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 Trouble Code (DTC) List - Vehicle»(/chevrolet/malibu/vi-2003-2006/remont/oem-general-information/#vehicle-dtc-information__diagnostic-trouble-code-dtc-list) in Vehicle DTC Information 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 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 | Units Displayed | Typical Data Value |
|---|---|---|---|
| Engine Idling/Radiator Hose Hot/Closed Throttle/Park or Neutral/Closed Loop/Accessories Off/Brake Pedal Released | |||
| 24X Crank Sensor | Ignition | RPM | 0-6,400 |
| A/C Relay Circuit Status | ODD | OK/Fault/Invalid State | OK |
| A/C Relay Circuit History | ODD | OK/Fault/Invalid State | OK |
| A/C Relay Command | Eng, Misfire, EGR, TAC | On/Off | Off |
| Air Fuel Ratio | Eng, Fuel Trim, HO2S | Ratio | 14.2:1-14.7:1 |
| APP Indicated Angle | Eng, EGR, EVAP, HO2S, Ignition, Misfire, TAC, Fuel Trim | Percent | 0 |
| APP Sensor 1 | TAC | Volts | Varies |
| APP Sensor 1 Circuit | TAC | OK/Not OK | OK |
| APP Sensor 2 | TAC | Volts | Varies |
| APP Sensor 2 Circuit | TAC | OK/Not OK | OK |
| APP Sensor 1 | TAC | Percent | Varies |
| APP Sensor 2 | TAC | Percent | Varies |
| APP Sensor 1 and 2 | TAC | Agree/Disagree | Agree |
| BARO | Eng, EGR, EVAP, Fuel Trim, HO2S, Ignition | KPa | 65-110 kPa |
| Catalytic Converter Protection Active | Fuel Trim, HO2S | Yes/No | No |
| CMP Sensor | Ignition | RPM | Varies |
| CMP Sensor Signal Present | Ignition, Misfire | Yes/No | Yes |
| Cruise Control Active | TAC | Yes/No | No |
| Cycles of Misfire Data | Misfire | Counts | 0-99 |
| Cyl. 1-6 Injector Circuit Status | ODD | OK/Stuck Low (open)/Stuck High | OK |
| Cylinder 1 and 4 IC Circuit Status | ODD | OK/Not OK | OK |
| Cylinder 2 and 5 IC Circuit Status | ODD | OK/Not OK | OK |
| Cylinder 3 and 6 IC Circuit Status | ODD | OK/Not OK | OK |
| Cylinder 1-6 Injector Circuit History | ODD | OK/Stuck Low (open)/Stuck High | OK |
| Decel Fuel Cut-off | Eng, EGR, Fuel Trim, HO2S | Active/Inactive | Inactive |
| Desired EGR Position | EGR, Misfire | Percent | 0 |
| Desired Idle Speed | Eng, EVAP, TAC | RPM | Varies |
| Driver Module 1 Status | ODD | Enabled/Off-High Volts/Off High Temp/Invalid State | Enabled |
| Driver Module 2 Status | ODD | Enabled/Off-High Volts/Off High Temp/Invalid State | Enabled |
| Driver Module 3 Status | ODD | Enabled/Off-High Volts/Off High Temp/Invalid State | Enabled |
| EC Ignition Relay Circuit Status | ODD | OK/Fault/Invalid State | OK |
| EC Relay Circuit History | ODD | OK/Fault/Invalid State | OK |
| ECT Sensor | Eng, EGR, EVAP, HO2S, Ignition, Misfire, Fuel Trim, TAC | °C/°F | Varies |
| EGR Flow Test Count | EGR | Counts | 0-12 |
| EGR Learned Minimum Position | EGR | Volts | 0.14-1.0 |
| EGR Position Sensor | Eng, EGR, Misfire | Percent | Varies |
| EGR Position Sensor | EGR | Volts | 0 |
| EGR Position Variance | EGR | Percent | 0 |
| EGR Solenoid Circuit History | ODD | OK/Open/Fault/Invalid State | OK |
| EGR Solenoid Circuit Status | ODD | OK/Fault/Invalid State | OK |
| EGR Solenoid Command | EGR | Percent | 0 |
| Engine Load | Eng, Misfire, Fuel Trim, EVAP, EGR, HO2S, Ignition, TAC | Percent | 0 |
| Engine Oil Pressure Switch | Eng | Low/OK | OK |
