Diagnostic Starting Point - Engine Controls
Begin the system diagnosis with Diagnostic System Check - Vehicle in Vehicle DTC Information. The Diagnostic System Check-Vehicle will provide the following information
- The identification of the control modules which command the system
- The ability of the control modules to communicate through the serial data circuit
- The identification of any stored diagnostic trouble codes (DTCs) and the codes' statuses
The use of the Diagnostic System Check-Vehicle will identify the correct procedure for diagnosing the system and where the procedure is located.
Scan Tool Data List
The Engine 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.
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 normal running engine at idle.
| IMPORTANT | A scan tool that displays faulty data should not be used. The scan tool problem 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 diagnosis.
The column labeled Data List indicates where a parameter can be located on the scan tool. Refer to the scan tool operating manual for the exact locations of the data lists. The following is a description of each term listed
| Scan Tool Parameter | Data List | Parameter Range/Units | Typical Data Values |
|---|---|---|---|
| Engine Idling/Radiator Hose Hot/Closed Throttle/Park/Closed Loop/Accessories OFF | |||
| 5-Volt Reference 1 Circuit | EE, Eng, Ign, TAC | OK/Fault | OK |
| 5-Volt Reference 2 Circuit | EE, Eng, Ign, TAC | OK/Fault | OK |
| 5-Volt Reference 1 | EE, Eng, Ign, TAC | Volts | 4.5 V |
| 5-Volt Reference 2 | EE, Eng, Ign, TAC | Volts | 4.5 V |
| A/C Relay Circuit Status | OD | OK, Incomplete, Short B+, Short Gnd/Open | OK/Incomplete |
| A/C Relay Command | Eng, MF, TAC | On/Off | Varies |
| Air Flow Calculated | EE, Eng, FT, HO2S, MF, TAC | Grams Per Seconds (g/s) | 1-9 g/s @ idle |
| Air Fuel Ratio | Eng, FT, HO2S | X:1 | 14.7:1 |
| Ambient Air Temperature | Eng | °C/°F | Varies |
| APP Indicated Angle | CD, EE, Eng, FT, HO2S, Ign, MF, TAC | 0-100% | 0 |
| APP Sensor 1 | TAC | 0-5.0 Volts | 0.4-1.0 Volt |
| APP Sensor 2 | TAC | 5.0-0 Volts | 4.5-4.1 Volts |
| APP Sensor 1 | TAC | 0-100% | 0% |
| APP Sensor 2 | TAC | 0-100% | 0% |
| APP Sensor 1 and 2 | TAC | Agree/Disagree | Agree |
| APP Sensor 1 Indicated Position | TAC | % | 0% |
| APP Sensor 2 Indicated Position | TAC | % | |
| APP Sensors | TAC | % | 0% |
| BARO | CD, EE, Eng, FT, HO2S, Ign | KPa | 50-104 kPa/ Varies w/Altitude |
| BPP Circuit Signal | TAC | Applied/Released | |
| Brake Booster Pressure | CD, Eng | KPa/in Hg | 54-81 kPa (16-24 in Hg) |
| Brake Booster Pressure | CD | Volts | 8.9-3.4 V |
| Calculated TWC Temp Bank 1 | FT, MF | Degrees C/F | 315-427°C (600-800°F) |
| Calculated TWC Temp Bank 2 | FT, MF | Degrees C/F | 315-427°C (600-800°F) |
| Catalytic Converter Protection Active | CD, FT, HO2S | Yes/No | No |
| CKP Active Counter | Ign | 0-250 Counts | Varies |
| CKP Resync Counter | Ign | Counts | 0 |
| CKP Sensor | Eng, Ign | RPM | 500-700 RPM |
| CMP Active Counter | Ign | 0-250 Counts | Varies |
| CMP Sensor | Eng, Ign, MF | RPM | 1,000-1,400 RPM |
| Cold Start-Up | Eng, EE | Yes/No | Varies |
| Cruise Control Active | Eng, TAC | Active/Inactive | Inactive |
| Cycles of Misfire Data | MF | 0-100 Counts | Varies |
| Cylinder 1-8 IC Circuit Status | OD | OK, Incomplete, Short B+, Short Gnd/Open | OK |
| Cylinder 1-8 Injector Circuit Status | OD | OK, Incomplete, Short B+, Short Gnd/Open | OK |
