Part 1 - A to F

SCAN TOOL DATA DEFINITIONS

A/C High Side Pressure: Scan tool displays 0.00 to 5.00 Volts. Represents the A/C refrigerant pressure sensor signal. The amount of pressure indicates the amount of load that the A/C compressor is placing on the engine. The PCM uses this information to adjust idle and to control the cooling fans.

A/C Pressure Out Of Range: Scan tool displays YES or NO. YES displayed indicates that the PCM is monitoring an A/C Refrigerant Pressure signal voltage which is too high or too low to allow the A/C compressor clutch to engage.

A/C Relay: A/C Relay indicates the diagnostic state of the output driver for the A/C Relay control circuit. The Scan tool displays Fault or OK.

A/C Request: Scan tool displays YES or NO. YES displayed indicates that the PCM is detecting an A/C request from the HVAC control head.

Actual EGR Position: Scan tool range 0 percent to 100 percent. Represents the actual position of the EGR pintle in percent. 0 percent displayed indicates a fully extended pintle (EGR valve closed).

A.I.R. Active Test Air Injection: A.I.R. Active Test Air Injection represents whether the active test has been run. The Scan tool displays Yes or No.

A.I.R. Active Test Inhibited: A.I.R. Active Test Inhibited indicates whether the PCM is inhibiting the AIR active test. The Scan tool displays Yes or No.

A.I.R. Active Test Passed: A.I.R. Active Test Passed indicates whether the active test has been run and has passed. The Scan tool displays Yes or No.

A.I.R. Passive Test Inhibited: A.I.R. Passive Test Inhibited indicates whether the AIR passive test is being inhibited by the PCM. The Scan tool displays Yes or No.

A.I.R. Passive Test In Progress: A.I.R. Passive Test In Progress indicates whether the AIR passive test is currently running. The Scan tool displays Yes or No.

A.I.R. Passive Test Passed: A.I.R. Passive Test Passed indicates whether the passive test has passed. The Scan tool displays Yes or No.

A.I.R. Passive Test 1 Passed: A.I.R. Passive Test 1 Passed indicates whether the first passive test has passed. The Scan tool displays Yes or No.

A.I.R. Passive Test 2 Failed: A.I.R. Passive Test 2 Failed indicates whether the second passive test has failed. The Scan tool displays Yes or No.

A.I.R. Pump Relay: A.I.R. Pump Relay indicates the commanded state of the AIR pump relay. The Scan tool displays On or Off.

A.I.R. Pump Relay: A.I.R. Pump Relay indicates the diagnostic state of the output driver for the AIR pump relay control circuit. The Scan tool displays Fault or OK.

A.I.R. Solenoid: A.I.R. Solenoid indicates the commanded state of the AIR solenoid. The Scan tool displays On or Off.

A.I.R. Solenoid: A.I.R. Solenoid indicates the diagnostic state of the output driver for the AIR solenoid control circuit. The Scan tool displays Fault or OK.

Air Fuel Ratio: Scan tool range 0.0 to 25.5. Air Fuel Ratio indicates the PCM commanded value. In closed loop, Air Fuel Ratio should normally be around 14.2 - 14.7. A lower Air Fuel Ratio indicates a richer commanded mixture, which may be seen during Power Enrichment or TWC Protection modes. A higher Air Fuel Ratio indicates a leaner commanded mixture. This can be seen during Decel Fuel Mode.

BARO: Scan tool range 10 to 105 kPa / 0.00 to 5.00 volts. The barometric pressure reading is determined from the MAP sensor signal monitored during key up and Wide-Open Throttle (WOT) conditions. Barometric pressure is used to adjust fuel delivery and spark advance to compensate for altitude changes.

Boost Solenoid: Scan tool range 0 percent to 100 percent. Represents the amount of manifold boost pressure commanded by the PCM. 100 percent displayed indicates full boost commanded.

Brake Switch: Scan tool displays Engaged or Released. Engaged indicated the brake pedal is depressed.

Cam Signal Present: Scan tool displays YES or NO. YES indicates the PCM is detecting cam sensor pulses from the ignition control module.

