Engine Control System & Fuel System - 6.6l (Lmm) - Introduction (2 of 2) Chevrolet Chevy Express H1500

Temperature Versus Resistance (Exhaust Gas Temperature Sensor)

EGT 1 and 2 Sensors

Temperature Versus Resistance (Fuel Temperature Sensor)

Temperature Versus Resistance (Fuel Temperature Sensor)

Temperature Versus Resistance (IAT Sensor 1)

Temperature Versus Resistance (IAT Sensor 1)

Temperature Versus Resistance (ECT Sensors)

Temperature Versus Resistance (ECT Sensors)

Temperature Versus Resistance (IAT Sensor 2)

Temperature Versus Resistance (IAT Sensor 2)

Altitude Versus Barometric Pressure

Altitude Versus Barometric Pressure

Fastener Tightening Specifications

Fastener Tightening Specifications

What Fuel to Use in the United States

In the United States, for best results use Number 2-D diesel fuel year-round, above and below freezing conditions, as oil companies blend Number 2-D fuel to address climate differences. Number 1-D diesel fuel may be used in very cold temperatures when the temperature stays below -18°C (0°F). However, the fuel will produce a power and fuel economy loss. The use of Number 1-D diesel fuel in warm or hot climates may result in stalling, poor starting when the engine is hot and may damage the fuel injection system.

Diesel fuel may foam when filling the tank. This can cause the automatic pump nozzle to shut OFF, even though the tank is not full. If this happens, just wait for the foaming to stop and then continue to fill the tank.

What Fuel to Use in Canada

Canadian fuels are blended for seasonal changes. Diesel Type A fuel is blended for better cold weather starting, when it stays below -18°C (0°F). However, the fuel will produce a power and fuel economy loss. The use of Type A diesel fuel in warmer climates may result in stalling, poor starting. Diesel Type B fuel is blended for temperatures above -18°C (0°F). The emission control system requires the use of diesel fuel with low sulfur, 0.05 percent by weight, content. Both low and higher sulfur fuels will be available in Canada. Only low sulfur diesel fuels are available in the United States. Diesel-powered trucks must be refueled only with low sulfur fuel. Use of fuels with higher-sulfur content will affect the function of the emission components and may caused reduced performance, excessive smoke and unpleasant odor.

Very Cold Weather Operation

If the vehicle is driven in very cold temperatures and can not get a winterized Number 2-D that has been adapted to cold weather or a Number 1-D, use one gallon of kerosene for every 2 gallons of diesel fuel. Once you add kerosene, run the engine for several minutes to mix the fuels. Only add kerosene when the temperature falls below -18°C (0°F), because the fuel economy and lubricating qualities of kerosene is not as good as that of diesel fuel.

In cold weather, the fuel filter may become clogged (waxed). To unclog the filter, move the vehicle to a warm garage area and warm the filter to a temperature between 0-10°C (32-50°F). Replacing the filter is not necessary.

Fuel Specific Gravity Testing

Use a J 38641-B Diesel Fuel Quality Tester to measure the fuel specific gravity (API Rating). Follow the instructions on the tool to btain the proper temerpature-adjusted value. This information must be accurate for the proper diagnosis of the fuel system.

Fuel Injector Return Flow and Fuel Pressures

The fuel return from the fuel injectors to the tank will vary based on the API value of the fuel. Measure the Fuel API with the Diesel Fuel Quality Tester. For this reason the Fuel System Diagnosis - High Pressure Side values will vary for identifying a fuel injector or fuel pump concern. Use the following tables when referred to by the diagnostic. The first table is to be used during the initial diagnosis to identify the worst fuel injectors. After the fuel injectors that fail the first part of the test are capped off, the return flow from each uncapped fuel injector must be measured again. This is because the fuel system is returning less fuel to the tank, and thus the fuel pressure is higher during the retest. Failure to use the correct table may result in the replacement of good fuel injectors.

Initial Fuel Injector Return Flow Values

Retesting Fuel Injector Return Flow Values

Water in Fuel

Sometimes, water can be pumped into the fuel tank along with diesel fuel. This can happen if the service station does not regularly inspect and clean their fuel tanks, or the fuel gets contaminated for the service stations suppliers.

If water is pumped into the fuel tank, a water in fuel light will illuminate. If the water in fuel light illuminates, the excess water must be drained from the fuel system on the vehicle.

If the vehicle is driven in very cold temperatures and can not get a winterized Number 2-D that has been adapted to cold weather or a Number 1-D, use one gallon of kerosene for every 2 gallons of diesel fuel. Once you add kerosene, run the engine for several minutes to mix the fuels. Only add kerosene when the temperature falls below -18°C (0°F), because the fuel economy and lubricating qualities of kerosene is not as good as that of diesel fuel.

In cold weather, the fuel filter may become clogged (waxed). To unclog the filter, move the vehicle to a warm garage area and warm the filter to a temperature between 0-10°C (32-50°F). Replacing the filter is not necessary.

Scheme 145

Engine Controls Schematic Icons

Engine Controls Schematic Icons Icon Icon Definition IMPORTANT: Twisted-pair wires provide an effective shield that helps protect sensitive electronic components from electrical interference. If the wires were covered with shielding, install new shielding. In order to prevent electrical interference from degrading the performance of the connected components, you must maintain the proper specification when making any repairs to the twisted-pair wires shown : The wires must be twisted a minimum of 9 turns per 31 cm (12 in) as measured anywhere along the length of the wires The outside diameter of the twisted wires must not exceed 6.0 mm (0.25 in)

Scheme 146

Scheme 147

Scheme 148

Scheme 149

Scheme 150

Scheme 151

Scheme 152

Scheme 153

Scheme 154

Scheme 155

Scheme 156

Scheme 157

Scheme 158

Scheme 159

Scheme 160

Scheme 161

Scheme 162

Scheme 163

Scheme 164

Scheme 165

Scheme 166

Scheme 167

Scheme 168

Engine Control Module (ECM) - C1 Connector & Terminal Parts Information

Engine Control Module (ECM) - C1 Terminal Identification

Scheme 169

Engine Control Module (ECM) - C2 Connector & Terminal Parts Information

Engine Control Module (ECM) - C2 Terminal Identification

Scheme 170

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

Accelerator Pedal Position (APP) Sensor Terminal Identification

Scheme 171

Camshaft Position (CMP) Sensor Connector & Terminal Parts Information

Camshaft Position (CMP) Sensor Terminal Identification

Crankshaft Position (CKP) Sensor

Crankshaft Position (CKP) Sensor Connector & Terminal Parts Information

Crankshaft Position (CKP) Sensor Terminal Identification

Scheme 172

DPF Differential Pressure Sensor Connector & Terminal Parts Information

DPF Differential Pressure Sensor Terminal Identification

Scheme 173

Engine Coolant Temperature (ECT) Sensor 1 Connector & Terminal Parts Information

Engine Coolant Temperature (ECT) Sensor 1 Terminal Identification

Engine Coolant Temperature (ECT) Sensor 2

Engine Coolant Temperature (ECT) Sensor 2 Connector & Terminal Parts Information

Engine Coolant Temperature (ECT) Sensor 2 Terminal Identification

Scheme 174

Exhaust Gas Recirculation (EGR) Valve Connector & Terminal Parts Information

Exhaust Gas Recirculation (EGR) Valve Terminal Identification

Exhaust Gas Temperature (EGT) Sensor 1

Exhaust Gas Temperature (EGT) Sensor 1 Connector & Terminal Parts Information

Exhaust Gas Temperature (EGT) Sensor 1 Terminal Identification

Exhaust Gas Temperature (EGT) Sensor 2

Exhaust Gas Temperature (EGT) Sensor 2 Connector & Terminal Parts Information

Exhaust Gas Temperature (EGT) Sensor 2 Terminal Identification

Scheme 175

Fuel Heater Connector & Terminal Parts Information

Fuel Heater Terminal Identification

Scheme 176

Fuel Injector 1 Connector & Terminal Parts Information

Fuel Injector 1 Terminal Identification

Fuel Injector 2

Fuel Injector 2 Connector & Terminal Parts Information

Fuel Injector 2 Terminal Identification

Fuel Injector 3

Fuel Injector 3 Connector & Terminal Parts Information

Fuel Injector 3 Terminal Identification

Fuel Injector 4

Fuel Injector 4 Connector & Terminal Parts Information

Fuel Injector 4 Terminal Identification

Fuel Injector 5

Fuel Injector 5 Connector & Terminal Parts Information

Fuel Injector 5 Terminal Identification

Fuel Injector 6

Fuel Injector 6 Connector & Terminal Parts Information

Fuel Injector 6 Terminal Identification

Fuel Injector 7

Fuel Injector 7 Connector & Terminal Parts Information

Fuel Injector 7 Terminal Identification

Fuel Injector 8

Fuel Injector 8 Connector & Terminal Parts Information

Fuel Injector 8 Terminal Identification

Fuel Pressure Regulator

Fuel Pressure Regulator Connector & Terminal Parts Information

Fuel Pressure Regulator Terminal Identification

Scheme 177

Fuel Pump Connector & Terminal Parts Information

Fuel Pump Terminal Identification

Scheme 178

Fuel Rail Pressure (FRP) Sensor Connector & Terminal Parts Information

Fuel Rail Pressure (FRP) Sensor Terminal Identification

Scheme 179

Fuel Rail Temperature (FRT) Sensor Connector & Terminal Parts Information

Fuel Rail Temperature (FRT) Sensor Terminal Identification

Scheme 180

Glow Plug Control Module (GPCM) - C1 Connector & Terminal Parts Information

Glow Plug Control Module (GPCM) - C1 Terminal Identification

Scheme 181

Glow Plug Control Module (GPCM) - C2 Connector & Terminal Parts Information

Glow Plug Control Module (GPCM) - C2 Terminal Identification

Scheme 182

High Idle Switch (UF3) Connector & Terminal Parts Information

High Idle Switch (UF3) Terminal Identification

Scheme 183

Intake Air (AI) Flow Valve Connector & Terminal Parts Information

Intake Air (AI) Flow Valve Terminal Identification

Scheme 184

Intake Air Heater (IAH) Module Connector & Terminal Parts Information

Intake Air Heater (IAH) Module Terminal Identification

Scheme 185

Intake Air Temperature (IAT) Sensor 2 Connector & Terminal Parts Information

Intake Air Temperature (IAT) Sensor 2 Terminal Identification

Scheme 186

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

Manifold Absolute Pressure (MAP) Sensor Terminal Identification

Scheme 187

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

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

Scheme 188

Turbocharger Vane Position Control Solenoid Valve Connector & Terminal Parts Information

Turbocharger Vane Position Control Solenoid Valve Terminal Identification

Scheme 189

Turbocharger Vane Position Sensor Connector & Terminal Parts Information

Turbocharger Vane Position Sensor Terminal Identification

DIAGNOSTIC CODE INDEX

DIAGNOSTIC CODE INDEX

Engine Control Module Replacement

Service of the engine control module (ECM) should consist of either replacement of the ECM or programming of the electrically erasable programmable read only memory (EEPROM). If the diagnostic procedures call for the ECM to be replaced, the replacement ECM should be checked to ensure that the correct part is being used. If the correct part is being used, remove the faulty ECM and install the new service ECM.

