Engine Control System & Fuel System - 4.8l, 5.3l, and 6.0l - Introduction (2 of 2) Chevrolet Chevy Express H1500

Temperature Versus Resistance

Temperature Versus Resistance

Altitude Versus Barometric Pressure

Altitude Versus Barometric Pressure

Ignition System Specifications

Ignition System Specifications

Fastener Tightening Specifications

Fastener Tightening Specifications

Emissions Related DTCs

Action Taken When the DTC Sets - Type A

1. The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.

Action Taken When the DTC Sets - Type B

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

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

1. The control module turns OFF the malfunction indicator lamp (MIL) after 4 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. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

Non-Emissions Related DTCs

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 malfunction indicator lamp (MIL) will not illuminate.
3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
4. The driver information center, if equipped, may display a message.

Conditions for Clearing the DTC - Type C

1. A current DTC Last Test Failed clears when the diagnostic runs and passes.
2. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
3. Clear the DTC with a scan tool.

Conditions for Clearing the DTC - Type X

This DTC is available in the control module 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.

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Powertrain Control Module (PCM) - C1 Connector & Terminal Parts Information

Powertrain Control Module (PCM) - C1 Terminal Identification

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Powertrain Control Module (PCM) - C2 Connector & Terminal Parts Information

Powertrain Control Module (PCM) - C2 Terminal Identification

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Accelerator Pedal Position (APP) Sensor Connector & Terminal Parts Information

Accelerator Pedal Position (APP) Sensor Terminal Identification

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Camshaft Position (CMP) Sensor Connector & Terminal Parts Information

Camshaft Position (CMP) Sensor Terminal Identification

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Crankshaft Position (CKP) Sensor Connector & Terminal Parts Information

Crankshaft Position (CKP) Sensor Terminal Identification

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Engine Coolant Temperature (ECT) Sensor Connector & Terminal Parts Information

Engine Coolant Temperature (ECT) Sensor Terminal Identification

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Evaporative Emission (EVAP) Canister Purge Solenoid Valve Connector & Terminal Parts Information

Evaporative Emission (EVAP) Canister Purge Solenoid Valve Terminal Identification

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Evaporative Emission (EVAP) Canister Vent Solenoid Valve Connector & Terminal Parts Information

Evaporative Emission (EVAP) Canister Vent Solenoid Valve Terminal Identification

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Fuel Injector 1 (L59) Connector & Terminal Parts Information

Fuel Injector 1 (L59) Terminal Identification

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Fuel Injector 1 (w/o L59) Connector & Terminal Parts Information

Fuel Injector 1 (w/o L59) Terminal Identification

Fuel Injector 2 (L59)

Fuel Injector 2 (L59) Connector & Terminal Parts Information

Fuel Injector 2 (L59) Terminal Identification

Fuel Injector 2 (w/o L59)

Fuel Injector 2 (w/o L59) Connector & Terminal Parts Information

Fuel Injector 2 (w/o L59) Terminal Identification

Fuel Injector 3 (L59)

Fuel Injector 3 (L59) Connector & Terminal Parts Information

Fuel Injector 3 (L59) Terminal Identification

Fuel Injector 3 (w/o L59)

Fuel Injector 3 (w/o L59) Connector & Terminal Parts Information

Fuel Injector 3 (w/o L59) Terminal Identification

Fuel Injector 4 (L59)

Fuel Injector 4 (L59) Connector & Terminal Parts Information

Fuel Injector 4 (L59) Terminal Identification

Fuel Injector 4 (w/o L59)

Fuel Injector 4 (w/o L59) Connector & Terminal Parts Information

Fuel Injector 4 (w/o L59) Terminal Identification

Fuel Injector 5 (L59)

Fuel Injector 5 (L59) Connector & Terminal Parts Information

Fuel Injector 5 (L59) Terminal Identification

Fuel Injector 5 (w/o L59)

Fuel Injector 5 (w/o L59) Connector & Terminal Parts Information

Fuel Injector 5 (w/o L59) Terminal Identification

Fuel Injector 6 (L59)

Fuel Injector 6 (L59) Connector & Terminal Parts Information

Fuel Injector 6 (L59) Terminal Identification

Fuel Injector 6 (w/o L59)

Fuel Injector 6 (w/o L59) Connector & Terminal Parts Information

Fuel Injector 6 (w/o L59) Terminal Identification

Fuel Injector 7 (L59)

Fuel Injector 7 (L59) Connector & Terminal Parts Information

Fuel Injector 7 (L59) Terminal Identification

Fuel Injector 7 (w/o L59)

Fuel Injector 7 (w/o L59) Connector & Terminal Parts Information

Fuel Injector 7 (w/o L59) Terminal Identification

Fuel Injector 8 (L59)

Fuel Injector 8 (L59) Connector & Terminal Parts Information

Fuel Injector 8 (L59) Terminal Identification

Fuel Injector 8 (w/o L59)

Fuel Injector 8 (w/o L59) Connector & Terminal Parts Information

Fuel Injector 8 (w/o L59) Terminal Identification

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Fuel Pump and Sender Assembly Connector & Terminal Parts Information

Fuel Pump and Sender Assembly Terminal Identification

Fuel Tank Pressure (FTP) Sensor

Fuel Tank Pressure (FTP) Sensor Connector & Terminal Parts Information

Fuel Tank Pressure (FTP) Sensor Terminal Identification

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Heated Oxygen Sensor (HO2S) Bank 1 Sensor 1 (California Emissions w/LM7/L59) Connector & Terminal Parts Information

Heated Oxygen Sensor (HO2S) Bank 1 Sensor 1 (California Emissions w/LM7/L59) Terminal Identification

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Heated Oxygen Sensor (HO2S) Bank 1 Sensor 1 (California Emissions w/LR4) Connector & Terminal Parts Information

Heated Oxygen Sensor (HO2S) Bank 1 Sensor 1 (California Emissions w/LR4) Terminal Identification

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Heated Oxygen Sensor (HO2S) Bank 1 Sensor 1 (Federal Emissions) Connector & Terminal Parts Information

Heated Oxygen Sensor (HO2S) Bank 1 Sensor 1 (Federal Emissions) Terminal Identification

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Heated Oxygen Sensor (HO2S) Bank 1 Sensor 2 (California Emissions w/LM7/L59) Connector & Terminal Parts Information

Heated Oxygen Sensor (HO2S) Bank 1 Sensor 2 (California Emissions w/LM7/L59) Terminal Identification

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Heated Oxygen Sensor (HO2S) Bank 1 Sensor 2 (Cutaway w/LQ4/LR4) Connector & Terminal Parts Information

Heated Oxygen Sensor (HO2S) Bank 1 Sensor 2 (Cutaway w/LQ4/LR4) Terminal Identification

Heated Oxygen Sensor (HO2S) Bank 1 Sensor 2 (Passenger/Cargo w/LQ4/LR4 and Passenger/Cargo Federal Emissions w/LM7/L59)

Heated Oxygen Sensor (HO2S) Bank 1 Sensor 2 (Passenger/Cargo w/LQ4/LR4 and Passenger/Cargo Federal Emissions w/LM7/L59) Connector & Terminal Parts Information

Heated Oxygen Sensor (HO2S) Bank 1 Sensor 2 (Passenger/Cargo w/LQ4/LR4 and Passenger/Cargo Federal Emissions w/LM7/L59) Terminal Identification

Heated Oxygen Sensor (HO2S) Bank 2 Sensor 1 (California Emissions w/LM7/L59)

Heated Oxygen Sensor (HO2S) Bank 2 Sensor 1 (California Emissions w/LM7/L59) Connector & Terminal Parts Information

Heated Oxygen Sensor (HO2S) Bank 2 Sensor 1 (California Emissions w/LM7/L59) Terminal Identification

Heated Oxygen Sensor (HO2S) Bank 2 Sensor 1 (California Emissions w/LR4)

Heated Oxygen Sensor (HO2S) Bank 2 Sensor 1 (California Emissions w/LR4) Connector & Terminal Parts Information

Heated Oxygen Sensor (HO2S) Bank 2 Sensor 1 (California Emissions w/LR4) Terminal Identification

Heated Oxygen Sensor (HO2S) Bank 2 Sensor 1 (Federal Emissions)

Heated Oxygen Sensor (HO2S) Bank 2 Sensor 1 (Federal Emissions) Connector & Terminal Parts Information

Heated Oxygen Sensor (HO2S) Bank 2 Sensor 1 (Federal Emissions) Terminal Identification

Heated Oxygen Sensor (HO2S) Bank 2 Sensor 2 (California Emissions w/LM7/L59)

Heated Oxygen Sensor (HO2S) Bank 2 Sensor 2 (California Emissions w/LM7/L59) Connector & Terminal Parts Information

Heated Oxygen Sensor (HO2S) Bank 2 Sensor 2 (California Emissions w/LM7/L59) Terminal Identification

Heated Oxygen Sensor (HO2S) Bank 2 Sensor 2 (Cutaway w/LQ4/LR4)

Heated Oxygen Sensor (HO2S) Bank 2 Sensor 2 (Cutaway w/LQ4/LR4) Connector & Terminal Parts Information

Heated Oxygen Sensor (HO2S) Bank 2 Sensor 2 (Cutaway w/LQ4/LR4) Terminal Identification

Heated Oxygen Sensor (HO2S) Bank 2 Sensor 2 (Passenger/Cargo w/LQ4/LR4 and Passenger/Cargo Federal Emissions w/LM7/L59)

Heated Oxygen Sensor (HO2S) Bank 2 Sensor 2 (Passenger/Cargo w/LQ4/LR4 and Passenger/Cargo Federal Emissions w/LM7/L59) Connector & Terminal Parts Information

Heated Oxygen Sensor (HO2S) Bank 2 Sensor 2 (Passenger/Cargo w/LQ4/LR4 and Passenger/Cargo Federal Emissions w/LM7/L59) Terminal Identification

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Ignition Coil 1 Connector & Terminal Parts Information

Ignition Coil 1 Terminal Identification

Ignition Coil 2

Ignition Coil 2 Connector & Terminal Parts Information

Ignition Coil 2 Terminal Identification

Ignition Coil 3

Ignition Coil 3 Connector & Terminal Parts Information

Ignition Coil 3 Terminal Identification

Ignition Coil 4

Ignition Coil 4 Connector & Terminal Parts Information

Ignition Coil 4 Terminal Identification

Ignition Coil 5

Ignition Coil 5 Connector & Terminal Parts Information

Ignition Coil 5 Terminal Identification

Ignition Coil 6

Ignition Coil 6 Connector & Terminal Parts Information

Ignition Coil 6 Terminal Identification

Ignition Coil 7

Ignition Coil 7 Connector & Terminal Parts Information

Ignition Coil 7 Terminal Identification

Ignition Coil 8

Ignition Coil 8 Connector & Terminal Parts Information

Ignition Coil 8 Terminal Identification

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Knock Sensor (KS) 1 Connector & Terminal Parts Information

Knock Sensor (KS) 1 Terminal Identification

Knock Sensor (KS) 2

Knock Sensor (KS) 2 Connector & Terminal Parts Information

Knock Sensor (KS) 2 Terminal Identification

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Manifold Absolute Pressure (MAP) Sensor Connector & Terminal Parts Information

Manifold Absolute Pressure (MAP) Sensor Terminal Identification

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Mass Air Flow (MAF)/Intake Air Temperature (IAT) Sensor Connector & Terminal Parts Information

Mass Air Flow (MAF)/Intake Air Temperature (IAT) Sensor Terminal Identification

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Throttle Actuator Control (TAC) Module - C1 Connector & Terminal Parts Information

Throttle Actuator Control (TAC) Module - C1 Terminal Identification

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Throttle Actuator Control (TAC) Module - C2 Connector & Terminal Parts Information

Throttle Actuator (TAC) Module - C2 Terminal Identification

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Throttle Body Connector & Terminal Parts Information

Throttle Body Terminal Identification

DIAGNOSTIC CODE INDEX

DIAGNOSTIC CODE INDEX

Powertrain Control Module Replacement

Service of the powertrain control module (PCM) should normally consist of either replacement of the PCM or electrically erasable programmable read only memory (EEPROM) programming. If the diagnostic procedures call for the PCM to be replaced, the PCM should be inspected first to see if the correct part is being used. If the correct part is being used, remove the faulty PCM and install the new service PCM.

