Engine Controls - 2.2l - (Introduction) Chevrolet Cobalt I

Temperature vs Resistance

Temperature vs Resistance

Altitude vs Barometric Pressure

Altitude vs Barometric Pressure

Ignition System Specifications

Ignition System Specifications

Fastener Tightening Specifications

Fastener Tightening Specifications

Action Taken When the DTC Sets - Type A

The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.

Action Taken When the DTC Sets - Type B

The control module illuminates the MIL on the second consecutive ignition cycle that the diagnostic runs and fails.

Conditions for Clearing the MIL/DTC - Type A or Type B

1. The control module turns OFF the MIL after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC Last Test Failed clears when the diagnostic runs and passes.
3. Use a scan tool in order to clear the MIL and the DTC.

Action Taken When the DTC Sets - Type C

1. The control module stores the DTC information into memory when the diagnostic runs and fails.
2. The MIL will not illuminate.
3. The driver information center, if equipped, may display a message.

Conditions for Clearing the DTC - Type C

1. A last test failed, or current DTC, clears when the diagnostic runs and passes.
2. Use a scan tool in order to clear the DTC.

Conditions for Clearing the DTC - Type X

This DTC is available in the PCM software, but has been disabled, or turned OFF. In this case, the diagnostic does not run, no DTCs are stored, and the MIL does not illuminate. Type X DTCs are used primarily for export vehicles that do not require MIL illumination or DTC storing.

Diagnostic Trouble Code (DTC) Type(s)

Diagnostic Trouble Code (DTC) Type(s)

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Engine Controls Schematic Icons

Engine Controls Schematic Icons Icon Icon Definition NOTE: The OBD II symbol is used on the circuit diagrams in order to alert the technician that the circuit is essential for proper OBD II emission control circuit operation. Any circuit which fails and causes the malfunction indicator lamp (MIL) to turn ON, or causes emissions-related component damage, is identified as an OBD II circuit. IMPORTANT: Twisted-pair wires provide an effective shield that helps protect sensitive electronic components from electrical interference. If the wires were covered with shielding, install new shielding. In order to prevent electrical interference from degrading the performance of the connected components, you must maintain the proper specification when making any repairs to the twisted-pair wires shown : The wires must be twisted a minimum of 9 turns per 31 cm (12 in) as measured anywhere along the length of the wires The outside diameter of the twisted wires must not exceed 6.0 mm (0.25 in)

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Engine Control Module (ECM) Connector End Views

Engine Control Module (ECM) C1 Connector Part Information OEM: 15452125 Service: See Catalog 56-Way F Micro 64 Series Sealed (BU) Pin Wire Color Circuit No. Function 1 PU 1589 Primary Fuel Level Sensor Signal 2 L-BU 1162 Accelerator Pedal Position Signal (2) 3 D-GN 890 Fuel Tank Pressure Sensor Signal 4 D-BU 1161 Accelerator Pedal Position Signal (1) 5 - - Not Used 6 D-GN 1433 Clutch Start Switch Signal 7 - - Not Used 8 BN/WH 379 Cruise Control Clutch Pedal Position Switch Signal 9 PU 420 Torque Converter Clutch Brake Switch Signal 10 WH/BK 1164 Accelerator Pedal Position 5-Volt Reference (1) 11 L-BU 20 Stop Lamp Supply Voltage 12 BN 4 Accessory Voltage 13 GY 2709 Fuel Tank Pressure Sensor 5-Volt Reference 14 D-GN/WH 465 Fuel Pump Primary Relay Control 15-17 - - Not Used 18 BN 5069 Engine Main Relay Coil Control 19-27 - - Not Used 28 PK/BK 1039 Run/Crank Ignition 1 Voltage 29 PU 421 Air Injection Reaction Solenoid Relay Coil Control 30 WH 1310 EVAP Canister Vent Solenoid Control 31 D-GN/WH 459 A/C Compressor Clutch Relay Control 32-40 - - Not Used 41 TN 1274 Accelerator Pedal Position 5-Volt Reference (2) 42 - - Not Used 43 D-BU 473 High Speed Cooling Fan Relay Control 44 - - Not Used 45 BN/WH 419 Check Engine Indicator Control 46 YE 447 Starter Relay Coil Control 47-51 - - Not Used 52 RD/WH 840 Battery Positive Voltage 53 BN 1271 Accelerator Pedal Position Low Reference (1) 54 TN 2759 Fuel Tank Pressure Sensor Low Reference 55 - - Not Used 56 PU 1272 Accelerator Pedal Position Low Reference (2)

Engine Control Module (ECM) C2 Connector Part Information OEM: 15452126 Service: See Catalog 73-Way F GT 280 Series Micro 64 Sealed Pin Wire Color Circuit No. Function 1-2 - - Not Used 3 YE 581 Throttle Actuator Control Open 4 - - Not Used 5 BN 582 Throttle Actuator Control Close 6-9 - - Not Used 10 TN 1744 Fuel Injector Control (1) 11 PK/BK 1746 Fuel Injector Control (3) 12 L-BU/BK 844 Fuel Injector Control (4) 13 L-GN/BK 1745 Fuel Injector Control (2) 14 - - Not Used 15 D-GN/WH 428 EVAP Canister Purge Solenoid Control 16 - - Not Used 17 GY/WH 1423 Heated Oxygen Sensor Heater Low Control Bank 1 Sensor (2) 18 YE 400 Vehicle Speed Sensor Signal 19 PU 401 Vehicle Speed Sensor Low Reference 20-23 - - Not Used 24 GY 2701 Throttle Position Sensor 5-Volt Reference 25 GY/BK 2704 Manifold Absolute Pressure Sensor 5-Volt Reference 26 L-BU/BK 1688 5-Volt Reference 27 - - Not Used 28 GY 2700 A/C Pressure Sensor 5-Volt Reference (C67) 29 TN/WH 1704 Sensor Low Reference 30 - - Not Used 31 TN 2752 Throttle Position Sensor Low Reference 32-33 - - Not Used 34 PK 5293 Engine Main Relay Fused Control (4) 36 PU 486 Throttle Position Sensor Signal (2) 37 - - Not Used 38 TN 2760 Intake Air Temperature Sensor Low Reference 39 - - Not Used 40 OG/BK 469 Manifold Absolute Pressure Sensor Low Reference 41 PU/WH 3110 Heated Oxygen Sensor High Signal Bank 1 Sensor (1) 42 TN/WH 3111 Heated Oxygen Sensor Low Signal Bank 1 Sensor (1) 43 PU/WH 1668 Heated Oxygen Sensor High Signal Bank 1 Sensor (2) 44 TN/WH 1669 Heated Oxygen Sensor Low Signal Bank 1 Sensor (2) 45-46 - - Not Used 47 D-GN 335 Low Speed Cooling Fan Relay Control 48 TN/BK 231 Oil Pressure Switch Signal 49 OG/BK 380 A/C Refrigerant Pressure Sensor Signal (C67) 50 YE 410 Engine Coolant Temperature Sensor Signal 51 GY/WH 23 Generator Field Duty Cycle Signal 52 YE 492 Mass Air Flow Sensor Signal 53 GY/WH 3113 Heated Oxygen Sensor Heater Low Control Bank 1 Sensor (1) 54 WH 423 Ignition Control Timing Control (1) 55 OG 406 Ignition Control Timing Control (2) 56-57 - - Not Used 58 D-GN 485 Throttle Position Sensor Signal (1) 59 BK/WH 2751 Signal Ground 60 - - Not Used 61 TN 2761 Coolant Temperature Sensor Low Reference 62 L-GN 432 Manifold Absolute Pressure Sensor Signal 63 OG 225 Generator Turn On Signal 64 TN/BK 2500 High Speed GMLAN Serial Data (+) (1) 65 TN 2501 High Speed GMLAN Serial Data (-) (1) 66 YE 573 Crankshaft Position Sensor Signal (1) 67 PU 574 Crankshaft Position Sensor Low Reference (1) 68 TN 472 Intake Air Temperature Sensor Signal 69 - - Not Used 70 BN/WH 633 Camshaft Position Sensor Signal 71 GY 1716 Knock Sensor Low Reference (1) 72 D-BU 496 Knock Sensor Signal (1) 73 BK/WH 451 Signal Ground

Engine Controls Connector End Views

Accelerator Pedal Position (APP) Sensor Connector Part Information OEM: 15326830 Service: See Catalog 6-Way F GT 150 Series Sealed (BK) Pin Wire Color Circuit No. Function A PU 1272 Accelerator Pedal Position Low Reference (2) B L-BU 1162 Accelerator Pedal Position Signal (2) C TN 1274 Accelerator Pedal Position 5-Volt Reference (2) D BN 1271 Accelerator Pedal Position Low Reference (1) E D-BU 1161 Accelerator Pedal Position Signal (1) F WH/BK 1164 Accelerator Pedal Position 5-Volt Reference (1)

Crankshaft Position (CKP) Sensor Connector Part Information OEM: 15449028 Service: See Catalog 2-Way F GT 150 Series Sealed (BK) Pin Wire Color Circuit No. Function A PU 574 Crankshaft Position Sensor Low Reference (1) B YE 573 Crankshaft Position Sensor Signal (1)

Engine Coolant Temperature (ETC) Sensor Connector Part Information OEM: 15449028 Service: See Catalog 2-Way F GT 150 Series Sealed (BK) Pin Wire Color Circuit No. Function A TN 2761 Coolant Temperature Sensor Low Reference B YE 410 Engine Coolant Temperature Sensor Signal

Evaporative Emission (EVAP) Canister Purge Solenoid Valve Connector Part Information OEM: 12052643 Service: See Catalog 2-Way F Metri-Pack 150 Series Sealed (RD) Pin Wire Color Circuit No. Function A PK/WH 5291 Engine Main Relay Fused Control (2) B D-GN/WH 428 EVAP Canister Purge Solenoid Control

Evaporative Emissions (EVAP) Canister Vent Solenoid Valve Connector Part Information OEM: 12052643 Service: See Catalog 2-Way F Metri-Pack 150 Series Sealed (RD) Pin Wire Color Circuit No. Function A RD/WH 1840 Battery Positive Voltage B WH 1310 EVAP Canister Vent Solenoid Control

Fuel Injector 1 Connector Part Information OEM: 15326181 Service: See Catalog 2-Way F (BK) Pin Wire Color Circuit No. Function A PK 139 Ignition 1 Voltage B BK 1744 Fuel Injector 1 Control

Fuel Injector 2 Connector Part Information OEM: 15326181 Service: See Catalog 2-Way F (BK) Pin Wire Color Circuit No. Function A PK 139 Ignition 1 Voltage B L-GN/BK 1745 Fuel Injector 2 Control

Fuel Injector 3 Connector Part Information OEM: 15326181 Service: See Catalog 2-Way F (BK) Pin Wire Color Circuit No. Function A PK 139 Ignition 1 Voltage B PK/BK 1746 Fuel Injector 3 Control

Fuel Injector 4 Connector Part Information OEM: 15326181 Service: See Catalog 2-Way F (BK) Pin Wire Color Circuit No. Function A PK 139 Ignition 1 Voltage B L-BU/BK 844 Fuel Injector 4 Control

Fuel Pump and Sender Assembly Connector Part Information OEM: 776127-2 Service: See Catalog 2-Way F AMP (BK) Pin Wire Color Circuit No. Function 1 PK/BK 120 Fuel Pump Supply Voltage 2 BK 650 Ground

Fuel Tank Pressure (FTP) Sensor Connector Part Information OEM: 12059595 Service : See Catalog 3-Way Metri-Pack 150 Series Sealed (BK) Pin Wire Color Circuit No. Function A RD/PK 469 Low Reference B GY/RD 890 Fuel Tank Pressure Sensor Signal C BN/WH 416 5-Volt Reference

Heated Oxygen Sensor (HO2S) - 1 Connector Part Information OEM: 12176897 Service: See Catalog 4-Way F Metri-Pack 150 Series Sealed (L-GY) Pin Wire Color Circuit No. Function A TN/WH 3111 Heated Oxygen Sensor Low Signal Bank 1 Sensor (1) B PU/WH 3110 Heated Oxygen Sensor High Signal Bank 1 Sensor (1) C GY/WH 3113 Heated Oxygen Sensor Heater Low Control Bank 1 Sensor (1) D PK/BK 5291 Engine Main Relay Fused Control (2)

