Engine Controls and Fuel - 6.2l, or 7.0l - Troubleshooting & Diagnosis Chevrolet Corvette C6

Diagnostic Instructions

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

Symptoms Description

Symptoms cover conditions that are not covered DTCs. Certain conditions can cause multiple symptoms. These conditions are listed together under Symptoms Testing. Conditions that may only cause certain symptoms are listed separately under Additional Symptoms Test. Perform the Symptoms Testing before using the Additional Symptoms Tests. Poor Fuel Fill Quality test may be performed separately from the Symptoms Testing and Additional Symptoms Tests procedures.

Symptoms Verification

Before using the Symptom tables, perform the following inspections

1. Ensure that the engine control module (ECM) and malfunction indicator lamp (MIL) are operating correctly.
2. Ensure that there are no DTCs that are stored.
3. Ensure that the scan tool data is within a normal operating range.
4. Verify the customer concern.
5. Perform the Visual/Physical Inspection in this section. The visual/physical inspection is extremely important, and can lead to correcting a condition without additional testing. It may also help reveal the cause of an intermittent condition.

Identifying Intermittent Conditions

Many intermittent conditions occur with harness or connector movement due to engine torque, rough pavement, vibration or physical movements of a component. Refer to the following for a list of issues that may cause an intermittent condition

1. Moisture and water intrusion in connectors, terminals, and components
2. Incomplete connector mating
3. Poor terminal contact
4. High circuit or component resistance-High resistance can include any resistance, regardless of the amount, which can interrupt the operation of the component.
5. Harness that is too short or tight.
6. Wire insulation that is chaffed or cut.
7. High or low ambient temperature
8. High or low engine coolant temperatures
9. High underhood temperatures
10. Heat build up in component or circuit due to circuit resistance, poor terminal contact, or high electrical load
11. High or low system voltage
12. High vehicle load conditions
13. Rough road surfaces
14. Electro-magnetic interference (EMI)/circuit interference from relays, solenoids or other electrical surge
15. Incorrect installation of aftermarket, add on accessories

Visual/Physical Check

1. Ensure that the control module grounds are clean, tight, and correctly located. Refer to «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs) .
2. Ensure that the vacuum hoses are not split, kinked, and properly connected, as shown on the Vehicle Emission Control Information label.
3. Ensure that the air filter is clean and free from restrictions.
4. Ensure that there is no water intrusion in connectors terminals and components.
5. Inspect the air intake ducts for the following conditions: Collapsed Damaged areas Looseness Incorrect installation Leaking
6. Inspect for air leaks at the throttle body mounting area, the mass air flow (MAF) sensor and intake manifold sealing surfaces.
7. Inspect the wiring harness for the following conditions: Poor connections Pinches Cuts
8. Inspect for loose, damaged, unseated, or missing sensors/components.
9. Inspect the terminals for corrosion and correct contact.

Symptoms Testing

Backfire, Cuts Out/Misses, Detonation/Spark Knock, Dieseling/Run-On, Hard Start, Hesitation/Sag/Stumble, Lack of Power/Sluggishness/Sponginess, Poor Fuel Economy, Rough, Unstable, or Incorrect Idle and Stalling, or Surges/Chuggles

1. Test for the following conditions: The fuel system for the following: Correct fuel pressure - Refer to «Fuel System Diagnosis (W/LS3 or LS7)»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis) or «Fuel System Diagnosis (W/LS9)»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis) . Fuel injectors that are leaking or improper operation - Refer to «Fuel Injector Diagnosis (w/CH47976)»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis) or «Fuel Injector Diagnosis (w/J39021 or w/Tech 2)»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis) . Contaminated or a poor fuel quality condition - Refer to «Alcohol/Contaminants-in-Fuel Diagnosis (without Special Tool)»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis) or «Alcohol/Contaminants-in-Fuel Diagnosis (with Special Tool)»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis) . The ignition system for the following: Spark plugs for incorrect heat range or an abnormal condition - Refer to «Spark Plug Inspection»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction__spark-plug-inspection) . For diagnosis of coolant or oil fouled spark plugs, refer to «Loss of Coolant (LS3, LS7)»(/chevrolet/corvette/c6-2004-2014/remont/cooling-system-mechanical/#engine-cooling-system__loss-of-coolant-ls3-ls7) or «Loss of Coolant (LS9)»(/chevrolet/corvette/c6-2004-2014/remont/cooling-system-mechanical/#engine-cooling-system__loss-of-coolant-ls9) or «Symptoms - Engine Mechanical»(/chevrolet/corvette/c6-2004-2014/remont/mechanical/#engine-mechanical-62l-or-70l-1-of-8) . Wet down the secondary ignition system with water from a spray bottle. Wetting down the secondary ignition system may help locate damaged or deteriorated components. Look/listen for arcing or misfiring as the water is applied. Weak spark using the J 26792 Spark Tester - Refer to «Electronic Ignition System Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis) . See «Special Tools»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) . The operation of the transmission torque converter clutch (TCC)-The scan tool should indicate an engine speed drop when the TCC is commanded ON. The operation of the A/C compressor Items that can cause an engine to run rich or lean. Inspect the heated oxygen sensors (HO2S). The HO2S should respond quickly to different throttle positions. CAUTION: Refer to «Heated Oxygen and Oxygen Sensor Caution»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#dangers-warnings-and-cautions__heated-oxygen-and-oxygen-sensor-caution) . Water intrusion in the HO2S connector NOTE: The embossed arrows on the MAF sensor indicate the direction of the intake air flow. The arrows must point toward the engine. Inspect the MAF sensor installation. A MAF sensor that is incorrectly installed may cause a hard start. Install the MAF in the proper direction. Refer to «Mass Airflow Sensor with Intake Air Temperature Sensor Replacement»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) . Inspect the MAF sensor connections. Engine oil contaminated by fuel The engine for the following mechanical failures - Refer to «Symptoms - Engine Mechanical»(/chevrolet/corvette/c6-2004-2014/remont/mechanical/#engine-mechanical-62l-or-70l-1-of-8) : Excessive oil in the combustion chamber or leaking valve seals Incorrect cylinder compression Sticking or leaking valves Worn camshaft lobes Incorrect valve timing Worn rocker arms Broken valve springs Excessive carbon buildup in the combustion chambers-Clean the chambers with top engine cleaner. Follow the instructions on the can. Incorrect engine parts Vacuum hoses for splits or kinks-Verify that the routing and connections are as shown on the Vehicle Emission Control Information label. Knock sensor (KS) system for excessive spark retard activity - Refer to «DTC P0324, P0325, P0326, P0327, P0328, P0330, P0332, or P0333»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-dtc-p0153-to-dtc-p0507) . The exhaust system components for the following: Physical damage or possible internal failure The three-way catalytic converters for a restriction For more information, refer to «Symptoms - Engine Exhaust»(/chevrolet/corvette/c6-2004-2014/remont/exhaust/#engine-exhaust-system__symptoms-engine-exhaust) . Electromagnetic interference (EMI) on the reference circuit can cause a misfire condition. You can usually detect EMI with a scan tool by monitoring the engine speed parameter. A sudden increase in the engine speed parameter with little change in actual engine speed indicates that EMI is present. Inspect the high voltage components near the ignition control circuit if a condition exists. The crankcase ventilation valve for proper operation - Refer to «Crankcase Ventilation System Inspection/Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/mechanical/#engine-mechanical-62l-or-70l-1-of-8__crankcase-ventilation-system-inspectiondiagnosis) . Evaporative emission (EVAP) canister purge solenoid that is stuck open The engine cooling system for the following conditions: The thermostat is the correct heat range. Refer to «Thermostat Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/cooling-system-mechanical/#engine-cooling-system__thermostat-diagnosis) . Proper engine coolant level - Refer to «Cooling System Draining and Filling (Static Fill)»(/chevrolet/corvette/c6-2004-2014/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (GE 47716)»(/chevrolet/corvette/c6-2004-2014/remont/cooling-system-mechanical/#engine-cooling-system) .
2. If the above conditions do not address the symptom, refer to the «Additional Symptoms Tests»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis) .

Hard Start

1. Test the engine coolant temperature (ECT) sensor. Compare the ECT sensor value to the intake air temperature (IAT) sensor value on a cold engine. The ECT and IAT sensor values should be within ± 3°C (5°F). If the ECT sensor is out of range with the IAT sensor, test the resistance of the ECT sensor. Refer to «Temperature Versus Resistance»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction__temperature-versus-resistance) for resistance specifications. Replace the ECT sensor if the resistance is not within specification. Refer to «Engine Coolant Temperature Sensor Replacement»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) . If the sensor is within the specification, test the ECT circuits for a high resistance.
2. Test the idle air control (IAC) system.
3. Test the fuel pump relay operation. The fuel pump should turn ON for 2 seconds when the ignition is turned ON. Refer to «Fuel System Diagnosis (W/LS3 or LS7)»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis) or «Fuel System Diagnosis (W/LS9)»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis) .

