For 1990-2009 cars

Use the Typical Scan Data Values table only after the Powertrain On-Board Diagnostic System Check has been completed, no DTC(s) were noted and you have determined the on-board diagnostics are functioning properly. Scan tool values from a properly running engine may be used for comparison with the engine you are diagnosing. The Typical Scan Data values represent values that would be seen on a normally running engine.

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

Only the parameters listed below are referred to in this service manual for use in diagnosis. For further information on using the scan tool to diagnose the PCM and related sensors, refer to the applicable reference section listed below. If all values are within the typical range described below, refer to Symptoms section for diagnosis. The Typical Scan Data Values table contains all the parameters included in the following data lists arranged in alphabetical order:

Engine Idling, Fully Warmed-Up, Closed Loop - Park or Neutral

#### Engine Data

• | ENG 1- Contains general information regarding fuel delivery and basic engine operating conditions.

• | ENG 2 - Contains general information regarding IC, KS, A/C, and basic engine operating conditions.

• | EGR - Contains information specific to the Exhaust Gas Recirculation system flow diagnostics and the EGR valve pintle position sensor diagnostics. Also displays parameters required to verify proper EGR system operation.

• | EVAP - Contains information specific to the EVAP system diagnostics. Also displays parameters required to verify proper EVAP system operation.

• | CATALYST - Contains information specific to the TWC diagnostics and parameters required to verify proper TWC system operation.

• | HO2S - Contains information specific to the Heated Oxygen Sensor diagnostics and parameters required to verify proper HO2S operation.

• | MISFIRE - Contains information specific to the misfire diagnostics and parameters required to verify proper operation with regard to misfire.

### Engine Data

• | ENG 1- Contains general information regarding fuel delivery and basic engine operating conditions.

• | ENG 2 - Contains general information regarding IC, KS, A/C, and basic engine operating conditions.

### Specific Engine Data

• | EGR - Contains information specific to the Exhaust Gas Recirculation system flow diagnostics and the EGR valve pintle position sensor diagnostics. Also displays parameters required to verify proper EGR system operation.

• | EVAP - Contains information specific to the EVAP system diagnostics. Also displays parameters required to verify proper EVAP system operation.

• | CATALYST - Contains information specific to the TWC diagnostics and parameters required to verify proper TWC system operation.

• | HO2S - Contains information specific to the Heated Oxygen Sensor diagnostics and parameters required to verify proper HO2S operation.

• | MISFIRE - Contains information specific to the misfire diagnostics and parameters required to verify proper operation with regard to misfire.

#### Typical Scan Tool Data Values

Scan Tool Parameter | Data List | Units Displayed | Typical Data Value | Reference
--- | --- | --- | --- | ---
A/C High Side Pressure | Engine 2 | Volts | Varies with refrigerant temperature | DTC P0530 Air Conditioning (A/C) Refrigerant Pressure Sensor Circuit
A/C Pressure Out Of Range | Engine 2 | Yes / No | No (Yes with low or high A/C refrigerant pressure) | Powertrain Control Module Controlled Air Conditioning (A/C) Circuit Diagnosis
A/C Request | Engine 2 | Yes / No | No (Yes with A/C ON) | Powertrain Control Module Controlled Air Conditioning (A/C) Circuit Diagnosis
Actual EGR Position | Engine 1 EGR Misfire | Percent | 0% | DTC P1404 Exhaust Gas Recirculation (EGR) Closed Position Performance
Air/Fuel Ratio | Engine 1 HO2S | Ratio | 14.2:1 - 14.7:1 | DTC P0171 Fuel Trim System Lean
BARO | Engine 1 Engine 2 EGR EVAP | kPa / Volts | 65 - 110 kPa (Depends on altitude and barometric pressure). | DTC P0107 Manifold Absolute Pressure (MAP) Sensor Circuit Low Voltage
Boost Solenoid PWM | Engine 2 | Percent | 100% | Boost Control System Diagnosis
Cam Signal Present | Misfire | Yes/No | Yes | Information Sensors/Switches Description
Commanded A/C | Engine 2 | On / Off | Off (On with A/C compressor engaged) | Powertrain Control Module Controlled Air Conditioning (A/C) Circuit Diagnosis
Commanded Fan 1/Commanded Fan 2 | Engine 2 | On / Off | Off (On with fans running) | Electric Cooling Fan Diagnosis
Commanded Gen | Engine 1 | On / Off | On when running | DTC P0560 System Voltage
Cruise | Engine 1 | Engaged / Disengaged | Disengaged | DTC P1554 Cruise Control Feedback Circuit
Cruise Inhibited | Engine 1 | Yes / No | Yes | DTC P1554 Cruise Control Feedback Circuit
Current Gear | Engine 1 | 1 / 2 /3 / 4 | 1 | Functional Test
Decel Fuel Mode | Engine 1 Engine 2 Catalyst HO2S Misfire | Active / Inactive | Inactive | Fuel Metering Modes of Operation
Desired EGR Position | Engine 1 EGR Misfire | Percent | 0% | DTC P1404 Exhaust Gas Recirculation (EGR) Closed Position Performance
Desired Idle Speed | Engine 1 Engine 2 | RPM | PCM commanded idle speed (varies with temperature). | Idle Air Control (IAC) System Diagnosis
ECT | Engine 1 Engine 2 EGR EVAP Catalyst