Heated Oxygen Sensor (HO2S) - 2 Connector Part Information OEM: 12160825 Service: See Catalog 4-Way M Metri-Pack 150 Series Sealed (BK) Pin Wire Color Circuit No. Function A TN/WH 1669 Heated Oxygen Sensor Low Signal Bank 1 Sensor (2) B PU/WH 1668 Heated Oxygen Sensor High Signal Bank 1 Sensor (2) C PK/BK 5291 Engine Main Relay Fused Control (2) D GY/WH 1423 Heated Oxygen Sensor Heater Low Control Bank 1 Sensor (2)

Ignition Control Module (ICM) Connector Part Information OEM: 15464996 Service: See Catalog 9-Way F GT 150 Series Sealed (BK) Pin Wire Color Circuit No. Function A PK/WH 5292 Engine Main Relay Fused Control (3) B WH 423 Ignition Control Timing Control (1) C-D - - Not Used E BK 450 Ground F BN/WH 633 Camshaft Position Sensor Signal G OG 406 Ignition Control Timing Control (2) H-J - - Not Used

Knock Sensor (KS) Connector Part Information OEM: 12077900 Service: See Catalog 2-Way F Metri-Pack 280 Series Sealed (BK) Pin Wire Color Circuit No. Function A D-BU 496 Knock Sensor Signal (1) B GY 1716 Knock Sensor Low Reference (1)

Mass Air Flow (MAF)/Inlet Air Temperature (IAT) Sensor Connector Part Information OEM: 15326822 Service: See Catalog 5-Way F GT 150 Series Sealed (BK) Pin Wire Color Circuit No. Function A YE 492 Mass Air Flow Sensor Signal B BK/WH 451 Signal Ground C PK/BK 5291 Engine Main Relay Fused Control (2) D TN 2760 Intake Air Temperature Sensor Low Reference E TN 472 Intake Air Temperature Sensor Signal

Manifold Absolute Pressure (MAP) Sensor Connector Part Information 12129946 3-Way F Metri-Pack 150 Series Sealed (M-GY) Pin Wire Color Circuit No. Function A OG/BK 469 Low Reference B L-GN 432 MAP Sensor Signal C GY 2704 5-Volt Reference

Throttle Actuator Control (TAC) Module Connector Part Information OEM: 15326836 Service: See Catalog 8-Way F GT 150 Series Sealed (BK) Pin Wire Color Circuit No. Function A D-GN 485 Throttle Position Sensor Signal (1) B TN/WH 1704 Sensor Low Reference C GY 2701 Throttle Position Sensor 5 Volt Reference D PU 486 Throttle Position Sensor Signal (2) E BN 582 Throttle Actuator Control Close F YE 581 Throttle Actuator Control Open G TN 2752 Throttle Position Sensor Low Reference H L-BU/BK 1688 5-Volt Reference

Removal Procedure

Note. In order to prevent any possible electrostatic discharge damage to the ECM, do not touch the connector pins or the soldered components on the circuit board.

Note. Always turn the ignition off when installing or removing the ECM connectors in order to prevent damage to the components.

1. Using a scan tool, retrieve the percentage of remaining engine oil. Record the remaining engine oil life.
2. Disconnect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
3. Disconnect the small ECM harness connector (3) from the ECM.
4. Remove the bolt retaining the large ECM connector to the ECM.
5. Disconnect the large ECM harness connector (4) from the ECM.
6. Use the retaining tab to release the ECM from the underhood junction block bracket.

Installation Procedure

1. Use the retaining tab to secure the ECM, when installing the ECM to the underhood junction block bracket.
2. Connect the large ECM harness connector (4) to the ECM. Tighten: Tighten the bolt to 4 N.m (35 lb in).
3. Connect the small ECM harness connector (3) to the ECM.
4. Connect the negative Battery Cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
5. Program the ECM. Refer to «Control Module References»(/chevrolet/cobalt/i-2004-2010/remont/communication-devices/#computerintegrating-systems__control-module-references) in Computer/Integrating Systems.

CKP System Variation Learn Procedure

1. Install a scan tool.
2. Monitor the engine control module (ECM) for DTCs with a scan tool. If other DTCs are set, except DTC P0315, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/cobalt/i-2004-2010/remont/oem-general-information/#vehicle-dtc-information__diagnostic-trouble-code-dtc-list) for the applicable DTC that set.
3. With a scan tool, select the CKP system variation learn procedure within the Special Functions menu and perform the following: Observe the fuel cut-off for the applicable engine. Block the drive wheels. Set the parking brake. Place the vehicle's transmission in Park or Neutral. Turn the air conditioning (A/C) OFF. Cycle the ignition from OFF to ON. Apply and hold the brake pedal for the duration of the procedure. Start and idle the engine. Accelerate to wide open throttle (WOT). The engine should not accelerate beyond the calibrated fuel cut-off RPM value noted in step 3.1. Release the throttle immediately if the value is exceeded. IMPORTANT: While the learn procedure is in progress, release the throttle immediately when the engine starts to decelerate. The engine control is returned to the operator and the engine responds to throttle position after the learn procedure is complete. Release the throttle when fuel cut-off occurs.
4. The scan tool displays Learn Status: Learned this Ignition. If the scan tool indicates that DTC P0315 ran and passed, the CKP variation learn procedure is complete. If the scan tool indicates DTC P0315 failed or did not run, refer to «DTC P0315»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-dtc-p0137-to-p0449) . If any other DTCs set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/cobalt/i-2004-2010/remont/oem-general-information/#vehicle-dtc-information__diagnostic-trouble-code-dtc-list) for the applicable DTC that set.
5. Turn OFF the ignition for 30 seconds after the learn procedure is completed successfully.

Note. Use care when handling the coolant sensor. Damage to the coolant sensor will affect the operation of the fuel control system.

1. Turn OFF the ignition.
2. Drain the coolant system to below the engine coolant temperature (ECT) sensor. Refer to «Draining and Filling Cooling System (2.0L (LSJ))»(/chevrolet/cobalt/i-2004-2010/remont/cooling-system-mechanical/#engine-cooling-system) or «Draining and Filling Cooling System (2.2L (L61))»(/chevrolet/cobalt/i-2004-2010/remont/cooling-system-mechanical/#engine-cooling-system) in Engine Cooling.
3. Disconnect the engine coolant temperature ECT sensor electrical connector.
4. Carefully remove the ECT sensor.

Note. Replacement components must be the correct part number for the application. Components requiring the use of the thread locking compound, lubricants, corrosion inhibitors, or sealants are identified in the service procedure. Some replacement components may come with these coatings already applied. Do not use these coatings on components unless specified. These coatings can affect the final torque, which may affect the operation of the component. Use the correct torque specification when installing components in order to avoid damage.

Note. Use care when handling the coolant sensor. Damage to the coolant sensor will affect the operation of the fuel control system.

1. If you are reinstalling the original sensor, or if you are installing a new sensor without a sealer, coat the threads with sealer Saturn P/N 21485278 or an equivalent.
2. Install the ECT sensor. Tighten: Tighten the ECT sensor to 10 N.m (89 lb in).
3. Connect the ECT sensor electrical connector.
4. Refill the engine coolant system. Refer to «Draining and Filling Cooling System (2.0L (LSJ))»(/chevrolet/cobalt/i-2004-2010/remont/cooling-system-mechanical/#engine-cooling-system) or «Draining and Filling Cooling System (2.2L (L61))»(/chevrolet/cobalt/i-2004-2010/remont/cooling-system-mechanical/#engine-cooling-system) in Engine Cooling.

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Mass Air Flow (MAF) Sensor Replacement

1. Remove the air cleaner outlet resonator. Refer to «Air Cleaner Outlet Resonator Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
2. Remove the throttle body. Refer to «Throttle Body Assembly Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
3. Disconnect the manifold absolute pressure (MAP) sensor harness connector.
4. Remove the MAP sensor (2) from the intake manifold.
5. Inspect the seal for damage.

1. Install the MAP sensor (2) into the intake manifold.
2. Connect the MAP sensor harness connector.
3. Install the throttle body. Refer to «Throttle Body Assembly Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
4. Install the air cleaner outlet resonator. Refer to «Air Cleaner Outlet Resonator Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .

Tools Required

J 39194-C Oxygen Sensor Wrench

Note. The oxygen sensor uses a permanently attached pigtail and connector. Do not remove the pigtail from the oxygen sensor. Damage to or removal of the pigtail connector could affect proper operation of the oxygen sensor.

Note. The use of excessive force may damage the threads in the exhaust manifold/pipe.

1. Remove the exhaust manifold heat shield. Refer to «Exhaust Manifold Replacement (L61)»(/chevrolet/cobalt/i-2004-2010/remont/exhaust/#engine-exhaust-system) in Engine Exhaust.
2. Disconnect the oxygen sensor harness connector.
3. Remove the oxygen sensor using J 39194-C .

1. Coat the threads of the oxygen sensor with anti-seize compound Saturn P/N 21485279, if necessary.
2. Install the oxygen sensor. Tighten: Tighten the oxygen sensor to 30 N.m (22 lb ft).
3. Connect the oxygen sensor harness connector.
4. Install the exhaust manifold heat shield. Refer to «Exhaust Manifold Replacement (L61)»(/chevrolet/cobalt/i-2004-2010/remont/exhaust/#engine-exhaust-system) in Engine Exhaust.

J 39194-C Oxygen Sensor Wrench

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cobalt/i-2004-2010/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
2. Remove the wheel drive shaft heat shield. Refer to «Wheel Drive Shaft Heat Shield Replacement»(/chevrolet/cobalt/i-2004-2010/remont/exhaust/#engine-exhaust-system) in Engine Exhaust.
3. Note the routing of the heated oxygen sensor (HO2S) electrical harness.
4. Disconnect the HO2S electrical connector (2), in the engine compartment.
5. Carefully bend the edge of the channel on the LH side of the exhaust heat shield outboard, just enough to release the HO2S electrical harness (1).
6. Using the J 39194 carefully remove the HO2S.
7. Lower the HO2S electrical harness away from the underbody.

1. If reinstalling the old HO2S, coat the threads with anti-seize compound, Saturn P/N 24185279, or equivalent.
2. Carefully install the HO2S to the pipe.
3. Using the J 39194 , or equivalent, tighten the HO2S. Tighten: Tighten the HO2S to 41 N.m (30 lb ft).
4. Install the HO2S electrical harness into position as noted before removal.
5. Carefully bend the edge of the channel (1) on the LH side of the exhaust heat shield inboard, just enough to secure the HO2S electrical harness in the channel.
6. Connect the HO2S electrical connector (2).
7. Install the wheel drive shaft heat shield. Refer to «Wheel Drive Shaft Heat Shield Replacement»(/chevrolet/cobalt/i-2004-2010/remont/exhaust/#engine-exhaust-system) in Engine Exhaust.
8. Lower the vehicle.

1. Disconnect the connector position assurance (CPA) from the accelerator pedal position (APP) sensor connector.
2. Disconnect the APP sensor harness connector.
3. Remove the APP assembly attachment bolts from the brake pedal assembly.
4. Remove the APP assembly from the vehicle.

1. Install the upper attachment bolt into the APP assembly.
2. Install the APP assembly into the vehicle.
3. Install the attachment bolts into the APP assembly. Tighten: Tighten the accelerator pedal position assembly-to-brake bracket bolt to 9 N.m (80 lb in).
4. Connect the APP sensor harness connector. Push the connector in until the lock position is felt, then pull back to confirm engagement.
5. Install the APP sensor connect CPA.

Note. Do not use solvent of any type when cleaning the gasket surfaces on the intake manifold and the throttle body assembly, as damage to the gasket surfaces and throttle body assembly may result. Use care in cleaning the gasket surfaces on the intake manifold and the throttle body assembly, as sharp tools may damage the gasket surfaces.

Note. Do not use any solvent that contains Methyl Ethyl Ketone (MEK). This solvent may damage fuel system components.