Note. Turn the ignition OFF when installing or removing the control module connectors and disconnecting or reconnecting the power to the control module (battery cable, powertrain control module (PCM)/engine control module (ECM)/transaxle control module (TCM) pigtail, control module fuse, jumper cables, etc.) in order to prevent internal control module damage. Control module damage may result when the metal case contacts battery voltage. DO NOT contact the control module metal case with battery voltage when servicing a control module, using battery booster cables, or when charging the vehicle battery. In order to prevent any possible electrostatic discharge damage to the control module, do no touch the connector pins or the soldered components on the circuit board. Remove any debris from around the control module connector surfaces before servicing the control module. Inspect the control module connector gaskets when diagnosing or replacing the control module. Ensure that the gaskets are installed correctly. The gaskets prevent contaminant intrusion into the control module. The replacement control module must be programmed.

Removal Procedure

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 Disconnection and Connection»(/chevrolet/chevy-express-h1500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
3. Disconnect the PCM harness connectors.
4. Release the spring latch from the PCM.
5. Lift the PCM from the PCM mounting tray.
6. Remove the PCM from the engine compartment.

Installation Procedure

1. Install the PCM to the PCM mounting tray.
2. Secure the spring latch to the PCM.
3. Connect the PCM connectors to the PCM. Tighten: Tighten the PCM connector end fasteners to 8 N.m (71 lb in).
4. Connect the negative battery cable. Refer to «Battery Negative Cable Disconnection and Connection»(/chevrolet/chevy-express-h1500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
5. If a new PCM is being installed, program the PCM. Refer to «Control Module References»(/chevrolet/chevy-express-h1500/2003-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) .

1. Disconnect the instrument panel (I/P) harness electrical connector (2).
2. Release the red connector position assurance (CPA) retainer.
3. Disconnect the engine wiring harness electrical connector (1).
4. Remove the throttle actuator control (TAC) module nuts.
5. Remove the TAC module.

1. Install the TAC module.
2. Install the TAC module nuts. Tighten: Tighten the nuts to 9 N.m (80 lb in).
3. Connect the engine wiring harness electrical connector (1).
4. Install the red CPA retainer.
5. Connect the I/P harness electrical connector (2).
6. Refer to «Control Module References»(/chevrolet/chevy-express-h1500/2003-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for programming and setup information.

Crankshaft Position System Variation Learn

1. Install a scan tool.
2. Monitor the powertrain control module (PCM) for DTCs with a scan tool. If other DTCs are set, except DTC P0315, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-trouble-code-dtc-list) for the applicable DTC.
3. Select the crankshaft position variation learn procedure with a scan tool.
4. The scan tool instructs you to perform the following: Accelerate to wide open throttle (WOT). Release throttle when fuel cut-off occurs. Observe fuel cut-off for applicable engine. Engine should not accelerate beyond calibrated RPM value. Release throttle immediately if value is exceeded. Block drive wheels. Set parking brake. DO NOT apply brake pedal. Cycle ignition from OFF to ON. Apply and hold brake pedal. Start and idle engine. Turn the A/C OFF. Vehicle must remain in Park or Neutral. The scan tool monitors certain component signals to determine if all the conditions are met to continue with the procedure. The scan tool only displays the condition that inhibits the procedure. The scan tool monitors the following components: Crankshaft position (CKP) sensors activity-If there is a CKP sensor condition, refer to the applicable DTC. Camshaft position (CMP) signal activity-If there is a CMP signal condition, refer to the applicable DTC. Engine coolant temperature (ECT)-If the engine coolant temperature is not warm enough, idle the engine until the engine coolant temperature reaches the correct temperature.
5. Enable the CKP system variation learn procedure with the scan tool.
6. Accelerate to WOT.
7. Release throttle when fuel cut-off occurs.
8. The scan tool display reads Test In Progress.
9. 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/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-dtc-p0135-to-dtc-p0451) . If any other DTCs set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-trouble-code-dtc-list) for the applicable DTC.
10. Turn OFF the ignition for 30 seconds after the learn procedure is completed successfully.
11. The CKP system variation learn procedure is also required when the following service procedures have been performed, regardless of whether or not DTC P0315 is set: An engine replacement A PCM replacement A harmonic balancer replacement A crankshaft replacement A CKP sensor replacement Any engine repairs which disturb the crankshaft to CKP sensor relationship.

1. Turn OFF the ignition.
2. Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .
3. Drain the cooling system below the level of the ECT sensor. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/chevy-express-h1500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Draining and Filling Cooling System (Vac N Fill)»(/chevrolet/chevy-express-h1500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac) .
4. Lower the vehicle.
5. Disconnect the electrical connector from the engine coolant temperature (ECT) sensor.
6. Remove the ECT sensor.

1. Coat the ECT sensor threads with sealer GM P/N 12346004 (Canadian P/N 10953480) or the equivalent.
2. Install the ECT sensor. Tighten: Tighten the ECT sensor to 20 N.m (15 lb ft).
3. Connect the ECT sensor electrical connector.
4. Refill the engine coolant. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/chevy-express-h1500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Draining and Filling Cooling System (Vac N Fill)»(/chevrolet/chevy-express-h1500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac) .

1. Disconnect the MAF/IAT sensor electrical connector.
2. Remove the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) .
3. Loosen the clamp securing the MAF/IAT sensor to the air cleaner duct.
4. Remove the MAF/IAT sensor bolts from the air cleaner assembly.
5. Remove the MAF/IAT from the air cleaner.

1. Locate the air flow direction arrow (2) on the MAF/IAT sensor.
2. Install the MAF/IAT sensor onto the air cleaner housing.
3. Install the MAF/IAT sensor retaining bolts. Tighten: Tighten the bolts to 11 N.m (97 lb in).
4. Tighten the clamp securing the MAF/IAT sensor to the air cleaner duct.
5. Install the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) .
6. Connect the MAF/IAT electrical connector.

1. Remove the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .
2. Disconnect the manifold absolute pressure (MAP) sensor electrical connector.
3. Remove the MAP sensor (1) from the intake manifold.

1. Install the MAP sensor to the upper intake manifold.
2. Connect the MAP sensor electrical connector.
3. Install the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .

Tools Required

J 39194-B Oxygen Sensor Wrench

1. Raise the vehicle.
2. Disconnect the connector (1) for the HO2S.
3. Remove the HO2S (2) using a J 39194-B .

1. Coat the threads of the oxygen sensor with anti-seize compound GM P/N 5613695, if necessary.
2. Install the HO2S (2) using a J 39194-B . Tighten: Tighten the sensor to 42 N.m (31 lb ft).
3. Connect the HO2S harness connector (1).
4. Lower the vehicle.

J 39194-B Oxygen Sensor Wrench

1. Raise the vehicle.
2. Disconnect the connector (1) for the HO2S.
3. Remove the HO2S (2) using a J 39194-B .

1. Coat the threads of the oxygen sensor with anti-seize compound GM P/N 5613695, if necessary.
2. Install the HO2S (2) using a J 39194-B . Tighten: Tighten the sensor to 42 N.m (31 lb ft).
3. Connect the HO2S harness connector (1).
4. Lower the vehicle.

J 39194-B Oxygen Sensor Wrench

1. Raise the vehicle.
2. Disconnect the connector (1) for the HO2S.
3. Remove the HO2S (2) using a J 39194-B .

1. Coat the threads of the oxygen sensor with anti-seize compound GM P/N 5613695, if necessary.
2. Install the HO2S (2) using a J 39194-B . Tighten: Tighten the sensor to 42 N.m (31 lb ft).
3. Connect the HO2S harness connector (1).
4. Lower the vehicle.

J 39194-B Oxygen Sensor Wrench

1. Raise the vehicle.
2. Disconnect the connector (1) for the HO2S.
3. Remove the HO2S (2) using a J 39194-B .

1. Coat the threads of the oxygen sensor with anti-seize compound GM P/N 5613695, if necessary.
2. Install the HO2S (2) using a J 39194-B . Tighten: Tighten the sensor to 42 N.m (31 lb ft).
3. Connect the HO2S harness connector (1).
4. Lower the vehicle.

Note. The TP sensor is an electrical component. Do not soak the TP sensor in any liquid cleaner or solvent as damage may result.

1. Disconnect the negative battery cable.
2. Remove the generator. Refer to «Generator Replacement (4.8L, 5.3L, and 6.0L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
3. Disconnect the throttle position (TP) sensor electrical connector.
4. Remove the TP sensor attaching screws (5).
5. Remove the TP sensor (6).
6. Remove the TP sensor O-ring seal (7).

1. Install the TP sensor O-ring seal (7) on the TP sensor (6).
2. Install the TP sensor on the throttle body with the throttle valve in the closed position. Make sure the TP sensor lever lines up with the TP sensor drive lever on the throttle shaft. NOTE: Refer to «Fastener Notice»(/chevrolet/chevy-express-h1500/2003-2012/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
3. Install the TP sensor attaching screws (5). Tighten: Tighten the screws to 2 N.m (18 lb in).
4. Connect the TP sensor electrical connector.
5. Install the generator. Refer to «Generator Replacement (4.8L, 5.3L, and 6.0L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
6. Connect the negative battery cable.

Note. Handle the electronic throttle control components carefully. Use cleanliness in order to prevent damage. Do not drop the electronic throttle control components. Do not roughly handle the electronic throttle control components. Do not immerse the electronic throttle control components in cleaning solvents of any type.

1. Remove the connector position assurance (CPA) retainer.
2. Disconnect the accelerator pedal position (APP) sensor electrical connector.
3. Reposition the carpet to access the lower nut.
4. Remove the accelerator pedal nuts.
5. Remove the accelerator pedal assembly.

1. Install the accelerator pedal assembly.
2. Install the accelerator pedal nuts. Tighten: Tighten the nuts to 20 N.m (15 lb ft).
3. Connect the APP sensor electrical connector.
4. Reposition the carpet.
5. Connect a scan tool in order to test for proper throttle-opening and throttle-closing range.
6. Operate the accelerator pedal and monitor the throttle angles. The accelerator pedal should operate freely, without binding, between a closed throttle, and a wide open throttle (WOT).
7. Verify that the vehicle meets the following conditions: The vehicle is not in a reduced engine power mode. The ignition is ON. The engine is OFF.
8. Inspect the carpet fit under the accelerator pedal.

1. Remove the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) .
2. Disconnect the accelerator control cable and the cruise control cable from the throttle body.
3. Disconnect the vacuum hose from the throttle body.
4. Disconnect the throttle position (TP) sensor and idle air control (IAC) valve harness connectors.
5. Disconnect the coolant hose from the throttle body.
6. Disconnect the coolant hose from the vapor vent pipe.
7. Remove the throttle body attaching nuts.
8. Remove the throttle body and the gasket. Discard the gasket.
9. Clean the gasket sealing surfaces.

1. Install the throttle body with a new gasket.
2. Install the throttle body attaching nuts. Tighten: Tighten the nuts to 10 N.m (89 lb in).
3. Connect the coolant hose to the throttle body.
4. Connect the coolant hose to the vapor vent pipe.
5. Connect the accelerator control cable and the cruise control cable to the throttle body.
6. Connect the TP sensor and the IAC valve electrical connectors.
7. Connect the vacuum hose to the throttle body.
8. Install the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) .
9. With the engine OFF, verify that the accelerator pedal moves freely. Depress the accelerator pedal to the floor and release the pedal.
10. In order to reset the IAC valve, perform the following procedure: Turn ON the ignition for 10 seconds. Turn OFF the ignition for 5 seconds. Start the engine and check for the proper idle speed.

Fuel Pressure Relief (With CH 48027)

Tools Required

CH-48027 Digital Pressure Gage

1. Remove the engine cover, if required.
2. Loosen the fuel fill cap in order to relieve the fuel tank vapor pressure.
3. Remove the fuel rail service port cap.
4. Wrap a shop towel around the fuel rail service port.
5. Connect the CH-48027-3 (4) to the fuel rail service port.
6. Connect the CH-48027-2 (2) to the CH-48027-3 (4).
7. Place the hose on the CH-48027-2 (2) into an approved gasoline container.
8. Open the valve on the CH-48027-2 (2) in order to bleed any fuel from the fuel rail.
9. Close the valve on the CH-48027-2 (2).
10. Remove the hose on the CH-48027-2 (2) from the approved gasoline container.
11. Disconnect the CH-48027-2 (2) from the CH-48027-3 (4).
12. Disconnect the CH-48027-3 (4) from the fuel rail service port.
13. Remove the shop towel from around the fuel rail service port, and place in an approved gasoline container.
14. Install the fuel rail service port cap.
15. Install the engine cover, if required.
16. Tighten the fuel fill cap.

Fuel Pressure Relief (Without CH 48027)

1. Loosen the fuel fill cap in order to relieve the fuel tank vapor pressure.
2. Remove the engine cover, if required.
3. Remove the fuel rail service port cap.
4. Wrap a shop towel around the fuel rail service port and using a small flat bladed tool, depress (open) the fuel rail test port valve.
5. Remove the shop towel from around the fuel rail service port, and place in an approved gasoline container.
6. Install the fuel rail service port cap.
7. Install the engine cover, if required.
8. Tighten the fuel fill cap.