HO2S

Misfire

°C, °F

85°C - 105°C / 185°F - 220°F (varies with temperature).

DTC P0117 Engine Coolant Temperature (ECT) Sensor Circuit Low Voltage

EGR Closed Val. Pintle Position | EGR | Volts | 0.14-1.0 volt | Evaporative Emission Control System Operation Description
EGR Duty Cycle | EGR | Percent | 0% | Exhaust Gas Recirculation (EGR) System Description
EGR Feedback | EGR | Volts | 0.14 - 1.0 volt | Exhaust Gas Recirculation (EGR) System Description
EGR Flow Test Count | EGR | Counts | 0 - 10 | DTC P0401 Exhaust Gas Recirculation (EGR) Flow Insufficient
EGR Position Error | EGR | Percent | 0% - 9% | DTC P0404 Exhaust Gas Recirculation (EGR) Open Position Performance
Engine Hot Lamp | Engine 2 | On/Off | Off | --
Engine Load | Engine 1 Engine 2 Catalyst Misfire | Percent | 2% - 5% at idle 7% - 10% at 2500 RPM | --
Engine Oil Level | Engine 2 | Ok / Low | Ok | Engine Oil Level Sensor and/or Switch Diagnosis
Engine Oil Life | Engine 2 | Percent | 0%-100% (varies) | --
Engine Run Time | Engine 1 Engine 2 EVAP Catalyst | Hr: Min: Sec | Depends on time since startup. | --
Engine Speed | Engine 1 Engine 2 EGR EVAP Catalyst