1. Remove the air cleaner resonator. Refer to «Air Cleaner Outlet Resonator Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
2. Disconnect the idle air control (IAC) valve harness connector (1).
3. Disconnect the throttle position (TP) sensor harness connector (2).
4. Disconnect the vacuum hoses at the throttle body.
5. Remove the throttle body attaching bolts (1).
6. Remove the throttle body (4) from the intake manifold.

1. Inspect the throttle body gasket (3) and replace if necessary.
2. Install the throttle body (4) to the intake manifold.
3. Install the throttle body attaching bolts (1). Tighten: Tighten the throttle body attaching bolts to 10 N.m (89 lb in).
4. Connect the vacuum hoses to the throttle body.
5. Connect the TP sensor harness connector (2).
6. Connect the IAC valve harness connector (1).
7. Install the air cleaner resonator. Refer to «Air Cleaner Outlet Resonator Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
8. Test the accelerator movement by depressing the pedal to the floor and releasing the pedal.

Throttle Body Cleaning Procedure

1. Remove the air cleaner outlet duct. Refer to «Air Cleaner Outlet Resonator Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
2. Inspect the throttle body bore and the throttle valve plate for deposits. You must open the throttle valve in order to inspect all of the surfaces.
3. Clean the throttle body bore and the throttle valve plate using a clean shop towel with Top Engine Cleaner, Saturn P/N 21007129 or an equivalent product.
4. If the deposits are excessive, remove and disassemble the throttle body for cleaning. Refer to «Throttle Body Assembly Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
5. After disassembly, clean the throttle body using a parts cleaning brush. DO NOT immerse the throttle body in any cleaning solvent.
6. If you removed and disassembled the throttle body for cleaning, assemble and install the throttle body. Refer to «Throttle Body Assembly Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
7. Install the air cleaner outlet duct. Refer to «Air Cleaner Outlet Resonator Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .

SA9127E Gage Bar Set, or J 34730-1A Fuel Pressure Gage

1. Turn the ignition OFF.
2. Disconnect the battery negative cable in order to avoid possible fuel discharge if an accidental attempt is made to start the engine. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
3. Loosen the fuel filler cap to relieve the fuel tank vapor pressure.
4. Remove the cap from the fuel pressure service port.
5. Connect the SA9127E , or the J 34730-1A to the fuel pressure service port connection. Wrap a shop towel around the port while connecting the gauge in order to avoid spillage. Refer to «Fuel Pressure Gage Installation and Removal»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
6. Install the bleed hose of the SA9127E , or the J 34730-1A into an approved fuel container.
7. Open the bleed valve on the SA9127E , or the J 34730-1A in order to bleed the fuel system pressure. The fuel connections are now safe for servicing.
8. Place a shop towel under the fuel pressure service port to catch any remaining fuel spillage.
9. Disconnect the SA9127E , or the J 34730-1A from the fuel pressure service port connection. Refer to «Fuel Pressure Gage Installation and Removal»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
10. Drain any fuel remaining in the gauge into an approved fuel container.
11. Install the cap to the fuel pressure service port.

J 34730-1A Fuel Pressure Gage

Note. Clean all of the following areas before performing any disconnections in order to avoid possible contamination in the system: The fuel pipe connections The hose connections The areas surrounding the connections

1. Remove the cap from the fuel pressure service port connection.
2. Connect the J 34730-1A to the fuel pressure service connection. Wrap a shop towel around the fitting while connecting the gage to avoid spillage.
3. Turn the ignition ON, with the engine OFF.
4. Place the bleed hose of the J 34730-1A into an approved fuel container.
5. Open the bleed valve on the J 34730-1A in order to bleed the air from the fuel pressure gage.
6. Command the fuel pump ON with a scan tool.
7. Close the bleed valve on the J 34730-1A .
8. Inspect for fuel leaks.

1. Ensure the fuel pump is OFF.
2. Place the bleed hose of the J 34730-1A into an approved fuel container.
3. Open the bleed valve on the J 34730-1A in order to bleed the fuel system pressure.
4. Place a shop towel under the fuel pressure service connection to catch any remaining fuel spillage.
5. Remove the J 34730-1A from the fuel pressure service connection.
6. Drain any fuel remaining in the J 34730-1A into an approved fuel container.
7. Inspect for leaks using the following procedure: Turn the ignition ON, with the engine OFF for 2 seconds. Turn the ignition OFF for 10 seconds. Turn the ignition ON, with the engine OFF for 2 seconds. Turn the ignition OFF. Inspect for leaks.
8. Install the cap on the fuel pressure service connection.

J 37088-A Fuel Line Disconnect Tool Set

1. Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
2. Remove the retainer from the quick-connect fitting, if applicable.
3. Blow dirt out of the fitting using compressed air.
4. Choose the correct tool from J 37088-A tool set for the size of the fitting. Insert the tool into the female connector, then push inward to release the locking tabs.
5. Pull the connection apart.
6. Using a clean shop towel, wipe off the male pipe end.
7. Inspect both ends of the fitting for dirt and burrs. Clean or replace the components as required.

1. Apply a few drops of clean engine oil to the male pipe end.
2. Push both sides of the fitting together to cause the retaining tabs to snap into place.
3. Once installed, pull on both sides of the fitting to make sure the connection is secure.
4. Install the retainer to the quick-connect fitting, if applicable.

1. Blow dirt out of the fitting using compressed air.
2. Depress the tabs on the connector housing in order to release the connector.
3. Continue to depress the tabs while pulling the connector apart.
4. Wipe off the male end using a clean shop towel.
5. Inspect both ends of the fitting for dirt and burrs.
6. Clean or replace the components as required.

1. Apply a few drops of clean engine oil to the male pipe end.
2. Push both sides of the quick-connect fittings together in order to snap the retainer in place.
3. Pull on both sides of the quick-connect fitting in order to make sure the connection is secure.

Fuel Tank Draining Procedure

1. J 43290 Fuel Tank Siphoning Hose
2. J 42960-2 Fuel Flapper Door Holder

Draining Procedure

1. Remove the fuel filler cap.
2. Install the J 42960-2 , or equivalent, into the fuel fill pipe in order to hold the door open.
3. Insert the J 43290 (2) through the J 42960-2 (1) and into the filler pipe.
4. Continue to insert the J 43290 (2) into the filler pipe until the hose exits the valve (1) and reaches the bottom of the tank.
5. Use an air operated pump device in order to drain as much fuel through the J 43290 (1) as possible.

1. Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
2. Drain the fuel tank. Refer to «Fuel Tank Draining Procedure»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction__fuel-tank-draining-procedure) .
3. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cobalt/i-2004-2010/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
4. Disconnect the fuel feed and return lines from the fuel filter.
5. Cap or plug the fuel tank feed and return pipes to prevent fuel loss and/or contamination.
6. Disconnect the following evaporative emission (EVAP) pipe fittings, for access to disconnect the fuel filler hose from the tank. Refer to «Quick Connect Fitting(s) Service (Plastic Collar) (Press Release)»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) . Remove EVAP canister hose 1. Remove the tank vent hose 2. Remove the EVAP canister sensor electrical connector 4 from the sensor 4. Remove the EVAP canister electrical connector from the solenoid 5.
7. Cap or plug the EVAP canister and the vent hose 2 and the tank vent hose 1 to prevent contamination.
8. Loosen the fuel filler hose clamp (1) at the fuel tank.
9. Disconnect the fuel filler hose from the fuel tank.
10. Disconnect the fuel pump module harness electrical connector from the vehicle underbody connector.
11. Release the exhaust extension pipe insulators (1, 2) from the underbody hangers.
12. Release the muffler insulator (3) from the underbody hanger and slowly lower the exhaust to rest on the rear axle beam.
13. Have an assistant support the fuel tank during fuel tank strap removal, and during tank removal.
14. Remove the LH fuel tank strap bolts and the strap.
15. Remove the RH tank strap bolts and the strap.
16. In order to clear the exhaust extension pipe, slowly lower the RH side of the fuel tank. Use care in feeding the fuel feed and return pipes, the EVAP vapor pipe, and the fuel pump module electrical harness to clear the axle.
17. Once the tank is clear of the RH frame rail, remove the fuel tank down and toward the RH side of the vehicle.
18. If the fuel tank only is to be replaced, remove the fuel pump module assembly from the fuel tank. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .

1. If fuel tank replacement was necessary, install the fuel pump module assembly to the fuel tank. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
2. Have an assistant support the fuel tank during fuel tank and fuel tank strap installation.
3. Begin to install the LH side of the fuel tank over the exhaust pipe.
4. Raise the RH side of the fuel tank into position inboard of the RH frame rail. Use care in feeding the fuel feed and return pipes, the EVAP vapor pipe, and the fuel pump module electrical harness over the rear axle.
5. Install the RH fuel tank strap and strap bolts.
6. Install the LH fuel tank strap and strap bolts.
7. Tighten the fuel tank strap bolts. Tighten: Tighten the bolts to 25 N.m (18 lb ft).
8. Raise the exhaust into position and install the muffler insulator (3) to the underbody hanger.
9. Install the exhaust extension pipe insulators (1, 2) to the underbody hangers.
10. Connect the fuel pump module harness electrical connector to the vehicle underbody connector.
11. Connect the fuel filler hose to the fuel tank.
12. Tighten the fuel filler hose clamp (1) at the fuel tank. Tighten: Tighten the clamp to 4.5 N.m (40 lb in).
13. Remove the caps or plugs from the EVAP canister hose 2 and tank vent 1 pipes.
14. Connect the EVAP canister hose 2 and tank vent hose 1. Refer to «Quick Connect Fitting(s) Service (Plastic Collar) (Press Release)»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
15. Remove the caps or plugs from the fuel tank feed and return pipes.
16. Connect the fuel feed and return lines to the fuel filter.
17. Lower the vehicle.
18. Refill the fuel tank.
19. Connect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
20. Inspect for fuel leaks using the following procedure: Turn ON the ignition, with the engine OFF for 2 seconds. Turn OFF the ignition for 10 seconds. Turn ON the ignition, with the engine OFF. Inspect for fuel leaks.

1. Remove the fuel tank. Refer to «Fuel Tank Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
2. Disconnect the fuel pump module harness electrical connector from the fuel tank pressure sensor.
3. Position 2 flat-bladed screwdrivers, one on each side of the sensor, near the vacuum port.
4. Carefully use the screwdrivers to lift and release the sensor from the fuel pump module.

1. Install the fuel tank pressure sensor to the fuel pump module assembly. Ensure that the sensor grommet is fully seated to the pump module.
2. Connect the pump module electrical connector to the fuel tank pressure sensor.
3. Install the fuel tank. Refer to «Fuel Tank Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .

1. Remove the fuel pump module assembly. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
2. Release the fuel level sensor wiring harness from the molded-in tab (1) on the pump module bowl.
3. Disconnect the fuel level sensor electrical connector from the pump module.
4. Depress the retaining tab (2) on the sensor and begin to slide the level sensor away from the pump module.
5. Carefully slide the level sensor the rest of the way off of the pump module.

1. Carefully slide the fuel level sensor into the slots on the fuel pump module bowl.
2. Secure the retaining tab (2) on the sensor into the slot on the pump module bowl.
3. Connect the fuel level sensor electrical connector to the pump module.
4. Install the fuel level sensor wiring harness to the molded-in tab (1) on the pump module bowl.
5. Install the fuel pump module assembly. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .

J 39765 Fuel Sender Lock Nut Wrench

1. Remove the fuel tank. Refer to «Fuel Tank Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
2. Release the retaining tab on the fuel tank retainer used to secure the fuel pump module pipes in position on the tank.
3. Release the fuel pump module electrical harness from the retaining slot on the tank.
4. Disconnect the fuel pump module harness electrical connector from the fuel tank pressure sensor.
5. Using the J 39765 (1), carefully rotate to release the fuel pump module retaining lock ring.
6. Remove the fuel pump module retaining lock ring, by sliding the ring over the module pipes and electrical harness.
7. Slowly raise the fuel pump module assembly until the fuel level sensor float arm is just visible. Ensure that the fuel level sensor harness connector clears the tank opening.
8. Tilt the pump module toward the rear of the fuel tank to enable the level sensor float arm to clear the tank opening. Remove the pump module from the tank.
9. Carefully discard the fuel in the pump module reservoir bowl into an approved fuel container.
10. Remove and discard the fuel pump module-to-fuel tank seal (1).