CH-48027 Digital Pressure Gage

1. Relieve the fuel system pressure. Refer to «Fuel Pressure Relief (With CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-with-ch-48027) or «Fuel Pressure Relief (Without CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-without-ch-48027) .
2. Connect the CH-48027-1 (1) to the CH-48027-2 (2).
3. Remove the shop towel from around the fuel rail service port, and place in an approved gasoline container.
4. Perform any tests and/or diagnostics as needed. For the proper usage of the CH-48027 , refer to the manufacture's directions.

1. Relieve the fuel system pressure, if required. Perform the following steps: CAUTION: Wrap a shop towel around the fuel pressure connection in order to reduce the risk of fire and personal injury. The towel will absorb any fuel leakage that occurs during the connection of the fuel pressure gage. Place the towel in an approved container when the connection of the fuel pressure gage is complete. Wrap a shop towel around the fuel rail service port. Place the hose on the CH-48027-2 (2) into an approved gasoline container. Open the valve on the CH-48027-2 (2) in order to bleed any fuel from the fuel rail. Close the valve on the CH-48027-2 (2). Remove the hose on the CH-48027-2 (2) from the approved gasoline container. Remove the shop towel from around the fuel rail service port, and place in an approved gasoline container.
2. Disconnect the CH-48027-1 (1) from the CH-48027-2 (2).
3. Disconnect the CH-48027-2 (2) from the CH-48027-3 (4).
4. Disconnect the CH-48027-3 (4) from the fuel rail service port.
5. Install the fuel rail service port cap.
6. Install the engine cover, if required.
7. Tighten the fuel fill cap.

Tool Required

J 37088-A Fuel Line Quick-Connect Separator, Tool Set

1. Relieve the fuel system pressure before servicing any fuel system connection. Refer to the «Fuel Pressure Relief (With CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-with-ch-48027) or «Fuel Pressure Relief (Without CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-without-ch-48027) .
2. Remove the retainer from the quick-connect fitting.
3. Blow dirt out of the fitting using compressed air.
4. Choose the correct tool from the J 37088-A tool set for the size of the fitting. Insert the tool into the female connector, then push inward in order to release the locking tabs.
5. Pull the connection apart.
6. Use a clean shop towel in order to 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 in order to snap the retaining tabs into place.
3. Once installed, pull on both sides of the fitting in order to make sure the connection is secure.
4. Install the retainer to the quick-connect fitting.

1. Relieve the fuel system pressure before servicing any fuel system connection. Refer to «Fuel Pressure Relief (With CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-with-ch-48027) or «Fuel Pressure Relief (Without CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-without-ch-48027) .
2. Using compressed air, blow any dirt out of the quick-connect fitting.
3. Squeeze the plastic retainer release tabs.
4. Pull the connection apart.

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

Fuel Tank Draining (w/o L59)

1. Remove the fuel filler cap.
2. Use a hand or air operated pump device in order to drain as much fuel through the fuel tank filler pipe opening as possible.

Fuel Tank Draining (L59)

1. Remove the fuel filler cap.
2. Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .
3. Clean the area around the fuel filler pipe to tank connection.
4. Place a drain pan under the fuel filler pipe connection.
5. Disconnect the fuel fill hose (1) at the fuel tank.
6. Use a hand or air operated pump device in order to drain as much fuel through the fuel tank filler pipe opening as possible.
7. If not removing the fuel tank, connect the fuel fill hose to the fuel tank. Tighten: Tighten the clamp to 2.75 N.m (24 lb in).

1. Disconnect the negative battery cable.
2. Relieve the fuel system pressure. Refer to «Fuel Pressure Relief (With CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-with-ch-48027) or «Fuel Pressure Relief (Without CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-without-ch-48027) .
3. Drain the fuel tank. Refer to «Fuel Tank Draining»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-tank-draining) .
4. Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .
5. Clean all the fuel pipe connections and the surrounding areas before disconnecting the fuel pipes in order to avoid possible contamination of the fuel system.
6. Loosen the fuel fill hose clamp.
7. Disconnect the fuel fill hose (1) from the filler tube.
8. Disconnect the fuel fill vent hose (2) from the filler tube.
9. Disconnect the rear fuel return pipe at the chassis fuel return pipe. Refer to «Plastic Collar Quick Connect Fitting Service»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2) .
10. Disconnect the rear fuel feed pipe at the chassis fuel feed pipe. Refer to «Plastic Collar Quick Connect Fitting Service»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2) .
11. With the aid of an assistant, support the fuel tank.
12. Remove and discard the attaching bolts (1) from the fuel tank strap.
13. Remove the fuel tank straps (2).
14. Carefully lower the fuel tank.
15. Disconnect the fuel sender and the fuel pump electrical connectors.
16. Remove the fuel tank.
17. Place the fuel tank in a suitable work area.
18. Remove the fuel sender assembly (1) and the fuel pipes from the fuel tank. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2) .
19. Remove the evaporative emission (EVAP) hoses from the fuel tank.
20. On models with EVAP canister mounted to fuel tank, remove two tiedown straps from the (EVAP) canister (2) then remove the canister from the fuel tank. Discard tiedown straps.
21. On all models, remove the fuel fill hose from the fuel tank.
22. Remove the fuel tank from the fuel tank shield (3).

1. Install the fuel tank into the fuel tank shield (3).
2. Install the fuel fill hose to the fuel tank. Tighten: Tighten the fuel fill hose clamp to 2.75 N.m (24 lb in).
3. On models with EVAP canister mounted to fuel tank, place the (EVAP) canister in position on the (EVAP) canister bracket, then install two new tiedown straps.
4. On all models, install the (EVAP) hoses to the fuel tank.
5. Install the fuel sender assembly (1) and the fuel pipes to the fuel tank. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2) .
6. With the aid of an assistant, position and support the fuel tank.
7. Raise the fuel tank slightly.
8. Connect the electrical connectors to the fuel sender and fuel pump.
9. Raise the tank fully.
10. Install the fuel tank straps (2).
11. Install the new attaching bolts (4) to the fuel tank strap. Tighten: Tighten the bolts to 20.5 N.m (15 lb ft).
12. Connect the chassis fuel feed pipe to the rear fuel feed pipe. Refer to «Plastic Collar Quick Connect Fitting Service»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2) .
13. Connect the rear fuel return pipe to the chassis fuel return pipe. Refer to «Plastic Collar Quick Connect Fitting Service»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2) .
14. Connect the fuel fill vent hose (2) to the filler tube.
15. Connect the fuel fill hose (1) to the fuel tank. Tighten: Tighten the fuel fill hose clamp to 2.75 N.m (24 lb in).
16. Lower the vehicle.
17. Refill the fuel tank.
18. Tighten the fuel filler cap.
19. Connect the negative battery cable.
20. Inspect for leaks: Turn ON the ignition for 2 seconds. Turn OFF the ignition for 10 seconds. Turn ON the ignition. Inspect for fuel leaks.

1. Disconnect the negative battery cable.
2. Relieve the fuel system pressure. Refer to «Fuel Pressure Relief (With CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-with-ch-48027) or «Fuel Pressure Relief (Without CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-without-ch-48027) .
3. Drain the fuel tank. Refer to «Fuel Tank Draining»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-tank-draining) .
4. Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .
5. Clean all fuel pipe and hose connections and surrounding areas before disconnecting the fuel pipes in order to avoid contamination of the fuel system.
6. Loosen the fuel fill hose clamp.
7. Disconnect the fuel fill hose from the fuel fill pipe.
8. Disconnect the fuel fill vent hose from the fill pipe.
9. Disconnect the rear evaporative emission (EVAP) pipe at the EVAP canister.
10. With the aid of an assistant, support the fuel tank.
11. Remove the attaching bolts (1) from the fuel tank straps. Discard attaching bolts.
12. Remove the fuel tank straps (2).
13. Carefully lower the fuel tank.
14. Disconnect the fuel feed pipe and the fuel return pipe at the fuel sender. Refer to «Plastic Collar Quick Connect Fitting Service»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2) .
15. Disconnect the electrical connector from the fuel sender.
16. Remove the fuel tank.
17. Place the fuel tank in a suitable work area.
18. Cap the open fuel and EVAP pipes on the vehicle in order to prevent possible fuel system contamination.
19. Remove the EVAP pipe from the roll over valves and the retainer clips.
20. Remove the fuel sender assembly from the fuel tank. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2) .
21. Remove the fuel fill hose from the fuel tank.

1. Install the fuel tank insulators (6).
2. Remove the caps from the fuel and EVAP pipes.
3. Install the fuel fill hose to the fuel tank. Tighten: Tighten the fuel fill hose clamp to 2.75 N.m (24 lb in).
4. Install the fuel sender assembly to the fuel tank. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2) .
5. Connect the EVAP pipe to the roll-over valves and the retainer clips.
6. With the aid of an assistant, position and support the fuel tank.
7. Raise the fuel tank slightly.
8. Connect the electrical connector to the fuel sender.
9. Connect the fuel feed pipe and the fuel return pipe to the fuel sender. Refer to «Plastic Collar Quick Connect Fitting Service»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2) .
10. Raise the tank fully.
11. Install the fuel tank straps (2).
12. Install the new attaching bolts (1) to the fuel tank straps. Tighten: Tighten the fuel tank strap attaching bolts to 20.5 N.m (15 lb ft).
13. Connect the rear EVAP pipe (1) to the EVAP canister.
14. Connect the fuel fill vent hose to the fill pipe.
15. Connect the fuel fill hose to the fuel fill pipe. Tighten: Tighten the fuel fill hose clamp to 2.75 N.m (24 lb in).
16. Lower the vehicle.
17. Refill the fuel tank.
18. Tighten the fuel filler cap.
19. Connect the negative battery cable.
20. Inspect for leaks: Turn ON the ignition for 2 seconds. Turn OFF the ignition for 10 seconds. Turn ON the ignition. Inspect for fuel leaks.

1. Disconnect the negative battery cable.
2. Relieve the fuel system pressure. Refer to «Fuel Pressure Relief (With CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-with-ch-48027) or «Fuel Pressure Relief (Without CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-without-ch-48027) .
3. Drain the fuel tank. Refer to «Fuel Tank Draining»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-tank-draining) .
4. Raise the vehicle. This must be done with a frame hoist in order to allow the rear suspension to hang. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .
5. Disconnect the fuel fill hose (1) from the fuel fill tube.
6. Disconnect the fuel fill vent hose (2) from the fuel fill tube.
7. Clean all the fuel pipe connections and the surrounding areas before disconnecting the fuel pipes in order to avoid contamination of the fuel system.
8. Disconnect the rear fuel and evaporative emissions (EVAP) pipes (2) at the chassis fuel and EVAP pipes. Refer to «Plastic Collar Quick Connect Fitting Service»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2) .
9. Cap the fuel and EVAP pipes in order to prevent fuel system contamination.
10. With the aid of an assistant, support the fuel tank.
11. Remove the attaching bolts (4) from the fuel tank straps. Discard attaching bolts.
12. Remove the fuel tank straps (3) and two fuel tank strap insulators.
13. Carefully lower the fuel tank.
14. Disconnect the electrical connectors from the fuel sender and the fuel pressure sensor.
15. Remove the fuel tank.
16. Place the fuel tank in a suitable work area.
17. Remove the fuel fill hose and fuel fill vent hose from the fuel tank.
18. Remove the fuel sender assembly and the rear fuel and EVAP pipes from the fuel tank. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2) .

1. Install the fuel tank insulators.
2. Install the fuel sender assembly and the rear fuel and EVAP pipes to the fuel tank. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2) .
3. Install the fuel fill hose and fuel fill vent hose to the fuel tank.
4. With the aid of an assistant, position and support the fuel tank.
5. Raise the fuel tank slightly.
6. Connect the electrical connectors to the fuel sender and the fuel pressure sensor.
7. Raise the tank fully.
8. Install the fuel tank straps (3).
9. Install the new attaching bolts (4) to the fuel tank straps. Tighten: Tighten the bolts to 20.5 N.m (15 lb ft).
10. Remove the caps from the fuel and EVAP pipes.
11. Connect the rear fuel and EVAP pipes (2) to the chassis fuel and EVAP pipes. Refer to «Plastic Collar Quick Connect Fitting Service»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2) .
12. Connect the fuel fill vent hose (2) to the full pipe.
13. Connect the fuel fill hose to the fuel tank (1). Tighten: Tighten the fuel fill hose clamp (2) to 2.75 N.m (24 lb in).
14. Lower the vehicle.
15. Refill the fuel tank.
16. Tighten the fuel filler cap.
17. Connect the negative battery cable.
18. Inspect for leaks: Turn ON the ignition for 2 seconds. Turn OFF the ignition for 10 seconds. Turn ON the ignition. Inspect for fuel leaks.