Hesitation, Sag, Stumble

1. Test the manifold absolute pressure (MAP) sensor. Refer to «DTC P0106»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-dtc-p0016-to-dtc-p0158) .
2. Test the generator. Refer to «Symptoms - Engine Electrical»(/chevrolet/corvette/c6-2004-2014/remont/charging-system/#battery-charging-system-starting-system__symptoms-engine-electrical) . Repair the charging system if the generator output voltage is less than 9 volts or more than 16 volts.

Poor Fuel Economy

1. Heavy loads being carried or towed.
2. Acceleration rate too much or too often.
3. Inspect for foreign material accumulation in the throttle bore, and for carbon deposits on the throttle plate and shaft. Also inspect for throttle body tampering.

Poor Fuel Fill Quality

Test for the following conditions that is applicable to the current symptom.

Difficult to Fill

1. Restricted vent lines
2. The evaporative emission (EVAP) vent valve is stuck closed
3. High fuel temperature
4. A condition with the internal components of the fuel tank assembly. For more information, refer to
5. «Fuel Hose/Pipes Routing Diagram»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction)
6. «Evaporative Emissions Hose Routing Diagram»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction)
7. «Fuel System Description (W/LS9)»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) or «Fuel System Description (W/LS3 or LS7)»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction)
8. «Evaporative Emission Control System Description»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction)

Fuel Odor

1. Saturated EVAP canister - Refer to «Evaporative Emission Control System Description»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) .
2. A condition with the internal components of the fuel tank assembly - Refer to «Fuel System Description (W/LS9)»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) or «Fuel System Description (W/LS3 or LS7)»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) .

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit Description

Supercharger boost pressure is regulated under certain conditions to prevent engine and drive train damage. When the engine is operating under high boost conditions, the engine control module (ECM) can limit boost pressure to 83 kPa (12 psi) or less.

The ECM disables boost under the following conditions

1. Reverse gear is selected.
2. An intercooler pump failure is detected.
3. Electronic throttle control (ETC) fault is detected.
4. Intake air temperature (IAT) sensor 2 is equal to or greater than 120.5°C (248°F) boost pressure is limited to 145 kPa (7 psi). The ECM commands the boost control solenoid to 62 percent duty cycle (DC).
5. Engine coolant temperature (ECT) is greater than 125°C (257°F).
6. Drivetrain abuse is detected.
7. Vehicle speeds exceed 256 km/h (159 mph) in second, third, and fourth gears only, after 150 seconds boost is trimmed actively.

The ECM controls boost pressure by a pulse-width ground signal to the boost control solenoid. The boost control solenoid is a normally open valve. Under most conditions, the ECM commands the boost control solenoid to operate at a 99-100 percent DC. This keeps the boost control solenoid valve closed and allows only inlet vacuum from the supercharger plenum to the bypass valve actuator to control the position of the bypass valve. At idle, engine vacuum is applied to the upper side of the bypass valve actuator, counteracting spring tension to hold the bypass valve open. When the engine load is increased, the engine vacuum is decreased, causing the spring in the bypass valve actuator to overcome the applied vacuum, closing the bypass valve and allowing the boost pressure to increase. The bypass valve starts to close when the vacuum measure is 250 mm Hg (10 in Hg) and is fully closed at 90 mm Hg (3.5 in Hg). When reduced boost pressure is desired, the ECM commands the boost control solenoid to operate at a 0 percent DC, but may command a partial duty cycle, approximately 62 percent, depending on the operating conditions. This opens the boost control solenoid and allows boost pressure to enter the bypass valve actuator at the lower side to counteract the spring tension, opening the bypass valve, and re-circulating excess boost pressure back into the supercharger inlet.

Reference Information

Schematic Reference

Engine Controls Schematics (LS3) or Engine Controls Schematics (LS7) or Engine Controls Schematics (LS9)

connector End View Reference

Component Connector End Views

Description and Operation

1. «Supercharger Description and Operation»(/chevrolet/corvette/c6-2004-2014/remont/mechanical/#engine-mechanical-62l-or-70l-1-of-8)
2. «Boost Control System Description»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

1. J 23738-A Mityvac. See «Special Tools»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) .
2. J 35555 Metal Mityvac. See «Special Tools»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) .

Circuit/System Verification

1. Review the vacuum schematics in the Boost Control System Description. Refer to «Boost Control System Description»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) .
2. Ignition OFF, visually and physically inspect the supercharger components for any of the following conditions: Inspect the vacuum lines for: Cracking Loose fit Improper connections Improper routing Restrictions
3. Inspect the following components for damage, and for improper connections, improper adjustments, and improper installation: The bypass valve actuator The boost control solenoid The bypass valve lever The bypass valve cable. If a condition is found, refer to «Supercharger Cleaning and Inspection»(/chevrolet/corvette/c6-2004-2014/remont/mechanical/#engine-mechanical-62l-or-70l-6-of-8__supercharger-cleaning-and-inspection) .
4. Verify that the charge air cooler (CAC) coolant level is full. Refer to «Charge Air Cooling System Coolant Level Inspection»(/chevrolet/corvette/c6-2004-2014/remont/cooling-system-mechanical/#engine-cooling-system__charge-air-cooling-system-coolant-level) .
5. Ignition ON, command the CAC coolant pump ON and OFF with a scan tool. Listen for the CAC coolant pump to turn ON and OFF with each command. If the CAC coolant pump does not turn ON and OFF refer to «Supercharger Intercooler Relay Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis) .
6. Engine running, command the supercharger bypass (SCB) solenoid from 0 to 90 percent with a scan tool. Observe the operation of the bypass valve, it should move as the DC percentages are varied.
7. Verify there are no vacuum leaks at the supercharger manifold gaskets and supercharger intake plenum.

Circuit/System Testing

1. Ignition OFF, disconnect the boost source hose from the boost control solenoid, connect the J 35555 to the boost source hose. See «Special Tools»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) .
2. Engine running, observe the gage on the J 35555 or J 23738-A for a reading equal to or greater then 15 inch Hg. See «Special Tools»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) . If less than 15 inch Hg, repair the boost vacuum source hose or the intake manifold port for a restriction or blockage.
3. Ignition OFF, connect the vacuum source hose to the boost solenoid.
4. Disconnect the boost signal hose from the bottom port of the bypass valve actuator and connect the J 35555 or J 23738-A to the boost signal hose. See «Special Tools»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) .
5. Engine running, observe the gage on the J 35555 or J 23738-A for a reading of 0-1 inch Hg. See «Special Tools»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) . If greater than the specified range, replace the boost control solenoid.
6. Engine running, command the boost control solenoid to 0% DC with a scan tool. Observe the gage on the J 35555 or J 23738-A for a reading equal to or greater than 15 inch Hg. See «Special Tools»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) . If less than the specified range, test the boost signal hose for a restriction or blockage. If the boost signal hose tests normal, replace the boost control solenoid.
7. Disconnect the inlet vacuum signal hose from the top of the bypass valve actuator, and connect J 35555 or J 23738-A to the inlet vacuum signal hose. See «Special Tools»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) .
8. Engine running, observe the gage on the J 35555 or J 23738-A for a reading equal to or greater than 15 inch Hg. See «Special Tools»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) . If less than 15 inch Hg, repair the inlet vacuum signal hose or the intake manifold port for a restriction or blockage.

Component Testing

1. Ignition OFF, disconnect the inlet vacuum signal hose from the top of the bypass valve actuator.
2. Connect J 35555 or J 23738-A to the inlet vacuum signal port at the bypass valve actuator. See «Special Tools»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) .
3. Slowly apply 15 inch Hg of vacuum while observing the bypass valve actuator. The bypass valve actuator should retract. If the bypass valve actuator and linkage do not retract, inspect the bypass valve actuator and linkage for binding, sticking, or damage. If the bypass valve linkage operate normally, replace the bypass valve actuator.
4. Connect the inlet vacuum signal hose to the top of the bypass valve actuator.
5. Disconnect the boost signal hose from the bottom of the bypass valve actuator, and connect J 35555 or J 23738-A to the boost signal port on the bypass valve actuator. See «Special Tools»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) .
6. Start and idle the engine in park.
7. Slowly apply vacuum until you reach 20 inch Hg, and observe the bypass valve actuator. The bypass valve actuator should extend. If the bypass valve actuator does not extend, inspect the bypass valve and linkage for binding, sticking, or damage. If the bypass valve and linkage operate normally, replace the bypass valve actuator.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Charge Air Bypass Regulator Solenoid Valve Replacement»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction)
2. «Supercharger Bypass Valve Actuator Replacement»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction)

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The supercharger intercooler relay is a normally open relay. The relay armature is held in the open position by spring tension. The ignition 1 voltage is supplied directly to the relay coil and to the armature contact when the ignition is ON, or the engine is running. The engine control module (ECM) supplies the ground path to the relay coil control circuit via an internal integrated circuit called an output driver module (ODM). When the engine is running, the ECM commands the relay ON, and the relay coil creates an electromagnetic field. This electromagnetic field overcomes the spring tension and pulls the armature contact into the stationary contact of the relay load circuit. The closing of the relay contacts allow current to flow from the battery to the supercharger intercooler pump. When the ignition switch is turned to the OFF position, power is interrupted to the output driver module in the ECM and the relay electromagnetic field collapses. This allows the spring tension to separate the relay armature contact from the relay load circuit contact, which interrupts current flow to the supercharger intercooler pump.