1. Install a NEW fuel pump module-to-fuel tank seal (1).
2. Tilt the pump module toward the rear of the fuel tank to enable the level sensor float arm to clear the tank opening. Install the fuel pump module to the fuel tank.
3. Slowly lower the fuel pump module assembly into the tank. Ensure that the fuel level sensor harness connector is positioned properly.
4. Install the fuel pump module retaining lock ring over the module pipes and electrical harness, and into position on the top of the module.
5. Using the J 39765 (1), carefully rotate to fully secure the fuel pump module retaining lock ring.
6. Connect the fuel pump module harness electrical connector to the fuel tank pressure sensor.
7. Secure the fuel pump module electrical harness into the retaining slot on the tank.
8. Secure the retaining tab on the fuel tank retainer used to secure the fuel pump module pipes in position on the tank.
9. Install the fuel tank. Refer to «Fuel Tank Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .

1. Remove the fuel fill cap.
2. Drain the fuel tank. Refer to «Fuel Tank Draining Procedure»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction__fuel-tank-draining-procedure) .
3. Remove the fuel filler pocket. Refer to «Fuel Filler Pocket Replacement»(/chevrolet/cobalt/i-2004-2010/remont/exterior-body-panels/#body-rear-end) in Body Rear End.
4. Remove the fuel filler pipe assembly upper retaining bolt.
5. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cobalt/i-2004-2010/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
6. Disconnect the evaporative emission (EVAP) vent pipe (1) from the EVAP canister. Refer to «Quick Connect Fitting(s) Service (Plastic Collar) (Press Release)»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
7. Loosen the fuel filler hose clamp (1) at the fuel tank.
8. Remove the fuel filler pipe assembly lower retaining bolt.
9. Disconnect the fuel filler hose from the fuel tank.
10. Remove the fuel filler pipe assembly.

1. Install the fuel filler pipe assembly into position on the vehicle.
2. Connect the fuel filler hose to the fuel tank.
3. Install the fuel filler pipe assembly lower retaining bolt. Tighten: Tighten the bolt to 10 N.m (89 lb in).
4. Tighten the fuel filler hose clamp (1) at the fuel tank. Tighten: Tighten the clamp to 4.5 N.m (40 lb in).
5. Connect the EVAP vent pipe (1) to the EVAP canister. Refer to «Quick Connect Fitting(s) Service (Plastic Collar) (Press Release)»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
6. Lower the vehicle.
7. Install the fuel filler pipe assembly upper retaining bolt. Tighten: Tighten the bolt to 10 N.m (89 lb in).
8. Install the fuel filler pocket. Refer to «Fuel Filler Pocket Replacement»(/chevrolet/cobalt/i-2004-2010/remont/exterior-body-panels/#body-rear-end) in Body Rear End.
9. Refill the fuel tank.
10. Install the fuel fill cap.

1. Drain the fuel tank. Refer to «Fuel Tank Draining Procedure»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction__fuel-tank-draining-procedure) .
2. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cobalt/i-2004-2010/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
3. Loosen the fuel filler hose clamps (1, 2).
4. Disconnect the fuel filler hose from the fuel tank.
5. Disconnect the fuel filler hose from the fuel filler pipe.

1. Connect the fuel filler hose to the fuel filler pipe.
2. Connect the fuel filler hose to the fuel tank.
3. Tighten the fuel filler hose clamps (1, 2). Tighten: Tighten the clamps to 4.5 N.m (40 lb in).
4. Lower the vehicle.
5. Refill the fuel tank.

1. Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
2. Disconnect the engine fuel feed pipe from the chassis fuel flex hose. Refer to «Quick Connect Fitting(s) Service (Metal Collar)»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
3. Use a back up wrench on the fuel rail and disconnect the fuel feed pipe.
4. Remove the fuel feed pipe fastener located on the engine.
5. Remove the engine fuel feed pipe.

1. Install the fuel feed pipe to the fuel rail. Tighten: Using a backup wrench on the fuel rail tighten the fuel feed pipe to 10 N.m (89 lb in).
2. Install the engine fuel feed pipe fastener located on the engine. Tighten: Tighten the fuel feed pipe fastener to 10 N.m (89 lb in).
3. Connect the engine fuel feed pipe to the chassis fuel flex hose. Refer to «Quick Connect Fitting(s) Service (Metal Collar)»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
4. Connect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
5. Inspect for leaks using the following procedure: With the engine OFF, turn ON the ignition for 2 seconds. Inspect for fuel leaks. Turn the ignition OFF. With the engine OFF, turn ON the ignition for 2 seconds. Inspect for fuel leaks. Turn the ignition OFF.

1. Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
2. Remove the pipe retaining clip (1) from the fuel feed pipe.
3. Disconnect the fuel feed pipe from the engine fuel rail. Refer to «Quick Connect Fitting(s) Service (Metal Collar)»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
4. Cap or plug the fuel pipe and the engine fuel rail to prevent contamination.
5. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cobalt/i-2004-2010/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
6. Remove the evaporative emission (EVAP) canister for pipe removal access. Refer to «Evaporative Emission (EVAP) Canister Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction)
7. Disconnect the fuel filter from the engine feed fuel pipe. Refer to «Quick Connect Fitting(s) Service (Metal Collar)»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
8. Remove the rear brake pipe bracket retaining nuts and release the brackets from the body studs.
9. Release the pipe retainers (1) from the vehicle underbody.
10. Remove the fuel feed pipe from the pipe retainers.
11. Lower the rear of the pipe while moving the pipe rearward slightly, then lower the front of the pipe.
12. Remove the fuel feed pipe from the vehicle.

1. Position the fuel feed pipe to the vehicle.
2. With the rear of the pipe positioned slightly rearward and down, raise the front of the pipe into position.
3. Install the remainder of the pipe into position.
4. Install the fuel feed pipe to the pipe retainers.
5. Secure the pipe retainers (1) to the vehicle underbody.
6. Install the rear brake hose brackets to the body studs and install the rear brake hose bracket retaining nuts. Tighten: Tighten the nuts to 10 N.m (89 lb in).
7. Connect the fuel filter to the engine feed fuel pipe (1). Refer to «Quick Connect Fitting(s) Service (Metal Collar)»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
8. Install the EVAP canister. Refer to «Evaporative Emission (EVAP) Canister Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction)
9. Lower the vehicle.
10. Remove the caps or plugs from the fuel pipe and the engine fuel rail.
11. Connect the fuel feed pipe to the engine fuel rail. Refer to «Quick Connect Fitting(s) Service (Metal Collar)»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
12. Install the pipe retaining clip (1) to the fuel feed pipe.
13. Connect the negative battery cable.
14. Inspect for fuel leaks using the following procedure: Turn ON the ignition, with the engine OFF for 2 seconds. Turn OFF the ignition for 10 seconds. Turn ON the ignition, with the engine OFF. Inspect for fuel leaks.

Fuel System Cleaning

1. Remove the fuel tank. Refer to «Fuel Tank Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
2. Remove the fuel pump module assembly. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
3. Inspect the fuel pump module strainer. Replace the pump module assembly if the fuel strainer is contaminated.
4. Flush the fuel tank with hot water.
5. Pour the water out of the fuel sender assembly opening in the fuel tank. Rock the fuel tank in order to be sure that the removal of the water from the fuel tank is complete.
6. Allow the tank to dry completely before reassembly.
7. Disconnect the fuel feed pipe at the engine fuel rail. Refer to «Quick Connect Fitting(s) Service (Metal Collar)»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
8. Clean the fuel pipes by applying air pressure in the opposite direction of the fuel flow.
9. Connect the fuel feed pipe to the engine fuel rail. Refer to «Quick Connect Fitting(s) Service (Metal Collar)»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
10. Install the fuel pump module assembly. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
11. Install the fuel tank. Refer to «Fuel Tank Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .

1. Relieve the fuel system pressure. Refer to «Fuel Pressure Relief Procedure»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
2. Remove the air cleaner outlet resonator. Refer to «Air Cleaner Outlet Resonator Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
3. Use a back up wrench on the fuel rail and disconnect the fuel supply pipe.
4. Disconnect the fuel injector harness connectors.
5. Remove the fuel rail attaching studs.
6. Remove the fuel rail using the following procedure: Pull the fuel rail back and upward to remove the fuel injectors from the cylinder head ports. Rotate the fuel rail in order to position the injectors downward. Remove the fuel rail.
7. Remove the fuel injectors. Refer to «Fuel Injector Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .

1. Install the fuel injectors. Refer to «Fuel Injector Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
2. Install the fuel rail using the following procedure: With the fuel injectors positioned downward, lower the fuel injectors into the cylinder head ports. Align the injectors by rotating the fuel rail forward. Carefully push the fuel injectors into the cylinder head ports.
3. Install the fuel rail attaching studs. Tighten: Tighten the fuel rail studs to 10 N.m (89 lb in).
4. Connect the fuel injector harness connectors. Pull back to insure the connectors are locked in place.
5. Install the fuel supply pipe. Tighten: Using a backup wrench on the fuel rail tighten the fuel supply pipe to 10 N.m (89 lb in).
6. Install the air cleaner outlet resonator. Refer to «Air Cleaner Outlet Resonator Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
7. Connect the negative battery cable. Refer to «Battery Negative Cable Disconnect/Connect Procedure»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
8. Inspect for fuel leaks using the following procedure: Turn ON the ignition, with the engine OFF for 2 seconds. Turn OFF the ignition for 10 seconds. Turn ON the ignition. Inspect for fuel leaks.

1. Remove the fuel rail. Refer to «Fuel Rail Assembly Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
2. Remove the fuel injector retainer clip (3).
3. Remove the fuel injectors (5) from the fuel rail.
4. Remove and discard the fuel injector O-rings (4, 7).

1. Install the O-rings on the fuel injector (4, 7).
2. Install the fuel injector clip (3) on the fuel injector (5).
3. Install the fuel injector in the fuel rail with the connector facing upward.
4. Install the fuel rail. Refer to «Fuel Rail Assembly Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .

1. Disconnect the evaporative emission (EVAP) canister purge valve harness connector.
2. Disconnect the vacuum pipe from the EVAP canister purge valve.
3. Disconnect the purge pipe from the EVAP canister purge valve.
4. Remove the EVAP canister purge valve and bracket.
5. Remove the EVAP canister purge valve from the purge bracket.
6. Inspect for carbon release in the EVAP canister purge valve ports. Refer to «Evaporative Emission (EVAP) System Cleaning»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .

1. Install the EVAP canister purge valve on to the purge bracket.
2. Install the EVAP canister purge valve and bracket. Tighten: Tighten the purge bracket nut to 8 N.m (71 lb in).
3. Connect the purge pipe to the EVAP canister purge valve.
4. Connect the vacuum pipe to the EVAP canister purge valve.
5. Connect the EVAP canister purge valve harness connector.

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cobalt/i-2004-2010/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
2. Disconnect the electrical connector from the evaporative emission (EVAP) canister vent solenoid valve.
3. Clean away any debris that may be present around the EVAP canister vent valve.
4. Remove the EVAP canister retaining bolt (1).
5. Lower the EVAP canister.
6. Rotate the EVAP canister vent valve counterclockwise to release from the locked position.
7. Remove the vent valve from the EVAP canister.

1. Insert the EVAP canister vent solenoid valve into the EVAP canister, with the valve aligned to the released position.
2. Rotate vent valve clockwise to secure into the locked position.
3. Install the EVAP canister and retaining bolt (1). Tighten: Tighten the bolt to 10 N.m (89 lb in).
4. Connect the electrical connector to the EVAP canister vent valve.
5. Lower the vehicle.

1. Remove the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
2. Disconnect the engine purge pipe (1) from the evaporative emission (EVAP) canister purge valve (2).
3. Disconnect the engine purge pipe (1) from the intake manifold.
4. Remove the engine purge pipe (1).

1. Position the engine purge pipe (1) to the EVAP canister purge valve (2) and the intake manifold.
2. Connect the engine purge pipe (1) to the intake manifold.
3. Connect the engine purge pipe (1) to the EVAP canister purge valve (2).
4. Install the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .

1. Disconnect the EVAP purge pipe from the engine purge hose. Refer to «Quick Connect Fitting(s) Service (Plastic Collar) (Press Release)»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
2. Cap or plug the purge pipe and the engine purge hose to prevent contamination.
3. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cobalt/i-2004-2010/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
4. Remove the evaporative emission (EVAP) canister for pipe removal access. Refer to «Evaporative Emission (EVAP) Canister Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
5. Remove the rear brake pipe bracket retaining nuts and release the brackets from the body studs.
6. Release the pipe retainers (1) from the vehicle underbody.
7. Remove the purge pipe from the pipe retainers.
8. Lower the rear of the pipe while moving the pipe rearward slightly, then lower the front of the pipe.
9. Remove the purge pipe from the vehicle.

1. Position the purge pipe to the vehicle.
2. With the rear of the pipe positioned slightly rearward and down, raise the front of the pipe into position.
3. Install the remainder of the pipe into position.
4. Install the purge pipe to the pipe retainers.
5. Secure the pipe retainers (1) to the vehicle underbody.
6. Install the rear brake hose brackets to the body studs and install the rear brake hose bracket retaining nuts. Tighten: Tighten the nuts to 10 N.m (89 lb in).
7. Install the EVAP canister. Refer to «Evaporative Emission (EVAP) Canister Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
8. Lower the vehicle.
9. Remove the caps or plugs from the purge pipe and the engine purge hose.
10. Connect the purge pipe to the engine purge hose. Refer to «Quick Connect Fitting(s) Service (Plastic Collar) (Press Release)»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cobalt/i-2004-2010/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
2. Disconnect the electrical connector from the evaporative emission (EVAP) canister vent solenoid valve.
3. Disconnect the hose connections (1, 2, 3) from the EVAP canister. Refer to «Quick Connect Fitting(s) Service (Plastic Collar) (Press Release)»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
4. Remove the EVAP canister retaining bolt (1).
5. Remove the EVAP canister assembly toward the outboard side of the vehicle.
6. If the EVAP canister is to be reused, inspect the canister for loose carbon.

1. Insert the retaining tab of the EVAP canister into the slotted bracket on the vehicle underbody.
2. Install the EVAP canister retaining bolt (1). Tighten: Tighten the bolt to 10 N.m (89 lb in).
3. Connect the hose connections (1,2,3) to the EVAP canister. Refer to «Quick Connect Fitting(s) Service (Plastic Collar) (Press Release)»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
4. Connect the electrical connector to the EVAP canister vent solenoid valve.
5. Lower the vehicle.

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cobalt/i-2004-2010/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
2. Clean away any debris that may be present around the evaporative emission (EVAP) canister vent filter cover.
3. Carefully release the canister filter cover rear retaining tabs.
4. Carefully release the canister filter cover forward retaining tabs and remove the cover from the EVAP canister.
5. Remove the filter from the canister and discard the filter.
6. Remove the seal from the filter cover and discard the seal.
7. Clean the inside of the EVAP canister filter housing with a clean shop towel.

1. Install a NEW cover to the canister. Ensure that the seal is properly seated to the cover.
2. Install a NEW filter to the canister filter housing.
3. Install the filter cover to the EVAP canister.
4. Lower the vehicle.

J 41413 EVAP Pressure and Purge Station

Inspection Procedure

1. Turn OFF the ignition.
2. Remove the EVAP canister purge valve. Refer to «Evaporative Emission (EVAP) Canister Purge Solenoid Valve Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
3. Lightly tap the EVAP canister purge valve on a hard surface.
4. Inspect for carbon particles exiting either of the vacuum ports. If no carbon particles were detected, but a blockage was detected during a diagnostic procedure, install the original EVAP canister purge valve. Continue with the cleaning procedure. If carbon particles are found during the inspection procedure, continue with the cleaning procedure. If a diagnostic procedure directed you to replace the EVAP canister purge valve and no carbon particles were detected, replace the EVAP canister purge valve. Return to the published service procedure.

Cleaning Procedure

1. Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cobalt/i-2004-2010/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
2. Remove the EVAP canister. Refer to «Evaporative Emission (EVAP) Canister Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
3. Turn OFF the main valve on the J 41413 .
4. Disconnect the hose from the diagnostic station pressure regulator.
5. Using a section of vacuum hose, connect one end onto the EVAP pressure/purge diagnostic station pressure regulator.
6. Connect the other end of the vacuum hose to the canister side of the purge pipe.
7. Turn ON the main nitrogen cylinder valve and continue to discharge nitrogen for 15 seconds.
8. If the nitrogen does not clear the blockage, replace the purge pipe.
9. Return the EVAP pressure/purge diagnostic station to the stations original condition.
10. Install a new EVAP canister. Refer to «Evaporative Emission (EVAP) Canister Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
11. Lower the vehicle.
12. Install a new EVAP canister purge valve. Refer to «Evaporative Emission (EVAP) Canister Purge Solenoid Valve Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
13. Return to the diagnostic table that sent you here.

1. Remove the accelerator and cruise control cables from the bracket, if equipped.
2. Remove the bracket.
3. Remove the ignition control module (ICM). Refer to «Ignition Control Module Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
4. Remove the ignition coil housing retaining bolts.
5. Remove the ignition coil housing from the camshaft cover.

1. Install the ignition coil housing to the camshaft cover.
2. Install the ignition coil housing retaining bolts. Tighten: Tighten the retaining bolts to 10 N.m (89 lb in).
3. Install the ICM. Refer to «Ignition Control Module Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
4. Install the accelerator and cruise control cables bracket.
5. Install the accelerator and cruise control cables bracket bolts. Tighten: Tighten the retaining bolts to 10 N.m (89 lb in).
6. Install the accelerator and cruise control cables to the bracket.

1. Turn OFF the ignition.
2. Remove the accelerator cable from the bracket.
3. Remove the accelerator cable bracket bolt.
4. Remove the accelerator cable bracket.
5. Disconnect the ignition control module (ICM) harness connector.
6. Remove the ICM retaining screws.
7. Remove the ICM from the ignition coil housing.

1. Install the ignition control module in the ignition coil housing.
2. Install the ICM retaining screws. Tighten: Tighten the retaining screws to 1.5 N.m (13 lb in).
3. Connect the ICM harness connector.
4. Install the accelerator cable bracket.
5. Install the accelerator cable bracket bolt. Tighten: Tighten the retaining screws to 10 N.m (18 lb in).
6. Install the accelerator cable to the bracket.

Spark Plug Usage

1. Ensure that the correct spark plug is installed. An incorrect spark plug causes driveability conditions. Refer to «Ignition System Specifications»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction__ignition-system-specifications) for the correct spark plug.
2. Ensure that the spark plug has the correct heat range. An incorrect heat range causes the following conditions: Spark plug fouling - colder plug Pre-ignition causing spark plug and/or engine damage - hotter plug

Spark Plug Inspection

1. Inspect the terminal post (1) for damage. Inspect for a bent or broken terminal post (1). Test for a loose terminal post (1) by twisting and pulling the post. The terminal post (1) should NOT move.
2. Inspect the insulator (2) for flashover or carbon tracking, soot. This is caused by the electrical charge traveling across the insulator (2) between the terminal post (1) and ground. Inspect for the following conditions: Inspect the spark plug boot for damage. Inspect the spark plug recess area of the cylinder head for moisture, such as oil, coolant, or water. A spark plug boot that is saturated causes arcing to ground.
3. Inspect the insulator (2) for cracks. All or part of the electrical charge may arc through the crack instead of the electrodes (3, 4).
4. Inspect for evidence of improper arcing. Measure the gap between the center electrode (4) and the side electrode (3) terminals. Refer to «Ignition System Specifications»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction__ignition-system-specifications) . An excessively wide electrode gap can prevent correct spark plug operation. Inspect for the correct spark plug torque. Refer to «Ignition System Specifications»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction__ignition-system-specifications) . Insufficient torque can prevent correct spark plug operation. An over torqued spark plug, causes the insulator (2) to crack. Inspect for signs of tracking that occurred near the insulator tip instead of the center electrode (4). Inspect for a broken or worn side electrode (3). Inspect for a broken, worn, or loose center electrode (4) by shaking the spark plug. A rattling sound indicates internal damage. A loose center electrode (4) reduces the spark intensity. Inspect for bridged electrodes (3, 4). Deposits on the electrodes (3, 4) reduce or eliminates the gap. Inspect for worn or missing platinum pads on the electrodes (3, 4) If equipped. Inspect for excessive fouling.
5. Inspect the spark plug recess area of the cylinder head for debris. Dirty or damaged threads can cause the spark plug not to seat correctly during installation.

Spark Plug Visual Inspection

1. Normal operation-Brown to grayish-tan with small amounts of white powdery deposits are normal combustion by-products from fuels with additives.
2. Carbon Fouled-Dry, fluffy black carbon, or soot caused by the following conditions: Rich fuel mixtures Leaking fuel injectors Excessive fuel pressure Restricted air filter element Incorrect combustion Reduced ignition system voltage output Weak coils Worn ignition wires Incorrect spark plug gap Excessive idling or slow speeds under light loads can keep spark plug temperatures so low that normal combustion deposits may not burn off.
3. Deposit Fouling-Oil, coolant, or additives that include substances such as silicone, very white coating, reduces the spark intensity. Most powdery deposits will not effect spark intensity unless they form into a glazing over the electrode.

Note. This engine has aluminum cylinder heads. Do not remove the spark plugs from a hot engine, allow it to cool first. Removing the spark plugs from a hot engine may cause spark plug thread damage or cylinder head damage.

1. Remove the ignition coil housing. Refer to «Ignition Coil Housing Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .
2. Remove the spark plugs with a spark plug socket.
3. Inspect the spark plugs. Refer to «Spark Plug Inspection»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction__spark-plug-inspection) .

1. Gap the spark plug, using round wire type spark plug gap gage. Gap: Adjust the spark plug gap to 1.14 mm (0.045 in).
2. Install the spark plugs with a spark plug socket. Tighten: Tighten the spark plugs to 20 N.m (15 lb ft).
3. Install the ignition coil housing. Refer to «Ignition Coil Housing Replacement»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction) .

1. Remove the starter. Refer to «Starter Motor Replacement (2.2L (L61))»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) or «Starter Motor Replacement (2.0L (LSJ))»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
2. Disconnect the Crankshaft Position (CKP) sensor electrical connector.
3. Remove the CKP sensor bolt.
4. Remove the CKP sensor.

1. Inspect the CKP sensor O-ring and lubricate with a mineral based grease.
2. Gently insert the CKP sensor into the block.
3. Install the CKP sensor bolt. Tighten: Tighten the CKP sensor bolt to 8 N.m (71 lb in).
4. Reconnect the CKP sensor electrical connector.
5. Install the starter. Refer to «Starter Motor Replacement (2.2L (L61))»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) or «Starter Motor Replacement (2.0L (LSJ))»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
6. Perform the CKP system Variation Learn Procedure. Refer to «CKP System Variation Learn Procedure»(/chevrolet/cobalt/i-2004-2010/remont/testing-diagnostics/#engine-controls-22l-introduction__ckp-system-variation-learn-procedure) .

1. Remove the starter. Refer to «Starter Motor Replacement (2.2L (L61))»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) or «Starter Motor Replacement (2.0L (LSJ))»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
2. Disconnect the knock sensor (KS) harness connector.
3. Remove the KS retaining bolt.
4. Remove the KS.

1. Install the knock sensor. Tighten: Tighten the knock sensor retaining bolt to 25 N.m (18 lb ft).
2. Connect the knock sensor harness connector.
3. Install the starter. Refer to «Starter Motor Replacement (2.2L (L61))»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) or «Starter Motor Replacement (2.0L (LSJ))»(/chevrolet/cobalt/i-2004-2010/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.