1. Remove the fuel tank. Refer to «Fuel Tank Replacement (Passenger/Cargo)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) or «Fuel Tank Replacement (Cutaway Van Side Tank)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) or «Fuel Tank Replacement (Cutaway Van Rear Tank)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) .
2. Remove the fuel pressure sensor (1).

1. Install the fuel pressure sensor (1).
2. Install the fuel tank. Refer to «Fuel Tank Replacement (Passenger/Cargo)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) or «Fuel Tank Replacement (Cutaway Van Side Tank)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) or «Fuel Tank Replacement (Cutaway Van Rear Tank)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) .

1. Remove the fuel tank. Refer to «Fuel Tank Replacement (Passenger/Cargo)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) or «Fuel Tank Replacement (Cutaway Van Side Tank)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) or «Fuel Tank Replacement (Cutaway Van Rear Tank)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) .
2. Remove the fuel pressure sensor (1).

1. Install the fuel pressure sensor (1).
2. Install the fuel tank. Refer to «Fuel Tank Replacement (Passenger/Cargo)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) or «Fuel Tank Replacement (Cutaway Van Side Tank)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) or «Fuel Tank Replacement (Cutaway Van Rear Tank)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) .

1. Remove the fuel sender assembly. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) .
2. Remove the two wire fuel level sensor connectors from the fuel sender assembly.
3. Using one of two pocket screwdrivers, pull the front retaining tab away from the front of the fuel level sensor while with the second pocket screwdriver push the fuel level sensor away and down from the fuel sender assembly.
4. Remove the fuel level sensor from the fuel sender assembly.

1. Install the fuel level sensor (1).
2. Connect the electrical connector to the fuel tank sender.
3. Install the fuel sender assembly. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) .

1. Clean all the fuel pipe and hose connections and the surrounding areas before disconnecting in order to avoid contamination of the fuel system.
2. Remove the fuel filler cap.
3. Drain the fuel below the level of the fuel tank fill hose. Refer to «Fuel Tank Draining»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-tank-draining) .
4. Remove the 2 retaining bolts and push-pin that retain the filler neck to the body.
5. Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .
6. Remove the fuel filler tube ground strap bolt.
7. Loosen the fuel fill hose to fuel fill pipe clamp.
8. Disconnect the fuel fill hose from the fuel fill pipe.
9. Remove the fuel fill pipe assembly.

1. Install the fuel fill pipe to the fuel fill hose.
2. Align the fuel fill pipe to the fuel fill pipe housing. Tighten: Tighten the fuel fill hose clamp to 2.75 N.m (24 lb in).
3. Install the fuel filler tube ground strap bolt. Tighten: Tighten the fuel filler tube ground strap bolt to 8 N.m (70 lb in).
4. Lower the vehicle.
5. Install the fuel fill pipe housing bolts and push-pin. Tighten: Tighten the fuel fill pipe housing bolts to 6 N.m (53 lb in).
6. Refill the fuel tank.
7. Install the fuel filler cap.

1. Clean all the fuel pipe and hose connections and the surrounding areas before disconnecting in order to avoid contamination of the fuel system.
2. Remove the fuel filler cap.
3. Drain the fuel below the level of the fuel tank fill hose. Refer to «Fuel Tank Draining»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-tank-draining) .
4. Remove the 2 retaining bolts and push-pin that retain the filler neck to the body.
5. Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .
6. Remove the fuel filler tube ground strap bolt.
7. Loosen the fuel fill hose to fuel fill pipe clamp.
8. Disconnect the fuel fill hose from the fuel fill pipe.
9. Remove the fuel fill pipe assembly.

1. Install the fuel fill pipe to the fuel fill hose.
2. Align the fuel fill pipe to the fuel fill pipe housing. Tighten: Tighten the fuel fill hose clamp to 2.75 N.m (24 lb in).
3. Install the fuel filler tube ground strap bolt. Tighten: Tighten the fuel filler tube ground strap bolt to 8 N.m (70 lb in).
4. Lower the vehicle.
5. Install the fuel fill pipe housing bolts and push-pin. Tighten: Tighten the fuel fill pipe housing bolts to 6 N.m (53 lb in).
6. Refill the fuel tank.
7. Install the fuel filler cap.

1. Clean all the fuel pipe and hose connections and the surrounding areas before disconnecting in order to avoid contamination of the fuel system.
2. Remove the fuel filler cap.
3. Drain the fuel below the level of the fuel tank fill hose. Refer to «Fuel Tank Draining»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-tank-draining) .
4. Remove the 2 retaining bolts and push-pin that retain the filler neck to the body.
5. Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .
6. Remove the fuel filler tube ground strap bolt.
7. Loosen the fuel fill hose to fuel fill pipe clamp.
8. Disconnect the fuel fill hose from the fuel fill pipe.
9. Remove the fuel fill pipe assembly.

1. Install the fuel fill pipe to the fuel fill hose.
2. Align the fuel fill pipe to the fuel fill pipe housing. Tighten: Tighten the fuel fill hose clamp to 2.75 N.m (24 lb in).
3. Install the fuel filler tube ground strap bolt. Tighten: Tighten the fuel filler tube ground strap bolt to 8 N.m (70 lb in).
4. Lower the vehicle.
5. Install the fuel fill pipe housing bolts and push-pin. Tighten: Tighten the fuel fill pipe housing bolts to 6 N.m (53 lb in).
6. Refill the fuel tank.
7. Install the fuel filler cap.

J 45722 Fuel Sender Lock Nut Wrench

1. Disconnect the negative battery cable.
2. Relieve the fuel system pressure. Refer to «Fuel Pressure Relief (With CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-with-ch-48027) or «Fuel Pressure Relief (Without CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-without-ch-48027) .
3. Drain the fuel tank. Refer to «Fuel Tank Draining (w/o L59)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2__fuel-tank-draining-wo-l59) or «Fuel Tank Draining (L59)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2__fuel-tank-draining-l59) .
4. Remove the fuel tank. Refer to «Fuel Tank Replacement (Passenger/Cargo)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) or «Fuel Tank Replacement (Cutaway Van Side Tank)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) or «Fuel Tank Replacement (Cutaway Van Rear Tank)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) .
5. Use the J 45722 and a long breaker-bar in order to unlock the fuel sender lock ring.
6. Remove the fuel sender assembly and the seal. Discard the seal.
7. Clean the fuel sender sealing surfaces.
8. Place the lock ring on a flat surface. Measure the clearance between the lock ring and the flat surface using a feeler gage at 7 points.
9. If warpage is less than 0.41 mm (0.016 in), the lock ring does not require replacement.
10. If warpage is greater than 0.41 mm (0.016 in), the lock ring must be replaced.

1. Install the new seal on the fuel tank.
2. Install the fuel sender assembly into the fuel tank.
3. Use the J 45722 in order to install the fuel sender lock ring. Turn the fuel sender lock ring in a clockwise direction.
4. Install the fuel tank. Refer to «Fuel Tank Replacement (Passenger/Cargo)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) or «Fuel Tank Replacement (Cutaway Van Side Tank)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) or «Fuel Tank Replacement (Cutaway Van Rear Tank)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) .
5. Refill the fuel tank.
6. Tighten the fuel filler cap.
7. Connect the negative battery cable.
8. Inspect for leaks: Turn ON the ignition for 2 seconds. Turn OFF the ignition for 10 seconds. Turn ON the ignition. Inspect for fuel leaks.

1. Disconnect the negative battery cable.
2. Relieve the fuel system pressure. Refer to «Fuel Pressure Relief (With CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-with-ch-48027) or «Fuel Pressure Relief (Without CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-without-ch-48027) .
3. Disconnect the fuel feed and return pipes (3) from the engine compartment fuel pipes (4).
4. Remove the fuel pipes from the bellhousing stud retainer clip.
5. Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .
6. Disconnect the fuel feed pipe at the fuel filter.
7. Disconnect the chassis fuel return pipe at the rear fuel return pipe.
8. Remove the fuel pipe retaining clips. Note the location of the retaining clips for installation.
9. Remove the fuel feed and return pipes.

1. Position the fuel feed and return pipes in the vehicle.
2. Install the fuel pipe retaining clips (1). Tighten: Tighten the clips to 12 N.m (106 lb in).
3. Connect the chassis fuel return pipe (4) to the rear fuel return pipe.
4. Connect the fuel feed pipe (5) to the fuel filter.
5. Lower the vehicle.
6. Install the fuel feed and return pipes to the engine compartment fuel pipes. Tighten: Tighten the fuel pipe fittings to 27 N.m (20 lb ft).
7. Install the fuel pipes to the retainer clip. Tighten: Tighten the fuel pipe retainer clip nut to 28 N.m (21 lb ft).
8. Tighten the fuel filler cap.
9. Connect the negative battery cable.
10. Inspect for leaks: Turn ON the ignition for 2 seconds. Turn OFF the ignition for 10 seconds. Turn ON the ignition. Inspect for fuel leaks.
11. Install the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .

1. Disconnect the negative battery cable.
2. Relieve the fuel system pressure. Refer to «Fuel Pressure Relief (With CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-with-ch-48027) or «Fuel Pressure Relief (Without CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-without-ch-48027) .
3. Drain the fuel tank. Refer to «Fuel Tank Draining»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-tank-draining) .
4. Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .
5. Disconnect the fuel feed pipe at the fuel filter.
6. Disconnect the chassis fuel return pipe at the rear fuel return pipe.
7. Disconnect the chassis fuel feed and return pipes at the rear fuel feed and return pipes.
8. Remove the fuel pipe retaining clips.
9. Remove the fuel feed and return pipes.

1. Install the fuel feed and return pipes and the fuel pipe retaining clips (2) to the frame rail (1). Tighten: Tighten the bolts to 12 N.m (106 lb in).
2. Connect the chassis fuel feed and return pipes to the rear fuel feed and return pipes (2).
3. Connect the chassis fuel return pipe to the rear fuel return pipe.
4. Connect the fuel feed pipe to the fuel filter.
5. Lower the vehicle.
6. Refill the fuel tank.
7. Tighten the fuel filler cap.
8. Connect the negative battery cable.
9. Inspect for leaks: Turn ON the ignition for 2 seconds. Turn OFF the ignition for 10 seconds. Turn ON the ignition switch. Inspect for fuel leaks.
10. Install the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .

1. Disconnect the negative battery cable.
2. Relieve the fuel system pressure. Refer to «Fuel Pressure Relief (With CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-with-ch-48027) or «Fuel Pressure Relief (Without CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-without-ch-48027) .
3. Drain the fuel tank. Refer to «Fuel Tank Draining»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-tank-draining) .
4. Remove the fuel tank. Refer to «Fuel Tank Replacement (Passenger/Cargo Van)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2) .
5. Disconnect the fuel feed pipe at the fuel filter.
6. Disconnect the chassis fuel return pipe at the rear fuel return pipe.
7. Remove the fuel pipe retaining clips.
8. Remove the fuel feed and return pipes.

1. Install the fuel feed and return pipes and the fuel pipe retaining clips (1). Tighten: Tighten the bolts to 12 N.m (106 lb in).
2. Connect the chassis fuel return pipe to the rear fuel return pipe.
3. Connect the fuel feed pipe to the fuel filter.
4. Install the fuel tank. Refer to «Fuel Tank Replacement (Passenger/Cargo Van)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2) .
5. Lower the vehicle.
6. Refill the fuel tank.
7. Tighten the fuel filler cap.
8. Connect the negative battery cable.
9. Inspect for leaks: Turn ON the ignition for 2 seconds. Turn OFF the ignition for 10 seconds. Turn ON the ignition. Inspect for fuel leaks.
10. Install the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .

1. Disconnect the negative battery cable.
2. Relieve the fuel system pressure. Refer to «Fuel Pressure Relief (With CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-with-ch-48027) or «Fuel Pressure Relief (Without CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-without-ch-48027) .
3. Drain the fuel tank. Refer to «Fuel Tank Draining»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-tank-draining) .
4. Remove the fuel tank. Refer to «Fuel Tank Replacement (Passenger/Cargo Van)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2) .
5. Remove the fuel feed and return pipes (4) from the fuel sender (2).

1. Install the fuel feed and return pipes (4) to the fuel sender (2).
2. Install the fuel tank. Refer to «Fuel Tank Replacement (Passenger/Cargo Van)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2) .
3. Lower the vehicle.
4. Refill the fuel tank.
5. Tighten the fuel filler cap.
6. Connect the negative battery cable.
7. Inspect for leaks: Turn ON the ignition for 2 seconds. Turn OFF the ignition for 10 seconds. Turn ON the ignition. Inspect for fuel leaks.