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, capture the ECM data.
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. Remove the washer solvent container. Refer to «Washer Solvent Container Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/wiperwasher-systems/#wiper-system-washer-system) .
4. Disconnect the ECM electrical connectors.
5. Release the ECM upper retaining tabs.
6. Remove the ECM from the bracket.

Installation Procedure

1. Place the bottom edge of the ECM into the bracket lower retainers.
2. Push the ECM towards the bracket until the upper edge of the ECM snaps into place.
3. Connect the ECM electrical connectors.
4. Install the washer solvent container. Refer to «Washer Solvent Container Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/wiperwasher-systems/#wiper-system-washer-system) .
5. 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) .
6. If a NEW ECM was installed, program the ECM. Refer to «Control Module References»(/chevrolet/chevy-express-h1500/2003-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) .
7. Perform the turbocharger learn procedure. Refer to «Turbocharger Learn»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lbz-and-lly-introduction-2-of-2__turbocharger-learn) .

Before Programming a Control Module

Ensure the following conditions are met before programming a control module

1. Vehicle system voltage There is no charging system concern. All charging system concerns must be repaired before programming a control module. Battery voltage is greater than 12 volts but less than 16 volts. The battery must be charged before programming the control module if the battery voltage is low. A battery charger is NOT connected to the vehicle's battery. Incorrect system voltage or voltage fluctuations from a battery charger, may cause programming failure or control module damage. Turn OFF or disable any system that may put a load on the vehicle's battery. Twilight sentinel Interior lights Daytime running lights (DRL)-Applying the parking brake, on most vehicles, disables the DRL system. Refer to the Owner's Manual. HVAC systems Engine cooling fans, etc.
2. The ignition switch is in the proper position. The scan tool prompts you to turn ON the ignition, with the engine OFF. DO NOT change the position of the ignition switch during the programming procedure, unless instructed to do so.
3. All tool connections are secure. The connection at the data link connector (DLC) Voltage supply circuits
4. DO NOT disturb the tool harnesses while programming. If an interruption occurs during the programming procedure, programming failure or control module damage may occur.

High Idle Switch Programming

1. Using the Tech 2, select Module Setup/PTO Options
2. Use soft keys to select desired settings.
3. When setting selections are complete, select Reprogram.
4. Turn OFF the ignition until communication with the ECM is lost, as indicated on the scan tool.
5. Start the vehicle and confirm the new settings by operating the high idle switch.

Circuit/System Description

The control functions for the fuel injection system are integrated in the engine control module (ECM). Each injector's flow rate information and cylinder position are stored in the memory of both the glow plug control module (GPCM) and the ECM. The fuel injector flow rate programming must be done when any of the following procedures are performed

1. The ECM is replaced
2. The GPCM is replaced
3. Any fuel injectors are replaced

If the ECM does not communicate, the flow rate information can be retrieved from the GPCM. If both control modules fail to communicate, the fuel injector flow rate information, or injection quantity adjustment (IQA) flow rate numbers, will need to be retrieved from each individual injector.

Ensure the following conditions are met before programming a control module

1. Vehicle system voltage There is no charging system concern. All charging system concerns must be repaired before programming a control module. Battery voltage is between 12-16 volts. The battery must be charged before programming the control module if the battery voltage is low. A battery charger is NOT connected to the vehicle battery. Incorrect system voltage or voltage fluctuations from a battery charger may cause programming failure or control module damage. Turn OFF or disable any of the following systems that may put a load on the vehicle battery: Twilight sentinel Interior lights Daytime running lights (DRL)-Applying the parking brake, on most vehicles, disables the DRL system. Refer to the Owner's Manual. HVAC systems Engine cooling fans, etc.
2. The ignition switch is in the proper position-The scan tool prompts you to turn ON the ignition, with the engine OFF. DO NOT change the position of the ignition switch during the programming procedure, unless instructed to do so.
3. All of the following tool connections are secure: The connection at the data link connector (DLC) The voltage supply circuits
4. DO NOT disturb the tool harnesses while programming. If an interruption occurs during the programming procedure, programming failure or control module damage may occur.

Circuit/System Verification

Review the Display ECM & GPCM Inj. Flow Rates parameter with a scan tool. All cylinders should be programmed with a flow rate number. Both the GPCM and the ECM should be programmed with the same flow rate numbers for the corresponding cylinders.

Circuit/System Testing

Scheme 190

1. With a scan tool installed, enter the vehicle information and select the following options: Engine Control Module Module Setup Injector Flow Rate Programming Display ECM & GPCM Inj. Flow Rates
2. Record all flow rate numbers with the corresponding cylinders from the control modules. IMPORTANT: When installing a new fuel injector, ensure that the IQA data number from the yellow IQA Data Tag, shipped with the new injector, is programmed to the correct cylinder If any injectors are replaced, go to Reprogram Injector Flow Rates parameter and enter the flow rate number of the new injector to the corresponding cylinder. The flow rate numbers will automatically update both control modules. If the ECM was replaced, go to Copy GPCM Inj. Flow Rates to ECM parameter and reprogram the ECM. This will update the ECM with the GPCM flow rate numbers. If the GPCM was replaced or the flow rate numbers are not the same for both modules, go to Copy ECM Inj. Flow Rates to GPCM parameter and reprogram the GPCM. This will update the GPCM with the ECM flow rate numbers. If both control modules were replaced, go to Reprogram Injector Flow Rates parameter and enter the previously recorded flow rate numbers or the numbers retrieved from each individual injector, to the corresponding cylinders.

Repair Procedures

1. Install any components or connectors that have been removed or replaced during diagnosis.
2. Perform any adjustment, programming or setup procedures that are required when a component or module is removed or replaced.
3. Turn OFF the ignition for 60 seconds.
4. Turn ON the ignition, with the engine OFF.
5. Clear the DTCs.
6. If the repair was related to a DTC, duplicate the Conditions for Running the DTC and use the Freeze Frame/Failure Records, if applicable, in order to verify the DTC does not reset. If the DTC resets or another DTC is present, refer to the «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-trouble-code-dtc-list) and perform the appropriate diagnostic procedure. OR If the repair was symptom related, duplicate the conditions under which the customer concern occurred to verify the repair. If the customer concern reoccurs, return to «Symptoms - Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/oem-general-information/#vehicle-diagnostic-information) and perform the appropriate symptom diagnostic.

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

1. Remove the intake manifold tube. Refer to «Intake Manifold Tube Replacement (LLY, LBZ)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Intake Manifold Tube Replacement (LMM)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
2. Drain the coolant to a level below the engine coolant temperature (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) .
3. Disconnect the engine wiring harness electrical connector(s) (1) from the appropriate ECT sensor (s).
4. Remove the appropriate ECT sensor(s) (1).

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

1. If installing the old sensor(s), coat the threads with sealant GM P/N 12346004 (Canadian P/N 10953480), or equivalent.
2. Install the appropriate ECT sensor(s) (1). Tighten: Tighten the sensor(s) to 20 N.m (15 lb ft).
3. Connect the engine wiring harness electrical connector(s) (1) to the appropriate ECT sensor(s).
4. Fill the cooling system, if necessary. 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) .
5. Install the intake manifold tube. Refer to «Intake Manifold Tube Replacement (LLY, LBZ)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Intake Manifold Tube Replacement (LMM)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .

1. Disconnect the mass air flow (MAF)/intake air temperature (IAT) sensor electrical connector.
2. Remove the MAF/IAT sensor TORX® screws.
3. Remove the MAF/IAT sensor.

1. Install the MAF/IAT sensor.
2. Install the MAF/IAT sensor TORX® screws. Tighten: Tighten the screws to 8 N.m (70 lb in).
3. Connect the MAF/IAT sensor electrical connector.

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 air intake pipe. Refer to «Air Intake Pipe Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
3. Disconnect the intake air temperature (IAT) sensor (2) electrical connector.
4. Remove the IAT sensor from the center intake manifold.

1. Install the IAT sensor to the center intake manifold. Tighten: Tighten the IAT to 25 N.m (18 lb ft).
2. Connect the IAT sensor (2) electrical connector.
3. Install the air intake pipe. Refer to «Air Intake Pipe Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
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) .

1. Remove the charge air cooler outlet pipe. Refer to «Charged Air Cooler Hoses/Pipes Replacement (Inlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Charged Air Cooler Hoses/Pipes Replacement (Outlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
2. Disconnect the engine wiring harness electrical connector (2) from the intake air valve.
3. Remove the intake air valve bolts and valve.

1. Position the intake air valve to the IAH and install the intake air valve bolts. Tighten: Tighten the bolts to 20 N.m (15 lb ft).
2. Connect the engine wiring harness electrical connector (2) to the intake air valve.
3. Install the charge air cooler outlet pipe. Refer to «Charged Air Cooler Hoses/Pipes Replacement (Inlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Charged Air Cooler Hoses/Pipes Replacement (Outlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .

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 charge air cooler outlet pipe. Refer to «Charged Air Cooler Hoses/Pipes Replacement (Inlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Charged Air Cooler Hoses/Pipes Replacement (Outlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
3. Disconnect the engine wiring harness electrical connector (1) from the intake air heater (IAH).
4. Disconnect the engine wiring harness electrical connector (2) from the intake air valve.
5. Remove the nut and the positive battery cable from the IAH.
6. Remove the intake air valve bolts and valve.
7. Remove the IAH and remove and discard the IAH gasket.

1. Position a NEW IAH gasket to the intake manifold tube and position the IAH to the intake manifold tube.
2. Position the intake air valve to the IAH and install the intake air valve bolts. Tighten: Tighten the bolts to 20 N.m (15 lb ft).
3. Install the positive battery cable and nut to the IAH. Tighten: Tighten the nut to 4 N.m (34 lb in).
4. Connect the engine wiring harness electrical connector (2) to the intake air valve.
5. Connect the engine wiring harness electrical connector (1) from the intake air heater (IAH).
6. Install the charge air cooler outlet pipe. Refer to «Charged Air Cooler Hoses/Pipes Replacement (Inlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Charged Air Cooler Hoses/Pipes Replacement (Outlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
7. 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) .

1. Remove the air cleaner outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
2. Disconnect the manifold absolute pressure (MAP) sensor electrical connector.
3. Remove the MAP sensor bolt.
4. Remove the MAP sensor bracket and sensor.

1. Install the MAP sensor and bracket.
2. Install the MAP sensor bolt. Tighten: Tighten the MAP sensor to 10 N.m (89 lb in).
3. Connect the MAP sensor electrical connector (2).
4. Install the air cleaner outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .

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. Install the CPA retainer.
6. Connect a scan tool in order to test for proper throttle-opening and throttle-closing range.
7. 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).
8. 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.
9. Inspect the carpet fit under the accelerator pedal.

Metal Collar Quick Connect Fitting Service

Tools Required

1. J 44581 Fuel Line Disconnect Tool
2. J 43178 Fuel Line Disconnect Tool

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 fill cap.
3. Remove the retainers from the fuel feed and return pipe quick connect fittings.
4. Using compressed air, blow any dirt or debris from around the fitting.
5. Using the correct end of J 44581 for the size of the fitting. Insert J 44581 into the female connector, then push inward in order to release the locking tabs.
6. If the vehicle is a cab/chassis, it may be necessary to use J 43178 in order to release the quick connect fittings at the sending unit.
7. Pull the connection apart.
8. Use a clean shop towel in order to wipe off the male end. NOTE: If necessary, remove rust or burrs from the fuel pipes with an emery cloth. Use a radial motion with the fuel pipe end in order to prevent damage to the O-ring sealing surface. Use a clean shop towel in order to wipe off the male tube ends. Inspect all the connections for dirt and burrs. Clean or replace the components and assemblies as required.
9. 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 connection end.
2. Push both sides of the fittings together in order to snap the retaining tabs into place.
3. Once installed, pull on both sides of the connections in order to make sure the connection is secure.
4. Install the retainers to the fuel feed/return pipes.
5. Install the fuel fill cap.
6. 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) .

