Scan Tool Data Definitions Part 1

1-4 Shift Lamp: The scan tool displays On or Off. When the PCM enables the 1-4 shift solenoid, the 1-4 shift lamp comes on and the scan tool displays ON. The scan tool displays OFF under the normal operating conditions.

1-4 Shift Sol.: The scan tool displays Enabled or Disabled. When the PCM enables the 1-4 shift solenoid, the scan tool displays Enabled. The scan tool displays Disabled under the normal operating conditions.

A/C Clutch: The scan tool displays On or Off. The A/C Clutch represents the commanded state of the A/C clutch control relay. When the scan tool indicates ON, the A/C clutch should be engaged.

A/C High Side Pressure: The scan tool displays 15-452 psi/103-3116 kPa. This parameter represents the A/C refrigerant pressure sensor signal. The amount of pressure indicates the amount of load that the A/C compressor places on the engine. The PCM uses this information in order to adjust idle and in order to control the cooling fans.

A/C High Side Pressure: The scan tool displays 0-5.00 volts. This parameter represents the A/C refrigerant pressure sensor signal. The amount of pressure indicates the amount of load that the A/C compressor places on the engine. The PCM uses this information in order to adjust idle and in order to control the cooling fans.

A/C Request: The scan tool displays Yes or No. The A/C Request indicates the state of the A/C request input circuit from the HVAC controls (C60). Vehicles equipped with the CJ2 A/C system, uses the Class 2 serial data to inform the PCM that the A/C is requested. The PCM uses the A/C request signal in order to determine whether the A/C compressor operation is being requested.

A/C Status: The scan tool displays On or Off. The scan tool displays ON when the voltage is applied to the A/C compressor clutch.

AIR Pump Relay: The scan tool displays On or Off. When the PCM grounds the AIR pump relay control circuit, the scan tool indicates ON. When the PCM disables the ground circuit, the scan tool indicates OFF.

AIR Solenoid Relay: The scan tool displays On or Off. When the PCM grounds the AIR pump solenoid control circuit, the scan tool indicates ON. When the PCM disables the ground circuit, the scan tool indicates OFF.

APP Average: The scan tool displays 0-125 counts. The TAC Module takes the voltages from the 3 APP Sensors, averages the readings and converts the readings into counts. The scan tool displays the average. The average is different on every vehicle.

APP Indicated Angle: The scan tool displays 0-100%. The scan tool displays the Accelerator Pedal Position in percentage. When the APP is at rest, the display shows 0%. When the APP is fully depressed, the display shows 100%.

APP Sensor 1: The scan tool displays 0-5.0 Volts. When the accelerator pedal is at 0% (pedal at rest), the display shows less than 1 Volt. When the accelerator pedal is at 100% (pedal fully depressed), the display shows more than 3.3 Volts.

APP Sensor 2: The scan tool displays 5.0 Volts. When the accelerator pedal is at 0% (pedal at rest), the display shows more than 4 Volts. When the Accelerator pedal is at 100% (pedal fully depressed), display shows less than 1 Volt.

APP Sensor 3: The scan tool displays 5.0-0 Volts. When the accelerator pedal is at 0% (pedal at rest), display shows more than 3.5 Volts. When the accelerator pedal is at 100% (pedal fully depressed), display shows less than 2.6 Volts.

APP Sensor 1 Angle: The scan tool displays 0-100%. When the accelerator pedal is at rest, display shows 0%. When the accelerator pedal is fully depressed, display shows 100%. This percentage indicates to the TAC Module the actual pedal position.

APP Sensor 2 Angle: The scan tool displays 0-100%. When the accelerator pedal is at rest, display shows 0%. When the accelerator pedal is fully depressed, display shows 100%. This percentage indicates to the TAC Module the actual pedal position.

APP Sensor 3 Angle: The scan tool displays 0-100%. When the accelerator pedal is at rest, display shows 0%. When the accelerator pedal is fully depressed, display shows 100%. This percentage indicates to the TAC Module the actual pedal position.

APP Sensor 1 Out of Range: The scan tool displays Yes or No. If the APP Sensor voltage is not within the specifications, the scan tool displays YES. If the APP Sensor voltage is within the specifications, the scan tool displays No.

APP Sensor 2 Out of Range: The scan tool displays Yes or No. If the APP Sensor voltage is not within the specifications, the scan tool displays YES. If the APP Sensor voltage is within the specifications, the scan tool displays No.