1. Disconnect the negative battery cable.
2. Clean all the fuel pipe and hose connections and the surrounding areas before disconnecting in order to avoid possible contamination of the fuel system.
3. Remove the fuel filler cap.
4. Drain the fuel below the level of the fuel tank fill hose. Refer to «Fuel Tank Draining»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-tank-draining) .
5. Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .
6. Loosen the fuel fill hose clamps (2, 3).
7. Remove the fuel fill hose (6).
8. Cap the open end of the fuel tank.

1. Uncap the fuel tank.
2. Install the fuel fill hose (6). Tighten: Tighten the fuel fill hose clamps (2, 3) to 2.75 N.m (24 lb in).
3. Lower the vehicle.
4. Refill the fuel tank.
5. Install the fuel filler cap.
6. Connect the negative battery cable.

1. Disconnect the negative battery cable.
2. Relieve the fuel system pressure. Refer to «Fuel Pressure Relief (With CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-with-ch-48027) or «Fuel Pressure Relief (Without CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-without-ch-48027) .
3. Drain the fuel tank. Refer to «Fuel Tank Draining»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-tank-draining) .
4. Remove the fuel tank. Refer to «Fuel Tank Replacement (Passenger/Cargo Van)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2) .
5. Remove the fuel feed and return pipes (6) from the fuel sender (1), the fuel filter, and the retaining clips.

1. Install the fuel feed and return pipes (6) to the fuel sender (1), the fuel filter, and the retaining clips.
2. Install the fuel tank. Refer to «Fuel Tank Replacement (Passenger/Cargo Van)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2) .
3. Lower the vehicle.
4. Refill the fuel tank.
5. Tighten the fuel filler cap.
6. Connect the negative battery cable.
7. Inspect for leaks: Turn ON the ignition for 2 seconds. Turn OFF the ignition for 10 seconds. Turn ON the ignition. Inspect for fuel leaks.

Fuel Tank Cleaning

1. Disconnect the negative battery cable. Refer to «Battery Negative Cable Disconnection and Connection»(/chevrolet/chevy-express-h1500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
2. Remove the fuel sender assembly. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) .
3. Inspect the fuel pump strainer. Replace a contaminated strainer and inspect the fuel pump.
4. Inspect the fuel pump inlet for dirt and debris. Replace the fuel pump if you find dirt or debris in the fuel pump inlet.
5. Flush the fuel tank with hot water.
6. Pour the water out of the fuel sender assembly opening. Rock the tank to be sure that removal of the water from the tank is complete.
7. Remove the fuel rail assembly. Refer to «Fuel Injection Fuel Rail Assembly Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) .
8. Drain the fuel from the fuel rail. It will be necessary to remove the fuel injectors from the fuel rail to properly clear all debris from the fuel rail and fuel injectors. Use light shop air to remove any debris from the fuel rail and injectors.
9. Replace the fuel injector O-rings.
10. Use light shop air in the opposite direction of the fuel flow in order to remove any debris from the fuel lines. Catch any fuel from the fuel lines with an approved gasoline container.
11. Install the injectors to the fuel rail.
12. Install the fuel rail assembly onto the engine. Refer to «Fuel Injection Fuel Rail Assembly Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) .
13. If equipped with a serviceable fuel filter, replace the fuel filter.
14. Install the fuel sender assembly. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) .
15. Connect the negative battery cable. Refer to «Battery Negative Cable Disconnection and Connection»(/chevrolet/chevy-express-h1500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
16. Purge the fuel sender assembly. Disconnect the fuel feed line from the fuel filter, if equipped. Otherwise, disconnect the fuel feed line at the fuel tank. Connect a length of hose to the fuel feed pipe. Insert the other end of the hose into an empty 3.8 liter (1 gallon) approved gasoline container. Add 23 liters (6 gallons) of clean fuel into the fuel tank. Turn on the fuel pump using the scan tool until 2 liters (1/2 gallon) of fuel flows into the fuel container.
17. Inspect for leaks. Turn the ignition switch ON for 2 seconds. Turn the ignition switch OFF for 10 seconds. Turn the ignition switch ON. Inspect for fuel leaks.

1. Remove the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .
2. Remove the air cleaner resonator outlet duct. Refer to «Air Cleaner Resonator Outlet Duct Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) .
3. Before removal, if necessary, clean the fuel rail assembly with a spray type engine cleaner, use GM X-30A or equivalent. Follow the package instructions. Do not soak fuel rail assembly in any liquid cleaning solvent.
4. Disconnect the accelerator control cable and the cruise control cable from the cable bracket, if equipped.
5. Disconnect the cruise control cable engine-end fitting from the stud on the throttle lever, if equipped.
6. Disconnect the accelerator control cable and the cruise control cable from the throttle body, if equipped.
7. Remove the upper engine wire harness retainer nut.
8. Disconnect the evaporative emission (EVAP) purge valve harness connector.
9. Reposition the upper engine wire harness aside.
10. Relieve the fuel system pressure. Refer to «Fuel Pressure Relief (With CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-with-ch-48027) or «Fuel Pressure Relief (Without CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-without-ch-48027) .
11. Mark the electrical connectors to their corresponding injectors to ensure correct sequential injector firing order after reassembly.
12. Pull the connector position assurance (CPA) (2) on the injector connector up.
13. Push the tab (1) on the injector connector in.
14. While pushing the tab (1) on the injector connector in, release the CPA (2).
15. Disconnect the fuel injector connector electrical connector.
16. Repeat steps for each injector connector.
17. Disconnect the fuel feed and return pipes (1, 2) from the fuel rail.
18. Disconnect the fuel pressure regulator vacuum line.
19. Loosen the crossover tube to right fuel rail retainer screw (22).
20. Remove the fuel rail bolts.
21. Remove the fuel rail.
22. Remove and discard the fuel injector lower O-ring seals (4) from the injectors (3).

1. Lubricate the NEW fuel injector lower O-ring seals (4) with clean engine oil.
2. Install the NEW O-ring seals (4) to the end of each injector (3).
3. Remove the retaining clip attaching screw (22) and crossover pipe retainer (21) to the right hand fuel rail.
4. Remove the crossover pipe rail (25) from the right fuel rail (15).
5. Remove the crossover pipe O-ring (20).
6. Lubricate a NEW O-ring (20) with clean engine oil.
7. Install a NEW crossover pipe O-ring (20) on the crossover pipe (25).
8. Install the crossover pipe (25) into the right fuel rail (15). IMPORTANT: When installing the retaining clip attaching screw for the crossover pipe, always start the screw by hand. This will prevent consequent stripping of the threads in the fuel rail.
9. Loosely install the crossover pipe retainer (21) and retaining clip attaching screw (22) to the right fuel rail.
10. Install the fuel rail.
11. Apply a 5 mm (0.020 in) band of GM P/N 12345382 (Canadian P/N 10953489) threadlock, or equivalent, to the threads of the fuel rail bolts. NOTE: Refer to «Fastener Notice»(/chevrolet/chevy-express-h1500/2003-2012/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
12. Install the fuel rail bolts. Tighten: Tighten the bolts to 10 N.m (89 lb in). Tighten the screw to 3.8 N.m (34 lb in).
13. Connect the fuel pressure regulator vacuum line.
14. Connect the fuel feed and return pipes (1, 2) to the fuel rail.
15. Connect the fuel injector electrical connectors. Install each connector onto the correct injector in order to ensure correct sequential injector firing order. Rotate the injectors as required in order to avoid stretching the wire harness.
16. Position the upper engine wire harness in place.
17. Connect the EVAP purge solenoid connector.
18. Install the retainer nut to the upper engine wire harness. Tighten: Tighten the nut to 5.5 N.m (49 lb in).
19. Connect the accelerator control cable and the cruise control cable to the cable bracket, if equipped.
20. Connect the accelerator control cable to the throttle body, if equipped.
21. Connect the cruise control cable engine-end fitting to the stud on the throttle lever, if equipped.
22. Install the air cleaner resonator outlet duct. Refer to «Air Cleaner Resonator Outlet Duct Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) .
23. Install the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .
24. Use the following procedure in order to inspect for leaks: 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. Relieve the fuel system pressure. Refer to «Fuel Pressure Relief (With CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-with-ch-48027) or «Fuel Pressure Relief (Without CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-without-ch-48027) .
2. Disconnect the fuel feed (1) and the fuel return (2) pipes from the fuel rail.
3. Remove the fuel return pipe attaching screw (3) and the fuel return pipe retainer (2).
4. Remove the fuel return pipe (1).
5. Remove and discard the fuel return pipe O-ring (6).
6. Remove the fuel pressure connection core assembly (24) from the crossover pipe rail (25).
7. Remove the retaining clip attaching screw (22) and the crossover fuel pipe retainer clip (21).
8. Remove the retaining clip attaching screw (4) and the crossover fuel pipe retainer clip (5).
9. Remove the crossover pipe rail assembly (25) from the left hand rail assembly (14) and the right hand rail assembly (15).
10. Remove and discard the crossover fuel pipe O-rings (7, 20).

1. Lubricate the NEW crossover fuel pipe O-rings (7, 20) with clean engine oil.
2. Install the NEW crossover fuel pipe O-rings (7, 20) onto the crossover pipe rail assembly (25).
3. Install the crossover pipe rail assembly (25) to the left hand rail assembly (14) and the right hand rail assembly (15). NOTE: Refer to «FASTENER NOTICE»(/chevrolet/chevy-express-h1500/2003-2012/remont/oem-general-information/#warnings-and-cautions__fastener-notice) . IMPORTANT: When installing the retaining clip attaching screws for the crossover pipe, always start them by hand. This will prevent consequent stripping of the threads in the rail.
4. Install the crossover fuel pipe retainer clip (21). Loosely install the retaining clip attaching screw (22).
5. Lubricate the NEW fuel return pipe O-ring (6) with clean engine oil.
6. Install the NEW fuel return pipe O-ring (6) on the fuel return pipe (1).
7. Install the fuel return pipe (1).
8. Install the fuel return pipe retainer (2). Loosely install the fuel return pipe attaching screw (3). IMPORTANT: When installing the retaining clip attaching screws for the crossover pipe, always start them by hand. This will prevent consequent stripping of the threads in the rail.
9. Install the crossover fuel pipe retainer clip (5). Loosely install the retaining clip attaching screw (4). Tighten: Tighten the crossover fuel pipe retainer clip attaching screws to 3.8 N.m (34 lb in). Tighten the fuel return pipe attaching screw to 5 N.m (44 lb in).
10. Install the fuel pressure connection core assembly (24) to the crossover pipe rail assembly (25).
11. Connect the fuel return (2) and fuel feed (1) pipes to the fuel rail.
12. Tighten the fuel fill cap.
13. Connect the negative battery cable. Refer to «Battery Negative Cable Disconnection and Connection»(/chevrolet/chevy-express-h1500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
14. Use the following procedure in order to inspect for leaks: 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.
15. Install the fuel pressure connection cap.

1. Relieve the fuel system pressure. Refer to the «Fuel Pressure Relief (With CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-with-ch-48027) or «Fuel Pressure Relief (Without CH 48027)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2__fuel-pressure-relief-without-ch-48027) .
2. Disconnect the fuel feed (1) and fuel return (2) pipes from the fuel rail.
3. Remove the retaining clip attaching screw (4).
4. Remove the crossover fuel pipe retainer clip (5).
5. Remove the fuel return pipe attaching screw (3) and the fuel return pipe retainer (2).
6. Remove the fuel return pipe (1).
7. Remove and discard the fuel return pipe O-ring (6).

1. Lubricate a NEW fuel return pipe O-ring (6) with clean engine oil.
2. Install the fuel return pipe O-ring (6) onto the fuel return pipe (1).
3. Install the fuel return pipe (1). NOTE: Refer to the «FASTENER NOTICE»(/chevrolet/chevy-express-h1500/2003-2012/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
4. Install the fuel return pipe retainer (2) and the fuel return pipe attaching screw (3).
5. Install the crossover fuel pipe retainer clip (5).
6. Install the retaining clip attaching screw (4). Tighten: Tighten the crossover fuel pipe retainer clip attaching screw (4) to 3.8 N.m (34 lb in). Tighten the fuel return pipe attaching screw (3) to 5 N.m (44 lb in).
7. Connect the fuel return (2) and fuel feed (1) pipes to the fuel rail.
8. Tighten the fuel fill cap.
9. Connect the negative battery cable. Refer to «Battery Negative Cable Disconnection and Connection»(/chevrolet/chevy-express-h1500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
10. Use the following procedure in order to inspect for leaks: 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.
11. Install the fuel pressure connection cap.