Disconnect Procedure

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. Using compressed air, blow any dirt or debris from around the connection.
3. This step applies to Bartholomew style connector ONLY. Squeeze the plastic quick connect fitting release tabs.
4. This step applies to Release Tab style connector ONLY. Release the fitting by pushing the tab toward the other side of the slot in the fitting.
5. This step applies to the Squeeze to Release style connector ONLY. Squeeze where indicated by the arrows shown above on both sides of the plastic ring surrounding the quick connect fitting.
6. This step applies to the Sliding Retainer style connector ONLY. Release the fitting by pressing on one side of the release tab causing it to push in slightly. If the tab does not move try pressing the tab in from the opposite side. The tab will only move in one direction.
7. This step applies to the Push Down TI style connector ONLY. Release the fitting by pressing on the tab indicated by the arrow.
8. Pull the connection apart.

Connect Procedure

1. Apply a few drops of clean engine oil to the male connection end.
2. Push both sides of the quick-connect fitting together in order to cause the retaining feature to snap into place.
3. Once installed, pull on both sides of the connection in order to make sure the connection is secure.
4. Install the fuel fill cap.
5. 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) .

Fuel System Priming

1. Prior to priming the engine, ensure that the following has been completed: There is fuel in the fuel tank. The fuel filter has been installed and properly tightened. The fuel lines are properly connected. The fuel filter is cool to the touch. Any dirt or debris has been removed from the fuel filter head and vent valve.
2. Turn the ignition key on for two minutes. The fuel pump will be operating and starting the priming process. Do not start the engine during the first two minutes.
3. After completing the initial prime in step 2, turn the ignition off, then back to start and crank the engine for 15 seconds.
4. If the engine does not start, repeat steps 2 and 3 until the engine starts.
5. If the engine does not run after repeating steps 2 and 3 three times, turn the ignition key OFF for 60 seconds, allowing the electronic control module (ECM) to reset.
6. Repeat the above steps until the engine starts.
7. If the engine runs, but does not run smoothly, increase the engine speed slightly by pressing the accelerator pedal. This will help to force out air through the system.
8. If the engine starts and runs but stalls again, turn the ignition key OFF for 60 seconds to reset the ECM and repeat the steps above.
9. Start the engine and allow it to idle for a few minutes.
10. Check the filter for leaks.

1. Drain the fuel from the filter assembly. Refer to «Water-in-Fuel Draining»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__water-in-fuel-draining) .
2. Disconnect the fuel lines from the filter assembly.
3. Disconnect the electrical connectors.
4. Remove the diesel fuel conditioning module (DFCM) lower housing from the DFCM.
5. Disconnect filter assembly from the bracket.
6. Remove the filter assembly.

1. Install the filter assembly.
2. Bolt the filter assembly to the bracket.
3. Connect the electrical connectors.
4. Connect the fuel lines.
5. Install the filter assembly lower housing.
6. Prime the fuel system.
7. Start the vehicle and inspect for leaks.

1. Drain the fuel from the primary filter and the diesel fuel conditioning module (DFCM). Refer to «Water-in-Fuel Draining»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__water-in-fuel-draining) .
2. Unscrew the primary fuel filter.
3. Unscrew the DFCM lower housing.
4. Remove both filters.

1. Install the new O-ring seal to the DFCM lower housing.
2. Install the DFCM lower housing.
3. Install the new O-ring seals to the primary filter.
4. Install the primary filter.
5. Prime the fuel system. Refer to «Fuel System Priming»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__fuel-system-priming) .
6. Start the engine and check for leaks.

1. Drain the fuel from the diesel fuel conditioning module (DFCM). Refer to «Water-in-Fuel Draining»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__water-in-fuel-draining) .
2. Unbolt the DFCM from the bracket and secure out of the way.
3. Unbolt the DFCM brackets from the frame.
4. Remove the bracket.

1. Install the bracket.
2. Bolt the DFCM to the bracket.
3. Prime the fuel system.
4. Start the engine and check for leaks.

1. Drain the fuel from the secondary filter. Refer to «Water-in-Fuel Draining»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__water-in-fuel-draining) .
2. Disconnect the fuel hose.
3. Remove the secondary filter.
4. Remove the secondary fuel filter housing nuts.
5. Remove the secondary fuel filter bracket.

1. Install the secondary fuel filter bracket.
2. Install the secondary fuel filter housing bolts and nuts.
3. Install the secondary filter.
4. Install the fuel hose.
5. Prime the fuel system.
6. Start the engine and check for leaks.

1. Drain the fuel from the fuel filter. Refer to «Water-in-Fuel Draining»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__water-in-fuel-draining) .
2. Disconnect the electrical connectors.
3. Disconnect the diesel fuel conditioning module lower assembly.

1. Connect the diesel fuel conditioning module lower assembly.
2. Connect the electrical connector.
3. Prime the fuel system. Refer to «Fuel System Priming»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__fuel-system-priming) .
4. Start the engine. If the engine stalls, repeat the above step.
5. Once the engine starts, inspect for fuel leaks.

Water-in-Fuel Draining

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .
2. Attach a small piece of hose to the drain cock onto the water-in-fuel sensor.
3. Place an approved fuel-resistant container under the fuel filter.
4. Open the drain cock 3 or 4 turns or until the water contaminated fuel seeps from the drain cock.
5. Prime the fuel system until only diesel fuel is visible. Refer to «Fuel System Priming»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__fuel-system-priming) .
6. Tighten the drain cock.
7. Remove the container and hose.

Fuel Tank Draining

Tools Required

J 45004 Fuel Tank Siphon Hose

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 fill cap.
3. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .
4. Loosen the fuel fill pipe clamp (1).
5. Remove the fuel fill pipe from the fuel tank.
6. Insert the J 45004 hose into the tank.
7. Attach the J 45004 hose to the hose used with the hand or air operated pump devise.
8. Using a hand or air operated pump drain as much fuel from the tank as possible.

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. Drain the fuel tank. Refer to «Fuel Tank Draining»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__fuel-tank-draining) .
3. Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .
4. Disconnect the fuel fill hose (1) from the fuel tank.
5. Disconnect the fuel fill vent hose (2) from the fuel tank.
6. 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.
7. 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-66l-lmm-introduction-2-of-2) .
8. 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-66l-lmm-introduction-2-of-2) .
9. With the aid of an assistant, support the fuel tank.
10. Remove the attaching bolts (4) from the fuel tank strap. Discard attaching bolts.
11. Remove the fuel tank straps (3).
12. Carefully lower the fuel tank.
13. Disconnect the fuel sender and the fuel pressure sensor electrical connectors.
14. Remove the fuel tank.
15. Place the fuel tank in a suitable work area.
16. Remove the fuel sender assembly and the fuel pipes (6) from the fuel tank. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
17. On models with the evaporative emission (EVAP) canister attached to the fuel tank, remove the (EVAP) hoses from the fuel tank and (EVAP) canister (2).
18. Remove 2 tie-down straps from the (EVAP) canister (2) then remove the canister from the fuel tank. Discard tie-down straps.
19. On all models, remove the fuel fill hose from the fuel tank.
20. Remove the fuel tank from the fuel tank shield.

1. Install the fuel tank insulators (3).
2. Install the fuel tank into the fuel tank shield.
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. On models with the evaporative emission (EVAP) canister attached to the fuel tank, position the EVAP canister to the fuel tank, then install two new tie-down straps to the (EVAP) canister.
5. Install the (EVAP) hoses to the fuel tank and (EVAP) canister.
6. Install the fuel sender assembly and the fuel pipes (6) to the fuel tank and the fuel filter. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
7. With the aid of an assistant, position and support the fuel tank.
8. Raise the fuel tank slightly.
9. Connect the electrical connectors to the fuel sender and the fuel pressure sensor.
10. Raise the tank fully.
11. Install the fuel tank straps (3).
12. Install the new attaching bolts (4) to the fuel tank straps. Tighten: Tighten the bolts to 20.5 N.m (15 lb ft).
13. Connect the rear fuel feed pipe to 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-66l-lmm-introduction-2-of-2) .
14. 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-66l-lmm-introduction-2-of-2) .
15. Connect the fuel fill vent hose (2) to the fuel tank.
16. Connect the fuel fill hose (1) to the fuel fill pipe. Tighten: Tighten the fuel fill hose clamp to 2.75 N.m (24 lb in).
17. Lower the vehicle.
18. Refill the fuel tank.
19. Tighten the fuel filler cap.
20. 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)
21. Prime the fuel system. Refer to «Fuel System Priming»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__fuel-system-priming) .

1. Remove the sending unit. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
2. Disconnect the fuel level sensor electrical connector (1).
3. Remove the sensor retaining clip (3).
4. Squeeze the locking tangs (2) and remove the fuel level sensor.

1. Install the fuel level sensor.
2. Install the sensor retaining clip (3).
3. Connect the sensor electrical connector (1).
4. Install the sending unit. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .

Tools Required

J 45722 Fuel Sender Lock Ring Wrench

1. Remove the fuel tank. Refer to «Fuel Tank Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
2. Use the J 45722 and a long breaker-bar in order to unlock the fuel sender lock ring.
3. Remove the sending unit and seal. Discard the seal.
4. Clean the sending unit sealing surfaces.
5. 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.
6. If warpage is less than 0.41 mm (0.016 in), the lock ring does not require replacement.
7. If warpage is greater than 0.41 mm (0.016 in), the lock ring must be replaced.

1. Install the sending unit and a NEW seal.
2. Use the J 45722 in order to install the fuel sender lock ring. Turn the fuel sender lock ring in a clockwise direction.
3. Install the fuel tank. Refer to «Fuel Tank Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .

1. Drain the fuel from the filter.
2. Drain the fuel from the diesel fuel conditioning module. Refer to «Water-in-Fuel Draining»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__water-in-fuel-draining) .
3. Remove the hose clamps.
4. Remove the hose.

1. Install the hose.
2. Install the hose clamps.

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 fuel feed and return lines. Refer to «Metal Collar Quick Connect Fitting Service»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__metal-collar-quick-connect-fitting-service) .
3. Remove the fuel line bracket nut.
4. Remove the fuel line bracket from the stud.
5. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .
6. Remove the fuel bundle clips (2) from the transmission brackets (1).
7. Disconnect the chassis harness from the retaining clips.
8. Remove the fuel system cooler, if necessary. Refer to «Fuel Cooler Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
9. Disconnect the fuel feed and return lines from the fuel tank lines. Refer to «Plastic Collar Quick Connect Fitting Service»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
10. Remove the fuel bundle nuts from the chassis.
11. Loosen the electronic brake control module (EBCM) bracket bolts (4).
12. Allow the EBCM to remain loose in order to allow fuel pipe clearance.
13. Remove the fuel bundle using the following procedure: Guide the fuel bundle pipes towards the rear of vehicle to clear the engine. Lower the fuel bundle while moving it foreword and out.