HO2S

Misfire

RPM

±100 RPM from Desired Idle

--

EVAP Canister Purge | EVAP HO2S | Percent | 0% - 25% (varies) | Evaporative Emission Control System Operation Description
EVAP Vent Solenoid | EVAP | Open/Closed | 0% - 25% (varies) | Evaporative Emission Control System Operation Description
Fuel Pump | Engine 2 | On / Off | On | Fuel Supply Component Description
Fuel Pump Speed | Engine 2 | Normal / High | Normal | Fuel Supply Component Description
Fuel Tank Pressure | EVAP | In H20 Volts | 0 | Evaporative Emission Control System Diagnosis
Fuel Trim Cell | Engine 1 | Cell # | 0 | DTC P0171 Fuel Trim System Lean
Fuel Trim Learn | Engine 1 | Disabled / Enabled | Enabled | --
Generator PWM | Engine 2 | Percent | Varies | Charging System Description
HO2S Sen. 1 | Engine 1 HO2S | Not Ready / Ready | Ready | DTC P0135 HO2S Heater Performance Sensor 1
HO2S Sen. 1 | Engine 1 HO2S Catalyst | millivolts | 0 - 1000, constantly varying | Information Sensors/Switches Description
HO2S Sen. 2 | Engine 1 HO2S Catalyst | mIllivolts | 0 - 1000,varies | Information Sensors/Switches Description
HO2S Warm Up Sensor 1 / HO2S Warm Up Sensor 2 | HO2S | Min: Sec | Depends on startup intake air temperature, startup engine coolant temperature, and time to HO2S activity. | Information Sensors/Switches Description
HO2S XCount | HO2S | Counts | Varies | --
IAC Position | Engine 1 Engine 2 EGR Catalyst Misfire | Counts | 10 - 40 | Idle Air Control (IAC) System Diagnosis
IAT | Engine 1 Engine 2 EVAP Catalyst HO2S | °C, °F | Varies with ambient air temperature. | DTC P0112 Intake Air Temperature (IAT) Sensor Circuit Low Voltage
Ignition 1 | Engine 1 Engine 2 EGR HO2S | Volts | 13 (Varies) |
Ignition Mode | Engine 2 | IC / Bypass | IC | Electronic Ignition (EI) System Description
Injector Pulse Width | Engine 1 | milliseconds | 1.5 - 3.5 (Varies with engine load) | --
Knock Retard | Engine 2 | Degrees | 0° | Knock Sensor (KS) System Description
Long Term Fuel Trim | Engine 1 Misfire | Percent | -10% - 10% | DTC P0171 Fuel Trim System Lean
Loop Status | Engine 1 Catalyst HO2S Misfire | Open / Closed | Closed | DTC P0125 Engine Coolant Temperature (ECT) Insufficient for Closed Loop Fuel Control
Low Oil Lamp | Engine 2 | On / Off | Off | Powertrain Control Module Controlled Warning Lamps Diagnosis
MAF | Engine 1 Engine 2 Catalyst HO2S | gm/s | 3 - 6 gm/s at idle 13 - 16 gm/s at 2500 RPM (Depends on engine load and barometric pressure) | Information Sensors/Switches Description
MAF Frequency | Engine 1 | Hz | 1200 - 3000 (Depends on engine load and barometric pressure) | DTC P0102 Mass Air Flow (MAF) Sensor Circuit Low Frequency
MAP | Engine 1 Engine 2 EGR EVAP | kPa / Volts | 29 - 48 kPa / 1 - 2 Volts (Depends on engine load and barometric pressure). | DTC P0108 Manifold Absolute Pressure (MAP) Sensor Circuit High Voltage
MIL | Engine 2 | On / Off | Off | Malfunction Indicator Lamp (MIL) Inoperative
Misfire Current Cylinder # | Misfire | Counts | 0 - 4 | DTC P0300 Engine Misfire Detected
Misfire History Cylinder # | Misfire | Counts | 0 | DTC P0300 Engine Misfire Detected
Misfiring Cylinder | Misfire | 0 - 6 | 0 | DTC P0300 Engine Misfire Detected
Power Enrichment | Engine 1 Engine 2 Catalyst HO2S Misfire | Active / Inactive | Inactive | Fuel Metering Modes of Operation
Rich/Lean | Engine 1 | Rich / Lean | Constantly changing | Fuel Metering Modes of Operation
Short Term Fuel Trim | Engine 1 Misfire | Percent | -10% - 10% | DTC P0171 Fuel Trim System Lean
Spark | Engine 2 | Degrees | 20° (varies) | Electronic Ignition (EI) System Description
Start Up ECT | EVAP HO2S | °C, °F | Depends on engine coolant temperature at time of startup | DTC P0117 Engine Coolant Temperature (ECT) Sensor Circuit Low Voltage
Start Up IAT | EVAP HO2S | °C, °F | Depends on intake air temperature at time of startup | DTC P0113 Intake Air Temperature (IAT) Sensor Circuit High Voltage
Throttle at Idle | Engine 1 | Yes / No | Yes | --
Total Misfire Current Count | Misfire | Counts | 0 - 5 | DTC P0300 Engine Misfire Detected
Total Misfire Failures Since First Fail | Misfire | Counts | 0 | DTC P0300 Engine Misfire Detected
Total Misfire Passes Since First Fail | Misfire | Counts | 0 | DTC P0300 Engine Misfire Detected
TP Angle | Engine 1 Engine 2 EGR Catalyst HO2S

Misfire

Percent

0%

DTC P0121 Throttle Position (TP) Sensor Performance

TP Sensor | Engine 1 | Volts | 0.20 - 0.74 | DTC P0122 Throttle Position (TP) Sensor Circuit Low Voltage
Traction Control | Engine 2 | Active / Inactive | Inactive | ABS Operation
Traction Control Desired Torque | Engine 2 | Percent | 100% at idle | ABS Operation
Traction Control Torque | Engine 2 | Percent | 83% at idle (Varies with load) | ABS Operation
Transmission Range | Engine 2 | Park / Reverse / Neutral / Drive 4 / Drive 3 / Drive 2 / Low | Park | DTC P0706 Trans Range Switch Performance
TR Switch P / A / B / C | Engine 2 | High / Low | Low / Low / High / High | DTC P0705 Trans Range Switch Circuit
TWC Protection | Engine 1 Engine 2 Catalyst HO2S Misfire | Active / Inactive | Inactive | Fuel Metering Modes of Operation
Vehicle Speed | Engine 1 Engine 2 EGR Catalyst Misfire | MPH, Km/h | 0 | Functional Test
VTD Fuel Disable | Engine 2 | Active / Inactive | Inactive | DTC P1629 Theft Deterrent Fuel Enable Signal Not Received
3 X Crank Sensor | Misfire | RPM | Varies with engine RPM | Information Sensors/Switches Description
18 X Crank Sensor | Misfire | RPM | Varies with engine RPM | Information Sensors/Switches Description