Note. Use care in removing the fuel injectors in order to prevent damage to the fuel injector electrical connector pins or the fuel injector nozzles. Do not immerse the fuel injector in any type of cleaner. The fuel injector is an electrical component and may be damaged by this cleaning method.

1. Remove the fuel rail. Refer to «Fuel Injection Fuel Rail Assembly Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) .
2. Remove the fuel injector retainer clip (19).
3. Remove the fuel injector (17).
4. Discard the injector retainer clip (1).
5. Remove and discard the fuel injector O-ring seals (2, 4) from the injector.

1. The fuel injector (1) is stamped with a part number identification (2). A four-digit build date code (3), which indicates the month (4), day (5), year (6), and the shift (7) that built the fuel injector.
2. Lubricate the NEW fuel injector O-ring seals (2, 4) with clean engine oil.
3. Install the NEW injector O-ring seals onto the fuel injector.
4. Install a NEW retainer clip (1) onto the fuel injector.
5. Install the fuel injector (17) into the fuel rail injector socket with the electrical connector facing outward. The retainer clip (19) locks onto a flange on the fuel rail injector socket.
6. Install the fuel rail. Refer to «Fuel Injection Fuel Rail Assembly Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) .

Fuel Injector Cleaning

Tools Required

1. J 37287 Fuel Line Shut-Off Adapters
2. J 35800-A Fuel Injector Cleaner. See «Special Tools»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2__special-tools) .
3. J 42873-1 3/8 Fuel Line Shut-Off Valve. See «Special Tools»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2__special-tools) .
4. J 42873-2 5/16 Return Pipe Shut-Off Valve. See «Special Tools»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2__special-tools) .
5. J 42964-1 3/8 Fuel Pipe Shut-Off Valve. See «Special Tools»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2__special-tools) .
6. J 42964-2 5/16 Fuel Pipe Shut-Off Valve. See «Special Tools»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2__special-tools) .

Note. GM Top-Engine Cleaner is the only injector cleaning agent recommended. Do not use other cleaning agents, as they may contain methanol which can damage fuel system components. Under NO circumstances should the top engine cleaner be added to the vehicles fuel tank, as it may damage the fuel pump and other system components. Do not exceed a 10 percent cleaning solution concentration. Higher concentrations may damage fuel system components. Testing has demonstrated that exceeding the 10 percent cleaning solution concentration does not improve the effectiveness of this procedure.

1. Obtain J 35800-A (2). See «Special Tools»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2__special-tools) .
2. For US dealers, empty 2 pre-measured GM Top-Engine Cleaner containers, 24 ml (0.812 oz) each, GM P/N 12346535, into the J 35800-A . See «Special Tools»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2__special-tools) .
3. For Canadian dealers, measure and dispense 48 ml (1.62 oz) of Top-Engine Cleaner, Canadian P/N 992872, into the J 35800-A . See «Special Tools»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2__special-tools) .
4. If you are using any other brand of tank you will need a total of 96 ml (3.24 oz) of Top-Engine Cleaner mixed with 864 ml (29.16 oz) of regular unleaded gasoline.
5. Fill the injector cleaning tank with regular unleaded gasoline. Be sure to follow all additional instructions provided with the tool.
6. Electrically disable the vehicle fuel pump by removing the fuel pump relay and disconnecting the oil pressure switch connector, if equipped.
7. Disconnect the fuel feed and return line, if equipped, at the fuel rail. Plug the fuel feed and return line, if equipped, coming off the fuel rail with J 37287 , or J 42964-1 , and J 42964-2 or J 42873-1 , and J 42873-2 as appropriate for the fuel system. See «Special Tools»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2__special-tools) .
8. Connect the J 35800-A to the vehicle fuel rail. See «Special Tools»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2__special-tools) .
9. Pressurize the J 35800-A to 510 kPa (75 psi). See «Special Tools»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2__special-tools) .
10. Start and idle the engine until it stalls due to lack of fuel. This should take approximately 15-20 minutes.
11. Disconnect J 35800-A from the fuel rail. See «Special Tools»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2__special-tools) .
12. Reconnect the vehicle fuel pump relay and oil pressure switch connector, if equipped.
13. Remove J 37287 or J 42964-1 , and J 42964-2 or J 42873-1 , and J 42873-2 and reconnect the vehicle fuel feed and return lines. See «Special Tools»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2__special-tools) .
14. Start and idle the vehicle for an additional 2 minutes to ensure residual injector cleaner is flushed from the fuel rail and fuel lines.
15. Repeat steps 1-5 of the Injector Balance Test, and record the fuel pressure drop from each injector.
16. Subtract the lowest fuel pressure drop from the highest fuel pressure drop. If the value is 15 kPa (2 psi) or less, no additional action is required. If the value is greater than 15 kPa (2 psi), replace the injector with the lowest fuel pressure drop.
17. Add one ounce of Port Fuel Injector Cleaner, GM P/N 12345104 (Canadian P/N 10953467), to the vehicle fuel tank for each gallon of gasoline estimated to be in the fuel tank. Instruct the customer to add the reminder of the bottle of Port Fuel Injector Cleaner to the vehicle fuel tank at the next fill-up.
18. Advise the customer to change brands of fuel and to add GM Port Fuel Injector Cleaner every 5 000 km (3,000 mi). GM Port Fuel Injector Cleaner contains the same additives that the fuel companies are removing from the fuel to reduce costs. Regular use of GM Port Fuel Injector Cleaner should keep the customer from having to repeat the injector cleaning procedure.
19. Road test the vehicle to verify that the customer concern has been corrected.

1. Remove the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) .
2. Push the evaporative emission (EVAP) pipe quick connect fitting retainer inward.
3. Disconnect the EVAP pipe (2) from the EVAP purge solenoid (1).
4. Disconnect the EVAP purge solenoid electrical connector.
5. Remove the EVAP purge solenoid mount bolt (2).
6. Remove the EVAP purge solenoid (3) and the insulator (1) from the engine.

1. Install the insulator (1) on the EVAP canister purge valve (3).
2. Install the EVAP canister purge valve (3) to the engine. NOTE: Refer to «Fastener Notice»(/chevrolet/chevy-express-h1500/2003-2012/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
3. Install the EVAP canister purge valve mount bolt (2). Tighten: Tighten the EVAP canister purge valve mount bolt to 10.5 N.m (93 lb in).
4. Connect the EVAP pipe (2) to the EVAP canister purge valve (1).
5. Connect the EVAP canister purge valve electrical connector.
6. Install the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) .

1. Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .
2. Disconnect the electrical connector from the EVAP vent valve.
3. Disconnect the canister vent hose.
4. Bend back the tang on the bracket.
5. Slide the EVAP vent valve off the bracket.

1. Slide the EVAP vent valve onto the bracket.
2. Connect the canister vent hose.
3. Connect the electrical connector to the EVAP vent valve.
4. Lower the vehicle.

1. Clean the pipe connections and the surrounding areas before disconnecting in order to avoid possible contamination of the EVAP system.
2. Disconnect the engine compartment EVAP pipe at the EVAP canister purge valve.
3. Disconnect the engine compartment EVAP pipe (1) at the chassis EVAP pipe (2).
4. Remove the EVAP pipe from the engine.
5. Cap the EVAP canister purge valve and the chassis EVAP pipe in order to prevent possible EVAP system contamination.

1. Remove the caps from the EVAP canister purge valve and the chassis EVAP pipe.
2. Install the EVAP pipe on the engine.
3. Connect the engine compartment EVAP pipe (1) to the chassis EVAP pipe (2).
4. Connect the engine compartment EVAP pipe at the EVAP canister purge valve.

1. Remove the fuel tank. Refer to «Fuel Tank Replacement (Passenger/Cargo Van)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2) .
2. Disconnect the rear EVAP vapor pipe (1) from the fuel sender (2), the fuel tank roll over valve (3), and the fuel tank clips (6).
3. Remove the EVAP vapor pipe from the fuel tank.
4. Cap the fuel sender EVAP pipe and the fuel tank roll over valve.

1. Remove the caps from the fuel sender EVAP pipe and the fuel tank roll over valve.
2. Position the EVAP vapor pipe on the fuel tank.
3. Connect the EVAP vapor pipe (1) to the fuel sender (2), the fuel tank roll over valve (3), and the fuel tank clips (6).
4. Install the fuel tank. Refer to «Fuel Tank Replacement (Passenger/Cargo Van)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2) .

1. Remove the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .
2. Clean all the EVAP pipe connections and the surrounding areas before disconnecting the pipes in order to avoid possible contamination of the EVAP system.
3. Disconnect the engine compartment EVAP pipe (1) from the chassis EVAP pipe (2).
4. Cap the engine compartment EVAP pipe.
5. Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .
6. Remove the EVAP pipe from the bellhousing stud clip.
7. Remove the EVAP pipe from the transmission bracket clip.
8. Remove the EVAP pipe from the transfer case bracket clip, AWD drive only.
9. Disconnect the rear EVAP purge pipe (3) from the chassis EVAP purge pipe (2).
10. Cap the rear EVAP purge pipe (3).
11. Note the position of the EVAP pipe for aid in installation.
12. Remove the EVAP pipe from the retaining clips (1).
13. Remove the EVAP pipe.

1. Install the EVAP pipe into the retaining clips (1).
2. Remove the cap from the rear EVAP pipe.
3. Connect the rear EVAP purge pipe (3) to the chassis EVAP purge pipe (2).
4. Install the EVAP pipe into the transfer case bracket clip, AWD drive only.
5. Install the EVAP pipe into the transmission bracket clip.
6. Install the EVAP pipe into the bellhousing stud clip (3).
7. Lower the vehicle.
8. Remove the cap from the engine compartment EVAP pipe.
9. Connect the engine compartment EVAP pipe (1) to the chassis EVAP pipe (2).
10. Install the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .

1. Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .
2. Disconnect the vent hose from the canister.
3. Disconnect the chassis EVAP purge pipe from the EVAP canister.
4. Disconnect the fuel tank EVAP pipe from the canister.
5. Remove the EVAP canister from the EVAP Canister bracket.

1. Connect the fuel tank EVAP pipe to the canister.
2. Connect the chassis EVAP purge pipe to the EVAP canister.
3. Connect the vent hose to the canister.
4. Install the EVAP canister to the EVAP Canister bracket.
5. Install the EVAP canister bracket bolt. Tighten: Tighten the bolt to 12 N.m (106 lb in).
6. Lower the vehicle.

1. Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .
2. Disconnect the vent hose from the canister.
3. Disconnect the chassis EVAP purge pipe from the EVAP canister.
4. Disconnect the fuel tank EVAP pipe from the canister.
5. Remove the EVAP canister from the EVAP canister bracket.

1. Install the EVAP canister to the EVAP canister bracket.
2. Connect the fuel tank EVAP pipe to the canister.
3. Connect the chassis EVAP purge pipe to the EVAP canister.
4. Connect the vent hose to the canister.
5. Lower the vehicle.

J 41413 EVAP Pressure/Purge Diagnostic Station

Inspection Procedure

Note. Use the EVAP Pressure/Purge Diagnostic Station J 41413 in order to provide a clean, dry, low pressure gas source. Do not substitute any other pressurized gas source. Damage may result to the EVAP system.

1. Turn OFF the ignition.
2. Remove the EVAP canister purge solenoid valve. Refer to «Evaporative Emission Canister Purge Solenoid Valve Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) .
3. Lightly tap the EVAP canister purge solenoid valve on a clean hard surface.
4. Inspect for carbon particles exiting either of the vacuum ports. If no carbon particles are found reinstall the EVAP canister purge solenoid valve and continue with the EVAP cleaning procedure. Refer to «Evaporative Emission Canister Purge Solenoid Valve Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) If carbon particles are found during the inspection procedure, replace the EVAP canister purge solenoid valve and continue with the EVAP cleaning procedure. Refer to «Evaporative Emission Canister Purge Solenoid Valve Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) . If you were instructed to replace the EVAP canister purge solenoid valve, and no carbon particles are found, return to the EVAP diagnostic procedure. Do not perform the EVAP cleaning procedure.

EVAP Cleaning Procedure

1. Remove the EVAP canister. Refer to «Evaporative Emission Canister Replacement (Cutaway Van)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2) or «Evaporative Emission Canister Replacement (Passenger/Cargo Van)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2) .
2. Turn OFF the main valve on the J 41413 EVAP pressure/purge diagnostic station.
3. Disconnect the hose from the diagnostic station pressure regulator.
4. Using a section of vacuum hose, connect one end to the diagnostic station pressure regulator.
5. Connect the other end of the vacuum hose to the canister side of the purge pipe.
6. Turn ON the main nitrogen cylinder valve and continue to discharge nitrogen for 15 seconds.
7. If the nitrogen does not dislodge the carbon particles, replace the purge pipe. Refer to «Evaporative Emission System Hoses/Pipes Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) .
8. Return the EVAP pressure/purge diagnostic station to the stations original condition.
9. Install a new EVAP canister. Refer to «Evaporative Emission Canister Replacement (Cutaway Van)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2) or «Evaporative Emission Canister Replacement (Passenger/Cargo Van)»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-43l-introduction-2-of-2) .
10. Connect all previously disconnected EVAP pipe connectors.
11. Lower the vehicle.
12. Continue with the published service manual diagnostic DTC procedure.