Change Oil Lamp: Change Oil Lamp indicates the diagnostic state of the output driver for the Change Oil Lamp control circuit. The Scan tool displays Fault or OK.

Commanded A/C: Scan tool displays ON or OFF. Represents the PCM commanded state of the A/C compressor clutch relay driver circuit. The A/C compressor clutch should be engaged when Commanded A/C displays ON.

Commanded Gen: Scan tool displays ON or OFF. OFF displayed indicates that the PCM has commanded the generator control circuit OFF.

Cruise: Scan tool displays ENGAGED or DISENGAGED. Represents the state of the Cruise Status Input from the SMCC module. Cruise should not display ENGAGED unless the vehicle is operating in cruise control.

Cruise Inhibit: Scan tool displays YES or NO. YES displayed indicates that the PCM is commanding the SMCC module to inhibit cruise control operation. Should display YES with park, neutral, reverse or low gear selected.

Cruise Inhibit Reason: Scan tool displays vehicle speed. Cruise operation is inhibited below 25 mph.

Current Gear: Scan tool displays numbers 1, 2, 3, or 4. The PCM looks at Trans Range position and the gear commanded by the PCM. The actual forward gear that the Transaxle is in will be the lower of the two because the manual valve can override the PCM commanded gear.

Cylinder # Injector: Cylinder # Injector indicates the diagnostic state of the output driver for the Cylinder # Injector control circuit. The Scan tool displays Fault or OK.

Decel Fuel Mode: Scan tool displays ACTIVE or INACTIVE. ACTIVE displayed indicates that the PCM has detected conditions appropriate to operate in Deceleration Fuel Mode. The PCM will command deceleration fuel mode when a sudden decrease in throttle position has been detected while the vehicle is traveling over 25 mph. While in Deceleration Fuel mode, the PCM will decrease the amount of fuel delivered by entering Open Loop and decreasing the injector pulse width.

Desired EGR Position: Scan tool range 0 percent to 100 percent. Represents the EGR pintle position that the PCM is commanding. Desired EGR Position should stay close to Actual EGR Position.

Desired Idle Speed: Scan tool range 0 to 3187 RPM. The idle speed is commanded by the PCM. The PCM will compensate for various engine loads based on engine coolant temperature to keep the engine at the desired idle speed.

Driver Module Status: Scan tool displays Enabled or Disabled. Represents the state of the output driver module.

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. 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 decreases and the PCM interprets the lower voltage as a warm engine.

EGR Closed Valve Pintle Position: Scan tool range 0.0 to 5.0 volts. Represents the learned voltage that the PCM uses to determine whether or not the EGR valve is fully closed (0 percent pintle position). If the Desired EGR Position is 0 percent and a difference of more than 0.4 volt between EGR Feedback and EGR Closed Valve Pintle Position is detected, DTC P1404 will set.

EGR Duty Cycle: Scan tool range 0 percent to 100 percent. Represents the EGR valve driver PWM signal from the PCM. A duty cycle of 0 percent indicates that no EGR flow is being commanded; a 100 percent duty cycle indicates maximum EGR flow commanded.

EGR Feedback: Scan tool range 0.00 to 5.00 volts. Indicates the EGR pintle position sensor signal voltage being monitored by the PCM. A low voltage indicates a fully extended pintle (closed valve); a voltage near 5 volts indicates a fully retracted pintle (open valve).

EGR Flow Test Count: Scan tool range 0 to 255. Indicates the number of EGR flow test samples collected during the current ignition cycle. The maximum number of samples allowed is 1 during normal operation. If the PCM battery feed has been disconnected or a DTC P0401 has been cleared, several EGR flow test samples will be allowed during the next ignition cycle. This is to allow repair verification during a single ignition cycle.

EGR Position Error: Scan tool range 0 percent to 100 percent. Indicates the difference between Desired EGR Position and Actual EGR Position currently being monitored by the PCM. If the EGR Position Error reaches an unacceptable level, DTC P0404 will set.

Engine Hot Lamp: Scan tool displays ON or OFF. Represents the commanded state of the output driver.

