The ECM limits the engine power.
Exhaust Camshaft Actual | -- | -105 degrees | This parameter displays the actual exhaust camshaft position in degrees.
Fan Control 1 | -- | Inactive | This parameter displays Active or Inactive. This indicates the commanded state of the relay by the ECM.
Fan Control 2 | -- | Inactive | This parameter displays Active or Inactive. This indicates the commanded state of the relay by the ECM.
Fuel Lever Sensor | -- | Varies | This parameter displays the amount of fuel remaining in the fuel tank. The control module calculates this level using the signal from the sensor used to monitor the fuel level in the fuel tank.
Fuel Pump Relay | -- | Active | This parameter displays the commanded state of the fuel pump relay control circuit. The fuel pump relay should be ON when the scan tool indicates the Fuel Pump Relay Command is ON. The fuel pump relay should be OFF when the scan tool indicates the Fuel Pump Relay Command is OFF.
Fuel Tank Ventilation Valve | -- | Active | This parameter displays the state of the EVAP vent solenoid commanded by the control module expressed as a Venting or Not Venting. The scan tool will display Active when the control module is commanding the EVAP vent solenoid to be open. The scan tool will display Inactive when the control module is commanding the EVAP vent solenoid to be closed.
Full Load Enrichment | -- | Inactive | Scan tool displays Active or Inactive. Active displayed indicates that the ECM has detected conditions appropriate to operate in Power Enrichment mode. The ECM will command Power Enrichment mode when a large increase in throttle position and load is detected. While in Power Enrichment, the ECM will increase the amount of fuel delivered by entering Open Loop and increasing the injector pulse width. This is done to prevent a possible sag or hesitation from occurring during acceleration.
Idle Speed Offset | -- | Inactive | The scan tool displays Inactive, Cold Start, Hot Start, Vehicle Moving, Heater, A/C Performance, Low Battery. The scan tool indicates the condition that requires the ECM to make adjustments to maintain the desired idle speed.
Idle Speed Modified | -- | No | The scan tool displays Yes or No. The scan tool displays Yes when the desired idle speed has been modified using the scan tool program function. When the idle speed has not been modified, the scan tool displays No.
Ignition Dwell Time | -- | 2.7 ms | The ignition coil is charged a short time prior to delivery of the high voltage pulse. The coil will continue to deliver the high voltage for the spark plug for a predetermined amount of time, called spark dwell. This parameter is displayed in degrees.
Ignition Spark Angle | -- | 4 degrees | The ECM controls the ignition coil module assembly, and the spark plug firing for each cylinder in order to generate the ignition spark at a desired crankshaft angle. This controls engine knock noise, and promotes optimum combustion. This parameter is displayed in degrees.
Ignition Status | -- | ON | This parameter displays the voltage measured at the ignition 1 circuit of the control module. Voltage is applied to the control module when the ignition switch is in the ignition 1 position.
12 V
Injector Time | -- | 2.2 mS | The scan tool displays mS. Indicates the base PWM or ON time of the fuel injectors in milliseconds. When the engine load is increased, the injector pulse width will increase. Indicates the amount of time the PCM is commanding each injector ON during each engine cycle. A longer injector pulse width will cause more fuel to be delivered. Injector pulse width should increase with increased engine load.
Intake Air Temperature | -- | 2.56 V | his parameter displays the voltage of the intake air calculated by the engine control module based on the input from the intake air temperature (IAT). The scan tool will display a low value for a low intake air temperature, and a high value for a high intake air temperature.
Intake Air Temperature | -- | 9°C / 48.2°F | The scan tool displays a range of -39 to +140°C (-38 to +284°F). The ECM converts the resistance of the intake air temperature sensor to degrees. The ECM uses the IAT in order to adjust fuel delivery and spark timing according to incoming air density.
Intake Camshaft Actual | -- | 120 degrees | This parameter displays the actual intake camshaft position in degrees.
Intake Manifold Valve 1 | -- | Inactive | This parameter indicates the commanded state of the intake manifold valve. An Active command indicates that the intake manifold valve output is commanded ON, a calibration is used to select whether this results in the valve being commanded Closed or Open for a particular application.
Knock Control | -- | Inactive | This parameter indicates the timing retard commanded by the engine control module. The scan tool will display Inactive if no knock is detected, and Active if a knock is detected and the engine control module retards the ignition timing.