Diagnostic Aids

1. A slight resistance of 1-4ohms on the B+ or ground circuits to the CAC coolant pump or the CAC coolant pump relay may inhibit the supercharger coolant pump operation.
2. This test procedure assumes that the vehicle battery has passed a load test and is completely charged. Refer to «Battery Inspection/Test»(/chevrolet/corvette/c6-2004-2014/remont/charging-system/#battery-charging-system-starting-system) .
3. When disconnecting electrical connectors or removing fuses and relays from a fuse block, always inspect the component electrical terminals for corrosion and the mating electrical terminals for correct tension.

Schematic Reference

Engine Controls Schematics (LS3) or Engine Controls Schematics (LS7) or Engine Controls Schematics (LS9)

Connector End View Reference

Component Connector End Views

Description and Operation

1. «Supercharger Description and Operation»(/chevrolet/corvette/c6-2004-2014/remont/mechanical/#engine-mechanical-62l-or-70l-1-of-8)
2. «Boost Control System Description»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction)

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)
5. «Electrical Center Identification Views»(/chevrolet/corvette/c6-2004-2014/remont/electrical-component-locations/#wiring-systems-and-power-management-electrical-center-id-and-component-and-splice-pack-connector-end-views)

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 43244 Relay Puller Pliers. See Special Tools .

1. Ignition ON, command the CAC Coolant Pump ON and OFF with a scan tool. Listen for the CAC coolant pump to turn ON and OFF with each command.
2. Verify that the charge air cooler (CAC) coolant level is full. Refer to «Charge Air Cooling System Coolant Level Inspection»(/chevrolet/corvette/c6-2004-2014/remont/cooling-system-mechanical/#engine-cooling-system__charge-air-cooling-system-coolant-level) and «Charge Air Cooling System Draining and Filling (Static Fill)»(/chevrolet/corvette/c6-2004-2014/remont/cooling-system-mechanical/#engine-cooling-system) .
3. Ignition ON, command the CAC Clnt. Pump ON and OFF with a scan tool while observing the following control circuit status parameters: CAC Clnt. Pump Relay Ckt. Short Gnd Test Status CAC Clnt. Pump Relay Ckt. Open Test Status CAC Clnt. Pump Relay Ckt. Short Volts Test Status Each parameter should toggle between OK and Not run or Not Run and OK.

Note. You must perform the Circuit/System Verification before proceeding with the Circuit/System Testing.

1. Ignition OFF, disconnect the INCLR coolant pump relay.
2. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 86 and ground. If the test lamp illuminates, test the control circuit for a short to voltage.
3. Verify that a test lamp illuminates between the coil circuit terminal 85 and ground. If the test lamp does not illuminate, test the B+ coil circuit for an open/high resistance. If the circuit tests normal and the B+ circuit fuse is normal, test or replace the intercooler pump relay.
4. Verify that a test lamp illuminates between the B+ switch circuit terminal 30 and ground. If the test lamp does not illuminate, test the B+ switch circuit for an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, test the voltage output control circuit terminal 87 for a short to ground. If the circuit tests normal, test or replace the intercooler water pump.
5. Disconnect the harness connector at the intercooler water pump.
6. Test for less than 2 ohms between the intercooler water pump ground circuit terminal A and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
7. Connect the harness connector at the intercooler water pump.
8. Connect a 30A fused jumper wire between the B+ switch circuit terminal 30 and the voltage output control circuit terminal 87. Verify that intercooler water pump is activated. If the intercooler water pump does not activate, test the voltage output control circuit for an open/high resistance. If the circuit tests normal, test or replace the intercooler water pump.
9. Verify that a test lamp does not illuminate between the B+ coil circuit terminal 85 and the control circuit terminal 86. If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM.
10. Remove the test lamp.
11. Command the CAC Clnt. Pump ON with a scan tool. Verify the scan tool CAC Clnt. Pump Relay Ckt. Short Volts Test Status parameter is OK. If not the specified value, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM.
12. Install a 3A fused jumper wire between the control circuit terminal 86 and the B+ circuit terminal 85. Command the CAC Clnt. Pump ON with a scan tool. Verify the scan tool CAC Clnt. Pump Relay Ckt. Short Volts Test Status is Fault. If not the specified value, test the control circuit for an open/high resistance. If the circuit test normal, replace the ECM.
13. If all circuits test normal, replace the INCLR intercooler pump relay.

Coolant Pump Relay

1. Ignition OFF, disconnect the INCLR coolant pump relay.
2. Test for 135-175 ohms between terminals 85 and 86. If the resistance is not within the specified range, replace the relay.
3. Test for infinite resistance between the following terminals: 30 and 86 30 and 87 30 and 85 85 and 87 If not the specified value, replace the relay.
4. Install a 10A fused jumper wire between relay coil terminal 85 and 12V. Install a jumper wire between relay coil terminal 86 and ground. Test for less than 1.0ohms between switch terminals 30 and 87. If greater than the specified range, replace the relay.

CAC Pump Dynamic Test

1. Install a 30A fused jumper wire between the B+ terminal B and 12V.
2. Install a jumper wire between the ground terminal A and ground.
3. Observe for the CAC pump to activate. If the CAC pump does not activate, replace the CAC coolant pump.

Perform the Diagnostic Repair Verification after completing the repair.

1. «Control Module References»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming
2. «Relay Replacement (Attached to Wire Harness)»(/chevrolet/corvette/c6-2004-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction) or «Relay Replacement (Within an Electrical Center)»(/chevrolet/corvette/c6-2004-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction)
3. «Charge Air Cooler Coolant Pump Replacement»(/chevrolet/corvette/c6-2004-2014/remont/cooling-system-mechanical/#engine-cooling-system)

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit/System Description

Ignition voltage is supplied to the malfunction indicator lamp (MIL). The engine control module (ECM) turns the MIL ON by grounding the MIL control circuit.

Schematic Reference

1. «Instrument Cluster Schematics»(/chevrolet/corvette/c6-2004-2014/remont/gauges-instrument-panels/#instrument-panel-system-displays-gauges)
2. «Engine Controls Schematics (LS3)»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) or «Engine Controls Schematics (LS7)»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) or «Engine Controls Schematics (LS9)»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction)

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, the MIL should turn ON and OFF when commanded with a scan tool.

1. Ignition OFF, disconnect the harness connector at the instrument panel cluster (IPC).
2. Ignition ON, verify that a test lamp illuminates between the ignition circuit and ground. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, replace the IPC.
3. Connect a test lamp between the control circuit and the ignition circuit.
4. Command the MIL ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states. If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM. If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
5. If all circuits test normal, replace the IPC.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Instrument Cluster Replacement»(/chevrolet/corvette/c6-2004-2014/remont/gauges-instrument-panels/#instrument-panel-system-displays-gauges)
2. «Control Module References»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This Engine Cranks but Does Not Run diagnostic is an organized approach to identify a condition which causes the engine to crank but does not continue to run. This diagnostic directs the service technician to the appropriate system diagnosis. This diagnostic assumes the vehicle system voltage levels are adequate for starter motor operation. Refer to Battery Inspection/Test and Engine Cranks Slowly . The fuel level supply must be adequate, and the fuel quality must be able to sustain the combustion process.

1. When disconnecting electrical connectors or removing fuses and relays from a fuse block, always inspect both mating electrical terminals for corrosion and terminal tightness.
2. Use the J 35616 Connector Test Adapter Kit for any test that requires probing the underhood fuse block terminals, component wire harness terminals, or the ECM wire harness terminals.

Schematic Reference

Engine Controls Schematics (LS3) or Engine Controls Schematics (LS7) or Engine Controls Schematics (LS9)

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

1. J 34730-1A Fuel Pressure Gage. See «Special Tools»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) .
2. J 35616-A/BT-8637 Connector Test Adapter Kit
3. J 43244 Relay Puller Pliers. See «Special Tools»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) .

Attempt to start the engine. The engine should start and run.

1. If the vehicle passes the Circuit/System Verification test, refer to «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis) .