1. Remove the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .
2. Disconnect the spark plug wires at the ignition coils.
3. Disconnect the ignition coil harness connector.
4. Remove the ignition coil mounting bolts.
5. Remove the ignition coil.

1. Install the ignition coil to the bracket.
2. Install the ignition coil mounting bolts. Tighten: Tighten the ignition coil mounting bolts to 8 N.m (71 lb in).
3. Connect the ignition coil harness connector.
4. Connect the spark plug wires at the ignition coils.
5. Install the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .

Spark Plug Wire Inspection

Spark plug wire integrity is vital for proper engine operation. A thorough inspection will be necessary to accurately identify conditions that may affect engine operation. Inspect for the following conditions

1. Correct routing of the spark plug wires-Incorrect routing may cause cross-firing.
2. Any signs of cracks or splits in the wires
3. Inspect each boot for the following conditions: Tearing Piercing Arcing Carbon tracking Corroded terminal

If corrosion, carbon tracking or arcing are indicated on a spark plug wire boot or on a terminal, replace the wire and the component connected to the wire.

1. Remove the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .
2. Disconnect the spark plug wire at each spark plug. Twist each spark plug wire 1/2 turn. Pull only on the boot in order to remove the wire from each spark plug.
3. Disconnect the spark plug wire from the ignition coil. Twist each spark plug boot 1/2 turn. Pull only on the boot in order to remove the wires from the ignition coil.

Spark Plug Wire Length V8

1. The Melco® (square design) uses a spark plug wire (1) that is 145 mm (5.70 in) length cable seal to cable seal.
2. The Delphi® (round design) uses a spark plug wire (2) that is 110 mm (4.30 in) length cable seal to cable seal.
3. There are 2 different manufacturers for the ignition coils. the Melco® (1) (square design), and the Delphi® (2) (round design). These 2 coils use 2 different spark plug wire, and mounting brackets.
4. Melco® (square design) coil mounting bracket (1).
5. Delphi® (round design) coil mounting bracket (2).

1. Install the spark plug wires at the ignition coil.
2. Install the spark plug wire to each spark plug.
3. Inspect the wires for proper installation: Push sideways on each boot in order to inspect the seating. Reinstall any loose boot.
4. Install the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .

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/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2__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/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2__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/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2__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.

1. Remove the spark plug wires. Refer to «Spark Plug Wire Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) .
2. Loosen each spark plug 1 or 2 turns.
3. Brush or air blast away any dirt from around the spark plugs.
4. Remove the spark plugs 1 at a time. Place each plug in a tray marked with the corresponding cylinder numbers.

1. Properly position each spark plug washer.
2. Inspect each spark plug gap. Adjust each plug as needed. Specification: Spark plug gap: 1.524 mm (0.060 in)
3. Hand start the spark plugs in the corresponding cylinders.
4. Tighten the spark plugs. Tighten: For used heads tighten the spark plugs to 15 N.m (11 lb ft). For new aluminum heads tighten the spark plugs to 20 N.m (15 lb ft). For new iron heads, tighten the spark plugs to 30 N.m (22 lb ft).
5. Install the spark plug wires. Refer to «Spark Plug Wire Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) .

1. Disconnect the negative battery cable.
2. Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .
3. Remove the starter. Refer to «Starter Motor Replacement (4.8L, 5.3L, and 6.0L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
4. Disconnect the crankshaft position (CKP) sensor electrical connector.
5. Clean the area around the CKP sensor before removal in order to avoid debris from entering the engine.
6. Remove the CKP sensor retaining fastener.
7. Remove the CKP sensor.

1. Install the CKP sensor. NOTE: Refer to «FASTENER NOTICE»(/chevrolet/chevy-express-h1500/2003-2012/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
2. Install the CKP sensor retaining fastener. Tighten: Tighten the fastener to 25 N.m (18 lb ft).
3. Connect the CKP sensor electrical connector.
4. Install the starter. Refer to «Starter Motor Replacement (4.8L, 5.3L, and 6.0L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
5. Lower the vehicle.
6. Connect the negative battery cable.
7. Perform the CKP system variation learn procedure. Refer to «Crankshaft Position System Variation Learn»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2__crankshaft-position-system-variation-learn) .

1. Remove the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .
2. Disconnect the CMP sensor electrical connector.
3. Remove the CMP sensor bolt.
4. Remove the CMP sensor.

1. Install the CMP sensor.
2. Install the CMP sensor bolt. Tighten: Tighten the bolt to 25 N.m (18 lb ft).
3. Connect the CMP sensor electrical connector.
4. Install the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .

1. Remove the intake manifold. Refer to «Intake Manifold Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-48l-53l-and-60l-2-of-4) .
2. Remove the KS wiring harness assembly.
3. Remove the KS.

1. Install the KS. Tighten: Torque the sensor to 20 N.m (15 lb ft).
2. Install the KS wiring harness assembly.
3. Install the intake manifold. Refer to «Intake Manifold Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-48l-53l-and-60l-2-of-4) .

1. Unclip the air filter cover (2).
2. Lift and rotate the top cover (2) of the air cleaner housing to gain access to the air filter element.
3. Pull out the air filter element.
4. Inspect the air filter element for dust, dirt, or water. Clean or replace the air filter element if required.

1. Install the air filter element into the air cleaner housing (1).
2. Rotate and install the top cover (2) to the air cleaner housing (1).

1. Remove the air intake duct. Refer to «Air Cleaner Resonator Outlet Duct Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-48l-53l-and-60l-introduction-2-of-2) .
2. Disconnect the mass air flow/intake air temperature (MAF/IAT) sensor (5) connector.
3. Loosen the clamp securing the MAF/IAT sensor to the air cleaner assembly.
4. Remove the MAF/IAT sensor.
5. Pull up on the air cleaner assembly (1) to release the retainers from the air cleaner adaptor (2).

1. Position the air cleaner assembly (4) onto the air cleaner adaptor. Ensure the retainers fit properly into the air cleaner adaptor (3).
2. Secure the air cleaner assembly (4) onto the air cleaner adaptor (3).
3. Install the MAF/IAT sensor (5) to the air cleaner assembly.
4. Secure the clamps at the MAF/IAT sensor and the air cleaner assembly.
5. Connect the MAF/IAT connector (5).
6. Install the air intake duct.

1. Loosen the clamp and separate the air cleaner resonator outlet duct (1) from the mass air flow/intake air temperature (MAF/IAT) sensor assembly.
2. Loosen the clamp and separate the air cleaner resonator outlet duct from the throttle body assembly.
3. Remove the air cleaner resonator outlet duct.

1. Install the air cleaner resonator outlet duct to the throttle body assembly and the MAF/IAT sensor assembly.
2. Tighten the clamps at the throttle body assembly and the MAF/IAT sensor assembly.

Powertrain

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

The following are some of the functions that the PCM controls

1. The engine fueling
2. The ignition control (IC)
3. The knock sensor (KS) system
4. The evaporative emissions (EVAP) system
5. The secondary air injection (AIR) system (if equipped)
6. The exhaust gas recirculation (EGR) system
7. The automatic transmission functions
8. The generator
9. The A/C clutch control
10. The cooling fan control

Powertrain Control Module Function

The powertrain control module (PCM) constantly looks at the information from various sensors and other inputs and controls systems that affect vehicle performance and emissions. The PCM also performs diagnostic tests on various parts of the system. The PCM can recognize operational problems and alert the driver via the malfunction indicator lamp (MIL). When the PCM detects a malfunction, the PCM stores a diagnostic trouble code (DTC). The problem area is identified by the particular DTC that is set. The control module supplies a buffered voltage to various sensors and switches. The input and output devices in the PCM 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 PCM controlled components are operated via output drivers. The PCM 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 281

Scheme 282

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.

Trip

A trip is an interval of time during which the diagnostic test runs. A trip may consist of only a key cycle to power up the powertrain control module (PCM), allow the diagnostic to run, then cycle the key off to power down the PCM. A trip may also involve a PCM power up, meeting specific conditions to run the diagnostic test, then powering down the PCM. The definition of a trip depends upon the diagnostic. Some diagnostic tests run only once per trip (i.e., catalyst monitor) while other tests run continuously during each trip (i.e., misfire).

Warm-Up Cycle

The powertrain control module (PCM) 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 PCM counts the number of warm-up cycles in order to clear the malfunction indicator lamp (MIL). The PCM will clear the DTCs when 40 consecutive warm-up cycles occur without a malfunction.

Diagnostic Trouble Codes (DTCs)

The powertrain control module (PCM) is programmed with test routines that test the operation of the various systems the PCM controls. Some tests monitor internal PCM 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 PCM 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 PCM executes the Action Taken When the DTC Sets. Some DTCs alert the driver via the malfunction indicator lamp (MIL) or a message. Other DTCs do not trigger a driver warning, but are stored in memory. The PCM 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.

DTC Status

When the scan tool displays a DTC, the status of the DTC is also displayed. The following DTC statuses are indicated only when they apply to the DTC that is set.

Throttle Actuator Control (TAC) System Description

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 (APP) 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 components include the following

1. The APP sensors
2. The throttle body assembly
3. The TAC module
4. The powertrain control module (PCM)

Accelerator Pedal Position (APP) Sensor

The accelerator pedal assembly contains 2 individual accelerator pedal position (APP) sensors within the assembly. The APP sensors 1 and 2 are potentiometer type sensors, each with the following 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 control module provides each APP sensor a 5-volt reference circuit and a low reference circuit. The APP sensors then provide the control module with signal voltage proportional to pedal movement. Both APP sensor signal voltages are low at rest position and increase as the pedal is applied.

Throttle Body Assembly

The throttle body assembly consists of the throttle body, the throttle position (TP) sensors, and the throttle actuator motor. 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 1 and 2 are potentiometer type sensors, each with the following circuits

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

The TP sensors are used to determine the throttle plate angle. The control module provides each TP sensor a 5-volt reference circuit and a low reference circuit. The TP sensors then provide the control module with signal voltage proportional to throttle plate movement. Both TP sensor signal voltages are low at closed throttle and increase as the throttle opens.

Throttle Actuator Control Module

The throttle actuator control (TAC) module is the control center for the throttle actuator control system. The TAC system is self-diagnosing and provides diagnostic information to the powertrain control module (PCM) through a dedicated serial data line. The TAC achieves throttle positioning by providing a pulse width modulated voltage to the TAC, as directed by the PCM.

Powertrain Control Module

The powertrain control module (PCM) determines the driver's intent, then calculates the appropriate throttle response. This information is sent to the throttle actuator control (TAC) module through a dedicated serial data line.

Modes of Operation

Normal Mode

During the operation of the throttle actuator control (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 powertrain control module (PCM) updates the learned minimum pedal value.
2. Minimum throttle position (TP) values-At key-up the PCM 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 control module 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 control module 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 PCM detects a condition with the TAC system, the PCM may enter a reduced engine power mode. Reduced engine power may cause one or more of the following conditions

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

Fuel System Overview

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

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 Tanks

The fuel tanks store the fuel supply. The fuel tank is held in place by 2 metal straps that attach to the frame. 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. Once the fill vent is obstructed, fuel backs up the fill pipe and trips the dispensing nozzle. The fuel tank vent valves are connected and route to the canister to collect hydrocarbon emissions during operation of the vehicle.

Scheme 283

Scheme 284

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 clicks. This indicates that the cap is correctly torqued and fully seated. A built-in device indicates that the fuel filler cap is fully seated. A fuel filler cap that is not fully seated may cause a malfunction in the emission system.

Scheme 285

The fuel sender assembly on single tank applications consists of the following major components

1. The fuel level sensor
2. The fuel tank pressure (FTP) sensor
3. The fuel tank fuel pump module
4. The fuel strainer
5. The fuel filter

Fuel Level Sensor

The fuel level sensor consists of a float, a wire float arm, and a ceramic resistor cord. The position of the float arm indicates the fuel level. The fuel level sensor contains a variable resistor, which changes resistance in correspondence to the amount of fuel in the fuel tank. The powertrain control module (PCM) sends the fuel level information via the class 2 circuit to the instrument panel (I/P) cluster. This information is used for the I/P fuel gage and the low fuel warning indicator, if applicable. The PCM 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 rail at a specified flow and pressure. The fuel pump delivers a constant flow of fuel to the engine during low fuel conditions and aggressive vehicle maneuvers. The powertrain control module (PCM) 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. Fuel stoppage at this point indicates that the fuel tank contains an abnormal amount of sediment.