Knock Retard Cylinder 1 | -- | 0 degrees | This parameter indicates the timing retard commanded by the engine control module. The scan tool will display Inactive if no knock is detected, and Active if a knock is detected and the engine control module retards the ignition timing.
Knock Retard Cylinder 2 | -- | 0 degrees | This parameter indicates the timing retard commanded by the engine control module. The scan tool will display Inactive if no knock is detected, and Active if a knock is detected and the engine control module retards the ignition timing.
Knock Retard Cylinder 3 | -- | 0 degrees | This parameter indicates the timing retard commanded by the engine control module. The scan tool will display Inactive if no knock is detected, and Active if a knock is detected and the engine control module retards the ignition timing.
Knock Retard Cylinder 4 | -- | 0 degrees | This parameter indicates the timing retard commanded by the engine control module. The scan tool will display Inactive if no knock is detected, and Active if a knock is detected and the engine control module retards the ignition timing.
Main Relay | -- | Active | This parameter displays when the Main Relay is activated.
Malfunction Indicator | -- | OFF | This parameter displays the commanded state of the MIL control circuit. The malfunction indicator lamp should be ON when the scan tool indicates the MIL Command is ON. The malfunction indicator lamp should be OFF when the scan tool indicates the MIL command is OFF. The control module will command the MIL ON when the ignition is ON with the engine OFF in order to perform a bulb check.
Mass Air Flow Sensor | -- | 1.05 V | The scan tool displays in volts. This parameter indicates the voltage signal sent from the MAF sensor to the engine control module. The scan tool will display a high value indicates a higher engine speed. The scan tool will display a low value at idle.
Mass Air Flow Sensor | -- | 9 kg/h | The scan tool displays kg/h. This parameter indicates the airflow into the engine as calculated by the engine control module based on mass airflow (MAF) sensor inputs. The scan tool will display a high value at higher engine speeds, and a low value at idle.
Non ETC Related Limp Home Mode | -- | Inactive | The scan tool displays Active or Inactive. The scan tool displays Active when an ECM fault is occurring that requires the ECM to limit the engine power.
Normal Engine Operating | -- | Active | This parameter indicated when the engine is in the normal operating conditions.
Oil Level | -- | Normal | This parameter displays if the level of the engine oil is within range as determined by the engine control module from information received from the engine oil level switch.
Oil Pressure | -- | Normal | This parameter indicates if the oil pressure is within a normal range
Park/Neutral Switch | -- | P | The scan tool displays the position of the transmission selection as Park/Neutral or In Gear.
Starter Relay | -- | Active | The scan tool displays Active or Inactive. This displays the commanded state of the starter relay by the ECM.
Throttle Position | -- | Idle | This indicates what speed the engine is at.
Throttle Position PWM Servo Signal | -- | 91 % | This parameter displays the on-time or duty cycle commanded by the control module expressed as a percent. The scan tool will display a high percentage when the control module is moving the throttle blade. The scan tool will display a low percentage when the control module is maintaining throttle position.
TP Sensor 1 Learned Lower Position (Throttle Position) | -- | 0.52 V | This parameter displays the learned minimum voltage for TP sensor 1 as determined by the control module this ignition cycle.
TP Sensor 1 (Throttle Position) | -- | 0.63 V | This parameter displays the voltage signal sent to the control module from the sensor used to monitor the position of the throttle plates. This parameter is for sensor 1 of the TP sensor assembly. The scan tool will display a high voltage when the throttle plates are at rest. The scan tool will display a low voltage when the throttle plates are fully open.
TP Sensor 2 (Throttle Position) | -- | 4.36 V | This parameter displays the voltage signal sent to the control module from the sensor used to monitor the position of the throttle plates. This parameter is for sensor 2 of the TP sensor assembly. The scan tool will display a low voltage when the throttle plates are at rest. The scan tool will display a high voltage when the throttle plates are fully open.
TP Sensor 2 Learned Lower Position (Throttle Position) | -- | 2.04 V | This parameter displays the learned minimum voltage for TP sensor 2 as determined by the control module this ignition cycle.
Vehicle Speed | -- | 0 km/h/mph | The scan tool range is 0-200 km/h (0-125 mph). This parameter displays the vehicle speed. The ECM receives reference pulses from the vehicle speed sensor (VSS) and converts them into km/h and mph for display.
Vehicle Speed in Cruise Control Range | -- | Inactive | This parameter indicates that the vehicle speed is within the cruise control range. The scan tool will read Active if this condition has been met.