1. Install the fuel pipe bundle using the following procedure: Install the fuel bundle to the chassis by guiding the pipes towards the rear of vehicle. Lift the fuel pipes, while guiding the forward portion of the pipes up towards the engine connections.
2. Install the fuel bundle nuts to the chassis. Tighten: Tighten the nuts to 16 N.m (12 lb ft).
3. Connect the fuel feed and return lines to the fuel tank lines. Refer to «Plastic Collar Quick Connect Fitting Service»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
4. Install the fuel system cooler, if necessary. Refer to «Fuel Cooler Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
5. Connect the fuel bundle clips (2) to the transmission brackets (1).
6. Tighten the EBCM bracket bolts (4). Tighten: Tighten the bolts to 25 N.m (18 lb ft).
7. Lower the vehicle.
8. Install the fuel line bracket to the stud.
9. Install the fuel line bracket nut. Tighten: Tighten the nut to 16 N.m (12 lb ft).
10. Connect the fuel feed and return lines. Refer to «Metal Collar Quick Connect Fitting Service»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__metal-collar-quick-connect-fitting-service) .
11. Prime the fuel system. Refer to «Fuel System Priming»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__fuel-system-priming) .
12. Start the engine. If the engine stalls, repeat the above step.
13. Once the engine starts, inspect for fuel leaks.
14. 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 engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .
2. Remove the charge air inlet pipe. Refer to «Charged Air Cooler Hoses/Pipes Replacement (Inlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Charged Air Cooler Hoses/Pipes Replacement (Outlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
3. Remove the engine wiring harness bracket bolts (2), position the wiring harness and bracket aside.
4. Remove the fuel return hose clips (1).
5. Disconnect the fuel return hose from the injectors.
6. Disconnect the fuel return hose from the fuel line.

1. Connect the fuel return hose to the fuel line.
2. Connect the fuel return hose to the injectors.
3. Install the fuel return hose clips (1).
4. Position the wiring harness and bracket. Install the engine wiring harness bracket bolts (2).
5. Install the charge air inlet pipe. Refer to «Charged Air Cooler Hoses/Pipes Replacement (Inlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Charged Air Cooler Hoses/Pipes Replacement (Outlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
6. 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 engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .
2. Remove the generator. Refer to «Generator Replacement (6.6L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
3. Remove the fuel return hose clips (1).
4. Disconnect the fuel return hose from the injectors.
5. Disconnect the fuel return hose from the fuel line.

1. Connect the fuel return hose to the fuel line.
2. Connect the fuel return hose to the injectors.
3. Install the fuel return hose clips (1).
4. Install the generator. Refer to «Generator Replacement (6.6L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
5. Install the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .

Fuel Feed Pipe Replacement

Tools Required

1. J 43178 Fuel Line Disconnect Tool
2. J 44581 Fuel Line Disconnect Tool

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 charge air cooler inlet pipe. Refer to «Charged Air Cooler Hoses/Pipes Replacement (Inlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Charged Air Cooler Hoses/Pipes Replacement (Outlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
3. Remove the center intake manifold. Refer to «Intake Manifold Tube Replacement (LLY, LBZ)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Intake Manifold Tube Replacement (LMM)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
4. Using the J 43178 and J 44581 disconnect the fuel feed and return pipes.
5. Remove the fuel line bracket bolt.
6. Disconnect the electrical connectors.
7. Remove the nut, the 2 bolts, and position the bracket aside.
8. Disconnect the fuel rail temperature (FRT) sensor electrical connector.
9. Compress the clamp and disconnect the fuel pressure relief valve hose from the fuel pump.
10. Compress the clamp (1) and disconnect the fuel feed pipe from the fuel injector pump.
11. Remove the fuel feed pipe bracket bolt (2).
12. Remove the fuel feed block bolt and remove the fuel feed pipe.

1. Position the fuel feed pipe and install the fuel feed block bolt.
2. Install the fuel feed pipe bracket bolt (2). Tighten: Tighten the bolts to 25 N.m (18 lb ft).
3. Compress the clamp (1) and connect the fuel feed pipe to the fuel injector pump.
4. Compress the clamp and connect the fuel pressure relief valve hose to the fuel feed pipe.
5. Connect the FRT sensor electrical connector.
6. Position the bracket and install the nut and 2 bolts. Connect the electrical connectors.
7. Install the fuel line bracket bolt. Tighten: Tighten the bolts to 25 N.m (18 lb ft).
8. Connect the fuel feed and return pipes.
9. Install the center intake manifold. Refer to «Intake Manifold Tube Replacement (LLY, LBZ)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Intake Manifold Tube Replacement (LMM)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
10. Install the charge air cooler inlet pipe. Refer to «Charged Air Cooler Hoses/Pipes Replacement (Inlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Charged Air Cooler Hoses/Pipes Replacement (Outlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
11. Prime the fuel system. Refer to «Fuel System Priming»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__fuel-system-priming) .
12. Start the engine. If the engine does not start, repeat the above step.
13. Inspect the fuel system for fuel leaks.
14. Install the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .

Fuel Return Pipe Replacement

Tools Required

1. J 43178 Fuel Line Disconnect Tool
2. J 44581 Fuel Line Disconnect Tool

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 charge air cooler inlet pipe. Refer to «Charged Air Cooler Hoses/Pipes Replacement (Inlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Charged Air Cooler Hoses/Pipes Replacement (Outlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
3. Remove the center intake manifold. Refer to «Intake Manifold Tube Replacement (LLY, LBZ)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Intake Manifold Tube Replacement (LMM)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
4. Using the J 43178 and J 44581 , disconnect the fuel feed and return pipes.
5. Remove the fuel line bracket bolt.
6. Remove the fuel line bracket bolt (1).
7. Remove the fuel line bracket bolt.
8. Disconnect the fuel rail temperature (FRT) sensor electrical connector.
9. Compress the clamp and disconnect the hose from the fuel return line.
10. Disconnect the left fuel return hose from the fuel return pipe.
11. Disconnect the right fuel return hose from the fuel return pipe.
12. Remove the fuel return pipe from the vehicle.

1. Install the fuel return pipe from the vehicle.
2. Connect the right fuel return hose to the fuel return pipe.
3. Connect the left fuel return hose to the fuel return pipe.
4. Compress the clamp and connect the hose to the fuel return line.
5. Connect the FRT sensor electrical connector.
6. Install the fuel line bracket bolt. Tighten: Tighten the bolt to 25 N.m (18 lb ft).
7. Install the fuel line bracket bolt (1). Tighten: Tighten the bolt to 25 N.m (18 lb ft).
8. Install the fuel line bracket bolt. Tighten: Tighten the bolt to 25 N.m (18 lb ft).
9. Connect the fuel feed and return pipes.
10. Install the center intake manifold. Refer to «Intake Manifold Tube Replacement (LLY, LBZ)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Intake Manifold Tube Replacement (LMM)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
11. Install the charge air cooler inlet pipe. Refer to «Charged Air Cooler Hoses/Pipes Replacement (Inlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Charged Air Cooler Hoses/Pipes Replacement (Outlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
12. Prime the fuel system. Refer to «Fuel System Priming»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__fuel-system-priming) .
13. Start the engine. If the engine does not start, repeat the above step.
14. Inspect the fuel system for fuel leaks.
15. 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 engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .
2. Remove the charge air cooler inlet pipe. Refer to «Charged Air Cooler Hoses/Pipes Replacement (Inlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Charged Air Cooler Hoses/Pipes Replacement (Outlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
3. Remove the exhaust gas recirculation (EGR) valve. Refer to «Exhaust Gas Recirculation Valve Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
4. Remove the EGR bracket at front of engine.
5. Remove the fuel line/wire harness bracket bolts left front side of engine and position out of way.
6. Remove the fuel rail bracket bolt under the air cleaner snorkel.
7. Remove the pipe bracket bolt and bracket at front of the engine.
8. Remove the 2 fuel pipe bracket bolts.
9. Disconnect the fuel feed pipe fittings from the left fuel rail.
10. Disconnect the fuel feed pipe from the right fuel rail.
11. Remove the right fuel rail fuel feed pipe.

1. Install the right fuel rail fuel feed pipe.
2. Connect the fuel feed pipe fittings to the left fuel rail. Tighten: Tighten the fittings to 41 N.m (30 lb ft).
3. Connect the fuel feed pipe to the right fuel rail. Tighten: Tighten the fittings to 41 N.m (30 lb ft).
4. Install the 2 fuel pipe bracket bolts. Tighten: Tighten the bolts to 25 N.m (18 lb ft).
5. Install the fuel pipe bracket bolt and bracket at front of engine.
6. Install the fuel rail bracket bolt under the air snorkel.
7. Position back the fuel line/wire harness at the left front side of the engine and install the bolts.
8. Install the EGR bracket at the front of engine.
9. Install the EGR valve. Refer to «Exhaust Gas Recirculation Valve Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
10. Install the charge air cooler inlet pipe. Refer to «Charged Air Cooler Hoses/Pipes Replacement (Inlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Charged Air Cooler Hoses/Pipes Replacement (Outlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
11. Prime the fuel system. Refer to «Fuel System Priming»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__fuel-system-priming) .
12. Start the engine. If the engine does not start, repeat the above step.
13. Inspect the fuel system for fuel leaks.
14. 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 air conditioning (A/C) compressor. Refer to «Compressor Replacement (6.6L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. If equipped, remove the auxiliary generator. Refer to «Auxiliary Generator Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
3. Disconnect the fuel feed pipe fitting from the fuel injector pump.
4. Disconnect the fuel feed pipe fitting from the left fuel rail.
5. Remove the left fuel feed pipe.

1. Install the left fuel feed pipe.
2. Connect the fuel feed pipe fitting to the left fuel rail. Tighten: Tighten the fittings to 41 N.m (30 lb ft).
3. Connect the fuel feed pipe fittings to the fuel injector pump. Tighten: Tighten the fittings to 41 N.m (30 lb ft).
4. If equipped, install the auxiliary generator. Refer to «Auxiliary Generator Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
5. Install the A/C compressor. Refer to «Compressor Replacement (6.6L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
6. Prime the fuel system. Refer to «Fuel System Priming»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__fuel-system-priming) .
7. Start the engine. If the engine does not start, repeat the above step.
8. Inspect the fuel system for 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 upper fan shroud. Refer to «Engine Coolant Fan Upper Shroud Replacement (4.3L, 4.8L, 5.3L, 6.0L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (6.6L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
3. Remove the generator. Refer to «Generator Replacement (6.6L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
4. Prior to removing the fuel injector pipes, use compressed air to blow any debris from between the injector line and fittings. Wipe the fittings clean of debris.
5. Spray lithium grease, GM P/N 12346293 or equivalent, between the fuel injector line and fittings to assist in containing any debris during removal.
6. Remove the fuel injector pipes.

Note. Ensure proper torquing of the fuel injector line. An under-torqued fuel injector line will not seal properly and an over-torqued fuel injector line may damage the fuel injector fitting. An improperly sealed or damaged fuel injector line or fuel injector fitting will cause a fuel leak.