APP Sensor 3 Out of Range: The scan tool displays Yes or No. If the APP Sensor voltage is not within the specifications, the scan tool displays YES. If the APP Sensor voltage is within the specifications, the scan tool displays No.

APP Sen.1 and APP Sen.2 Disagree: The scan tool displays Yes or No. When the TAC module receives a signal voltage from APP Sensor 1 not in proper relationship to APP Sensor 2, the scan tool displays YES. The scan tool displays NO under the normal operating conditions.

APP Sen.1 and APP Sen.3 Disagree: The scan tool displays Yes or No. When the TAC module receives a signal voltage from APP Sensor 1 not in proper relationship to APP Sensor 3, the scan tool displays YES. The scan tool displays NO under the normal operating conditions.

APP Sen.2 and APP Sen.3 Disagree: The scan tool displays Yes or No. When the TAC module receives a signal voltage from APP Sensor 2 not in proper relationship to APP Sensor 3, the scan tool displays YES. The scan tool displays NO under the normal operating conditions.

Air Fuel Ratio: The scan tool displays the ratio of air to fuel. A typical ratio is 14.0:1.

BARO: Scan Tool Range 10-105 kPa/0.00-5.00 Volts. The Barometric Pressure reading is determined from the MAP sensor signal. The PCM monitors the MAP signal during key up and Wide-Open Throttle (WOT) conditions. The Barometric Pressure compensates for altitude differences.

CAM Signal Input High to Low: The scan tool displays 0-65535 counts. The counts increment as the PCM detects the Camshaft sensor signal voltage going from high to low.

CAM Signal Input Low to High: The scan tool displays 065535 counts. The counts increment as the PCM detects the camshaft sensor signal voltage going from low to high.

Clutch Switch: The scan tool displays Depressed or Released. When the vehicle clutch pedal is depressed the scan tool display shows Depressed, and the cruise control will disengage. When the vehicle clutch pedal is released, the scan tool displays Released, and the cruise control can be resumed.

Cruise Disengage History 1-8: The Scan tool displays the last 8 cruise control disengages in order from 1 to 8. There are 20 possible causes for the cruise control to disengage. Refer to Cruise Control System Circuit Description for descriptions.

Cruise Requested: The scan too; displays Yes or No. When the cruise control switch is in the on position and the Set/Coast switch is activated the scan tool displays YES. When the cruise control switch is in the on position and the Set/Coast switch is released the scan tool displays NO.

Cruise Resume/Accel: The scar tool displays On or Off. When the Cruise control switch is in the on position and the Resume/Accel switch is activated, the scan tool displays ON. When the Resume/Accel switch is released the scan tool displays OFF.

Cruise Set/Coast: The scan tool displays On or Off. When the Cruise control switch is in the on position and the Set/Coast switch is activated, the scan tool displays ON. When the Set/Coast switch is released the scan tool displays OFF.

Cruise Switch: The scan tool displays On or Off. When you activate the cruise control switch, the scan tool displays ON. The switch, when in the ON position, sends a signal voltage to the Throttle Actuator Control (TAC) Module. This allows all other functions of the Cruise Control. When you turn off the cruise control switch, the scan tool displays OFF.

Current Gear: The scan tool displays 04. The scan tool displays which gear the transmission is in. The scan tool displays 9 if the transmission gear is unknown.

Cycles of Misfire Data: Scan Tool Range 0-100. The PCM Counts the number of misfire tests during 200 revolutions.

Cyl. Mode Misfire Index: Scan Tool Range 065535. This parameter displays the amount of crankshaft decelerations. When an engine is operating without a misfire, the scan tool displays less then 1000 counts. When an engine misfire occurs, the counter displays more than 1000 counts.

DTC Set This Ign.: The scan tool displays Yes or No. This parameter indicates if a Diagnostic Trouble Code has set on the current ignition cycle.

Delivered Torque: The scan tool displays -349-349 ft-lbs/-473-473 N.m. This is the calculated torque output from the engine to the transaxle used by the EBTCM for the traction control system operation.

Desired Idle: Scan Tool Range 0-3187 RPM. The PCM commands the desired idle speed. The PCM compensates for various engine loads based on engine coolant temperature in order to keep the engine at the desired speed.

Desired Torque: The scan tool displays -349-349 ft-lbs/-473-473 N.m. The EBTCM sends a Desired Torque Level signal request to the PCM in order to decrease torque from the Powertrain in order to reduce wheel slip during acceleration for the traction control.