1. Crank the engine for up to 30 seconds.
2. Observe the vehicle DTC information with a scan tool. If any of the following DTCs are set, diagnose these DTCs first: DTC P0117, P0118, P0122, P0123, P0201-P0208, P0222, P0223, P0335, P0336, P0351-P0358, P0562, P0563, P0601-P0604, P0606, P0607, P062F, P0633, P0685, P0690, P1631, P1682, or P2610. Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-trouble-code-dtc-list) .
3. With the ignition ON and the engine OFF, test the fuses that are supplied ignition 1 voltage by the powertrain relay. The test lamp should illuminate ON for each test point of the fuses. If the test lamp does not illuminate ON for at least one test point of each fuse, refer to «DTC P0685, P0689, or P0690»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-dtc-p0601-to-dtc-p2534) .
4. Crank the engine for 15 seconds. Observe the engine speed parameter with a scan tool. If engine RPM is not indicated, refer to «DTC P0335»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-dtc-p0153-to-dtc-p0507) .
5. Install a spark plug tester onto one ignition module/coil assembly on each bank of the engine.
6. Observe both spark plug testers.
7. Crank the engine for 15 seconds. The ignition coil secondary voltage should be observed across the gap of both spark plug testers. If the ignition coil secondary voltage is not observed, is inconsistent, or weak on either spark plug tester, refer to «Electronic Ignition System Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis) .
8. With the ignition ON and the engine OFF, command the fuel pump ON and OFF with the scan tool. The fuel pump should energize when commanded ON, and de-energize when commanded OFF. If the fuel pump does not turn ON and OFF, refer to «Fuel System Diagnosis (W/LS3 or LS7)»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis) or «Fuel System Diagnosis (W/LS9)»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis) .
9. Turn OFF the ignition.
10. Install the J 34730-1A Fuel Pressure Gage. See «Special Tools»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) . With the ignition ON and the engine OFF, command the fuel pump ON several times with the scan tool. Refer to «Fuel System Diagnosis (W/LS3 or LS7)»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis) or «Fuel System Diagnosis (W/LS9)»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis) for the fuel pressure specification.
11. Inspect for the following conditions: Compare the actual engine coolant temperature to the ECT parameter. Filter and air intake system for restrictions and obstructions Test the fuel for contamination - Refer to «Alcohol/Contaminants-in-Fuel Diagnosis (without Special Tool)»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis) or «Alcohol/Contaminants-in-Fuel Diagnosis (with Special Tool)»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis) . Inspect the spark plugs - Refer to «Spark Plug Inspection»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction__spark-plug-inspection) . Test the exhaust system for restrictions - Refer to «Restricted Exhaust»(/chevrolet/corvette/c6-2004-2014/remont/exhaust/#engine-exhaust-system) . Engine mechanical conditions, such as worn timing chain, sprocket gears, low compression, etc. - Refer to «Symptoms - Engine Mechanical»(/chevrolet/corvette/c6-2004-2014/remont/mechanical/#engine-mechanical-62l-or-70l-1-of-8) .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Typical Scan Tool Data

EC Ignition Relay

The powertrain relay is a normally open relay. The relay armature is held in the open position by spring tension. Battery positive voltage is supplied directly to the relay coil and the armature contact at all times. The engine control module (ECM) supplies the ground path to the relay coil control circuit via an internal integrated circuit called an output driver module (ODM). The ODM output control is configured to operate as a low side driver for the powertrain relay. The ODM for the powertrain relay also incorporates a fault detection circuit, which is continuously monitored by the ECM. When the ECM commands the powertrain relay ON, ignition 1 voltage is supplied to the ECM, and to several additional circuits.

This test procedure requires that the vehicle battery has passed a load test and is completely charged. Refer to Battery Inspection/Test .

Schematic Reference

Engine Controls Schematics (LS3) or Engine Controls Schematics (LS7) or Engine Controls Schematics (LS9)

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Special Tools

1. J 35616 GM-Approved Terminal Test Kit
2. J 43244 Relay Puller Pliers. See «Special Tools»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) .

1. Engine running, command the powertrain relay ON and OFF, with a scan tool, while observing the following powertrain relay coil control circuit status parameters. Powertrain relay coil control Ckt. Short Gnd Test Status Powertrain relay coil control Ckt. Open Test Status Powertrain relay coil control Ckt. Short Volts Test Status Each parameter should toggle between OK and Not Run or Not Run and OK
2. Ignition ON, engine OFF, with a test lamp, probe both test points of all the fuses that are powered by the powertrain relay. The test lamp should illuminate ON for at least one test point of each fuse.
3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the powertrain relay.
2. Ignition ON, verify that a test lamp illuminates between the powertrain relay coil B+, and ground. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the battery positive cable to the underhood fuse block.
3. Ignition OFF, verify that a test lamp does not illuminate between the powertrain relay coil B+ circuit and the control circuit. If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM.
4. Remove the test lamp.
5. Command the powertrain relay ON, with a scan tool. Verify with a scan tool that the powertrain relay Ckt. Short Volts Test Status parameter is OK. If not the specified value, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM.
6. Test the coil side of the powertrain relay for 65-110 ohms. If not within the specified value, replace the relay.
7. Ignition OFF, disconnect the ECM C1 connector.
8. Test the powertrain relay control circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
9. Verify that a test lamp does not illuminate between the relay ignition 1 voltage circuit and ground. If the test lamp illuminates, test the relay ignition 1 voltage circuit for a short to voltage. If the circuit tests normal, replace the ECM.
10. Verify that a test lamp illuminates between the relay switch B+ and ground. If the test lamp does not illuminate, test the relay switch B+ circuit for a short to ground, or an open/high resistance. If the circuits test normal, and the fuse for the ignition 1 voltage circuit is open, test the ignition 1 voltage circuit to the ECM for a short to ground. If the circuit tests normal, replace the ECM.
11. Connect a 20 A fused jumper wire between the relay switch B+ and the relay ignition 1 voltage circuit.
12. Ignition ON, engine OFF, monitor the EC Ignition Relay Feedback parameter with a scan tool. The parameter should display B+. If the parameter does not display B+, test the ignition 1 voltage circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
13. If all circuits test normal, replace the relay.

1. «Engine Control Module Programming and Setup»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#programming-and-setup-all-systems__engine-control-module-programming-and-setup)
2. «Engine Control Module Replacement»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction__engine-control-module-replacement)
3. «Relay Replacement (Attached to Wire Harness)»(/chevrolet/corvette/c6-2004-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction) or «Relay Replacement (Within an Electrical Center)»(/chevrolet/corvette/c6-2004-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction)

Repair Verification

1. Install any components that have been removed or replaced during diagnosis.
2. Perform any adjustment, programming, or setup procedures that are required when a component or module is removed or replaced.
3. Clear the DTCs.
4. Turn OFF the ignition for 60 seconds.
5. Ignition ON, command the powertrain relay ON and OFF with a scan tool, while observing the powertrain relay circuit status parameters, The circuit status parameters should change from OK to Not Run or Not Run to OK. If another DTC is present, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-trouble-code-dtc-list) and perform the appropriate diagnostic procedure.

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

The control module enables the appropriate fuel injector pulse for each cylinder. The ignition voltage is supplied directly to the fuel injectors. The control module controls each fuel injector by grounding the control circuit via a solid state device called a driver. A fuel injector coil winding resistance that is too high or too low will affect the engine driveability. A fuel injector control circuit DTC may not set, but a misfire may be apparent. The fuel injector coil windings are affected by temperature. The resistance of the fuel injector coil windings will increase as the temperature of the fuel injector increases.

The CH-47976 , is used to test the fuel pump, fuel system leak down, and the fuel injectors. Following the User Guide, CH 47976-11, and the on screen prompts or selections, will indicate the steps required to perform each of the available tests. The tester will perform all of the tests automatically and display results of the test. The results can also be down loaded for storage and printing.

Schematic Reference

Engine Controls Schematics (LS3) or Engine Controls Schematics (LS7) or Engine Controls Schematics (LS9)

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Special Tools

CH-47976 Active Fuel Injector Tester

Fuel Injector Coil Test

Verify the resistance of each fuel injector with one of the following methods

1. If the engine coolant temperature (ECT) sensor is between 10-32°C (50-90°F), the resistance of each fuel injector should be 11-14 ohms. If the injectors measure OK, perform the AFIT Test Procedure. If not within the specified range, replace the fuel injector.
2. If the ECT sensor is not between 10-32°C (50-90°F), measure and record the resistance of each fuel injector with a DMM. Subtract the lowest resistance value from the highest resistance value. The difference between the lowest value and the highest value should be equal to or less than 3 ohms. If the difference is equal to or less than 3 ohms, refer to «AFIT Test Procedure»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis__afit-test-procedure) . If the difference is more than 3 ohms, add all of the fuel injector resistance values to obtain a total resistance value. Divide the total resistance value by the number of fuel injectors to obtain an average resistance value. Subtract the lowest individual fuel injector resistance value from the average resistance value. Compute the difference between the highest individual fuel injector resistance value and the average resistance value. Replace the fuel injector that displays the greatest difference above or below the average.

AFIT Test Procedure

1. Turn OFF all accessories.
2. Turn OFF the ignition.
3. Install the AFIT. Refer to the AFIT User Guide.
4. Turn ON the AFIT and select the vehicle.
5. Turn ON the ignition and perform the Injector Test. If the AFIT aborts testing due to fuel pressure or fuel leak down, refer to «Fuel System Diagnosis (W/LS3 or LS7)»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis) or «Fuel System Diagnosis (W/LS9)»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis) .
6. View the test results. If any injector exceeds the recommended tolerance, replace the injector(s).