Engine Load: Scan tool range 0 percent to 100 percent. Engine load is calculated by the PCM from engine speed and MAF sensor readings. Engine Load should increase with an increase in RPM or air flow.

Engine Oil Level: Scan tool displays OK or LOW. Indicates the oil level as determined by the Engine Oil Level switch.

Engine Oil Life: Scan tool range 0 percent to 100 percent. Indicates the engine oil life index. The PCM calculates Engine Oil Life based upon the number of engine revolutions seen and operating conditions such as calculated oil temperature. Pressing the Oil Life Monitor reset switch will return the displayed Engine Oil Life to 100 percent.

Engine Run Time: Scan tool range 00:00:00 to 99:99:99 Hrs:Min:Sec. Indicates the time elapsed since the engine was started. If the engine is stopped, ENGINE RUN TIME will be reset to 00:00:00.

Engine Speed: Scan tool range 0 to 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.

EVAP Canister Purge: Scan tool range 0 percent to 100 percent. Represents the PCM commanded PWM duty cycle of the EVAP Purge valve. 0 percent displayed indicates no purge; 100 percent displayed indicates full purge.

EVAP Fault History: Scan tool displays NO FAULT, EXCESS VACUUM, PURGE VALVE LEAK, SMALL LEAK, or WEAK VACUUM. The EVAP Fault History indicates the status of EVAP system diagnostics performed by the PCM.

EVAP Purge Sol: Scan tool displays Fault or OK. Represents the diagnostic state of the output driver for the Evap Purge Solenoid control circuit.

EVAP Vent Sol: Scan tool displays OPEN or CLOSED. Represents the state of the EVAP Canister fresh air vent solenoid. Should be open during normal operation.

Fans High Speed: Scan tool displays On or Off. Represents the commanded state of the output driver for the high speed fan relay control circuit.

Fans Low Speed: Scan tool displays On or Off. Represents the commanded state of the output driver for the low speed fan relay control circuit.

FC Relay 1: Scan tool displays Fault or OK. Represents the diagnostic state of the output driver for the low speed fan relay control circuit.

FC Relay 2 & 3: Scan tool displays Fault or OK. Represents the diagnostic state of the output driver for the high speed and the series/parallel fan relays control circuit.

Fuel Level: Scan tool range 0 percent to 100 percent. The PCM uses the fuel level sensor input to calculate the amount of fuel in the tank. The PCM uses the fuel level input for the EVAP system diagnostics and to control the fuel gauge.

Fuel Pump: Scan tool displays ON or OFF. Indicates the PCM commanded state of the fuel pump relay control circuit.

Fuel Pump Ckt Status: Scan tool displays Fault or OK. Represents the diagnostic state of the output driver for the Fuel Pump relay control circuit.

Fuel Pump Ckt Hist.: Scan tool displays Fault or OK. Represents the diagnostic state history of the output driver for the Fuel Pump relay control circuit.

Fuel Pump Speed: Scan tool displays NORMAL or HIGH. Indicates the PCM commanded state of the fuel pump speed control PWM circuit to the fuel pump control module. The fuel pump will be run at high speed to deliver more fuel volume when the MAP sensor indicates high engine load or when system voltage is less than 10 volts.

Fuel Tank Pressure: Scan tool displays 0 to 64 In. H2O / 0.00 to 5.00 Volts. The signal from the fuel tank pressure sensor is monitored by the PCM to verify that the evaporative emissions control system is operating correctly and leaks are not present. Fuel Tank Pressure level is used extensively for EVAP purge control and EVAP system diagnostics.

Fuel Trim Cell: Scan tool range 0 to 9. Fuel trim cell is dependent upon engine speed and MAF sensor readings. A plot of RPM vs. MAF is divided into 10 cells. Fuel trim cell indicates which cell is currently active.

Fuel Trim Learn: Scan tool displays DISABLED or ENABLED. When conditions are appropriate for enabling long term fuel trim corrections, FUEL TRIM LEARN will display ENABLED. This indicates that the long term fuel trim is responding to short term fuel trim. If the Fuel Trim Learn displays DISABLED, long term fuel trim will not respond to changes in short term fuel trim.