1. Disconnect the intake air temperature (IAT) sensor harness connector.
2. Loosen the air cleaner assembly clamp.
3. Disconnect the air cleaner assembly clips.
4. Remove the upper air cleaner cover.
5. Remove the air cleaner filter from the lower air cleaner housing.
6. Inspect the air cleaner filter for dust, dirt, and water contamination.
7. Replace as necessary. Refer to «Maintenance Schedule»(/chevrolet/cobalt/i-2004-2010/remont/lubrication-system/#maintenance-and-lubrication__maintenance-schedule) in Maintenance and Lubrication.

1. Install the air cleaner filter into the lower air cleaner housing.
2. Install the upper air cleaner cover to the lower air cleaner housing.
3. Secure the air cleaner housing cover.
4. Connect the air cleaner resonator to the air cleaner assembly. Tighten: Tighten the air cleaner intake duct clamp to 5 N.m (44 lb in).
5. Connect the IAT sensor harness connector.

1. Loosen the outlet duct clamp at the air cleaner assembly.
2. Remove the push pin (1).
3. Remove the air cleaner mounting nuts (2).
4. Remove the air cleaner.

1. Position the air cleaner assembly.
2. Install the air cleaner assembly attachment nut (2). Tighten: Tighten the nut to 10 N.m (89 lb in).
3. Install the push pin (1).
4. Connect the air cleaner resonator to the air cleaner assembly. Tighten: Tighten the air cleaner intake duct clamp to 5 N.m (44 lb in).

1. Disconnect the intake air temperature (IAT) sensor harness connector.
2. Loosen the air cleaner assembly fresh air duct to resonator clamp.
3. Remove the push-pin fastener from the air outlet resonator/duct assembly to support bracket.
4. Loosen the resonator to throttle body clamp.
5. Disconnect the air cleaner assembly fresh air duct from the resonator.
6. Remove the air outlet resonator from the throttle body.

1. Install the air outlet resonator to the throttle body.
2. Connect the fresh air duct to the air outlet resonator.
3. Tighten the air outlet resonator to throttle body clamp. Tighten: Tighten the clamp to 5 N.m (44 lb in).
4. Align the air outlet resonator to the bracket and install the push-pin fastener.
5. Connect the air cleaner assembly fresh air duct to the air outlet resonator. Tighten: Tighten the clamp to 5 N.m (44 lb in).
6. Connect the IAT sensor harness connector.

1. Remove the right front tire and wheel. Refer to «Tire and Wheel Removal and Installation»(/chevrolet/cobalt/i-2004-2010/remont/wheel-tire-system/#tires-and-wheels) in Tire and Wheels.
2. Remove the right front fender liner. Refer to «Front Fender Liner Replacement»(/chevrolet/cobalt/i-2004-2010/remont/exterior-body-panels/#body-front-end) in Body Front End.
3. Remove the air cleaner intake duct assembly push-in fasteners.
4. Remove the air cleaner intake duct assembly bolt.
5. Remove the intake duct assembly from the vehicle.

1. Position the intake duct assembly.
2. Install the intake duct assembly bolt. Tighten: Tighten the bolt to 10 N.m (89 lb ft).
3. Install the intake duct assembly push in fasteners.
4. Install the right front fender liner. Refer to «Front Fender Liner Replacement»(/chevrolet/cobalt/i-2004-2010/remont/exterior-body-panels/#body-front-end) in Body Front End.
5. Install the right front tire and wheel. Refer to «Tire and Wheel Removal and Installation»(/chevrolet/cobalt/i-2004-2010/remont/wheel-tire-system/#tires-and-wheels) in Tire and Wheels.

Powertrain

The powertrain has electronic controls to reduce exhaust emissions while maintaining excellent driveability and fuel economy. The engine control module (ECM) is the control center of this system. The ECM monitors numerous engine and vehicle functions. The ECM constantly looks at the information from various sensors and other inputs, and controls the systems that affect vehicle performance and emissions. The ECM also performs the diagnostic tests on various parts of the system. The ECM can recognize operational problems and alert the driver with the malfunction indicator lamp (MIL). When the ECM detects a malfunction, the ECM stores a diagnostic trouble code (DTC). The problem area is identified by the particular DTC that is set. Review the components and wiring diagrams in order to determine which systems are controlled by the ECM.

The following are some of the functions that the ECM controls

1. The engine fueling
2. The ignition control (IC)
3. The knock sensor (KS) system
4. The evaporative emissions (EVAP) system
5. The generator
6. The A/C clutch control
7. The cooling fan control

Engine Control Module Function

The ECM constantly looks at the information from various sensors and other inputs and controls systems that affect vehicle performance and emissions. The ECM also performs diagnostic tests on various parts of the system. The ECM can recognize operational problems and alert the driver with the malfunction indicator lamp (MIL). When the ECM detects a malfunction, the ECM stores a diagnostic trouble code (DTC). The problem area is identified by the particular DTC that is set. The input and output devices in the ECM include analog-to-digital converters, signal buffers, counters, and output drivers. The output drivers are electronic switches that complete a ground or voltage circuit when turned on. Most ECM controlled components are operated by output drivers. The ECM monitors these driver circuits for proper operation and, in most cases, can set a DTC corresponding to the controlled device if a problem is detected.

Malfunction Indicator Lamp (MIL) Operation

The malfunction indicator lamp (MIL) is located in the instrument panel cluster. The MIL will display as either SERVICE ENGINE SOON or one of the following symbols when commanded ON

Scheme 89

Scheme 90

The MIL indicates that an emissions related fault has occurred and vehicle service is required.

The following is a list of the modes of operation for the MIL

1. The MIL illuminates when the ignition is turned ON, with the engine OFF. This is a bulb test to ensure the MIL is able to illuminate.
2. The MIL turns OFF after the engine is started if a diagnostic fault is not present.
3. The MIL remains illuminated after the engine is started if the control module detects a fault. A diagnostic trouble code (DTC) is stored any time the control module illuminates the MIL due to an emissions related fault. The MIL turns OFF after three consecutive ignition cycles in which a Test Passed has been reported for the diagnostic test that originally caused the MIL to illuminate.
4. The MIL flashes if the control module detects a misfire condition which could damage the catalytic converter.
5. When the MIL is illuminated and the engine stalls, the MIL will remain illuminated as long as the ignition is ON.
6. When the MIL is not illuminated and the engine stalls, the MIL will not illuminate until the ignition is cycled OFF and then ON.

Warm-up Cycle

The ECM uses warm-up cycles to run some diagnostics and to clear any diagnostic trouble codes (DTCs). A warm-up cycle occurs when the engine coolant temperature increases 22°C (40°F) from the start-up temperature. The engine coolant must also achieve a minimum temperature of 71°C (160°F). The ECM counts the number of warm-up cycles in order to clear the malfunction indicator lamp (MIL). The ECM will clear the DTCs when 40 consecutive warm-up cycles occur without a malfunction.

Diagnostic Trouble Codes (DTCs)

The ECM is programmed with test routines that test the operation of the various systems the ECM controls. Some tests monitor internal ECM functions. Many tests are run continuously. Other tests run only under specific conditions, referred to as Conditions for Running the DTC. When the vehicle is operating within the conditions for running a particular test, the ECM monitors certain parameters and determines if the values are within an expected range. The parameters and values considered outside the range of normal operation are listed as Conditions for Setting the DTC. When the Conditions for Setting the DTC occur, the ECM executes the Action Taken When the DTC Sets. Some DTCs alert the driver via the MIL or a message. Other DTCs do not trigger a driver warning, but are stored in memory. The ECM also saves data and input parameters when most DTCs are set. This data is stored in the Freeze Frame and/or Failure Records.

The DTCs are categorized by type. The DTC type is determined by the MIL operation and the manner in which the fault data is stored when a particular DTC fails. In some cases there may be exceptions to this structure. Therefore, when diagnosing the system it is important to read the Action Taken When the DTC Sets and the Conditions for Clearing the DTC in the supporting text.

There are different types of DTCs and different actions taken when the DTCs set. Refer to Diagnostic Trouble Code (DTC) Type Definitions for a description of the general characteristics of each DTC type.

Fuel System Overview

The fuel tank stores the fuel supply. An electric turbine style fuel pump attaches to the fuel sender assembly inside the 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 fuel sender assembly. The function of the venturi pump is to fill the fuel sender assembly reservoir. The fuel pressure regulator, a part of the fuel sender assembly, maintains the correct fuel pressure to the fuel injection system. The fuel pump and sender assembly contains a reverse flow check valve. The check valve and the fuel pressure regulator maintain fuel pressure in the fuel feed pipe and the fuel rail in order to prevent long cranking times.

Fuel Tank

The fuel tank stores the fuel supply. The fuel tank is located in the rear of the vehicle. The fuel tank is held in place by 2 metal straps that attach to the under body of the vehicle. The fuel tank is molded from high-density polyethylene.

Fuel Fill Pipe

The fuel fill pipe has a built-in restrictor in order to prevent refueling with leaded fuel.

Fuel Filler Cap

Note. If a fuel tank filler cap requires replacement, use only a fuel tank filler cap with the same features. Failure to use the correct fuel tank filler cap can result in a serious malfunction of the fuel and EVAP system.

The fuel fill pipe has a tethered fuel filler cap. A torque-limiting device prevents the cap from being over-tightened. To install the cap, turn the cap clockwise until you hear audible clicks. This indicates that the cap is correctly torqued and fully seated. A fuel filler cap that is not fully seated may cause a malfunction in the emission system.

Fuel Sender Assembly

The fuel sender assembly consists of the following major components

1. The fill limit vent valve
2. The fuel level sensor
3. The fuel tank pressure (FTP) sensor
4. The fuel pump
5. The fuel strainer
6. The fuel pressure regulator

Scheme 91

The fuel level sensor consists of a float, a wire float arm, and a ceramic resistor card. The position of the float arm indicates the fuel level. The fuel level sensor contains a variable resistor which changes resistance in correspondence with the position of the float arm. The engine control module (ECM) sends the fuel level information via the GMLAN serial data circuit to the body control module (BCM). The BCM sends the GMLAN message to the instrument panel cluster (IPC). This information is used for the IPC fuel gage and the low fuel warning indicator, if applicable. The ECM also monitors the fuel level input for various diagnostics.

Fuel Pump

The fuel pump is mounted in the fuel sender assembly reservoir. The fuel pump is an electric high-pressure pump. Fuel is pumped to the fuel injection system at a specified flow and pressure. The fuel pump delivers a constant flow of fuel to the engine even during low fuel conditions and aggressive vehicle maneuvers. The control module controls the electric fuel pump operation through a fuel pump relay. The fuel pump flex pipe acts to dampen the fuel pulses and noise generated by the fuel pump.

Fuel Strainer

The fuel strainer attaches to the lower end of the fuel sender. The fuel strainer is made of woven plastic. The functions of the fuel strainer are to filter contaminants and to wick fuel. The fuel strainer normally requires no maintenance. Fuel stoppage at this point indicates that the fuel tank contains an abnormal amount of sediment or contamination.

Fuel Filter

The fuel filter is located on the fuel feed pipe between the fuel pump and the fuel injectors. The paper filter element traps particles in the fuel that may damage the fuel injection system. The filter housing is made to withstand maximum fuel system pressure, exposure to fuel additives, and changes in temperature. There is no service interval for fuel filter replacement.

Scheme 92

The fuel pressure regulator (2) is contained in the fuel sender assembly. The fuel pressure regulator is a diaphragm relief valve. The diaphragm has fuel pressure on one side and regulator spring pressure on the other side. The fuel pressure regulator is not vacuum based. Fuel pressure is controlled by a pressure balance across the regulator. The fuel system pressure is constant.

Fuel Feed Pipes

The fuel feed pipe carries fuel from the fuel tank to the fuel injection system. The fuel pipe consists of 3 sections

1. The rear fuel pipe is located from the top of the fuel tank to the chassis fuel pipe. The rear fuel pipe is constructed of nylon.
2. The chassis fuel pipe is located under the vehicle and connects the rear fuel pipe to the engine compartment fuel pipe. The chassis fuel pipe is constructed of galvanized aluminum.
3. The engine compartment fuel pipe connects the chassis fuel feed pipe to the fuel rail. The engine compartment fuel pipe is constructed of steel.

Nylon Fuel Pipes

Nylon pipes are constructed to withstand maximum fuel system pressure, exposure to fuel additives, and changes in temperature.