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Fuel Injector Replacement

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

The control module enables the appropriate fuel injector pulse for each cylinder. The ignition voltage is supplied directly to the fuel injectors. The control module controls each fuel injector by grounding the control circuit via a solid state device called a driver. A fuel injector coil winding resistance that is too high or too low will affect the engine driveability. A fuel injector control circuit DTC may not set, but a misfire may be apparent. The fuel injector coil windings are affected by temperature. The resistance of the fuel injector coil windings will increase as the temperature of the fuel injector increases.

When performing the fuel injector balance test, the scan tool is first used to energize the fuel pump relay. The fuel injector tester or the scan tool is then used to pulse each injector for a precise amount of time, allowing a measured amount of the fuel to be injected. This causes a drop in the system fuel pressure that can be recorded and used to compare each injector.

1. Monitoring the misfire current counters, or misfire graph, may help to isolate the fuel injector that is causing the condition.
2. Operating the vehicle over a wide temperature range may help isolate the fuel injector that is causing the condition.
3. Perform the fuel injector coil test within the conditions of the customer's concern. A fuel injector condition may only be apparent at a certain temperature, or under certain conditions.

Schematic Reference

Engine Controls Schematics (LS3) or Engine Controls Schematics (LS7) or Engine Controls Schematics (LS9)

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

1. CH-48027 Digital Pressure Gage. See «Special Tools»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) .
2. J 39021 Fuel Injector Coil and Balance Tester. See «Special Tools»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) .
3. J 44602 Injector Test Adapter. See «Special Tools»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) .

Verify the resistance of each fuel injector with one of the following methods

1. If the engine coolant temperature (ECT) sensor is between 10-32°C (50-90°F), the resistance of each fuel injector should be 11-14 ohms. If the injectors measure OK, perform the Fuel Injector Balance Test - Fuel Pressure Test. If not within the specified range, replace the fuel injector.
2. If the ECT sensor is not between 10-32°C (50-90°F), measure and record the resistance of each fuel injector with a DMM. Subtract the lowest resistance value from the highest resistance value. The difference between the lowest value and the highest value should be equal to or less than 3 ohms. If the difference is equal to or less than 3 ohms, refer to «Fuel Injector Balance Test-Fuel Pressure Test»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis__fuel-injector-balance-test-fuel-pressure-test) for further diagnosis of the fuel injectors. If the difference is more than 3 ohms, add all of the fuel injector resistance values to obtain a total resistance value. Divide the total resistance value by the number of fuel injectors to obtain an average resistance value. Subtract the lowest individual fuel injector resistance value from the average resistance value. Compute the difference between the highest individual fuel injector resistance value and the average resistance value. Replace the fuel injector that displays the greatest difference above or below the average.

Fuel Injector Balance Test-Fuel Pressure Test

1. Install a fuel pressure gage. Refer to «Fuel Pressure Gage Installation and Removal»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) .
2. Turn ON the ignition, with the engine OFF.
3. Command the fuel pump relay ON with a scan tool.
4. Observe the fuel pressure gage with the fuel pump commanded ON. The fuel pressure should be 345-414 kPa (50-60 psi). If the fuel pressure is not 345-414 kPa (50-60 psi), refer to «Fuel System Diagnosis (W/LS3 or LS7)»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis) or «Fuel System Diagnosis (W/LS9)»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis) .
5. Monitor the fuel pressure gage for one minute. The fuel pressure should not decrease more than 34 kPa (5 psi). If the fuel pressure decreases more than 34 kPa (5 psi), refer to «Fuel System Diagnosis (W/LS3 or LS7)»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis) or «Fuel System Diagnosis (W/LS9)»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis) .
6. Perform the Fuel Injector Balance Test with Special Tool or the Fuel Injector Balance Test with Tech 2.

Fuel Injector Balance Test with Special Tool

1. Set the amperage supply selector switch on the fuel injector tester to the Balance Test 0.5-2.5 amp position.
2. Connect the J 39021 to a fuel injector with a J 44602 . See «Special Tools»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) .
3. Command the fuel pump relay ON and then OFF three times with a scan tool. On the last command, as the fuel pressure begins to slowly degrade and stabilize, select a fuel pressure within 34 kPa (5 psi) of the maximum pump pressure. Record this fuel pressure. This is the starting pressure at which you will pulse each injector.
4. Command the fuel pump relay ON one more time and energize the fuel injector by depressing the Push to Start Test button on the J 39021 at the previously selected pressure. See «Special Tools»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) .
5. After the injector stops pulsing, select Min from the Display Mode and record the Min pressure.
6. Clear the Min/Max results.
7. Select Normal from the Display Mode.
8. Repeat steps 2 and 4 through 7 for each fuel injector.
9. Perform the Pressure Drop Calculation.

Fuel Injector Balance Test with Tech 2

1. Command the fuel pump relay ON and then OFF three times with a scan tool. On the last command, as the fuel pressure begins to slowly degrade and stabilize, select a fuel pressure within 34 kPa (5 psi) of the maximum pump pressure. Record this fuel pressure. This is the starting pressure at which you will pulse each injector.
2. With a scan tool, select the Fuel Injector Balance Test function within the Special Functions menu.
3. Select an injector to be tested.
4. Press Enter to prime the fuel system.
5. Energize the fuel injector by depressing the Pulse Injector button on the scan tool at the previously selected pressure.
6. After the injector stops pulsing, select Min from the Display Mode on the CH-48027 and record the Min pressure. See «Special Tools»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) .
7. Clear the Min/Max results on the CH-48027 . See «Special Tools»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) .
8. Select Normal from the Display Mode on the CH-48027 . See «Special Tools»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) .
9. Press Enter on the scan tool to bring you back to the Select Injector screen.
10. Repeat steps 3 through 9 for each fuel injector.
11. Perform the Pressure Drop Calculation.

Pressure Drop Calculation

1. Subtract the minimum pressure from the starting pressure for one fuel injector. The result is the pressure drop value.
2. Obtain a pressure drop value for each fuel injector.
3. Add all of the individual pressure drop values except for the injector suspected of being faulty. This is the total pressure drop.
4. Divide the total pressure drop by the number of fuel injectors that were added together. This is the average pressure drop. The difference between any individual pressure drop and the average pressure drop should not be more than 20 kPa (3 psi). If the difference between any individual pressure drop and the average pressure drop is more than 20 kPa (3 psi), replace the fuel injector.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Fuel Injector Replacement

System Description

The control module enables the fuel pump relay when the ignition switch is turned ON. The control module will disable the fuel pump relay within 2 seconds unless the control module detects ignition reference pulses. The control module continues to enable the fuel pump relay as long as ignition reference pulses are detected. The control module disables the fuel pump relay within two seconds if ignition reference pulses cease to be detected and the ignition remains ON.

The fuel system is a returnless on-demand design. The fuel pressure regulator is a part of the fuel tank module, eliminating the need for a return pipe from the engine. A returnless fuel system reduces the internal temperature of the fuel tank by not returning hot fuel from the engine to the fuel tank. Reducing the internal temperature of the fuel tank results in lower evaporative emissions.

Two fuel tanks store the fuel supply. An electric turbine style fuel pump attaches to the fuel tank module inside the left fuel tank. The fuel pump supplies high pressure fuel through the fuel filter and the fuel feed pipe to the fuel injection system. The fuel pump provides fuel at a higher rate of flow than is needed by the fuel injection system. The fuel pump also supplies fuel to a Venturi pump located on the bottom of the left fuel tank module. The function of the Venturi pump is to fill the left fuel tank module reservoir. The primary fuel pressure regulator, a part of the left fuel tank module, maintains the correct fuel pressure to the fuel injection system. The left fuel tank module contains a reverse flow check valve. The check valve, the primary fuel pressure regulator, and the secondary fuel pressure regulator maintain fuel pressure in the fuel feed pipe and the fuel rail in order to prevent long cranking times.

The fuel pump also supplies a small amount of pressurized fuel through the auxiliary fuel feed pipe to the siphon jet pump inside the right fuel tank. The pressurized fuel creates a Venturi action inside the siphon jet pump. The Venturi action causes the fuel to be drawn out of the right fuel tank. The fuel transfers from the right fuel tank to the left fuel tank through the auxiliary fuel return pipe. The auxiliary fuel return pipe inside the left fuel tank contains an anti-siphon hole in order to prevent fuel from siphoning from the left fuel tank into the right fuel tank. Both the auxiliary fuel feed pipe and the auxiliary fuel return pipe are located inside the convoluted stainless steel crossover hose.

The right fuel tank module contains a secondary fuel pressure regulator. The secondary fuel pressure regulator has a lower set point than the primary regulator in order to allow fuel to flow to the siphon jet pump on the right fuel tank module. When the engine is shut off, the pressure in the feed pipes immediately drops to the secondary regulator set point. This prevents the siphon jet pump from operating and in turn prevents the equalization of the left and right fuel tanks. The secondary fuel pressure regulator maintains fuel pressure in the auxiliary fuel feed pipe which reduces the time to prime the siphon jet pump. The pressurization also reduces fuel vaporization and boiling in the auxiliary fuel feed pipe.