| Engine Run Time | Eng, EVAP, Misfire, Fuel Trim, EGR, HO2S, Ignition, TAC, ODD | Hr: Min: Sec | Varies |
| Engine Speed | Eng, EGR, EVAP, Ignition, Misfire, Fuel Trim, TAC | RPM | Varies |
| EVAP Fault History | EVAP | No Fault/Excess Vacuum/Purge Valve Leak/Small Leak/Weak Vacuum/No Test Result | No Fault |
| EVAP Purge Solenoid Circuit History | ODD | OK/Open/Short | OK |
| EVAP Purge Solenoid Circuit Status | ODD | OK/Open/Short | OK |
| EVAP Purge Solenoid Command | Eng, EVAP, Fuel Trim, HO2S | Percent | Varies |
| EVAP Test Abort Reason | EVAP | No Aborted/Lost Enable/Small Leak/Veh. Not At Rest | Varies |
| EVAP Test Result | EVAP | No Result/Passed/Aborted OR Fail-DTC P0455 OR Fail-DTC P0442 OR Fail-DTC P0446 OR Fail-DTC P0496 | Varies |
| EVAP Test State | EVAP | Waiting for Purge/Test Running/Test Completed | Varies |
| EVAP Vent Solenoid Circuit History | ODD | OK/Open/Short | OK |
| EVAP Vent Solenoid Circuit Status | ODD | OK/Open/Short | OK |
| EVAP Vent Solenoid Command | Eng, EVAP | Venting/Not Venting | Varies |
| FC Relay 1 Circuit History | ODD | OK/Fault/Invalid State | OK |
| FC Relay 1 Circuit Status | ODD | OK/Fault/Invalid State | OK |
| FC Relay 2 and 3 Circuit History | ODD | OK/Fault/Invalid State | OK |
| FC Relay 2 and 3 Circuit Status | ODD | OK/Fault/Invalid State | OK |
| Fuel Level Sensor | EVAP | Volts | Varies |
| Fuel Pump Relay Circuit History | ODD | OK/Fault/Invalid State | OK |
| Fuel Pump Relay Circuit Status | ODD | OK/Fault/Invalid State | OK |
| Fuel Pump Relay Command | Eng | On/Off | On |
| Fuel Tank Level Remaining | EVAP | Percent | 0-104 |
| Fuel Tank Pressure Sensor | Eng, EVAP | Mm Hg/in H2O | Varies |
| Fuel Tank Pressure Sensor | EVAP | Volts | Varies |
| Fuel Trim Cell | EVAP, Eng, Fuel Trim | 0-4 | 0 |
| Fuel Trim Learn | Eng, EVAP, Fuel Trim | Enabled/Disabled | Varies |
| HO2S Bank 1 Sensor 1 | EVAP, Eng, Fuel Trim, HO2S | Millivolts | 0-1000 and Varying |
| HO2S Bank 1 Sensor 1 Ready | Fuel Trim, HO2S | Yes/No | Yes |
| HO2S Bank 1 Sensor 2 | Eng, Fuel Trim, HO2S | Millivolts | 0-1000 and Varying |
| HO2S Bank 2 Sensor 1 Ready | Fuel Trim, HO2S | Yes/No | Yes |
| HO2S Bank 2 Sensor 1 | Eng, EVAP, Fuel Trim, HO2S | Millivolts | 0-1000 and Varying |
| HO2S Bank 2 Sensor 2 | Eng, Fuel Trim, HO2S | Millivolts | 0-1000 and Varying |
| HO2S Htr. Bn. 1 Sen. 1 | HO2S | On/Off | On |
| HO2S Htr. Bank 1 Sensor 1 Command | HO2S | On/Off | On |
| HO2S Htr. Bn. 1 Sen. 2 | HO2S | On/Off | On |
| HO2S Htr. Bank 1 Sensor 2 Command | HO2S | On/Off | On |
| HO2S Heater Bn. 1 Sen. 1 | HO2S | Amps | Varies |
| HO2S Heater Bn. 1 Sen. 2 | HO2S | Amps | Varies |
| HO2S Heater Bn. 2 Sen. 1 | HO2S | Amps | Varies |
| HO2S Heater Bn. 2 Sen. 2 | HO2S | Amps | Varies |
| HO2S Htr. Bn. 1 Sen. 1 Circuit History | ODD | OK/Fault/Invalid State | OK |
| HO2S Htr. Bn. 1 Sen. 2 Circuit History | ODD | OK/Fault/Invalid State | OK |
| HO2S Htr. Bn. 2 Sen. 1 | HO2S | On/Off | On |
| HO2S Htr. Bn. 2 Sen. 1 Circuit History | ODD | OK/Fault/Invalid State | OK |
| HO2S Htr. Bn. 2 Sen. 2 | HO2S | On/Off | On |
| HO2S Htr. Bn. 2 Sen. 2 Circuit History | ODD | OK/Fault/Invalid State | OK |
| HO2S Htr. Bn. 1 Sen. 1 Circuit Status | ODD | OK/Fault/Invalid State | OK |
| HO2S Htr. Bn. 1 Sen. 2 Circuit Status | ODD | OK/Fault/Invalid State | OK |