1. Install the fuel injector pipes. Tighten: Tighten the fittings to 41 N.m (30 lb ft).
2. After installing the fuel injector pipes, clean the injector pipes and apply sealant GM P/N 97720043, at the fittings to prevent moisture and debris from collecting between the line and fitting.
3. Install the generator. Refer to «Generator Replacement (6.6L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
4. Install the upper fan shroud. Refer to «Generator Replacement (6.6L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
5. Prime the fuel system. Refer to «Fuel System Priming»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__fuel-system-priming) .
6. Start the engine. If the engine stalls, repeat the above step.
7. Inspect the fuel system 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 upper fan shroud. Refer to «Engine Coolant Fan Upper Shroud Replacement (6.6L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
3. If equipped, remove the auxiliary generator. Refer to «Auxiliary Generator Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
4. Remove the glow plug module and bracket Refer to «Glow Plug Control Module Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
5. Remove the positive crankcase ventilation (PCV) hose/pipe. Refer to «Crankcase Ventilation Hoses/Pipes Replacement (LLY, LBZ)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Crankcase Ventilation Hoses/Pipes Replacement (LMM)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
6. Remove the engine harness bracket bolts at the left front of engine and position out of the way.
7. Prior to removing the fuel injector pipes, use compressed air to blow any debris from between the injector line and fittings. Wipe the fittings clean of debris.
8. Spray lithium grease, GM P/N 12346293 or equivalent, between the fuel injector line and fittings to assist in containing any debris during removal.
9. Remove the fuel injector pipes.

Note. Ensure proper torquing of the fuel injector line. An under-torqued fuel injector line will not seal properly and an over-torqued fuel injector line may damage the fuel injector fitting. An improperly sealed or damaged fuel injector line or fuel injector fitting will cause a fuel leak.

1. Install the fuel injector pipes. Tighten: Tighten the fittings to 41 N.m (30 lb ft).
2. After installing the fuel injector pipes, clean the injector pipes and apply sealant GM P/N 97720043, at the fittings to prevent moisture and debris from collecting between the line and fitting.
3. Position back engine harness and install bolts to bracket at left front of engine. Tighten: Tighten the bolts to 21 N.m (15 lb ft).
4. Install the positive PCV hose/pipe. Refer to «Crankcase Ventilation Hoses/Pipes Replacement (LLY, LBZ)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Crankcase Ventilation Hoses/Pipes Replacement (LMM)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
5. Install the glow plug module and bracket. Refer to «Glow Plug Control Module Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
6. Install the auxiliary generator. Refer to «Auxiliary Generator Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
7. Install the upper fan shroud. Refer to «Engine Coolant Fan Upper Shroud Replacement (6.6L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
8. Prime the fuel system. Refer to «Fuel System Priming»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__fuel-system-priming) .
9. Start the engine. If the engine stalls, repeat the above step.
10. Inspect the fuel system 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. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .
2. Disconnect the fuel lines at the cooler. Refer to «Metal Collar Quick Connect Fitting Service»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__metal-collar-quick-connect-fitting-service) .
3. Remove the fuel cooler bolts.
4. Remove the fuel cooler.

1. Install the fuel cooler to the chassis and crossover.
2. Install the fuel cooler bolts. Tighten: Tighten the bolts to 18 N.m (13 lb ft).
3. Connect the fuel lines at the fuel cooler. Refer to «Metal Collar Quick Connect Fitting Service»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__metal-collar-quick-connect-fitting-service) .
4. Lower the vehicle.
5. Prime the fuel system. Refer to «Fuel System Priming»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__fuel-system-priming) .
6. Start the engine. If the engine stalls, repeat the above step.
7. Once the engine starts, inspect for fuel leaks.

1. Relieve the fuel system pressure.
2. Disconnect the fuel feed and pressure balance rear lines. Refer to «Metal Collar Quick Connect Fitting Service»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__metal-collar-quick-connect-fitting-service) .
3. Loosen the fuel fill hose clamp (1) at the tank.
4. Disconnect the fuel fill vent hose (2) from the fuel tank.
5. Remove the fuel fill hose from the tank.
6. Cap the fuel and vent holes in the fuel tank in order to prevent possible fuel system contamination.

1. Remove the caps from the fuel and vent holes in the fuel tank.
2. Install the fuel fill hose to the tank.
3. Connect the fuel fill vent hose (2) to the fuel tank.
4. Tighten the fuel fill hose clamp (1) at the tank. Tighten: Tighten the clamp to 2.5 N.m (22 lb in).
5. Connect the fuel feed and pressure balance rear lines. Refer to «Metal Collar Quick Connect Fitting Service»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__metal-collar-quick-connect-fitting-service) .

Fuel System Cleaning

Fungi and other microorganisms can survive and multiply in diesel fuel if water is present. The fungi can be present in any part of the fuel handling system. These fungi grow into long strings and will form into large globules. The growths appear slimy and are usually black, green, or brown. The fungi may grow anywhere in the fuel but are most plentiful where diesel fuel and water meet. As the fuel is agitated, when service station tanks are being filled, fungi are distributed throughout the tank and may be pumped into a vehicle.

Fungi use the fuel as their main energy supply and need only trace amounts of water and minerals. As they grow and multiply, they change fuel into water, sludge, acids, and products of metabolism. The most common symptom is fuel filter plugging; however, various metal components including the fuel sending unit, pipes, fuel injectors, and injection pump can corrode.

If fungi have caused fuel system contamination, use a diesel fuel biocide to sterilize the fuel system. Do not exceed the dosage recommended on the label. Discontinue the use of a biocide when towing a trailer. It is permissible to have biocide in the fuel when starting to tow, but do not add any biocide while towing.

Steam cleaning may be necessary if most of the fungus growth cannot be removed with biocides.

The presence of water or gasoline in diesel fuel may also cause injection pump and nozzle damage.

This procedure checks for the presence of water and gasoline in diesel fuel that may cause injection pump and nozzle damage.

Remove and inspect the fuel filter element.

1. If water, gasoline or fungi/bacteria are not present, end the inspection.
2. If water or fungi/bacteria are present, proceed to Cleaning Water from the Fuel System.
3. If gasoline is present, proceed to Cleaning Gasoline from the Fuel System.

Cleaning Water from the Fuel System

1. Disconnect the negative battery. 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 sending unit. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
3. Inspect the fuel tank and the fuel sender for rust, fungi or bacteria. If there is rust, replace the rusted components.
4. Clean the inside of the fuel tank and the fuel sender with hot water.
5. Use compressed air in order to dry the fuel tank and the fuel sender.
6. Disconnect the ends of the following lines: The fuel filter inlet line (both ends) The transfer pump pressure line and suction line (if applicable) The fuel filter outlet line (both ends) The fuel filter drain The fuel return line (both ends)
7. Inspect each of the pipes and lines.
8. Replace any rusted pipes.
9. Clean the inside of the fuel filter housing.
10. Dry the fuel filter housing with compressed air.
11. Dry the inside of each line with low pressure air.
12. Disconnect the crankshaft position (CKP) sensor. Refer to «Crankshaft Position Sensor Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
13. Install a new fuel filter. Refer to «Fuel Filter Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
14. Install the sending unit. Refer to «Fuel Sender Assembly Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
15. Add clean diesel fuel to the primary tank until the tank is 1/4 full.
16. Reconnect the following lines: The fuel filter inlet line The fuel filter outlet line The transfer pump pressure and suction (both ends) lines The fuel return line (tank end)
17. Connect the batteries.
18. Install a hose on the fuel return line near the glow plug relay, and insert other end into a 7.6 liters (2 gallon) metal container.
19. Turn ignition on with the engine OFF. Allow the fuel pump to run until the cycle ends or until 3.8 liters (1 gallon) of fuel has passed into the container.
20. Turn the ignition OFF.
21. Connect the fuel return line.
22. Clean any fuel spillage from the engine.
23. Reconnect the CKP sensor.
24. Start and run the engine.
25. Stop the engine.
26. Check for oil leaks.
27. Fill the fuel tank and add a biocide, if needed.

Cleaning Gasoline from the Fuel System

1. Drain the fuel tank.
2. Fill the fuel tank to 1/4 full.
3. Disconnect the CKP sensor. Refer to «Crankshaft Position Sensor Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
4. Install a hose on the fuel return line near the glow plug relay, and insert the other end into a 7.6 liters (2 gallon) metal container.
5. Turn the ignition ON with the engine OFF. Allow the fuel pump to run until the cycle ends or until 3.8 liters (1 gallon) of fuel has passed into the container.
6. Reconnect the fuel return line.
7. Clean any fuel spillage from the engine.
8. Reconnect the CKP sensor.
9. Attempt to start and run the engine for 15 minutes. If the engine does not start, cycle the ignition and allow the fuel pump to run until the cycle ends.
10. Start the engine.
11. Stop the engine.
12. Check for fuel leaks.
13. Clear the engine of any diagnostic trouble codes (DTCs).

Fuel Feed Pipe and Return Pipe Purging

1. Pump the primer located on top of the fuel filter 30 times or until stiff.
2. Attempt to start and run the engine. If the engine does not start, repeat step 1.
3. Allow to run for 5 minutes at idle.
4. Check for fuel leaks.
5. Clear all engine diagnostic trouble codes (DTCs).

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 exhaust gas recirculation (EGR) valve and bracket. Refer to «Exhaust Gas Recirculation Valve Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
3. Remove the right fuel injector feed pipes. Refer to «Fuel Injection Fuel Feed Pipe Replacement - Right Side»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
4. Disconnect the fuel rail pressure (FRP) sensor electrical connector (1).
5. Disconnect the right fuel fed pipe fitting from the fuel rail.
6. Remove the 2 fuel rail bolts and the fuel rail assembly.

1. Position the fuel rail assembly and install the 2 bolts. Tighten: Tighten the bolts to 25 N.m (18 lb ft).
2. Connect the right fuel rail feed pipe fitting to the fuel rail. Tighten: Tighten the fittings to 41 N.m (30 lb ft).
3. Connect the fuel rail pressure (FRP) sensor electrical connector (1).
4. Install the right fuel injector feed pipes. Refer to «Fuel Injection Fuel Feed Pipe Replacement - Right Side»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
5. Install the EGR valve and bracket. Refer to «Exhaust Gas Recirculation Valve Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
6. Prime the fuel system. Refer to «Fuel System Priming»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__fuel-system-priming) .
7. Start the engine. If the engine does not start, repeat the above step.
8. Inspect the fuel system for leaks.
9. 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 engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .
2. Remove the air conditioning (A/C) compressor. Refer to «Compressor Replacement (6.6L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
3. Remove the left fuel rail fuel feed pipe. Refer to «Fuel Rail Fuel Feed Pipe Replacement - Left Side»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
4. Remove the right fuel rail fuel feed pipe. Refer to «Fuel Rail Fuel Feed Pipe Replacement - Right Side»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
5. Remove the left fuel injector feed pipes. Refer to «Fuel Injection Fuel Feed Pipe Replacement - Left Side»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
6. Disconnect the fuel rail temperature (FRT) sensor electrical connector.
7. Remove the 2 fuel rail bolts and the fuel rail assembly.