The control module enables the fuel pump when the ignition switch is turned ON. The control module will disable the fuel pump within 2 seconds unless the control module detects ignition reference pulses. The control module continues to enable the fuel pump as long as ignition reference pulses are detected. The control module disables the fuel pump within two seconds if ignition reference pulses cease to be detected and the ignition remains ON.

The fuel system is a returnless on-demand design. The fuel pressure regulator is a part of the fuel tank module, eliminating the need for a return pipe from the engine. A returnless fuel system reduces the internal temperature of the fuel tank by not returning hot fuel from the engine to the fuel tank. Reducing the internal temperature of the fuel tank results in lower evaporative emissions.

Two fuel tanks store the fuel supply. An electric screw style fuel pump attaches to the fuel tank module inside the left fuel tank. The fuel pump supplies high pressure fuel through the fuel filter and the fuel feed pipe to the fuel injection system. The fuel pump provides fuel at a higher rate of flow than is needed by the fuel injection system. The fuel pump also supplies fuel to a Venturi pump located on the bottom of the left fuel tank module. The function of the Venturi pump is to fill the left fuel tank module reservoir. The primary fuel pressure regulator, a part of the left fuel tank module, maintains the correct fuel pressure to the fuel injection system. The left fuel tank module contains a reverse flow check valve. The check valve, the primary fuel pressure regulator, and the secondary fuel pressure regulator maintain fuel pressure in the fuel feed pipe and the fuel rail in order to prevent long cranking times.

The fuel pump also supplies a small amount of pressurized fuel through the auxiliary fuel feed pipe to the siphon jet pump inside the right fuel tank. The pressurized fuel creates a Venturi action inside the siphon jet pump. The Venturi action causes the fuel to be drawn out of the right fuel tank. The fuel transfers from the right fuel tank to the left fuel tank through the auxiliary fuel return pipe. The auxiliary fuel return pipe inside the left fuel tank contains an anti-siphon hole in order to prevent fuel from siphoning from the left fuel tank into the right fuel tank. Both the auxiliary fuel feed pipe and the auxiliary fuel return pipe are located inside the convoluted stainless steel crossover hose.

The right fuel tank module contains a secondary fuel pressure regulator. The secondary fuel pressure regulator has a lower set point than the primary regulator in order to allow fuel to flow to the siphon jet pump on the right fuel tank module. When the engine is shut off, the pressure in the feed pipes immediately drops to the secondary regulator set point. This prevents the siphon jet pump from operating and in turn prevents the equalization of the left and right fuel tanks. The secondary fuel pressure regulator maintains fuel pressure in the auxiliary fuel feed pipe which reduces the time to prime the siphon jet pump. The pressurization also reduces fuel vaporization and boiling in the auxiliary fuel feed pipe.

Description

Water contamination in the fuel system may cause driveability conditions such as hesitation, stalling, no start, or misfires in one or more cylinders. Water may collect near a single fuel injector at the lowest point in the fuel injection system, and cause a misfire in that cylinder. If the fuel system is contaminated with water, inspect the fuel system components for rust, or deterioration.

Alcohol concentrations of 10 percent or greater in fuel can be detrimental to fuel system components. Alcohol contamination may cause fuel system corrosion, deterioration of rubber components, and subsequent fuel filter restriction. Some types of alcohol are more detrimental to fuel system components than others. Ethanol is commonly used in gasoline, but in concentrations of no more than 10 percent. Some fuels, such as E85, contain a very high percentage of ethanol. Fuel with more than 10 percent ethanol may cause driveability conditions such as hesitation, lack of power, stalling, or no start.

Alcohol in Fuel Testing Procedure

The fuel sample should be drawn from the bottom of the tank so that any water present in the tank will be detected. The sample should be bright and clear. If alcohol contamination is suspected then use the following procedure to test the fuel quality.

1. Using a 100 ml (3.4 oz) specified cylinder with 1 ml (0.03 oz) graduation marks, fill the cylinder with fuel to the 90 ml (3.04 oz) mark.
2. Add 10 ml (0.34 oz) of water in order to bring the total fluid volume to 100 ml (3.4 oz) and install a stopper.
3. Shake the cylinder vigorously for 10-15 seconds.
4. Carefully loosen the stopper in order to release the pressure.
5. Re-install the stopper and shake the cylinder vigorously again for 10-15 seconds.
6. Put the cylinder on a level surface for approximately 5 minutes in order to allow adequate liquid separation.

If alcohol is present in the fuel, the volume of the lower layer, which would now contain both alcohol and water, will be more than 10 ml (0.34 oz). For example, if the volume of the lower layer is increased to 15 ml (0.51 oz), this indicates at least 5 percent alcohol in the fuel. The actual amount of alcohol may be somewhat more because this procedure does not extract all of the alcohol from the fuel.

Particulate Contaminants in Fuel Testing Procedure

The fuel sample should be drawn from the bottom of the tank so that any water present in the tank will be detected. The sample should be bright and clear. If the sample appears cloudy, or contaminated with water, as indicated by a water layer at the bottom of the sample, use the following procedure to diagnose the fuel.

1. Using an approved fuel container, draw approximately 0.5 liter (0.13 gal) of fuel.
2. Place the cylinder on a level surface for approximately 5 minutes in order to allow settling of the particulate contamination.

Particulate contamination will show up in various shapes and colors. Sand will typically be identified by a white or light brown crystals. Rubber will appear as black and irregular particles. If particles are found clean the entire fuel system thoroughly.

Water contamination in the fuel system may cause driveability conditions such as hesitation, stalling, no start, or misfires in one or more cylinders. Water may collect near a single fuel injector at the lowest point in the fuel injection system, and cause a misfire in that cylinder. If the fuel system is contaminated with water, inspect the fuel system components for rust or deterioration.

Ethanol concentrations of greater than 10 percent can cause driveability conditions and fuel system deterioration. Fuel with more than 10 percent ethanol could result in driveability conditions such as hesitation, lack of power, stalling, or no start. Excessive concentrations of ethanol used in vehicles not designed for it may cause fuel system corrosion, deterioration of rubber components, and fuel filter restriction.

Test Procedure

1. Test the fuel composition using J 44175 Fuel Composition Tester and J44175-3 Instruction Manual. See «Special Tools»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) .
2. Subtract 50 from the reading on the DMM in order to obtain the percentage of alcohol in the fuel sample. Refer to the examples in the Fuel Composition Test Examples table.
3. If the fuel sample contains more than 15 percent ethanol, add fresh, regular gasoline to the vehicle's fuel tank.
4. Test the fuel composition.
5. If testing shows the ethanol percentage is still more than 15 percent, replace the fuel in the vehicle.

Fuel Composition Test Examples

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This ignition system uses individual ignition module/coil assemblies for each cylinder. The engine control module (ECM) controls the spark events by transmitting the timing pulses on the ignition control (IC) circuits to the individual ignition module/coil assemblies in firing order sequence. Each ignition module/coil has the following circuits

1. An ignition 1 voltage circuit
2. A ground circuit
3. An IC circuit
4. A low reference circuit

1. This test procedure requires that the vehicle battery has passed a load test and is completely charged.
2. There is an adequate supply of fuel in the fuel tank.
3. When disconnecting electrical connectors or removing fuses and relays from a fuse block, always inspect both mating electrical terminals for corrosion and terminal tightness.
4. Use the J 35616 for any test that requires probing the underhood fuse block terminals, component wire harness terminals, or the ECM wire harness terminals.

Schematic Reference

Engine Controls Schematics (LS3) or Engine Controls Schematics (LS7) or Engine Controls Schematics (LS9)

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Special Tools

1. J 26792 Spark Plug Tester. See «Special Tools»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) .
2. J 35616-A/BT-8637 Connector Test Adapter Kit

Observe the Engine Controls Schematic for the ignition module/coils, and review the Ignition System Specifications to verify the following concerns

1. The ignition modules/coils are correctly wired and connected
2. The proper spark plug type
3. The proper spark plug gap and torque
4. The proper ohm values for the spark plug wires Refer to «Ignition System Specifications»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction__ignition-system-specifications) .