| Cyl Deactivation Cycles | CD | Counts | Varies |
| Cyl Deact Performance Test | CD, FT | OK/Fault | OK |
| Cyl Deact System Command | CD | V4/V8 | V8 |
| Cyl 1 Deact Sol Command | CD | Cyl On/Cyl Off | Cyl Off |
| Cyl 4 Deact Sol Command | CD | Cyl On/Cyl Off | Cyl Off |
| Cyl 6 Deact Sol Command | CD | Cyl On/Cyl Off | Cyl Off |
| Cyl 7 Deact Sol Command | CD | Cyl On/Cyl Off | Cyl Off |
| Cyl 1 Deact Sol CKT Status | CD | OK, Incomplete, Short B+, Short Gnd/Open | OK/Incomplete |
| Cyl 4 Deact Sol CKT Status | CD | OK, Incomplete, Short B+, Short Gnd/Open | OK/Incomplete |
| Cyl 6 Deact Sol CKT Status | CD | OK, Incomplete, Short B+, Short Gnd/Open | OK/Incomplete |
| Cyl 7 Deact Sol CKT Status | CD | OK, Incomplete, Short B+, Short Gnd/Open | OK/Incomplete |
| Deact Inhibit APP High | CD | Yes/No | No |
| Deact Inhibit APP Rate High | CD | Yes/No | No |
| Deact Inhibit Axle Torque Limiting | CD | Yes/No | No |
| Deact Inhibit Brake Booster Pressure Sensor DTC | CD | Yes/No | No |
| Deact Inhibit Cyl Deactivation Solenoid DTC | CD | Yes/No | No |
| Deact Inhibit DCC Override | CD | Yes/No | No |
| Deact Inhibit ECT Low | CD | Yes/No | No |
| Deact Inhibit ECT Sensor DTC | CD | Yes/No | No |
| Deact Inhibit Eng Oil Temperature | CD | Yes/No | No |
| Deact Inhibit Eng Overtemperature Protection | CD | Yes/No | No |
| Deact Inhibit Eng RPM | CD | Yes/No | No |
| Deact Inhibit EOP | CD | Yes/No | Yes |
| Deact Inhibit EOP Sensor DTC | CD | Yes/No | No |
| Deact Inhibit Hot Coolant Mode | CD | Yes/No | No |
| Deact Inhibit Ignition Voltage | CD | Yes/No | No |
| Deact Inhibit Low Brake Booster Vac | CD | Yes/No | No |
| Deact Inhibit Manifold Vacuum Low | CD | Yes/No | Yes |
| Deact Inhibit MAP Sensor DTC | CD | Yes/No | No |
| Deact Inhibit Maximum Deactivation Time Exceeded | CD | Yes/No | No |
| Deact Inhibit Minimum Time On All Cylinders | CD | Yes/No | No |
| Deact Inhibit Oil Aeration | CD | Yes/No | No |
| Deact Inhibit Piston Protection | CD | Yes/No | No |
| Deact Inhibit TAC System DTC | CD | Yes/No | No |
| Deact Inhibit Torque Reduction | CD | Yes/No | No |
| Deact Inhibit Trans Gear | CD | Yes/No | No |
| Deact Inhibit Trans Range | CD | Yes/No | No |
| Deact Inhibit Trans Shifting | CD | Yes/No | No |
| Deact Inhibit TWC Overtemperature Protection | CD | Yes/No | No |
| Deact Inhibit VSS DTC | CD | Yes/No | No |
| Deact Inhibit VSS Low w/TCC On | CD | Yes/No | No |
| Decel Fuel Cutoff | CD, Eng, FT, HO2S | Active/Inactive | Inactive |
| Desired Idle Speed | EE, Eng, TAC | RPM | ECM Controlled |
| Distance Since DTC Cleared | Eng | Km/miles | Varies |
| Distance with Cyl Activated | CD | Km/miles | Varies |
| Distance with Cyl Deactivated | CD | Km/miles | Varies |
| EC Ignition Relay Circuit Status | OD | OK, Incomplete, Short B+, Short Gnd/Open | OK/Incomplete |
| EC Ignition Relay Command | Eng, TAC | On/Off | On |
| EC Ignition Relay Feedback | Eng, TAC | Volts | 2.25-2.95 Volts |
| ECM Reset | CD, EE, Eng, Ign | Yes/No | No |
| ECT Sensor | All | 39 to +140°C (-38 to +284°F) | 88-105°C (190-221°F) |
| Engine Load | All | 0-100% | 18% @ Idle 21% @ 2500 RPM |
| Engine Off EVAP Test Connections Met | EE | Yes/No | Yes |
| Engine Oil Level Switch | CD | OK/Low | OK |
| Engine Oil Life Remaining | CD | 0-100% | Varies |
| Engine Oil Pressure Sensor | CD, Eng, MF | KPa/psi | 290-330 kPa (42-88 psi) |
| Engine Oil Pressure Switch | CD | OK/Low | OK |