| HO2S Htr. Bn. 2 Sen. 1 Circuit Status | ODD | OK/Fault/Invalid State | OK |
| HO2S Htr. Bn. 2 Sen. 2 Circuit Status | ODD | OK/Fault/Invalid State | OK |
| Hot Open Loop | Fuel Trim, HO2S | Active/Inactive | Inactive |
| IAT Sensor | Eng, EVAP, EGR, Fuel Trim, HO2S, Ignition, Misfire, TAC | °C/°F | Varies |
| Ignition 1 Signal | EVAP, Eng, EGR, Fuel Trim, HO2S, Ignition, Misfire, ODD, TAC | Volts | Varies |
| Ignition Off Time | EVAP, Eng | Minutes/Varies | Varies |
| Initial Brake Apply Signal | TAC | Released/Applied | Released |
| Injector PWM | Fuel Trim, Misfire | Milliseconds | Varies |
| Knock Retard | EGR, Ignition | Degrees | 0 |
| Long Term FT Bank 1 | Eng, EVAP, Fuel Trim, HO2S | Percent | 10% to +10% |
| Long Term FT Bank 2 | Eng, EVAP, Fuel Trim, HO2S | Percent | 10% to +10% |
| Loop Status | Eng, Fuel Trim, EVAP, HO2S | Open/Closed | Closed |
| MAF Sensor | Eng, EGR, Misfire, EVAP, Fuel Trim, HO2S, Ignition, TAC | G/s | 3-6 (Varies with altitude) |
| MAF Sensor | EVAP, Fuel Trim, HO2S, Misfire, TAC | Hz | 1,200-3,000 (depends on altitude) |
| MAP Sensor | Eng, EGR, Fuel Trim, HO2S, Misfire, TAC | Volts | 0.4-2.0 Volts |
| MAP Sensor | Eng, EVAP, Fuel Trim, HO2S, Ignition, Misfire, EGR, TAC | KPa | 20-48 kPa (Varies with altitude) |
| MIL Circuit History | ODD | OK/Fault/Invalid State | OK |
| MIL Command | EVAP, Eng, EGR, Ignition | On/Off | Off |
| MIL Circuit Status | ODD | OK/Fault/Invalid State | OK |
| Mileage Since DTC Cleared | Eng | Km/h/mph | Varies |
| Misfire Current Cyl. 1-6 | Misfire | Counts | 0 |
| Misfire History Cyl. 1-6 | Misfire | Counts | 0 |
| Moderate Brake Apply Signal | TAC | Applied/Released | Released |
| Number of DTCs | Eng EVAP, Fuel Trim, TAC | Number | 0 |
| PCM Reset | Eng | Yes/No | No |
| Power Enrichment | Eng, Fuel Trim, HO2S, Misfire | Active/Inactive | Inactive |
| Reduced Engine Power | TAC | Active/Inactive | Inactive |
| Short Term FT Bank 1 | Eng, EVAP, Fuel Trim, HO2S | Percent | 10 to +10 |
| Short Term FT Bank 2 | Eng, EVAP, Fuel Trim, HO2S | Percent | 10 to +10 |
| Spark | Eng, Misfire, Fuel Trim, HO2S, Ignition | Degrees | 22 (varies) |
| Start Up ECT | EVAP, Fuel Trim, HO2S | °C/°F | Varies |
| Start Up IAT | EVAP, Fuel Trim, HO2S | °C/°F | Varies |
| Starter Relay Circuit Status | ODD | OK/Fault | OK |
| Starter Relay Circuit History | ODD | OK/Fault/Invalid State | OK |
| Stop Lamp Pedal Switch | Eng, TAC | Released/Applied | Released |
| TAC/PCM Communications Signal | TAC | OK/Fault | OK |
| TAC Stop Lamp Pedal Switch | Eng | Released/Applied | Released |
| TAC Stop Lamp Pedal Switch | TAC | Applied/Released | Released |
| TAC Vehicle Speed Signal | TAC | OK/Fault | OK |
| TCS Delivered Torque Circuit Status | ODD | OK/Fault | OK |
| Torque Request Signal | TAC | Percent | 100% |
| Torque Delivered Signal | TAC | Percent | 75% |
| Total Misfire Count | Misfire | 1-255 | 0 |
| TP Desired Angle | TAC | Percent | Varies |
| TP Indicated Angle | Eng, EGR, Fuel Trim, HO2S, Ignition, EVAP, Misfire, TAC | Percent | % |
| TP Sensor 1 | TAC | Percent | Varies |
| TP Sensor 1 | TAC | Volts | Varies |
| TP Sensors 1 and 2 | TAC | Agree/Disagree | Agree |
| TP Sensor 1 | TAC | OK/Not OK | OK |
| TP Sensor 2 | TAC | Percent | Varies |