1. Position the fuel rail assembly and install the 2 bolts. Tighten: Tighten the bolts to 25 N.m (18 lb ft).
2. Connect the FRT sensor electrical connector.
3. Install the left fuel injector feed pipes. Refer to «Fuel Injection Fuel Feed Pipe Replacement - Left Side»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
4. Install the right fuel rail fuel feed pipe. Refer to «Fuel Rail Fuel Feed Pipe Replacement - Right Side»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
5. Install the left fuel rail fuel feed pipe. Refer to «Fuel Rail Fuel Feed Pipe Replacement - Left Side»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
6. Install the A/C compressor. Refer to «Compressor Replacement (6.6L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
7. Prime the fuel system. Refer to «Fuel System Priming»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__fuel-system-priming) .
8. Start the engine. If the engine does not start, repeat the above step.
9. Inspect the fuel system 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. Remove the air intake pipe. Refer to «Air Intake Pipe Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
2. Disconnect the fuel pressure regulator electrical connector (1).
3. Reposition the distribution block hose clamps.
4. Remove the distribution block hoses from the distribution block.
5. Clean the fuel pressure regulator and high pressure injection pump thoroughly with solvent, such as GM P/N 12377981 (Canadian P/N 10953463) or equivalent.
6. Using compressed air, thoroughly blow dry the regulator and pump.
7. Remove the 3 fuel pressure regulator screws (1) using a T25 TORX®.
8. Remove the fuel pressure regulator (1).
9. If dirt or debris is found in the bore or seating surfaces of the fuel injection pump, perform the following: Place a clean rag over the bore on order to collect the excess fuel. Bump the engine over in order to flush any debris out of the regulator bore.

1. Lubricate and install NEW O-rings onto the regulator. Lubricate the O-rings with clean, NEW engine oil.
2. Install the fuel pressure regulator (1).
3. Install the 3 fuel pressure regulator screws (1) using a T25 TORX®. Tighten: Tighten the screws a first pass to 4 N.m (35 lb in). Tighten the screws a final pass to 7 N.m (62 lb in).
4. Install the distribution block hoses to the distribution block.
5. Position the distribution block hose clamps.
6. Connect the fuel pressure regulator electrical connector (1).
7. Install the air outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
8. Install the air intake pipe. Refer to «Air Intake Pipe Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
9. Prime the fuel system. Refer to «Fuel System Priming»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__fuel-system-priming) .
10. Start the engine. If the engine stalls, repeat the above step.
11. Once the engine starts, 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 glow plug module and bracket. Refer to «Glow Plug Control Module Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
3. Remove the fuel pressure relief valve from the left fuel rail.

1. Install the fuel pressure relief valve to the left fuel rail. Tighten: Tighten the fuel pressure relief valve to 100 N.m (74 lb ft).
2. Install the glow plug module and bracket. Refer to «Glow Plug Control Module Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
3. Prime the fuel system. Refer to «Fuel System Priming»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__fuel-system-priming) .
4. Start the engine. If the engine does not start, repeat the above step.
5. Inspect the fuel system for leaks.
6. 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 thermostat housing crossover. Refer to «Thermostat Housing Crossover Replacement (LLY, LBZ)»(/chevrolet/chevy-express-h1500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Thermostat Housing Crossover Replacement (LMM)»(/chevrolet/chevy-express-h1500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the left fuel rail fuel feed pipe. Refer to «Fuel Rail Fuel Feed Pipe Replacement - Left Side»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
3. Remove the right fuel rail fuel feed pipe. Refer to «Fuel Rail Fuel Feed Pipe Replacement - Right Side»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
4. Remove the center intake manifold. Refer to «Center Intake Manifold Replacement (LLY, LBZ)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Center Intake Manifold Replacement (LMM)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
5. Disconnect the injection pump electrical connector.
6. Compress the injection pump hose clamps at the fuel line.
7. Disconnect the hoses from fuel lines.
8. Remove the fuel injection pump bolts.
9. Remove the fuel injection pump from the block. Use 2 screwdrivers to work the pump from the block towards the rear of engine keeping the pump straight.
10. The fuel injection pump may need to be rotated in order to remove it from the vehicle.

Preparing The Fuel Injection Pump

1. Hold the fuel pump by the drive gear in a vice with copper jaw liners.
2. Loosen the gear nut until the nut is even with the end of the gear shaft.
3. Remove the gear from the tapered shaft of the injection pump.
4. Separate the injection pump and adapter by removing the 3 bolts and spacers.
5. Inspect the O-ring for damage on the pump adapter and replace, if necessary. Lubricate the O-ring with clean engine oil.
6. Clean all mating surfaces.
7. Install the adapter on the pump. NOTE: Refer to «Fastener Notice»(/chevrolet/chevy-express-h1500/2003-2012/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
8. Install the 3 bolts and spacers. Tighten: Tighten the bolts to 20 N.m (15 lb ft).
9. Install the gear and nut. Tighten: Tighten nut to 70 N.m (52 lb ft).

1. Install the fuel injection pump to the block.
2. Install the fuel injection pump bolts. Tighten: Tighten the bolts to 21 N.m (15 lb ft).
3. Install the hoses to fuel lines.
4. Position the injection pump hose clamps at the fuel line.
5. Connect the injection pump electrical connector.
6. Install the center intake manifold. Refer to «Center Intake Manifold Replacement (LLY, LBZ)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Center Intake Manifold Replacement (LMM)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
7. Install the left fuel rail fuel feed pipe. Refer to «Fuel Rail Fuel Feed Pipe Replacement - Right Side»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
8. Install the left fuel rail fuel feed pipe. Refer to «Fuel Rail Fuel Feed Pipe Replacement - Left Side»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
9. Install the thermostat housing crossover. Refer to «Thermostat Housing Crossover Replacement (LLY, LBZ)»(/chevrolet/chevy-express-h1500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Thermostat Housing Crossover Replacement (LMM)»(/chevrolet/chevy-express-h1500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
10. Prime the fuel system. Refer to «Fuel System Priming»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__fuel-system-priming) .
11. Start the engine. If the engine stalls, repeat the above step.
12. Once the engine starts, inspect for fuel leaks.

Fuel Injector Replacement (Right)

Tools Required

1. EN-47909 Injector Bore and Sleeve Cleaning Kit
2. J-46594 Fuel Injector Puller

1. Remove the upper right valve cover. Refer to «Valve Rocker Arm Cover Replacement - Upper Right Side (LLY, LBZ)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Valve Rocker Arm Cover Replacement - Upper Right Side (LMM)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
2. Remove the fuel injector bracket bolts.
3. Install J-46594 into the bolt hole in the fuel injector bracket.
4. Install a flare nut wrench onto J-46594 and pull back away from the fuel injector, until the injector releases from its seat.
5. Remove the J-46594 .
6. Remove the fuel injectors with brackets.
7. Remove and discard the copper washer from the fuel injector bore.
8. Remove and discard the fuel injector O-ring from the injector.

Fuel Injector Cleaning and Inspection

1. Use a soft bristle non-metallic brush and Top Engine Cleaner, GM P/N 1052626 or equivalent, to remove any deposits from the nozzle tip (1) and the copper washer sealing area (2) before re-installation.
2. Inspect the fuel injector nozzle tip (1) for any signs of discoloration (dark yellow, tan or blue) due to excessive heat.
3. Replace the injector if any damage is found.
4. Clean the fuel injector high pressure line.
5. Inspect the fuel injector line for excessive corrosion or damage to the sealing surfaces (1, 2). Replace the line if any damage is found.

Injector Bore Cleaning

1. Install the EN-47909-2 Radial Brush (brass), to the EN-47909-1 Handle Assembly.
2. Insert the brush into the injector bore and rotate the handle in order to break loose any carbon deposits from the injector bore walls and the combustion deck hole.
3. Using compressed air, evacuate any debris from the injector bore.
4. Remove the radial brush from the handle assembly.
5. Install the EN-47909-3 Axial Brush (nylon), to the EN-47909-1.
6. Insert the axial brush into the injector bore and rotate the handle while also applying a slight downward pressure, in order to force the brush ends into the bottom corners of the injector bore.
7. Using compressed air, evacuate any debris from the injector bore.
8. Lightly dampen EN-47909-20 Cotton Swab with Top Engine Cleaner, GM P/N 1052626 (Canadian P/N 993026) or equivalent, and wipe away any deposits from the injector bore.
9. Inspect the injector bore for any deposits and repeat brushing if necessary.
10. If necessary, crank the engine in order to expel any solvent before starting the engine. Remove the glow plugs. Refer to «Glow Plug Replacement - Bank 1»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) and/or «Glow Plug Replacement - Bank 2»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) . Disable the fuel system. Disconnect the crankshaft position (CKP) sensor electrical connector. Crank the engine in order to expel any excessive solvent. Using the cotton swabs supplied with the kit, wipe the injector bore clean of any solvent and/or debris. Connect the CKP sensor electrical connector. Enable the fuel system. Reinstall the glow plugs. Refer to «Glow Plug Replacement - Bank 1»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) and/or «Glow Plug Replacement - Bank 2»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .

1. Install a NEW copper washer to the fuel injector bore.
2. Install a NEW fuel injector O-ring to the injector.
3. Install the fuel pressure regulator bracket nut and bolt. Tighten: Tighten the bracket bolt and nut to 10 N.m (89 lb in).
4. Install the upper right valve cover. Refer to «Valve Rocker Arm Cover Replacement - Upper Right Side (LLY, LBZ)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Valve Rocker Arm Cover Replacement - Upper Right Side (LMM)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
5. If the fuel injectors were replaced, refer to «Fuel Injector Flow Rate Programming»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
6. Prime the fuel system. Refer to «Fuel System Priming»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__fuel-system-priming) .
7. Start the engine. If the engine stalls, repeat the above step.
8. Once the engine starts, inspect for fuel leaks.
9. Install the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .

Fuel Injector Replacement (Left)

Tools Required

1. EN-47909 Injector Bore and Sleeve Cleaning Kit
2. J-46594 Fuel Injector Puller

1. Remove the upper fan shroud. Refer to «Engine Coolant Fan Upper Shroud Replacement (4.3L, 4.8L, 5.3L, 6.0L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (6.6L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system)
2. If equipped, remove the auxiliary generator. Refer to «Auxiliary Generator Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system)
3. Remove the glow plug module and bracket. Refer to «Glow Plug Control Module Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
4. Remove the injector/glow plug wire harness retaining bolt at lower upper valve cover.
5. Remove the fuel feed/return line bracket and bolt located under the glow plug mount bracket.
6. Disconnect the left engine wiring harness connector.
7. Remove the engine wiring harness to bracket bolt, the 2 engine wiring harness bracket to upper valve cover bolts and remove the bracket (1).
8. Remove the left fuel injector pipes.
9. Remove the fuel return hose clips (1).
10. Disconnect the fuel return hose from the injectors.
11. Disconnect the fuel injector electrical connectors.
12. Remove the fuel injector bracket bolts.
13. Install J-46594 into the bolt hole in the fuel injector bracket.
14. Install a flare nut wrench onto J-46594 and pull back away from the fuel injector, until the injector releases from its seat.
15. Remove J-46594 .
16. Remove the fuel injectors with brackets.
17. Remove and discard the copper washer from the fuel injector bore.
18. Remove and discard the fuel injector O-ring from the injector.

1. Use a soft bristle non-metallic brush and Top Engine Cleaner, GM P/N 1052626 or equivalent, to remove any deposits from the nozzle tip (1) and the copper washer sealing area (2) before re-installation.
2. Inspect the fuel injector nozzle tip (1) for any signs of discoloration (dark yellow, tan or blue) due to excessive heat.
3. Replace the injector if any damage is found.
4. Clean the fuel injector high pressure line.
5. Inspect the fuel injector line for excessive corrosion or damage to the sealing surfaces (1, 2). Replace the line if any damage is found.