| Engine Oil Temperature | CD | Degrees C/F | 85-105°C (185-220°F) |
| Engine Run Time | All | Hrs, Min, Sec | Varies |
| Engine Speed | All | 0-10,000 RPM | 500-700 RPM |
| Engine Speed Circuit Status | OD | OK, Incomplete, Short B+, Short Gnd/Open | OK |
| EVAP Purge Solenoid Circuit Status | OD | OK, Incomplete, Short B+, Short Gnd/Open | OK/Incomplete |
| EVAP Purge Solenoid Command | EE, Eng, FT, HO2S | 0-100% | 10-25% |
| EVAP Vent Solenoid Circuit Status | OD | OK, Incomplete, Short B+, Short Gnd/Open | OK/Incomplete |
| EVAP Vent Solenoid Command | EE, Eng, FT | Not Venting/Venting | Venting |
| FC Circuit Status | OD | OK, Incomplete, Short B+, Short Gnd/Open | OK/Incomplete |
| Fuel Level Sensor | EE | 0-5 Volts | 0.7-2.5 Volts |
| Fuel Pump Relay Circuit Status | OD | OK, Incomplete, Short B+, Short Gnd/Open | OK/Incomplete |
| Fuel Pump Relay Command | Eng, FT | On/Off | ON |
| Fuel Tank Level Remaining | Eng, MF | 0-100% | Varies |
| Fuel Tank Pressure Sensor | EE, Eng | 32.7 to +14.0 mm/Hg (-17.5 to +7.5 in/H2O) | Varies |
| Fuel Tank Pressure Sensor | EE, Eng | 0-5.0 Volts | Varies |
| Fuel Tank Rated Capacity | EE | 98 Liters (25.9 Gallons) or 96.2 Liters (25 Gallons) | Varies with Fuel Tank Option |
| Fuel Trim Cell | EE, Eng, FT | 0-23 | 19 |
| Fuel Trim Learn | EE, Eng, FT | Enabled/Disabled | Enabled, May Toggle |
| Fuel Volatility | EE, FT, HO2S | Low/Moderate/High | Varies |
| HO2S Bank 1 Sensor 1 | EE, Eng, FT, HO2S | Millivolts | 10-1,000 mV and Varying |
| HO2S Bank 1 Sensor 2 | Eng, FT, HO2S | Millivolts | 10-1,000 mV and Varying |
| HO2S Bank 2 Sensor 1 | EE, Eng, FT, HO2S | Millivolts | 10-1,000 mV and Varying |
| HO2S Bank 2 Sensor 2 | Eng, FT, HO2S | Millivolts | 10-1,000 mV and Varying |
| HO2S BN 1 Sensor 1 Heater | HO2S | Amps | 0.7-0.9 Amps |
| HO2S BN 1 Sensor 2 Heater | HO2S | Amps | 0.4-0.6 Amps |
| HO2S BN 2 Sensor 1 Heater | HO2S | Amps | 0.7-0.9 Amps |
| HO2S BN 2 Sensor 2 Heater | HO2S | Amps | 0.4-0.6 Amps |
| HO2S BNK 1 Sen 1 Heater Circuit Status | OD | OK, Incomplete, Short B+, Short Gnd/Open | OK/Incomplete |
| HO2S BNK 1 Sen 2 Heater Circuit Status | OD | OK, Incomplete, Short B+, Short Gnd/Open | OK/Incomplete |
| HO2S BNK 2 Sen 1 Heater Circuit Status | OD | OK, Incomplete, Short B+, Short Gnd/Open | OK/Incomplete |
| HO2S BNK 2 Sen 2 Heater Circuit Status | OD | OK, Incomplete, Short B+, Short Gnd/Open | OK/Incomplete |
| HO2S Bnk 1 Sensor 1 Heater Command | HO2S | On/Off | ON |
| HO2S Bnk 1 Sensor 1 Heater Command | HO2S | % | 100% |
| HO2S Bnk 1 Sensor 2 Heater Command | HO2S | On/Off | ON |
| HO2S Bnk 1 Sensor 2 Heater Command | HO2S | % | 100% |
| HO2S Bnk 2 Sensor 1 Heater Command | HO2S | On/Off | ON |
| HO2S Bnk 2 Sensor 1 Heater Command | HO2S | % | 100% |
| HO2S Bnk 2 Sensor 2 Heater Command | HO2S | On/Off | ON |
| HO2S Bnk 2 Sensor 2 Heater Command | HO2S | % | 100% |
| Hot Open Loop | CD, FT, HO2S | Active/Inactive | Inactive |
| IAT Sensor | All | 39 to +140°C (-38 to +284°F) | 35°C (91°F) Depends on Ambient Temperature |
| Ignition Accessory Signal | Eng, TAC | On/Off | ON |
| Ignition 1 Signal | All | 0-25 Volts | 11.5-14.5 Volts |
| Inj. PWM Bank 1 Average | Eng, FT, HO2S | Milliseconds | 2-6 |
| Inj. PWM Bank 2 Average | Eng, FT, HO2S | Milliseconds | 2-6 |
| Knock Retard | Ign | 0.0-16° | 0° |
| KS Active Counter | Ign | Counts | Varies |
| KS Bank 1 Circuit Status | Ign | OK/Fault/Incomplete | OK/Incomplete |