Drive 4/OD: The scan tool displays Drive 4/OD. The Scan Tool indicates if the transmission gear selector lever is in Drive 4/OD.

Drive 3/D: The scan tool displays Drive 3/D. The Scan Tool indicates if the transmission gear selector lever is in Drive 3/D.

Drive 2: The scan tool displays 2. The Scan Tool indicates if the transmission gear selector lever is in Drive 2.

Drive 1: The scan tool displays 1. The Scan Tool indicates if the transmission gear selector lever is in Drive 1.

ECT: Scan Tool Range -39°C-140°C (-38°F-284°F). The Engine Coolant Temperature (ECT) sensor is mounted in the cylinder head of the left bank. 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 the voltage as a cold engine. As the sensor warms (internal resistance decreases), the voltage signal decreases and the PCM interprets the lower voltage as a warm engine.

EOP Sensor: The scan tool displays 0-5.0 volts. Scan tool displays engine oil pressure in volts.

Engine Load: Scan Tool Range 0%-100%. The PCM calculates the Engine load from engine speed and MAF sensor readings. The Engine Load increases with an increase in RPM or airflow.

Engine Oil Life Remaining: The scan tool displays 0-100%. The scan tool displays the percent of engine oil life remaining. The PCM calculates the Engine Oil Life by monitoring engine load, engine temperature, and engine speed, etc.

Engine Oil Pressure: The scan tool displays 0-144 psi/0-992 kpa. The scan tool displays engine oil pressure.

Engine Run Time: The scan tool displays Hours, Minutes, Seconds. This indicates the amount of engine run time. When the ignition is cycled off, the timer will reset to zero.

Engine Speed: Scan Tool Range 0-10,000 RPM. The PCM computes Engine speed from the ignition reference pulses. The Engine speed should remain close to desired idle under various engine loads with the engine idling.

EVAP Canister Purge: Scan Tool Range 0%-100%. The PCM commands the PWM duty cycle of the EVAP Purge Solenoid valve. 0% displayed indicates no purge; 100% displayed indicates full purge.

EVAP Vacuum SW.: The scan tool displays Purge or No Purge. The EVAP purge vacuum switch is a normally closed switch positioned in the purge line between the canister and the EVAP purge solenoid. The EVAP purge vacuum switch opens when the vacuum increases to greater than 5 inches of water in the purge line. The PCM uses the EVAP Purge Vacuum Switch to monitor EVAP canister purge solenoid operation and purge system integrity. The EVAP Purge Vacuum Switch is closed to ground with no vacuum present (0% EVAP Purge PWM). With EVAP Purge PWM at 25% or greater, the EVAP Purge Vacuum Switch is open and purge is indicated.

Extended Brake Travel Switch: The scan tool displays Applied or Released. This parameter indicates the state of the extended travel brake switch. This switch is normally closed with the brake pedal released. Scan tool displays Released with the brake pedal released. Scan tool displays Applied with the brake pedal applied approximately greater than 40%.

FC Relay 1: The scan tool displays On or Off. When the PCM commands a coolant fan ON, the scan tool indicates ON. When the PCM commands the fan one relay control ON, both fans enable on low speed.

FC Relay 2 and 3: The scan tool displays On or Off. When the PCM commands a coolant fan ON, the scan tool indicates ON. When both fan control relays are activated, cooling fans enabled on high speed.

Fuel Level Sensor Left Tank: The scan tool displays 5.00-0 Volts. The PCM supplies a 5 volt signal circuit to the fuel level sensor. The float inside the fuel tank is a variable resistor which varies the resistance based on fuel level. The PCM then interprets this voltage as well as the signal voltage from the right tank in order to determine fuel level. The scan tool displays close to 0.8 volts for an empty tank, and close to 2.5 volts for a full tank.

Fuel Level Sensor Right Tank: The scan tool displays 0-5.00 Volts The PCM supplies a 5 volt signal circuit to the fuel level sensor. The float inside the fuel tank is a variable resistor which varies resistance based on fuel level. The PCM then interprets this voltage as well as the signal voltage from the left tank in order to determine fuel level. The scan tool displays close to 0.8 volts for an empty tank, and close to 2.5 volts for a full tank.

Fuel Tank Level Remaining: The scan tool displays 0-72 L (0-19 gal). The scan tool displays in Liters or Gallons the amount of fuel remaining in the fuel tank.

Fuel Tank Level Remaining: The scan tool displays 0-100%. The scan tool displays in percentage the amount of fuel remaining in the fuel tank.