1. Install the EN-47909-2 Radial Brush (brass), to the EN-47909-1 Handle Assembly.
2. Insert the brush into the injector bore and rotate the handle in order to break loose any carbon deposits from the injector bore walls and the combustion deck hole.
3. Using compressed air, evacuate any debris from the injector bore.
4. Remove the radial brush from the handle assembly.
5. Install the EN-47909-3 Axial Brush (nylon), to the EN-47909-1.
6. Insert the axial brush into the injector bore and rotate the handle while also applying a slight downward pressure, in order to force the brush ends into the bottom corners of the injector bore.
7. Using compressed air, evacuate any debris from the injector bore.
8. Lightly dampen EN-47909-20 Cotton Swab with Top Engine Cleaner, GM P/N 1052626 (Canadian P/N 993026) or equivalent, and wipe away any deposits from the injector bore.
9. Inspect the injector bore for any deposits and repeat brushing if necessary.
10. If necessary, crank the engine in order to expel any solvent before starting the engine. Remove the glow plugs. Refer to «Glow Plug Replacement - Bank 1»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) and/or «Glow Plug Replacement - Bank 2»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) . Disable the fuel system. Disconnect the crankshaft position (CKP) sensor electrical connector. Crank the engine in order to expel any excessive solvent. Using the cotton swabs supplied with the kit, wipe the injector bore clean of any solvent and/or debris. Connect the CKP sensor electrical connector. Enable the fuel system. Reinstall the glow plugs. Refer to «Glow Plug Replacement - Bank 1»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) and/or «Glow Plug Replacement - Bank 2»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .

1. Install a NEW copper washer to the fuel injector bore.
2. Install a NEW fuel injector O-ring to the injector.
3. Install the fuel injectors with brackets.
4. Install the fuel injector bracket bolts. Tighten: Tighten the fuel injector bracket bolts to 30 N.m (22 lb ft).
5. Connect the fuel injector electrical connectors.
6. Connect the fuel return hose to the injectors.
7. Install the fuel return hose clips (1).
8. Install the left fuel injector pipes. Tighten: Tighten the fuel injector pipes to 41 N.m (30 lb ft).
9. After installing the fuel injector pipes, clean the injector pipes and apply sealant GM P/N 97720043, at the fittings to prevent moisture and debris from collecting between the line and fitting.
10. Position the engine wiring harness bracket (1), install the engine wiring harness to bracket bolt and the 2 engine wiring harness bracket to upper valve cover bolts. Tighten: Tighten the bolts to 21 N.m (15 lb ft).
11. Connect the left engine wiring main harness connector.
12. Install the fuel feed/return line bracket and bolt located under glow plug module bracket.
13. Install the injector/glow plug wire harness retaining bolt at the lower part of the upper valve cover.
14. Install the glow plug module and bracket. Refer to «Glow Plug Control Module Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
15. If equipped, install the auxiliary generator. Refer to «Auxiliary Generator Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
16. Install the upper fan shroud. Refer to «Engine Coolant Fan Upper Shroud Replacement (4.3L, 4.8L, 5.3L, 6.0L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (6.6L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
17. If the fuel injectors were replaced, refer to «Fuel Injector Flow Rate Programming»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
18. Prime the fuel system. Refer to «Fuel System Priming»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__fuel-system-priming) .
19. Start the engine. If the engine stalls, repeat the above step.
20. Once the engine starts, 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 exhaust gas recirculation (EGR) cooler tube. Refer to «Exhaust Gas Recirculation Valve Cooler Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
3. Disconnect the fuel rail pressure sensor electrical connector (1).
4. Prior to removal, clean the fuel pressure sensor and surrounding area thoroughly with solvent, such as GM P/N 12377981 (Canadian P/N 10953463) or equivalent.
5. Using compressed air, thoroughly blow dry the sensor and surrounding area.
6. Remove the fuel pressure sensor (3).

1. Install the fuel pressure sensor (3). Tighten: Tighten the sensor to 70 N.m (52 lb ft).
2. Connect the fuel rail pressure sensor electrical connector (1).
3. Install the EGR cooler tube. Refer to «Exhaust Gas Recirculation Valve Cooler Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
4. Prime the fuel system. Refer to «Fuel System Priming»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__fuel-system-priming) .
5. Start the engine. If the engine stalls, repeat the above step.
6. Once the engine starts, inspect for fuel leaks.
7. 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 engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .
2. Remove the charged air inlet tube. Refer to «Charged Air Cooler Hoses/Pipes Replacement (Inlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Charged Air Cooler Hoses/Pipes Replacement (Outlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
3. Remove the rear fuel line retainer and bolt.
4. Remove the fuel line retainer at center of engine.
5. Remove the glow plug module and bracket. Refer to «Glow Plug Control Module Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
6. Disconnect the fuel rail temperature (FRT) sensor electrical connector.
7. Remove the FRT sensor from the fuel line.

1. Install the FRT sensor electrical connector. Tighten: Tighten the FRT sensor to 22 N.m (16 lb ft).
2. Connect the FRT sensor electrical connector.
3. Install the fuel line retainer center of engine.
4. Install the rear fuel line retainer.
5. Install the charged air inlet tube. Refer to «Charged Air Cooler Hoses/Pipes Replacement (Inlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Charged Air Cooler Hoses/Pipes Replacement (Outlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5)
6. Install the glow plug module and bracket. Refer to «Glow Plug Control Module Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
7. Prime the fuel system. Refer to «Fuel System Priming»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2__fuel-system-priming) .
8. Once engine starts, inspect for leaks.
9. 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 engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .
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. If necessary, remove the left front wheel and tire. Refer to «Tire and Wheel Removal and Installation»(/chevrolet/chevy-express-h1500/2003-2012/remont/wheel-tire-system/#tires-and-wheels) .
4. Remove the engine splash shield. Refer to «Wheelhouse Splash Shield Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
5. Remove the glow plug harness nut(s).
6. Remove the harness from the glow plug(s).
7. Remove the glow plug(s).

1. Install the glow plug(s). Tighten: Tighten the plug to 18 N.m (13 lb ft).
2. Install the harness to the glow plug(s).
3. Install the glow plug harness nut(s). Tighten: Tighten the nut to 1.7 N.m (15 lb in).
4. Install the left front wheel and tire. Refer to «Tire and Wheel Removal and Installation»(/chevrolet/chevy-express-h1500/2003-2012/remont/wheel-tire-system/#tires-and-wheels) .
5. 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) .
6. Install the engine splash shield. Refer to «Wheelhouse Splash Shield Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
7. 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 engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .
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. If necessary, remove the right front wheel and tire. Refer to «Tire and Wheel Removal and Installation»(/chevrolet/chevy-express-h1500/2003-2012/remont/wheel-tire-system/#tires-and-wheels) .
4. Remove the engine splash shield. Refer to «Wheelhouse Splash Shield Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
5. Remove the glow plug harness nut(s).
6. Remove the harness from the glow plug(s).
7. Remove the glow plug(s).

1. Install the glow plug(s). Tighten: Tighten the plug to 18 N.m (13 lb ft).
2. Install the harness to the glow plug(s).
3. Install the glow plug harness nut(s). Tighten: Tighten the nut to 1.7 N.m (15 lb in).
4. Install the right front wheel and tire. Refer to «Tire and Wheel Removal and Installation»(/chevrolet/chevy-express-h1500/2003-2012/remont/wheel-tire-system/#tires-and-wheels) .
5. Install the engine splash shield. Refer to «Wheelhouse Splash Shield Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/frames-subframes-crossmembers/#frame-and-underbody) .
6. 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) .
7. 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. 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 engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .
3. Remove the charged air cooler inlet hose/pipe assembly. Refer to «Charged Air Cooler Hoses/Pipes Replacement (Inlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Charged Air Cooler Hoses/Pipes Replacement (Outlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
4. Disconnect the engine wiring harness electrical connector (1) from the glow plug control module.
5. Disconnect the positive battery cable (1) from the glow plug control module.
6. Remove the glow plug control module bolts (1).
7. Remove the glow plug control module (2).
8. Remove the glow plug control module bracket bolts (3), if required.
9. Remove the glow plug control module bracket (4), if required.

1. Position the glow plug control module bracket (4), if required.
2. Install the glow plug control module bracket bolts (3), if required. Tighten: Tighten the bolts to 10 N.m (89 lb in).
3. Position the glow plug control module (2).
4. Install the glow plug control module bolts (1). Tighten: Tighten the bolts to 10 N.m (89 lb in).
5. Connect the positive battery cable (1) to the glow plug control module.
6. Connect the engine wiring harness electrical connector (1) to the glow plug control module.
7. Install the charged air cooler inlet hose/pipe assembly. Refer to «Charged Air Cooler Hoses/Pipes Replacement (Inlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Charged Air Cooler Hoses/Pipes Replacement (Outlet)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
8. 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) .
9. If a NEW glow plug control module was installed, program the module. Refer to «Control Module References»(/chevrolet/chevy-express-h1500/2003-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) .
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. Refer to «Battery Negative Cable Disconnection and Connection»(/chevrolet/chevy-express-h1500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
2. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .
3. Remove the upper fan shroud. Refer to «Engine Coolant Fan Upper Shroud Replacement (4.3L, 4.8L, 5.3L, 6.0L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (6.6L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
4. Disconnect the crankshaft position (CKP) sensor electrical connector.
5. Remove the CKP sensor bolt.
6. Remove the CKP sensor.
7. If necessary, remove the CKP sensor spacer bolts.
8. If necessary, remove the CKP sensor spacer.

1. If necessary, lubricate a NEW CKP spacer O-ring with clean engine oil.
2. If necessary, install the NEW O-ring to the CKP sensor spacer. IMPORTANT: The crankshaft position sensor spacers are machined with different timing positions. However, if the crankshaft position sensor spacer requires replacement, replace with a grade "C" spacer.
3. If necessary, install the CKP sensor spacer.
4. If necessary, install the CKP sensor spacer bolts. Tighten: Tighten the bolts to 10 N.m (89 lb in).
5. Lubricate a NEW CKP sensor O-ring with clean engine oil.
6. Install the NEW O-ring to the CKP sensor.
7. Install the CKP sensor.
8. Install the CKP sensor bolt. Tighten: Tighten the bolt to 10 N.m (89 lb in).
9. Connect the CKP sensor electrical connector.
10. Install the upper fan shroud. Refer to «Engine Coolant Fan Upper Shroud Replacement (4.3L, 4.8L, 5.3L, 6.0L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Coolant Fan Upper Shroud Replacement (6.6L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
11. Lower the vehicle.
12. 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) .