| KS Bank 2 Circuit Status | Ign | OK/Fault/Incomplete | OK/Incomplete |
| KS Module Status | Ign | OK/Fault/Incomplete | OK/Incomplete |
| Long Term FT Bank 1 | EE, Eng, FT, HO2S | Percentage | Near 0% |
| Long Term FT Bank 2 | EE, Eng, FT, HO2S | Percentage | Near 0% |
| Loop Status | EE, Eng, FT, HO2S | Open/Closed | Closed |
| MAF Sensor | CD, EE, Eng, FT, HO2S, Ign, MF, TAC | Grams Per Seconds (g/s) | 1-9 g/s @ Idle, Depends on Altitude 15-26 g/s @ 2,500 RPM, Depends on Altitude |
| MAF Sensor | EE, Eng, FT, HO2S, MF | 0-31,999 Hz | 1,150-1,350 Hz |
| MAP Sensor | CD, EE, Eng, FT, HO2S, Ign, MF, TAC | KPa | 20-48 kPa |
| MAP Sensor | CD, Eng, FT, HO2S, MF, TAC | Volts | 1.0-2.0 Volts Varies with Altitude |
| MIL Circuit Status | OD | OK, Incomplete, Short B+, Short Gnd/Open | OK/Incomplete |
| MIL Command | EE, Eng, Ign | Off/On | Off |
| MIL Requested by DTC | CD, EE, Eng, Ign | Yes/No | No |
| Misfire Current Cyl. 1-8 | MF | 0-200 Counts | 0 |
| Misfire History Cyl. 1-8 | MF | 0-65,535 Counts | 0 |
| PNP Switch | CD, Eng | P/N Yes/No in gear | P/N |
| Power Enrichment | Eng, FT, HO2S, MF | Active/Inactive | Inactive |
| Reduced Engine Power | CD, TAC | Active/Inactive | Inactive |
| Short Term FT Bank 1 | EE, Eng, FT, HO2S | Percentage | Near 0% |
| Short Term FT Bank 2 | EE, Eng, FT, HO2S | Percentage | Near 0% |
| Spark | Eng, FT, HO2S, Ign, MF | Degrees | 10-17° |
| Starter Relay Circuit Status | OD | OK, Incomplete, Short B+, Short Gnd/Open | OK/Incomplete |
| Start-Up ECT | EE, FT | °C/°F | Varies |
| Start-Up IAT | EE, HO2S | °C/°F | Varies |
| TAC Forced Engine Shutdown | TAC | Yes/No | No |
| TAC Motor | TAC | Enabled/Disabled | Enabled |
| TAC Motor Command | TAC | 0-100% | 15-35% |
| TCC/Cruise Brake Pedal | Eng | Applied/Released/Invalid | Released |
| TCC/Cruise Brake Pedal Switch | TAC | Applied/Released/Invalid | Released |
| TCS Circuit Status | OD | OK, Incomplete, Short B+, Short Gnd/Open | OK/Incomplete |
| TCS Torque Request Signal | CD, TAC | 0-100% | 100% |
| Torque Delivered Signal | TAC | 0-100% | 5-15% |
| Torque Management Spark Retard | Ign | Degrees | 0° |
| Total Knock Retard | Ign | Degrees | 0° |
| Total Misfire | MF | Counts | Varies |
| TP Desired Angle | TAC | 0-100% | 5.5% |
| TP Indicated Angle | CD, EE, Eng, FT, HO2S, Ign, MF, TAC | 0-100% | 5.5% |
| TP Sensor 1 | TAC | 0-5.0 Volts | 4.1-4.95 Volts |
| TP Sensor 1 | TAC | 0-100% | Varies near 5% |
| TP Sensor 2 | TAC | 5.0-0 Volts | 0.4-0.85 V |
| TP Sensor 2 | TAC | 100-0% | Varies near 5% |
| TP Sensors 1 and 2 | TAC | Agree/Disagree | Agree |
| TP Sensor 1 Indicated Position | TAC | % | 5% |
| TP Sensor 2 Indicated Position | TAC | % | 5% |
| TWC Temperature Calculated | FT, MF | Degrees C/F | 570°C (1,075°F) |
| Vacuum Calculated | CD, EE, Eng, FT, HO2S | KPa/in Hg | 59 kPa/16 in Hg |
| Vehicle Speed Circuit Status | OD | OK, Incomplete, Short B+, Short Gnd/Open | OK/Incomplete |
| Vehicle Speed Circuit 2 Status | OD | OK, Incomplete, Short B+, Short Gnd/Open | OK/Incomplete |
| Vehicle Speed Sensor | CD, EE, Eng, FT, HO2S, Ign, MF, TAC | Km/h mph | 0 |
| Warm-Ups w/o Emission Faults | Eng | 0-255 Counts | Varies |
| Warm-Ups w/o Non-Emission Faults | Eng | 0-255 Counts | Varies |
| Warm-Ups Since DTC Cleared | Eng | Counts | Varies |
| Wide Open Throttle | TAC | Yes/No | No |
Scan Tool Data List
Scan Tool Data Definitions