| TP Sensor 2 | TAC | Volts | Varies |
| TP Sensor 2 | TAC | OK/Not OK | OK |
| Traction Control Status | TAC | Active/Inactive | Inactive |
| Vehicle Speed Circuit History | ODD | OK/Fault/Invalid State | OK |
| Vehicle Speed Circuit Status | ODD | OK/Fault/Invalid State | OK |
| Vehicle Speed Sensor | Eng, EGR, EVAP, HO2S, Ignition, Fuel Trim, Misfire, TAC | Mph/km/h | 0 |
| Warm-ups w/o Emission Faults | Eng | 1-10 | 0 |
| Warm-ups w/o Non-Emission Faults | Eng | 1-10 | 0 |
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 arranged 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 specific value All the instructions on the scan tool have been completed The accelerator pedal 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 the fuel cut-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 instructions on the scan tool are completed. Stabilized engine speed Fuel injector selected When DISABLE is selected, the PCM turns the injector OFF for 30 seconds. During this period, the engine operates with a misfire. |
| EGR Solenoid | Engine Output Controls | Activates the exhaust gas recirculation (EGR) solenoid in 10 percent increments from 0 to 100 percent or a maximum of 30 seconds at 100 percent. |
| 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 400-2,200 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 purge solenoid in 10 percent increments from 0 to 100 percent. The device control will be aborted and inhibited if the fuel tank pressure (FTP) sensor exceeds 19 mm Hg (10 in H2O). |
| EVAP Vent Solenoid | Engine Output Controls/EVAP System | Activates the vent solenoid. The device control will be aborted and inhibited if the FTP sensor exceeds 19 mm Hg (10 in H2O). |
| EVAP Purge/Seal | Engine Output Controls/EVAP System | Simultaneously activates the purge solenoid in 10 percent increments from 0 to 100 percent and the vent solenoid. The device control will be aborted and inhibited if the FTP sensor exceeds 19 mm Hg (10 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 | Activates the fuel pump relay for 2 seconds. Also turns fuel pump ON and OFF while engine is running. |
| Fuel Trim Enable | Fuel System | Disables the PCMs ability to learn new fuel trim parameters. The commanded states are NONE, ENABLED, DISABLED. The normal commanded state is NONE. 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 fuel trim cells. |
| 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. |
| MIL | Engine Output Controls/Dash Lamps | Activates the malfunction indicator lamp (MIL). The MIL will remain illuminated 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. | |
| HO2S Heater Driver | Engine Output Controls | Activates the heated oxygen sensor (HO2S) heater. The commanded states include NONE, ON, and OFF. The normal commanded state is NONE. The system remains in the commanded state until cancelled by the tool. |
| Throttle Position | TAC System | Operates TAC motor in 10 percent increments to open or close the throttle blade. The test operates during key ON, engine OFF. |
| APP Learn | APP Learn | This procedure allows the TAC system to re-learn the minimum accelerator pedal position in the even of the bracket and rod assembly replacement. |
Powertrain Control Module Scan Tool Output Control