1. Turn OFF the ignition.
2. Inspect both fuses that supply ignition voltage to the ignition module/coils. If a fuse is open, test all 8 ignition voltage circuits to the ignition module/coils or the fuel injectors on that engine bank, for a short to ground.
3. Disconnect the 4 ignition module/coil, and the 4 fuel injector electrical connectors, for the engine bank that has the open fuse.
4. Replace the open fuse with a new fuse.
5. Ignition ON, engine OFF.
6. Reconnect each ignition module/coil, and fuel injector electrical connectors, one at a time. If the fuse opens when connecting an ignition module/coil or fuel injector electrical connector, then replace the component that caused the fuse to open.
7. Ignition OFF, disconnect the appropriate ignition module/coil electrical connector.
8. Ignition ON, verify that a test lamp illuminates between the ignition voltage circuit and ground. If the test lamp does not illuminate test the ignition voltage circuit for an open/high resistance.
9. Verify that a test lamp illuminates between the ignition module/coil ground circuit and B+. If the test lamp does not illuminate, test the ignition module/coil ground circuit for an open/high resistance.
10. Inspect and measure the resistance of the spark plug wire. Refer to «Spark Plug Wire Inspection»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction__spark-plug-wire-inspection) and «Ignition System Specifications»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction__ignition-system-specifications) . If the resistance value is not within the specified range, or does not pass the inspection, replace the spark plug wire.
11. Exchange the misfiring cylinder, ignition module/coil assembly with the ignition module/coil assembly from a non-misfiring cylinder.
12. Start and idle the engine. Observe the misfire counters on the scan tool. If the misfire transfers with the suspect ignition module/coil, then replace the ignition module/coil assembly. If the misfire does not transfer with the suspect ignition module/coil, then measure the resistance of the IC circuit. The IC circuit should measure less than 5 ohms. If the circuit tests normal, replace the ECM.

1. Use the Spark Plug Inspection procedure to verify the integrity of the spark plugs. Refer to «Spark Plug Inspection»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction__spark-plug-inspection) . Replace the spark plug if necessary.
2. Use the J 26792 to verify the output of each ignition module/coil. See «Special Tools»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) . If no spark is detected across the gap of the spark plug tester, then replace the ignition module/coil assembly.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Engine Control Module Programming and Setup»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#programming-and-setup-all-systems__engine-control-module-programming-and-setup)
2. «Engine Control Module Replacement»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction__engine-control-module-replacement)
3. «Ignition Coil Replacement»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction)
4. «Spark Plug Replacement»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction)

Vehicle Setup

1. Engine OFF, open the hood. Position a large fan to blow air under the vehicle onto the fuel tank area.
2. Connect the red battery clip from the tester to the positive battery terminal.
3. Connect the black battery clip from the tester to chassis ground.

Flowmeter Test - Leak Detection

1. Open the Nitrogen tank valve and turn the NITROGEN/SMOKE valve on the front control panel to NITROGEN.
2. Connect the hose to the correct test orifice on the bottom front of the tester. For orifice size, refer to the GM Service manual for the vehicle being tested. The vehicle specific information can be found in service procedures for DTCs that relate to evaporative emission (EVAP) system leaks.
3. Press and release the remote switch to activate the tester.
4. Position the sliding red flag on the flowmeter to align with the floating indicator. When the red flag is set, press and release the remote switch to deactivate the tester.
5. Remove the hose from the test orifice and install the hose onto the vehicle. For proper connection location, and the special tool numbers for any adapters that may be required, refer to the service manual for the vehicle being tested. The vehicle specific information can be found in service procedures for DTCs that relate to EVAP system leaks.
6. Seal the EVAP system per instructions in the service manual. Most systems can be sealed using a scan tool output control for the EVAP canister vent solenoid valve. Other systems require that the system be plugged. Refer to the service manual for vehicle being tested for specific instructions.
7. Press and release the remote switch to activate the nitrogen flow and fill the system.
8. Compare the stable floating indicator position to the red flag. ABOVE the red flag, the result is UNACCEPTABLE, FAIL-Go to Smoke Procedure BELOW the red flag, the result is ACCEPTABLE, PASS-Test complete
9. Press and release the remote switch to deactivate the tester.

Smoke Procedure - Locate the Leak

1. Turn OFF any fans that may cause air movement around or near the vehicle.
2. Connect the nitrogen/smoke hose to the vehicle as directed in the service manual. Some vehicles require that the nitrogen/smoke hose be connected at the front of the EVAP system at the EVAP service port. An adapter may be necessary. Other vehicles require the connection be made at the rear of the system using an adapter at the fuel fill cap. Consult the service manual for vehicle specific instructions regarding connection location and adapters.
3. Open the nitrogen tank valve and turn the NITROGEN/SMOKE valve on the control panel to SMOKE.
4. Press and release the remote switch to activate the tester and inject smoke into the EVAP system.
5. Verify smoke has filled the EVAP system by opening the system opposite the end where smoke is injected. When injecting smoke at the service port, remove the fuel fill cap, or temporarily leave the EVAP canister vent valve open, until smoke is observed. Then close the system and continue testing. If using a special tool fuel fill cap adapter at the filler neck, use the J 41413-VLV EVAP Service Port Vent Fitting tool at the service port until smoke is observed, then remove the J 41413-VLV tool and continue with the test. See «Special Tools»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-introduction) .
6. Press and release the remote switch to deactivate the tester.
7. Introduce smoke into the system for an additional 60 seconds. Continue introducing smoke at 15-second intervals, as necessary.
8. Using the a high-intensity white light, inspect the entire EVAP system path, and look for the source of the leak indicated by the exiting smoke. Introduce smoke at 15-second intervals, as needed, until leak source is identified.

The Concern

Ideal circumstances for conducting the EVAP Flowmeter Test require equal temperatures between the nitrogen gas and the vehicle EVAP system. Significant differences in temperature between them can result in a flow or pressure change during testing, causing misleading results. Typically, the Evaporative Emissions System Tester is stored indoors, approximately 21°C (70°F). Vehicles brought in for diagnosis may have an EVAP system at significantly different temperatures -40 to +43°C (-40 to +110°F).

For Example

When the EVAP Flowmeter Tests are performed with significant differences in temperature between the nitrogen gas and the vehicle EVAP system, the following results can occur

1. An increase in flow during the flowmeter test can be caused by a vehicle's warm EVAP system cooling down.
2. A decrease in flow during the flowmeter test can be caused by a vehicle's cool EVAP system warming up.

The Solution

When working on a vehicle with significant temperature differences between the vehicle EVAP system and the nitrogen gas, allow the vehicle EVAP system temperature to stabilize as close as possible to the temperature of the nitrogen gas before conducting the Flowmeter Test.

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Several states require that a vehicle pass on-board diagnostic (OBD) system tests and the inspection/maintenance (I/M) emission inspection in order to renew license plates. This is accomplished by viewing the I/M System Status display on a scan tool. Using a scan tool, the technician can observe the I/M System Status in order to verify that the vehicle meets the criteria that comply with the local area requirements.

Conditions for Updating the I/M System Status

Each system monitor requires at least one, and sometimes several diagnostic tests. The result of each test is reported by a DTC. A system monitor is complete when either all of the DTCs composing the monitor have Run and Passed, or when any one of the DTCs comprising the monitor has illuminated the malfunction indicator lamp (MIL). Once the system monitor is complete, the I/M System Status display will indicate YES in the Completed column.

For example, when the HO2S Heater Status indicates YES, either all of the oxygen sensor heater tests have passed or one of the tests has illuminated the MIL. If the vehicle has 4 heated oxygen sensors, either all 4 heater circuit tests have passed or one of the heater circuit tests has illuminated the MIL. The I/M System Status will indicate NO under the Completed column when any of the required tests for that system have not run. The following is a list of conditions that would set the I/M System Status indicator to NO

1. The vehicle is new from the factory and has not yet been driven through the necessary drive conditions to complete the tests.
2. The battery has been disconnected or discharged below operating voltage.
3. The control module power or ground has been interrupted.
4. The control module has been reprogrammed.
5. The control module DTCs have been cleared.

Monitored Emission Control Systems

The OBD II System monitors all emission control systems that are on-board. The OBD II regulations require monitoring of the following

1. The air conditioning system
2. The catalytic converter efficiency
3. Comprehensive component monitoring-Emission related inputs and outputs
4. The evaporative emission (EVAP) system
5. The fuel delivery system
6. Heated catalyst monitoring
7. Misfire monitoring
8. The oxygen sensor system (O2S or HO2S)
9. The oxygen sensor heater system (HO2S heater)

For the specific DTCs required for each system, refer to Inspection/Maintenance System DTC Table . Systems such as fuel delivery, misfire, and comprehensive components may not be listed in a system status list. These tests run continuously and do not require an I/M System Status indicator.

Review the I/M System Status indicators. All I/M System Status indicators should report YES.

1. Observe the Engine DTC information with a scan tool. If a DTC is set that would prevent the I/M System Status tests from completing, diagnose that DTC before continuing. Refer to «Inspection/Maintenance System DTC Table»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis__inspectionmaintenance-system-dtc-table) .
2. Review applicable service bulletins for software updates that would prevent the I/M System Status tests from completing. If a control module re-program or other repair is required, perform the «Inspection/Maintenance Complete System Set Procedure»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis) .
3. Observe the I/M System Status indicators. If any I/M System Status indicators report NO, perform the «Inspection/Maintenance Complete System Set Procedure»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis) .