Fuel Filter

The fuel filter is contained in the fuel sender assembly inside the fuel tank. the paper filter element of the fuel filter traps particles in the fuel that may damage the fuel injection system. The fuel 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.

Nylon Fuel Pipes

Nylon pipes are constructed to withstand maximum fuel system pressure, exposure to fuel additives, and changes in temperature. There are 3 sizes of nylon pipes used: 9.5 mm (3/8 in) ID for the fuel supply, 7.6 mm (5/16 in) ID for the fuel return, and 12.7 mm (1/2 in) ID for the vent. Heat resistant rubber hose or corrugated plastic conduit protects the sections of the pipes that are exposed to chafing, to high temperatures, or to 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.

On-Board Refueling Vapor Recovery System (ORVR)

The On-Board Refueling Vapor Recovery System (ORVR) is an on-board vehicle system designed to recover fuel vapors during the vehicle refueling operation. The flow of liquid fuel down the fuel filler pipe provides a liquid seal which prevents vapor from leaving the fuel filler pipe. An EVAP pipe transports the fuel vapor to the EVAP canister for use by the engine.

Fuel Pipe O-Rings

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

Scheme 286

The fuel rail assembly attaches to the engine intake manifold. The fuel rail assembly performs the following functions

1. Positions the injectors (3) in the intake manifold
2. Distributes fuel evenly to the injectors
3. Integrates the fuel dampener (2) into the fuel metering system

Fuel Injectors

The fuel injector assembly is a solenoid device controlled by the PCM that meters pressurized fuel to a single engine cylinder. The PCM energizes the injector solenoid to open a normally closed ball valve. This allows the fuel to flow into the top of the injector, past the ball valve, and through a director plate 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. 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.

Fuel Pressure Regulator

The fuel pressure regulator is contained in the left fuel sender assembly.

Fuel Metering Modes of Operation

The PCM monitors voltages from several sensors in order to determine how much fuel to give the engine. The PCM 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 PCM energizes the fuel pump relay for 2 seconds. This allows the fuel pump to build pressure in the fuel system. The PCM calculates the air/fuel ratio based on inputs from the engine coolant temperature (ECT), mass air flow (MAF), 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 TP sensor is at wide open throttle (WOT), the PCM reduces the fuel injector pulse width in order to increase the air to fuel ratio. The PCM 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 PCM 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 PCM ignores the signal from the heated oxygen sensors (HO2S). The PCM calculates the air/fuel ratio based on inputs from the ECT, MAF, MAP, and TP sensors. The system stays in Open Loop until meeting the following conditions

1. Both front HO2S have varying voltage output, showing that both HO2S are 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 PCM 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 PCM increases the pulse width to the injectors to provide extra fuel during acceleration. This is also known as power enrichment. The PCM determines the amount of fuel required based upon the TP, the ECT, the MAP, the MAF, and the engine speed.

Deceleration Mode

When the driver releases the accelerator pedal, air flow into the engine is reduced. The PCM monitors the corresponding changes in the TP, the MAP, and the MAF. The PCM 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 PCM 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 Cutoff Mode

The PCM 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 powertrain control module (PCM) controls the air/fuel metering system in order to provide the best possible combination of driveability, fuel economy, and emission control. The PCM monitors the HO2S signal voltage while in Closed Loop and regulates the fuel delivery by adjusting the pulse width of the fuel injectors based on this signal. The ideal fuel trim values are around 0 percent for both short term and long term fuel trim. A positive fuel trim value indicates the PCM is adding fuel in order to compensate for a lean condition by increasing the pulse width. A negative fuel trim value indicates that the PCM 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 short term and long 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 the fueling in order to re-center and restore control to short term fuel trim. A scan tool can be used to monitor the short term 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 PCM selects the cells based on the engine speed and engine load. If the PCM detects an excessive lean or rich condition, the PCM will set a fuel trim diagnostic trouble code (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 valve 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 restrictions to the purge path in the evaporative emission (EVAP) system. When the enabling criteria has been met, the control module commands the EVAP vent solenoid valve ON and the EVAP purge solenoid valve ON, allowing 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.

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 ignition OFF. Because of this, it may be normal for the control module to remain active for up to 40 minutes after the ignition is turned OFF. This is important to remember when performing a parasitic draw test on vehicles equipped with EONV.

The EONV 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 starts to drop. The EONV diagnostic relies on this temperature change and the corresponding pressure change in a sealed system, to determine if an EVAP system leak is present.

The EONV diagnostic is designed to detect leaks as small as 0.51 mm (0.020 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 (0.020 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 Valve 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

The control module sends a class 2 message to the driver information center (DIC) illuminating the Check Gas Cap message when a malfunction in the evaporative emission (EVAP) system and a large 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 EVAP purge solenoid valve controls the flow of vapors from the EVAP system to the intake manifold. The purge solenoid 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 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.

Electronic Ignition (EI) System Description

The electronic ignition (EI) system is responsible for producing and controlling 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 consists of a separate ignition coil connected to each spark plug by a short secondary wire. The driver modules within each coil assembly are commanded ON/OFF by the powertrain control module (PCM). The PCM primarily uses engine speed and position information from the crankshaft and camshaft position (CMP) sensors to control the sequence, dwell, and timing of the spark. The EI system consists of the following components

Crankshaft Position (CKP) Sensor

The crankshaft position (CKP) sensor is a three wire sensor based on the magneto resistive principle. A magneto resistive sensor uses two magnetic pickups between a permanent magnet. As an element such as a reluctor wheel passes the magnets the resulting change in the magnetic field is used by the sensor electronics to produce a digital output pulse. The PCM supplies a 12-volt, low reference, and signal circuit to the CKP sensor. The sensor returns a digital ON/OFF pulse 24 times per crankshaft revolution.

Crankshaft Reluctor Wheel

The crankshaft reluctor wheel is mounted on the rear of the crankshaft. The wheel is comprised of four 90 degree segments. Each segment represents a pair of cylinders at TDC, and is further divided into six 15 degree segments. Within each 15 degree segment is a notch of 1 of 2 different sizes. Each 90 degree segment has a unique pattern of notches. This is known as pulse width encoding. This pulse width encoded pattern allows the PCM to quickly recognize which pair of cylinders are at top dead center (TDC). The reluctor wheel is also a dual track-or mirror image-design. This means there is an additional wheel pressed against the first, with a gap of equal size to each notch of the mating wheel. When one sensing element of the CKP sensor is reading a notch, the other is reading a set of teeth. The resulting signals are then converted into a digital square wave output by the circuitry within the CKP sensor.

Camshaft Position (CMP) Sensor

The CMP sensor is also a magneto resistive sensor, with the same type of circuits as the CKP sensor. The CMP sensor signal is a digital ON/OFF pulse, output once per revolution of the camshaft. The CMP sensor information is used by the PCM to determine the position of the valve train relative to the CKP.

Camshaft Reluctor Wheel

The camshaft reluctor wheel is either pressed onto the camshaft or part of the timing gear depending on the application. The feature-or target- is read in a radial or axial fashion respectively. The wheel is a smooth track, half of which is of a lower profile than the other half. This feature allows the CMP sensor to supply a signal as soon as the key is turned ON, since the CMP sensor reads the track profile, instead of a notch.

Ignition Coils

Each ignition coil has an ignition 1 feed and a ground. The PCM supplies a low reference and an ignition control (IC) circuit. Each ignition coil contains a solid state driver module. The PCM will command the IC circuit ON, this allows the current to flow through the primary coil windings for the appropriate time or dwell. When the PCM commands the IC circuit OFF, this will interrupt current flow through the primary coil windings. The magnetic field created by the primary coil windings will collapse across the secondary coil windings, which induces a high voltage across the spark plug electrodes. The coils are current limited to prevent overloading if the IC current is held high too long. The spark plugs are connected to their respective coils by a short secondary wire. The spark plugs are tipped with iridium for long life and efficiency.

Powertrain Control Module (PCM)

The PCM controls all ignition system functions, and constantly corrects the basic spark timing. The PCM 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 mass air flow (MAF) sensor
4. The intake air temperature (IAT) sensor
5. The vehicle speed sensor (VSS)
6. The transmission gear position or range information sensors
7. The engine knock sensors (KS)

There is one normal mode of operation, with the spark under PCM control. If the CKP pulses are lost the engine will not run. The loss of a CMP signal may result in a longer crank time since the PCM cannot determine which stroke the pistons are on. Diagnostic trouble codes are available to accurately diagnose the ignition system with a scan tool.

Purpose

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

Sensor Description

This knock sensor (KS) system uses one or 2 broadband one-wire sensors. 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 dependant upon the level of knock that the KS detects. The control module receives the KS signal through a signal circuit. The KS ground is supplied by the engine block through the sensor housing.

One way the control module monitors the system is by output of a bias voltage on the KS signal wire. The bias voltage creates a voltage drop that the control module monitors and uses to help diagnose KS faults. The KS noise signal rides along this bias voltage, and due to the constantly fluctuating frequency and amplitude of the signal, will always be outside of the bias voltage parameters.

Another way the control module monitors the system is by learning the average normal noise output from the KS. The control module 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 control module uses the minimum noise level to calculate a noise channel. The control module uses this noise channel, and the KS signal that rides along the noise channel, in much the same way as the bias voltage type does. As engine speed and load change, the noise channel upper and lower parameters will change to accommodate the normal KS signal.

In order to determine which cylinders are knocking, the control module only uses KS signal information when each cylinder is near top dead center (TDC) of the firing stroke. If the control module has determined that knock is present, it will retard the ignition timing to attempt to eliminate the knock. The control module will always try to work back to a zero compensation level, or no spark retard. An abnormal KS signal will fall within the noise channel or will not be present. KS diagnostics are calibrated to detect faults with the KS circuitry inside the control module, the KS wiring, or the KS voltage output.

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) sensor is attached to the outlet of the air cleaner housing. The air cleaner life indicator is located on an intake duct between the air cleaner housing and the throttle plate.

Special Tools

Special Tools Illustration Tool Number/Description GE 41415-50 Fuel Tank Cap Adapter J 23738-A Mityvac J 26792 HEI Spark Tester J 34730-1A Fuel Pressure Gage J 34730-375 Harness Test Lamp J 34730-405 Injector Test Lamp J 35616 GM-Approved Terminal Test Kit J 35800-A Fuel Injector Cleaner J 37027-1A IAC Motor Driver J 37088-A Fuel Line Disconnect Tool Set J 37287 Fuel Line Shut-Off Adapters J 38522 Variable Signal Generator J 39021 Fuel Injector Coil and Balance Tester J 39021-380 Injector Tester Adapter J 39194-B Heated Oxygen Sensor Wrench J 41413 EVAP Pressure and Purge Station 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 42873-1 3/8 Fuel Line Shutoff Valve J 42873-2 5/16 Return Pipe Shutoff Valve J 42964-1 3/8 Fuel Pipe Shut-Off Valve J 42964-2 5/16 Fuel Pipe Shut-Off Valve J 44175 Fuel Composition Tester J 45722 Fuel Sender Lock Ring Wrench

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See also:
• DTC P0030, P0036, P0050, or P0056
• DTC P0135, P0141, P0155, or P0161
• DTC P0452
• DTC P2138
• Battery Negative Cable Disconnection and Connection
• Fastener Notice
• Control Module References
• Diagnostic Trouble Code (DTC) List - Vehicle
• Lifting and Jacking the Vehicle
• Draining and Filling Cooling System (Static Fill)
• Draining and Filling Cooling System (Vac N Fill)
• Engine Cover Replacement
• VEHICLE LIFTING CAUTION
• HEATED OXYGEN AND OXYGEN SENSOR NOTICE
• EXCESSIVE FORCE AND OXYGEN SENSOR NOTICE
• COMPONENT FASTENER TIGHTENING NOTICE
• Gasoline/Gasoline Vapors Caution
• Fuel Pressure Relief (With CH 48027)
• Fuel Pressure Relief (Without CH 48027)
• Fuel Tank Draining
• Plastic Collar Quick Connect Fitting Service
• Battery Disconnect Caution
• Road Test Caution
• Intake Manifold Replacement
• Fuel and Evaporative Emission Pipe Caution
• Air Cleaner Assembly Replacement
• Fuel Tank Draining (w/o L59)
• Fuel Tank Draining (L59)
• Special Tools
• Ignition System Specifications
• Crankshaft Position System Variation Learn