The Engine Scan Tool Data Definitions contains a brief description of all engine related parameters available on the scan tool. The list is in alphabetical order. A given parameter may appear in any one of the data lists. In some cases, the parameter may appear more than once or in more than one data list in order to group certain related parameters together.
Scan Tool Output Controls
| Scan Tool Output Control | Additional Menu Selection(s) | Description |
|---|---|---|
| Crankshaft Position Variation Learn | Enables the powertrain control module (PCM) to learn the variations in the crankshaft position (CKP) system. The PCM will learn the variations once the following conditions are met: Engine coolant temperature (ECT) is more than a specified value. All instructions on the scan tool have been completed. The accelerator pedal is smoothly applied until the fuel cut-OFF, as specified on the scan tool, is achieved, and then immediately released. The PCM learns the variation values on the deceleration from fuel cut-OFF. | |
| Cylinder 1, Cylinder 4, Cylinder 6, Cylinder 7 | DOD System | This function will enable or disable V8 mode, by energizing or de-energizing each individual, VLOM solenoid either ON or OFF. The normal commanded state is OFF. |
| Cylinder Deactivation System | DOD System | This function will enable or disable V4 mode, by energizing or de-energizing all 4 VLOM solenoids, either ON or OFF. The normal commanded state is OFF. |
| Cylinder Power Balance | Fuel System | Enables/Disables a cylinder by turning OFF the fuel injector to the cylinder. The fuel injector is normally enabled. The PCM disables the fuel injector when the following conditions are met: All instruction on the scan tool are completed Stabilized engine speed The fuel injector is selected When Disable is selected the PCM turns the injector OFF for 30 seconds. During this period, the engine operates with a misfire. |
| Engine Controls Ignition Relay | Engine Output Controls | This function will enable or disable the Engine Controls Ignition Relay. The scan tool will command the engine controller to turn the relay ON or OFF. The normal commanded state is ON. |
| Engine Speed Control | TAC System | Activates the throttle activation control (TAC) system to change engine RPM. The normal commanded state is None. To enable the RPM control, all instruction on the scan tool must be completed. The system will increase or decrease the RPM within a range of 350-2000 RPM. The set step value changes the RPM by increments of 25 RPM, 100 RPM, and 500 RPM. The system remains in the commanded state until cancelled by the scan tool. |
| EVAP Purge Solenoid | Engine Output Controls/EVAP System | Activates the evaporative emission (EVAP) purge valve. The normal commanded state is None. The system will increase or decrease the amount of EVAP purge valve opening by 10 percent increments within a range of 0-100 percent. The system remains in the commanded state until cancelled by the tool or the fuel tank pressure (FTP) exceeds 32 mm Hg (17 in H2O). |
| EVAP Purge/Seal | Engine Output Controls/EVAP System | This control enables two functions. One function increases or decreases the amount of purge by changing the duty cycle of the purge valve and commanding the vent ON, non-venting. The normal commanded state of both valves is None. The system will increase or decrease the amount of EVAP purge valve opening by 10 percent increments within a range of 0-100 percent. The second function seals the system after using the purge function to obtain a specific amount of FTP. When activated the purge valve is commanded to 0 percent and the vent valve is commanded ON, non-venting. Both functions remain in the commanded state until one of the following conditions occurs: Cancelled by the tool The FTP exceeds 32 mm Hg (17 in H2O) |