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The purpose of the Inspection/Maintenance (I/M) Complete System Set Procedure is to satisfy the enable criteria necessary to execute all of the I/M readiness diagnostics and complete the drive cycles for those particular diagnostics. When all I/M monitored diagnostic tests are completed, the I/M System Status indicators are set to YES. Perform the I/M Complete System Set Procedure if any I/M System Status indicators are set to NO.

I/M Data List

To determine if the I/M readiness diagnostic tests can be run this ignition cycle, use a scan tool to observe the I/M monitor enabled parameters in the I/M Data List.

Conditions for Meeting a Cold Start

1. The ignition voltage between 11-18 volts.
2. The barometric pressure (BARO) is more than 75 kPa.
3. The start-up engine coolant temperature (ECT) is between 4-30°C (39-86°F).
4. The start-up intake air temperature (IAT) is between 4-30°C (39-86°F).
5. The difference between the IAT and the ECT is less than or equal to 6°C (10.8°F).
6. The ambient air temperature is between 4-30°C (39-86°F).
7. The fuel level is between 15-85 percent.

Review the I/M Status indicators with a scan tool. All I/M System Status indicators should report YES.

Inspection/Maintenance (I/M) System Set Procedure

1. Ensure that the vehicle meets the conditions for a cold start listed above.
2. The evaporative emission (EVAP) I/M System Status indicator should display YES. If the EVAP I/M System Status indicator displays NO, perform the EVAP Service Bay Test, if applicable. If the EVAP Service Bay Test is NOT available, it may take up to 6 drive cycles, with up to 17 hours between drive cycles, for the EVAP I/M System Status indicator to transition to YES.
3. The O2S Heater I/M System Status indicator should display YES. If the O2S Heater I/M System Status indicator displays NO, ensure that the ignition has been turned OFF for at least 10 hours.
4. Turn OFF all accessories; HVAC system, other electrical loads, including aftermarket/add-on equipment, etc.
5. Set the vehicle parking brake and ensure the vehicle is in Park for automatic transmission or Neutral for manual transmission.
6. Turn OFF all accessories; HVAC system, other electrical loads, including aftermarket/add-on equipment, etc.
7. Start and idle the engine for at least 2 minutes and until 65°C (149°F) is achieved.
8. Run the engine for 6.5 minutes within the following conditions: MAF parameter between 4-30 g/s Engine speed steady between 1,000-3,000 RPM
9. Return the engine to idle for 1 minute.
10. Apply and hold the brake pedal, and shift to Drive for automatic transmission, or apply the clutch pedal for manual transmission and operate the vehicle within the following conditions for 2 minutes: Depress the accelerator pedal until throttle position (TP) sensor angle is more than 2 percent. Mass air flow (MAF) signal between 15-30 g/s RPM steady between 1,200-2,000 RPM
11. Release the accelerator pedal and shift the vehicle to Park for automatic transmission, or Neutral and release the clutch pedal for manual transmission, and allow the engine to idle for 2 minutes.
12. Quickly depress the accelerator pedal until TP sensor angle is more than 8 percent and return to idle, repeat 3 times.
13. Allow engine to idle for at least 2 minutes.
14. Release the parking brake and drive vehicle at 24 km/h (15 mph) or slower for 2 minutes.
15. Continue to drive the vehicle for at least 5.5 miles between 45-112 km/h (28-70 mph) with the vehicle reaching at least 80 km/h (50 mph).
16. Release the accelerator pedal for at least 2 seconds. This will allow the vehicle to enter decel fuel cut-off.
17. Depress the accelerator pedal until the TP sensor angle is increased 3-20 percent and maintain a safe speed for 1 minute.
18. Safely stop the vehicle, with the engine in Drive for automatic transmission or in Neutral with the clutch pedal depressed and parking brake applied for manual transmission, idle for 2 minutes.
19. Shift to Park for automatic and apply the parking brake, or neutral and release clutch pedal for manual.
20. Turn OFF the ignition and exit the vehicle. Do NOT disturb the vehicle for 60 minutes.
21. Observe the Inspection/Maintenance (I/M) System Status with a scan tool. All of the I/M System Status indicators should display YES. If the EVAP I/M System Status indicator displays NO, turn OFF the ignition for 17 hours, ensure that the vehicle meets the conditions for a cold start, and repeat steps 12-18 six more times, or until the EVAP I/M System Status indicator transitions to YES. If the indicator continues to display NO, refer to the «Inspection/Maintenance System DTC Table»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis__inspectionmaintenance-system-dtc-table) to identify the DTCs that did not run. Follow the Conditions for Running the DTC in order to set the EVAP I/M System Status indicator

1. If any of the I/M System Status indicators display NO, refer to the «Inspection/Maintenance System DTC Table»(/chevrolet/corvette/c6-2004-2014/remont/testing-diagnostics/#engine-controls-and-fuel-62l-or-70l-troubleshooting-diagnosis__inspectionmaintenance-system-dtc-table) for the indicator which did not display YES. The I/M System DTC Table identifies the DTCs associated with each I/M System Status Indicator. Follow the Conditions for Running the DTC in order to set the associated status indicator.

Inspection/Maintenance System DTC Table

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The purpose of the evaporative emission (EVAP) Service Bay Test is to aid in resetting the EVAP inspection/maintenance (I/M) system status. For this vehicle that is equipped with the engine off natural vacuum (EONV) diagnostic, the Service Bay Test uses the scan tool to initiate the engine control module (ECM) regular sequence of EVAP system DTC tests, but with different enable criteria. By using the Service Bay Test the I/M indicator can be set without the need for multiple cold soaks.

The scan tool displays for the Service Bay Test are based on the events that occur within the following three categories

1. The engine running portion of the tests-The vehicle must remain at rest, in Park, or in Neutral, during this portion of the test. This test inspects for large leaks, a leaking purge valve and/or vent system restrictions. The scan tool will display test progress or the reason for an abort or failure.
2. Drive cycle-The scan tool will display time and distance needed to warm the fuel.
3. Ignition OFF-During this portion of the test, the engine controller will remain active for up to 45 minutes when the ignition is turned OFF to allow control of the EVAP vent valve and run the EONV test. The engine controller inspects for small leaks during this period by monitoring fuel tank pressure or vacuum. If the system is sealed, there will be a pressure or vacuum change. Pressure or vacuum changes that are less than the calibrated values indicate a leak.

When the EVAP diagnostics are initiated by the Service Bay Test, the scan tool will indicate if the enable conditions listed below are not met, or will display a specific reason if the test aborts. When complete, the display will indicate that the tests passed or failed.

Conditions for Running the Test

The following conditions must be met in order to enable the Service Bay Test

1. The battery voltage is between 11-18 volts.
2. The engine coolant temperature (ECT) is less than 70°C (158°F) at start-up.
3. The EVAP I/M system status indicator is set to NO.
4. The fuel level is 15-85 percent capacity and cannot be refueled during the tests.
5. There are no DTCs displayed.
6. The vehicle must be driven for the time and distance specified on the scan tool.
7. The ambient air temperature is between 0-40°C (32-104°F).
8. The ignition must remain OFF during the engine OFF portion of the test, and the vehicle must remain at rest.

Note. If the Service Bay Test aborts or fails, a DTC will NOT be set.

1. Install a scan tool.
2. Select the Service Bay Test with the scan tool.
3. Follow the instructions on the scan tool. If the test aborts, correct the condition for running the test, then retest. If the test fails, repair the vehicle for the condition indicated by the failure message on the scan tool.
4. Verify that the EVAP I/M system status is set to YES.

See also:
• Diagnostic System Check - Vehicle
• Strategy Based Diagnosis
• Diagnostic Procedure Instructions
• Wiring Repairs
• Spark Plug Inspection
• Loss of Coolant (LS3, LS7)
• Loss of Coolant (LS9)
• Symptoms - Engine Mechanical
• Special Tools
• Heated Oxygen and Oxygen Sensor Caution
• DTC P0324, P0325, P0326, P0327, P0328, P0330, P0332, or P0333
• Symptoms - Engine Exhaust
• Crankcase Ventilation System Inspection/Diagnosis
• Thermostat Diagnosis
• Cooling System Draining and Filling (Static Fill)
• Symptoms - Engine Cooling
• Temperature Versus Resistance
• DTC P0106
• Symptoms - Engine Electrical
• Component Connector End Views
• Control Module References
• Supercharger Cleaning and Inspection
• Charge Air Cooling System Coolant Level Inspection
• Diagnostic Repair Verification
• Battery Inspection/Test
• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Relay Replacement (Attached to Wire Harness)
• Instrument Cluster Schematics
• Engine Cranks Slowly
• Diagnostic Trouble Code (DTC) List - Vehicle
• DTC P0685, P0689, or P0690
• Restricted Exhaust
• Engine Control Module Programming and Setup
• Engine Control Module Replacement
• Fuel Pressure Relief (Without CH 48027)
• Ignition System Specifications
• Spark Plug Wire Inspection
• Road Test Warning
• Fuel System Diagnosis (W/LS3 or LS7)
• AFIT Test Procedure
• Fuel Injector Balance Test-Fuel Pressure Test
• Inspection/Maintenance System DTC Table