Heat resistant rubber hose or corrugated plastic conduit protect the sections of the pipes that are exposed to chafing, high temperature, or vibration.

Nylon fuel pipes are somewhat flexible and can be formed around gradual turns under the vehicle. However, if nylon fuel pipes are forced into sharp bends, the pipes kink and restrict the fuel flow. Also, once exposed to fuel, nylon pipes may become stiffer and are more likely to kink if bent too far. Take special care when working on a vehicle with nylon fuel pipes.

Quick-Connect Fittings

Quick-connect fittings provide a simplified means of installing and connecting fuel system components. The fittings consist of a unique female connector and a compatible male pipe end. O-rings, located inside the female connector, provide the fuel seal. Integral locking tabs inside the female connector hold the fittings together.

Fuel Pipe O-Rings

O-rings seal the threaded connections in the fuel system. The fuel system O-ring seals are made of special material. Service the O-ring seals with the correct service part.

Fuel Rail Assembly

The fuel rail assembly attaches to the engine cylinder head. The fuel rail assembly performs the following functions

1. Positions the injectors in the cylinder head
2. Distributes fuel evenly to the injectors
3. Integrates the fuel pulse dampener into the fuel metering system

Scheme 93

The fuel injector assembly is a solenoid device controlled by the control module that meters pressurized fuel to a single engine cylinder. The control module energizes the high-impedance, 12 ohms, injector solenoid (4) to open a normally closed ball valve (1). This allows fuel to flow into the top of the injector, past the ball valve, and through a director plate (3) at the injector outlet. The director plate has machined holes that control the fuel flow, generating a spray of finely atomized fuel at the injector tip (2). Fuel from the injector tip is directed at the intake valve, causing the fuel to become further atomized and vaporized before entering the combustion chamber. This fine atomization improves fuel economy and emissions.

Scheme 94

The fuel pulse dampener attaches inside a housing on the fuel rail assembly. The fuel pulse dampener is diaphragm-operated, with fuel pump pressure on one side and with spring pressure on the other side. The function of the dampener is to dampen the fuel pump pressure pulsations.

Fuel Metering Modes of Operation

The control module monitors voltages from several sensors in order to determine how much fuel to give the engine. The control module controls the amount of fuel delivered to the engine by changing the fuel injector pulse width. The fuel is delivered under one of several modes.

Starting Mode

When the ignition is first turned ON, the control module energizes the fuel pump relay for 2 seconds. This allows the fuel pump to build pressure in the fuel system. The control module calculates the air/fuel ratio based on inputs from the engine coolant temperature (ECT), manifold absolute pressure (MAP), and throttle position (TP) sensors. The system stays in starting mode until the engine speed reaches a predetermined RPM.

Clear Flood Mode

If the engine floods, clear the engine by pressing the accelerator pedal down to the floor and then crank the engine. When the throttle position (TP) sensor is at wide open throttle (WOT), the control module reduces the fuel injector pulse width in order to increase the air to fuel ratio. The control module holds this injector rate as long as the throttle stays wide open and the engine speed is below a predetermined RPM. If the throttle is not held wide open, the control module returns to the starting mode.

Run Mode

The run mode has 2 conditions called Open Loop and Closed Loop. When the engine is first started and the engine speed is above a predetermined RPM, the system begins Open Loop operation. The control module ignores the signal from the heated oxygen sensor (HO2S). The control module calculates the air/fuel ratio based on inputs from the engine coolant temperature (ECT), manifold absolute pressure (MAP), and throttle position (TP) sensors. The system stays in Open Loop until meeting the following conditions

1. The HO2S has varying voltage output, showing that the HO2S is hot enough to operate properly.
2. The ECT sensor is above a specified temperature.
3. A specific amount of time has elapsed after starting the engine.

Specific values for the above conditions exist for each different engine, and are stored in the electrically erasable programmable read-only memory (EEPROM). The system begins Closed Loop operation after reaching these values. In Closed Loop, the control module calculates the air/fuel ratio, injector ON time, based upon the signal from various sensors, but mainly from the HO2S. This allows the air/fuel ratio to stay very close to 14.7:1.

Acceleration Mode

When the driver pushes on the accelerator pedal, air flow into the cylinders increases rapidly. To prevent possible hesitation, the control module increases the pulse width to the injectors to provide extra fuel during acceleration. This is also known as power enrichment. The control module determines the amount of fuel required based upon the throttle position, the engine coolant temperature (ECT), the manifold absolute pressure (MAP), and the engine speed.

Deceleration Mode

When the driver releases the accelerator pedal, air flow into the engine is reduced. The control module monitors the corresponding changes in the throttle position, and the manifold absolute pressure (MAP). The control module shuts OFF fuel completely if the deceleration is very rapid, or for long periods, such as long, closed-throttle coast-down. The fuel shuts OFF in order to prevent damage to the catalytic converters.

Battery Voltage Correction Mode

When the battery voltage is low, the control module compensates for the weak spark delivered by the ignition system in the following ways

1. Increasing the amount of fuel delivered
2. Increasing the idle RPM
3. Increasing the ignition dwell time

Fuel Cut-off Mode

The control module cuts OFF fuel from the fuel injectors when the following conditions are met in order to protect the powertrain from damage and improve driveability

1. The ignition is OFF. This prevents engine run-on.
2. The ignition is ON but there is no ignition reference signal. This prevents flooding or backfiring.
3. The engine speed is too high, above red line.
4. The vehicle speed is too high, above rated tire speed.
5. During an extended, high speed, closed throttle coast down-This reduces emissions and increases engine braking.
6. During extended deceleration, in order to prevent damage to the catalytic converters

Fuel Trim

The control module controls the air/fuel metering system in order to provide the best possible combination of driveability, fuel economy, and emission control. The control module monitors the heated oxygen sensor (HO2S) signal voltage while in Closed Loop and regulates the fuel delivery by adjusting the pulse width of the injectors based on this signal. The ideal fuel trim values are around 0 percent for both short and long term fuel trim. A positive fuel trim value indicates the control module is adding fuel in order to compensate for a lean condition by increasing the pulse width. A negative fuel trim value indicates that the control module is reducing the amount of fuel in order to compensate for a rich condition by decreasing the pulse width. A change made to the fuel delivery changes the long and short term fuel trim values. The short term fuel trim values change rapidly in response to the HO2S signal voltage. These changes fine tune the engine fueling. The long term fuel trim makes coarse adjustments to fueling in order to re-center and restore control to short term fuel trim. A scan tool can be used to monitor the short and long term fuel trim values. The long term fuel trim diagnostic is based on an average of several of the long term speed load learn cells. The control module selects the cells based on the engine speed and engine load. If the control module detects an excessively lean or rich condition, the control module will set a fuel trim DTC.

EVAP System Operation

The evaporative emission (EVAP) control system limits fuel vapors from escaping into the atmosphere. Fuel tank vapors are allowed to move from the fuel tank, due to pressure in the tank, through the vapor pipe, into the EVAP canister. Carbon in the canister absorbs and stores the fuel vapors. Excess pressure is vented through the vent line and EVAP vent solenoid valve to the atmosphere. The EVAP canister stores the fuel vapors until the engine is able to use them. At an appropriate time, the control module will command the EVAP purge solenoid valve ON, allowing engine vacuum to be applied to the EVAP canister. With the EVAP vent solenoid valve OFF, fresh air is drawn through the vent solenoid and the vent line to the EVAP canister. Fresh air is drawn through the canister, pulling fuel vapors from the carbon. The air/fuel vapor mixture continues through the EVAP purge pipe and EVAP purge solenoid valve into the intake manifold to be consumed during normal combustion. The control module uses several tests to determine if the EVAP system is leaking.

Large Leak Test

This tests for large leaks and blockages in the evaporative emission (EVAP) system. The control module commands the EVAP vent solenoid valve ON and commands the EVAP purge solenoid valve ON, with the engine running, allowing engine vacuum into the EVAP system. The control module monitors the fuel tank pressure (FTP) sensor voltage to verify that the system is able to reach a predetermined level of vacuum within a set amount of time. The control module then commands the EVAP purge solenoid valve OFF, sealing the system, and monitors the vacuum level for decay. If the control module does not detect that the predetermined vacuum level was achieved, or the vacuum decay rate is more than a calibrated level on 2 consecutive tests, DTC P0455 will set.

Small Leak Test

The engine off natural vacuum (EONV) diagnostic is the small-leak detection diagnostic for the evaporative emission (EVAP) system. While previous leak detection methods were performed with the engine running, the EONV diagnostic monitors the EVAP system pressure or vacuum with the key OFF. Because of this, it may be normal for the control module to remain active for up to 40 minutes after the engine is turned OFF. This is important to remember when performing a parasitic draw test on vehicles equipped with EONV.

The EONV diagnostic utilizes the temperature changes in the fuel tank immediately following a drive cycle to use the naturally occurring vacuum or pressure in the fuel tank. When the vehicle is driven, the temperature rises in the tank. After the vehicle is parked, the temperature in the tank continues to rise for a period of time, then start to drop. The EONV diagnostic relies on this temperature change and it's corresponding pressure change to determine if an EVAP system leak is present.

The EONV diagnostic is designed to detect leaks as small as 0.51 mm (0.02 in). The diagnostic can determine if a small leak is present based on vacuum or pressure readings in the EVAP system. When the system is sealed, a finite amount of pressure or vacuum will be observed. When a 0.51 mm (0.02 in) leak is present, often little or no pressure or vacuum is observed. If the test reports a failing value, DTC P0442 will set.

Canister Vent Restriction Test

If the evaporative emission (EVAP) vent system is restricted, fuel vapors will not be properly purged from the EVAP canister. The control module tests this by commanding the EVAP purge solenoid valve ON, commanding the EVAP vent solenoid valve OFF, and monitoring the fuel tank pressure (FTP) sensor for an increase in vacuum. If the vacuum increases more than a calibrated value, DTC P0446 will set.

Purge Solenoid Leak Test

If the evaporative emission (EVAP) purge solenoid valve does not seal properly, fuel vapors could enter the engine at an undesired time, causing driveability concerns. The control module tests for this by commanding the EVAP purge solenoid valve OFF and the vent solenoid valve ON, sealing the system, and monitors the fuel tank pressure (FTP) for an increase in vacuum. If the control module detects that the EVAP system vacuum increases above a calibrated value, DTC P0496 will set.

Check Gas Cap Message

If equipped, the powertrain control module (PCM) sends a class 2 message to the driver information center (DIC) illuminating the Check Gas Cap message when any of the following occur

1. A malfunction in the evaporative emission (EVAP) system and a large leak test fails
2. A malfunction in the EVAP system and a small leak test fails

EVAP System Components

The evaporative emission (EVAP) system consists of the following components

EVAP Canister

The canister is filled with carbon pellets used to absorb and store fuel vapors. Fuel vapor is stored in the canister until the control module determines that the vapor can be consumed in the normal combustion process.

EVAP Purge Solenoid Valve

The evaporative emission (EVAP) purge solenoid valve controls the flow of vapors from the EVAP system to the intake manifold. The valve opens when commanded ON by the control module. This normally closed valve is pulse width modulated (PWM) by the control module to precisely control the flow of fuel vapor to the engine. The valve will also be opened during some portions of the EVAP testing, allowing engine vacuum to enter the EVAP system.

EVAP Vent Solenoid Valve

The evaporative emission (EVAP) vent solenoid valve controls fresh airflow into the EVAP canister. The valve is normally open. The control module commands the valve ON, closing the valve during some EVAP tests, allowing the system to be tested for leaks.

Fuel Tank Pressure Sensor

The fuel tank pressure (FTP) sensor measures the difference between the pressure or vacuum in the fuel tank and outside air pressure. The control module provides a 5-volt reference and a ground to the FTP sensor. The FTP sensor provides a signal voltage back to the control module that can vary between 0.1-4.9 volts. A high FTP sensor voltage indicates a low fuel tank pressure or vacuum. A low FTP sensor voltage indicates a high fuel tank pressure.

EVAP Service Port

The evaporative emission (EVAP) service port is located in the EVAP purge pipe between the EVAP purge solenoid valve and the EVAP canister. The service port is identified by a green colored cap.