Fuel Tank Rated Capacity: The scan tool displays 0-72 L (0-19 gal). The scan tool displays the capacity of the fuel tank in Liters or Gallons.

Fuel Trim Learn: The scan tool displays Enabled or Disabled. When conditions are appropriate for enabling long term fuel trim corrections, the scan tool displays Enabled. This indicates that the long term fuel trim is responding to the short term fuel trim. If the scan tool displays Disabled, then long term fuel trim will not respond to changes in short term fuel trim.

Generator F Terminal: The scan tool displays 0-255 counts. The display shows Generator F Terminal duty cycle in counts from 0 to 255. The generator is able to produce the desired voltage by varying the duty cycle of the field current.

Generator L Terminal: The scan tool displays Active or Inactive. The scan tool displays Inactive if the PCM does not detect a correct voltage on the L terminal circuit. The scan tool displays Active under the normal operating conditions.

HO2S Bn1 and Bn2 Sensor 1: Scan Tool Range 0-1000 mV. The HO2S Bn1 and Bn2 Sensor 1 parameter represents the fuel control exhaust oxygen sensor output voltage. The voltage should fluctuate constantly within a range between 10 mV (lean exhaust) and 1000 mV (rich exhaust) while operating in Closed Loop.

HO2S Bn1 and Bn2 Sensor 2: Scan Tool Range 0-1000 mV. The HO2S Bn1 and Bn2 Sensor 2 parameter 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.

IAT: Scan Tool Range -39°C to 140°C (-38°F to 284°F). The PCM converts the resistance of the intake air temperature sensor to degrees. The PCM uses the Intake Air Temperature (IAT) in order to adjust fuel delivery and spark timing according to incoming air density.

IC Circuit Cylinder 1-8: The scan tool displays OK or Fault. If there is a problem with an ignition control circuit, the scan tool displays Fault. The scan tool displays OK under the normal operating conditions.

Ignition 1: The scan tool displays 0-25.5 Volts. The Ignition 1 represents the system voltage measured by the PCM at its ignition feed.

Inj. Avg. PWM Bn1 and Bn2: Scan Tool Range 0-1000 m/sec. The Injector average Indicates the amount of time the PCM commands each injector ON during each engine cycle. A longer injector pulse width causes more fuel to be delivered. The Injector Pulse Width should increase with an increased engine load.

Knock Retard: Scan Tool Range 0.0°-16°. Knock Retard indicates the amount of spark the PCM removes from the IC spark advance in response to the signal from the Knock sensors.

KS Activity: The scan tool displays Yes or No. KS activity indicates whether or not the PCM detects KS activity. With the engine idling, the scan tool should indicate NO.

LT FT Avg. Bn1 and Bn2: The scan tool displays Percentage. This parameter indicates the average of all long term fuel trim cells. The short term fuel trim cells are rated (Weighted) for the amount of which they are used. For example, an idle cell is rated higher then a wide open cell. If a fueling malfunction occurs in the idle cell and the wide open cell, the average would be more affected by the idle cell then the wide open cell. A negative value significantly below 0% indicates that the fuel system is rich and fuel delivery is being reduced (decreased injector pulse width). A positive value significantly greater than 0% indicates that a lean condition exists and the PCM compensates by adding fuel (increased injector pulse width). When the average of the cells reach a predetermined high or low, a fuel trim DTC will set.

Long Term FT Bn1 and Bn2: The scan tool displays Percentage. The PCM derives the Long Term Fuel Trim from the Short Term Fuel Trim value. The Long Term Fuel Trim represents a long-term correction of fuel delivery. A value of 0% indicates that fuel delivery requires no compensation in order to maintain the PCM commanded air/fuel ratio. A negative value significantly below 0% indicates that the fuel system is rich and the PCM is reducing the fuel delivery (decreased injector pulse width). A positive value significantly greater than 0% indicates that a lean condition exists and the PCM compensates by adding fuel (increased injector pulse width). Fuel trim values at maximum authority may indicate an excessively rich or lean system.

Loop Status: The scan tool displays Open or Closed. Closed Loop indicates that the PCM is controlling fuel delivery according to oxygen sensor voltage. In Open Loop, the PCM ignores the oxygen sensor voltage and bases the amount of fuel to be delivered on TP sensor, engine coolant, and MAF sensor inputs only.

Low Oil Level: The scan tool displays Yes or No. This parameter indicates when the engine oil level is low. The scan tool displays YES when the PCM detects the engine oil level is low.