| EVAP Vent Solenoid | Engine Output Controls/EVAP System | Activates the EVAP vent solenoid. The normal commanded state is None. When commanded ON, the vent valve switches to non-venting. The system remains in the commanded state until one of the following conditions occurs: Cancelled by the tool Purge is greater than 0 percent, and the fuel tank pressure exceeds 32 mm Hg (17 in H2O) |
| Fuel Injector Balance | Fuel System | Enables the fuel injector in order to verify proper fuel injector flow. The PCM will pulse the selected injector when the following conditions are met: All instruction on the scan tool completed Fuel injector selected Key ON, engine OFF The selected fuel injector can only be flowed/pulsed once per ignition cycle. |
| Fuel Pump | Engine Output Controls | Controls the fuel pump relay. The normal commanded state is None. When commanded ON/OFF, the PCM turns the fuel pump ON/OFF. If the engine is running, and the fuel pump is commanded OFF, the engine will stall. The system remains in the commanded state until cancelled by the scan tool. |
| Fuel Trim Enable | Fuel System | Disables the PCMs ability to learn new fuel trim parameters. The system remains in the commanded state until cancelled by the scan tool. |
| Fuel Trim Reset | Fuel System | Activates the reset of fuel trim data in all of the fuel trim cells. |
| HO2S Heater Command | Heated Oxygen Sensors | Commands HO2S Heater ON, 0-100% in 10% increments while the engine is running. |
| Loop Status | Engine Output Controls | Controls the system loop status. The commanded states include None, Open, or Closed. The normal commanded state is None. When commanded Open or Closed, the system remains in the commanded state until cancelled by the scan tool. |
| Malfunction Indicator Lamp | Engine Output Controls | Controls the malfunction indicator lamp (MIL). The commanded states include None, ON, and OFF. When commanded ON or OFF, the system remains in the commanded state until cancelled by the scan tool. |
| Misfire Graphic | Graphs the accumulated misfires occurring in each cylinder. The scan tool allows for a reset of the misfire graph. | |
| O2S Heater Control | Engine Output Controls | Activates the HO2S Heater. The commanded states include None, ON, and OFF. The normal commanded state is None. On a cold engine, with the key ON, engine OFF, the HO2S signal will continue to drop below bias when commanded ON. The system remains in the commanded state until cancelled by the tool. |
| Spark Retard | Engine Output Controls | This function controls the amount of spark retard. The scan tool will command an increase or decrease in the amount of spark retard in 1-degree increments, within a range of 1-10 degrees. The degrees of spark retard will remain in the commanded state until cancelled by the scan tool. The normal commanded state is NONE. |
| Throttle Position | TAC System/Throttle Blade Control | Operates TAC motor in 10 percent increments to open or close the throttle blade. The test operates during key ON, engine OFF. |
Scan Tool Output Controls