Electronic Ignition (EI) System Description

The electronic ignition (EI) system produces and controls a high energy secondary spark. This spark is used to ignite the compressed air/fuel mixture at precisely the correct time. This provides optimal performance, fuel economy, and control of exhaust emissions. This ignition system uses one coil for each pair of cylinders. Each pair of cylinders that are at top dead center (TDC) at the same time are known as companion cylinders. The cylinder that is at TDC of its compression stroke is called the event cylinder. The cylinder that is at TDC of its exhaust stroke is called the waste cylinder. When the ignition coil is triggered, both companion cylinder spark plugs fire at the same time, completing a series circuit. Because the lower pressure inside the waste cylinder offers very little resistance, the event cylinder uses most of the available voltage to produce a very high energy spark. This is known as waste spark ignition. The ignition coils and ignition control module (ICM) are contained within one assembly. The ignition coil/ICM assembly is mounted in the center of the engine camshaft cover, with short boots connecting the ignition coils to the spark plugs. The ignition coil driver modules within the ICM are commanded ON/OFF by the engine control module (ECM). The EI system consists of the following components

Crankshaft Reluctor Wheel

The crankshaft reluctor wheel is part of the crankshaft. The reluctor wheel has 7 machined notches, 6 of which are equally spaced 60 degrees apart. The 7th notch is spaced 10 degrees after one of the 60-degree notches. The 10-degree notch is used to synchronize the engine position, while the other notches are used to provide cylinder location during a revolution.

Crankshaft Position (CKP) Sensor

The crankshaft position (CKP) sensor is a permanent magnet generator, known as a variable reluctance sensor. The CKP sensor produces an AC voltage of different amplitude and frequency. The frequency depends on the velocity of the crankshaft. The AC voltage output depends on the crankshaft position and the battery voltage. The CKP sensor works in conjunction with a 7X reluctor wheel attached to the crankshaft. The CKP sensor produces 7 pulses for each revolution of the crankshaft. The pulse from the 10-degree notch is known as the sync pulse. The sync pulse is used to synchronize the coil firing sequence with the CKP. The CKP sensor is used for ignition timing, the fuel injector timing, misfire diagnostics and tachometer display. The CKP sensor is connected to the engine control module (ECM) by a signal circuit and a low reference circuit.

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The engine control module (ECM) supplies a signal on each of the ignition control (IC) timing control circuits to the ignition control module (ICM). The ICM fires the correct ignition coil at the correct time based on the signals. The ICM detects if cylinder 1 or cylinder 3 is on the compression stroke by sensing the secondary voltage and polarity of each side of the ignition coil. The ICM detects this voltage with sensing circuitry integrated into each ignition coil. The higher voltage is on the compressing cylinder. This is called compression sense ignition. The ICM provides a synthesized cam signal to the ECM based on these inputs. The ECM uses the cam signal to synchronize fuel injection.

This system consists of the following circuits

1. An ignition voltage circuit
2. A ground circuit
3. A camshaft position (CMP) sensor signal circuit
4. An IC timing control circuit for cylinders #1 and #4
5. An IC timing control B circuit for cylinders #2 and #3

Engine Control Module (ECM)

The ECM controls all ignition system functions, and constantly corrects the spark timing. The ECM monitors information from various sensor inputs that include the following

1. The throttle position (TP) sensor
2. The engine coolant temperature (ECT) sensor
3. The intake air temperature (IAT) sensor
4. The vehicle speed sensor (VSS)
5. The transmission gear position or range information sensors
6. The engine knock sensors (KS)

Modes of Operation

There is one normal mode of operation during which the engine control module (ECM) controls spark. If the crankshaft position (CKP) pulses are lost the engine will not run. The loss of a camshaft position (CMP) signal may result in a longer crank time since the ECM cannot determine which stroke the pistons are ON. DTCs are available to accurately diagnose the ignition system with a scan tool.

Purpose

The throttle actuator control (TAC) system delivers improved throttle response and greater reliability and eliminates the need for mechanical cable. The TAC system performs the following functions

1. Accelerator pedal position sensing
2. Throttle positioning to meet driver and engine demands
3. Throttle position sensing
4. Internal diagnostics
5. Cruise control functions
6. Manage TAC electrical power consumption

The TAC system includes the following components

1. The accelerator pedal position (APP) sensors
2. The throttle body assembly
3. The engine control module (ECM)

Accelerator Pedal Position (APP) Sensor

The accelerator pedal contains 2 individual APP sensors within the assembly. The APP sensors 1 and 2 are potentiometer type sensors each with 3 circuits

1. A 5-volt reference circuit
2. A low reference circuit
3. A signal circuit

The APP sensors are used to determine the pedal angle. The ECM provides each APP sensor a 5-volt reference circuit and a low reference circuit. The APP sensors provide the ECM with signal voltage proportional to the pedal movement. The APP sensor 1 signal voltage at rest position is near the low reference and increases as the pedal is actuated. The APP sensor 2 signal voltage at rest position is near the 5-volt reference and decreases as the pedal is actuated.

Throttle Body Assembly

The throttle assembly contains the following components

1. The throttle blade
2. The throttle actuator motor
3. The throttle position (TP) sensor 1 and 2

The throttle body functions similar to a conventional throttle body with the following exceptions

1. An electric motor opens and closes the throttle valve.
2. The throttle blade is spring loaded in both directions and the default position is slightly open.
3. There are 2 individual TP sensors within the throttle body assembly.

The TP sensors are used to determine the throttle plate angle. The TP sensors provide the ECM with a signal voltage proportional to throttle plate movement. The TP sensor 1 signal voltage at closed throttle is near the 5-volt reference and decreases as the throttle plate is opened. The TP sensor 2 signal voltage at closed throttle is near the low reference and increases as the throttle plate is opened.

Engine Control Module

The ECM is the control center for the TAC system. The ECM determines the drivers intent and then calculates the appropriate throttle response. The ECM achieves throttle positioning by providing a pulse width modulated voltage to the TAC motor.

Normal Mode

During the operation of the TAC system, several modes or functions are considered normal. The following modes may be entered during normal operation

1. Minimum pedal value-At key-up the ECM updates the learned minimum pedal value.
2. Minimum TP values-At key-up the ECM updates the learned minimum TP value. In order to learn the minimum TP value, the throttle blade is moved to the closed position.
3. Ice break mode-If the throttle is not able to reach a predetermined minimum throttle position, the ice break mode is entered. During the ice break mode, the ECM commands the maximum pulse width several times to the throttle actuator motor in the closing direction.
4. Battery saver mode-After a predetermined time without engine RPM, the ECM commands the battery saver mode. During the battery saver mode, the TAC module removes the voltage from the motor control circuits, which removes the current draw used to maintain the idle position and allows the throttle to return to the spring loaded default position.

Reduced Engine Power Mode

When the ECM detects a condition with the TAC system, the ECM may enter a reduced engine power mode. Reduced engine power may cause one or more of the following conditions

1. Acceleration limiting-The ECM will continue to use the accelerator pedal for throttle control; however, the vehicle acceleration is limited.
2. Limited throttle mode-The ECM will continue to use the accelerator pedal for throttle control; however, the maximum throttle opening is limited.
3. Throttle default mode-The ECM will turn off the throttle actuator motor and the throttle will return to the spring loaded default position.
4. Forced idle mode-The ECM will perform the following actions: Limit engine speed to idle by positioning the throttle position, or by controlling the fuel and spark if the throttle is turned off. Ignore the accelerator pedal input.
5. Engine shutdown mode-The ECM will disable fuel and de-energize the throttle actuator.

The knock sensor (KS) system enables the engine control module (ECM) to control the ignition timing for the best possible performance while protecting the engine from potentially damaging levels of detonation. The ECM uses the KS system to test for abnormal engine noise that may indicate detonation, also known as spark knock.

Sensor Description

The knock sensor (KS) system uses a flat response 2-wire sensor. The sensor uses piezo-electric crystal technology that produces an AC voltage signal of varying amplitude and frequency based on the engine vibration, or noise, level. The amplitude and frequency are dependent upon the level of knock that the KS detects. The engine control module (ECM) receives the KS signal through a signal circuit. The KS ground is supplied by the ECM through a low reference circuit.

The ECM learns a minimum noise level, or background noise, at idle from the KS and uses calibrated values for the rest of the RPM range. The ECM uses the minimum noise level to calculate a noise channel. A normal KS signal will ride within the noise channel. As engine speed and load change, the noise channel upper and lower parameters will change to accommodate the KS signal, keeping the signal within the channel. In order to determine which cylinders are knocking, the ECM only uses KS signal information when each cylinder is near top dead center (TDC) of the firing stroke. If knock is present, the signal will range outside of the noise channel.

If the ECM has determined that knock is present, it will retard the ignition timing to attempt to eliminate the knock. The ECM will always try to work back to a zero compensation level, or no spark retard. An abnormal KS signal will stay outside of the noise channel or will not be present. KS diagnostics are calibrated to detect faults with the KS circuitry inside the ECM, the KS wiring, the KS voltage output, or constant noise from an outside influence such as a loose/damaged component or excessive engine mechanical noise.

Air Intake System Description

The primary function of the Air Intake System is to provide filtered air to the engine. The system uses a cleaner element mounted in a housing. The cleaner housing is remotely mounted and uses intake ducts to route the incoming air into the throttle body. The secondary function of the Air Intake System is to muffle air induction noise. This is achieved through the use of resonators attached to the air intake ducts. The resonators are tuned to the specific powertrain. The mass air flow (MAF)/intake air temperature (IAT) sensor is used to measure the temperature and the volume of the air entering the engine.

Special Tools

Special Tools Illustration Tool Number/ Description GE 41415-50 Fuel Tank Cap Adapter J 26792 Spark Tester J 34730-1A Fuel Pressure Gage J 35616-A GM Terminal Test Kit J 36012-A Ignition System Diagnostic Harness J 37027-1A IAC Motor Driver You may also use an IAC Motor Driver from one of the approved manufacturers listed below: OTC Thexton CTI Snap On MAC Tools NAPA/Balkamp J 37088-A Fuel Line Disconnect Tool Set J 37287 Fuel Pipe Shut-Off Adapter J 38500-A Fuel Injector Cleaner J 38522 Variable Signal Generator J 39021 Fuel Injector Tester J 39194-C Oxygen Sensor Wrench J 39765 Fuel Sender Lock Nut Wrench J 41413-200 Evaporative Emissions System Tester (EEST) J 41413-VLV EVAP Service Port Vent Fitting J 41413-SPT High Intensity White Light J 41415-40 Fuel Tank Cap Adapter J 41416 Ultrasonic Leak Detector J 42873-1 Fuel Line Shut-Off Adapter J 42873-2 Fuel Line Shut-Off Adapter J 42960-1 Fuel Drain Hose J 42960-2 Fuel Flapper Door Holder J 42964-1 Fuel Line Shut-Off Adapter J 42964-2 Fuel Line Shut-Off Adapter J 43244 Relay Puller Pliers J 43298 Ignition Module Tester J 44062 Injector Test Adapter J 44175 Fuel Composition Tester J 44603 Injector Test Lamp J 45004 Fuel Tank Drain Hose J 45722 Fuel Sender Lock Ring Wrench 7000061 Tech II Diagnostic Scan Tool

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See also:
• Battery Negative Cable Disconnect/Connect Procedure
• Fastener Notice
• Control Module References
• Diagnostic Trouble Code (DTC) List - Vehicle
• DTC P0315
• Draining and Filling Cooling System (2.0L (LSJ))
• Exhaust Manifold Replacement (L61)
• Lifting and Jacking the Vehicle
• Heated Oxygen and Oxygen Sensor Notice
• Excessive Force and Oxygen Sensor Notice
• Component Fastener Tightening Notice
• Gasoline/Gasoline Vapors Caution
• Fuel Filler Pocket Replacement
• Maintenance Schedule
• Tire and Wheel Removal and Installation
• Front Fender Liner Replacement
• Fastener Tightening Specifications
• Air Cleaner Outlet Resonator Replacement
• Fuel Tank Draining Procedure
• Ignition System Specifications
• Spark Plug Inspection
• CKP System Variation Learn Procedure