Scheme 191

Camshaft Position Sensor Replacement

J 43181 Quick Connect Connector Removal Tool

1. Remove the generator. Refer to «Generator Replacement (6.6L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
2. Remove the intake manifold tube. Refer to «Intake Manifold Tube Replacement (LLY, LBZ)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Intake Manifold Tube Replacement (LMM)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
3. Remove the right exhaust pipe. Refer to «Exhaust Pipe Replacement - Right Side (6.6L (LBZ/LLY))»(/chevrolet/chevy-express-h1500/2003-2012/remont/exhaust/#engine-exhaust-system) or «Exhaust Pipe Replacement - Right Side (6.6L (LMM))»(/chevrolet/chevy-express-h1500/2003-2012/remont/exhaust/#engine-exhaust-system) .
4. Remove the crankcase ventilation hose/pipe. Refer to «Crankcase Ventilation Hoses/Pipes Replacement (LLY, LBZ)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Crankcase Ventilation Hoses/Pipes Replacement (LMM)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
5. Drain the cooling system. 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) .
6. Remove the heater inlet pipe bracket bolt (1).
7. Using the J 43181 , disconnect the exhaust gas recirculation (EGR) cooler hose fitting (2) from the heater inlet pipe.
8. Reposition the EGR cooler pipe clamp (1) and remove the EGR cooler pipe hose from the EGR cooler tube.
9. Disconnect the engine wiring harness electrical connector (1) from the EGR valve.
10. Remove the EGR valve/cooler tube assembly bolts and nut.
11. Remove the EGR valve/cooler tube assembly from the engine and place on a clean work surface.
12. On the bench, remove the EGR valve to EGR cooler tube bolts (2).
13. Separate the EGR valve (3) from the EGR cooler tube (4).
14. Remove and discard the intake manifold tube gaskets (1) as required.
15. If required, remove the EGR bracket bolt, nut, and EGR bracket.

1. If required, install the EGR bracket, the EGR bracket bolt, and nut. Tighten: Tighten the bolt and nut to 25 N.m (18 lb ft).
2. Install NEW intake manifold tube gaskets (1) as required.
3. Position the EGR valve (3) to the EGR cooler tube (4).
4. Install the EGR valve to EGR cooler tube bolts (2). Tighten: Tighten the bolts to 20 N.m (15 lb ft).
5. Install the EGR valve/cooler tube assembly to the engine.
6. Install the EGR valve/cooler tube assembly bolts and nut. Tighten: Tighten the bolts to 25 N.m (18 lb ft).
7. Connect the engine wiring harness electrical connector (1) to the EGR valve.
8. Install the EGR cooler pipe hose to the EGR cooler tube and reposition the EGR cooler pipe clamp (1).
9. Connect the EGR cooler hose fitting (2) to the heater inlet pipe.
10. Install the heater inlet pipe bracket bolt (1). Tighten: Tighten the bolt to 25 N.m (18 lb ft).
11. Fill the cooling system. 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) .
12. Install the crankcase ventilation hose/pipe. Refer to «Crankcase Ventilation Hoses/Pipes Replacement (LLY, LBZ)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Crankcase Ventilation Hoses/Pipes Replacement (LMM)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
13. Install the right exhaust pipe. Refer to «Exhaust Pipe Replacement - Right Side (6.6L (LBZ/LLY))»(/chevrolet/chevy-express-h1500/2003-2012/remont/exhaust/#engine-exhaust-system) or «Exhaust Pipe Replacement - Right Side (6.6L (LMM))»(/chevrolet/chevy-express-h1500/2003-2012/remont/exhaust/#engine-exhaust-system) .
14. Install the intake manifold tube. Refer to «Intake Manifold Tube Replacement (LLY, LBZ)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Intake Manifold Tube Replacement (LMM)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
15. Install the generator. Refer to «Generator Replacement (6.6L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .

J 43181 Quick Connect Connector Removal Tool

1. Remove the generator. Refer to «Generator Replacement (6.6L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
2. Remove the intake manifold tube. Refer to «Intake Manifold Tube Replacement (LLY, LBZ)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Intake Manifold Tube Replacement (LMM)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
3. Remove the right exhaust pipe. Refer to «Exhaust Pipe Replacement - Right Side (6.6L (LBZ/LLY))»(/chevrolet/chevy-express-h1500/2003-2012/remont/exhaust/#engine-exhaust-system) or «Exhaust Pipe Replacement - Right Side (6.6L (LMM))»(/chevrolet/chevy-express-h1500/2003-2012/remont/exhaust/#engine-exhaust-system) .
4. Remove the crankcase ventilation hose/pipe. Refer to «Crankcase Ventilation Hoses/Pipes Replacement (LLY, LBZ)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Crankcase Ventilation Hoses/Pipes Replacement (LMM)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
5. Drain the cooling system. 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) .
6. Remove the heater inlet pipe bracket bolt (1).
7. Using the J 43181 , disconnect the exhaust gas recirculation (EGR) cooler hose fitting (2) from the heater inlet pipe.
8. Reposition the EGR cooler pipe clamp (1) and remove the EGR cooler pipe hose from the EGR cooler tube.
9. Disconnect the engine wiring harness electrical connector (1) from the EGR valve.
10. Remove the EGR valve/cooler tube assembly bolts and nut.
11. Remove the EGR valve/cooler tube assembly from the engine and place on a clean work surface.
12. On the bench, remove the EGR valve to EGR cooler tube bolts (2).
13. Separate the EGR valve (3) from the EGR cooler tube (4).
14. Remove and discard the intake manifold tube gaskets (1) as required.
15. Reposition the EGR cooler hose clamp (6) and remove the EGR cooler hose (5) from the EGR cooler.
16. If required, remove the EGR cooler tube bracket bolts and bracket.

1. If required, position the EGR cooler tube bracket to the cylinder head and install the bolts. Tighten: Tighten the bolts to 25 N.m (18 lb ft).
2. Install the EGR cooler hose (5) onto the EGR cooler tube and position the EGR cooler hose clamp (6).
3. Install NEW intake manifold tube gaskets (1) as required.
4. Position the EGR valve (3) to the EGR cooler tube (4).
5. Install the EGR valve to EGR cooler tube bolts (2). Tighten: Tighten the bolts to 20 N.m (15 lb ft).
6. Install the EGR valve/cooler tube assembly to the engine.
7. Install the EGR valve/cooler tube assembly bolts and nut. Tighten: Tighten the bolts to 25 N.m (18 lb ft).
8. Connect the engine wiring harness electrical connector (1) to the EGR valve.
9. Install the EGR cooler pipe hose to the EGR cooler tube and reposition the EGR cooler pipe clamp (1).
10. Connect the EGR cooler hose fitting (2) to the heater inlet pipe.
11. Install the heater inlet pipe bracket bolt (1). Tighten: Tighten the bolt to 25 N.m (18 lb ft).
12. Fill the cooling system. 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) .
13. Install the crankcase ventilation hose/pipe. Refer to «Crankcase Ventilation Hoses/Pipes Replacement (LLY, LBZ)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Crankcase Ventilation Hoses/Pipes Replacement (LMM)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
14. Install the right exhaust pipe. Refer to «Exhaust Pipe Replacement - Right Side (6.6L (LBZ/LLY))»(/chevrolet/chevy-express-h1500/2003-2012/remont/exhaust/#engine-exhaust-system) or «Exhaust Pipe Replacement - Right Side (6.6L (LMM))»(/chevrolet/chevy-express-h1500/2003-2012/remont/exhaust/#engine-exhaust-system) .
15. Install the intake manifold tube. Refer to «Intake Manifold Tube Replacement (LLY, LBZ)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) or «Intake Manifold Tube Replacement (LMM)»(/chevrolet/chevy-express-h1500/2003-2012/remont/mechanical/#engine-mechanical-66l-2-of-5) .
16. Install the generator. Refer to «Generator Replacement (6.6L)»(/chevrolet/chevy-express-h1500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .
2. Disconnect the engine wiring harness electrical connector (1) from the exhaust differential pressure sensor.
3. Reposition the exhaust differential pressure sensor pipe assembly hose clamps (1).
4. Remove the exhaust differential pressure sensor pipe assembly hoses from the sensor.
5. Remove the exhaust differential pressure sensor bracket bolt (2).
6. Remove the exhaust differential pressure sensor.

1. Position the exhaust differential pressure sensor to the frame.
2. Install the exhaust differential pressure sensor bracket bolt (2). Tighten: Tighten the bolt to 9 N.m (80 lb in).
3. Install the exhaust differential pressure sensor pipe assembly hoses to the sensor.
4. Position the exhaust differential pressure sensor pipe assembly hose clamps (1).
5. Connect the engine wiring harness electrical connector (1) to the exhaust differential pressure sensor.
6. Lower the vehicle.

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .
2. Reposition the exhaust differential pressure sensor pipe assembly hose clamps (3).
3. Remove the exhaust differential pressure sensor pipe assembly hoses from the sensor.
4. Remove the exhaust differential pressure sensor pipe assembly fittings (2).
5. Remove the exhaust differential pressure sensor bracket bolts (1).
6. Remove the exhaust differential pressure sensor pipe assembly.

1. Position and install the exhaust differential pressure sensor pipe assembly.
2. Loosely install the exhaust differential pressure sensor bracket bolts (1).
3. Install the exhaust differential pressure sensor pipe assembly fittings (2). Tighten: Tighten the exhaust differential pressure sensor pipe fittings to 45 N.m (33 lb ft). Tighten the exhaust differential pressure sensor bracket bolts to 9 N.m (80 lb in).
4. Install the exhaust differential pressure sensor pipe assembly hoses to the sensor.
5. Position the exhaust differential pressure sensor pipe assembly hose clamps (3).
6. Lower the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .
2. Disconnect the exhaust temperature sensor electrical connector (2) from the engine wiring harness electrical connector (1).
3. Remove the exhaust temperature sensor.

1. Install the exhaust temperature sensor. Tighten: Tighten the sensor to 45 N.m (33 lb ft).
2. Connect the exhaust temperature sensor electrical connector (2) to the engine wiring harness electrical connector (1).
3. Lower the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .
2. Disconnect the exhaust temperature sensor (2) electrical connector from the engine wiring harness electrical connector (1).
3. Remove the exhaust temperature sensor.

1. Install the exhaust temperature sensor. Tighten: Tighten the sensor to 45 N.m (33 lb ft).
2. Connect the exhaust temperature sensor (2) electrical connector to the engine wiring harness electrical connector (1).
3. Lower the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-h1500/2003-2012/remont/hoistjack/#general-information) .

1. Remove the exhaust gas recirculation (EGR) cooler tube. Refer to «Exhaust Gas Recirculation Valve Cooler Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
2. Remove the EGR cooler pipe bolt.
3. Reposition the EGR cooler pipe (4) out of the way.
4. Remove the EGR valve adapter pipe bracket bolts (1).
5. Remove the EGR valve adapter pipe bracket (2) and turbocharger heat shield (3).
6. Remove the turbocharger oil feed pipe banjo bolt and washer.
7. Reposition the oil feed pipe out of the way.
8. Disconnect the turbocharger vane control solenoid valve electrical connector.
9. Remove the vane control solenoid valve bracket bolt and bracket.
10. Remove the turbocharger vane control solenoid valve from the turbocharger.

1. Install the turbocharger vane control solenoid valve to the turbocharger.
2. Install the vane control solenoid valve bracket and bolt. Tighten: Tighten the bolt to 23 N.m (17 lb ft).
3. Connect the turbocharger vane control solenoid valve electrical connector.
4. Position the oil feed pipe to the turbocharger.
5. Install a NEW turbocharger oil feed pipe washer and the banjo bolt. Tighten: Tighten the bolt to 34 N.m (25 lb ft).
6. Install the turbocharger heat shield (3) and EGR valve adapter pipe bracket (2).
7. Install the EGR valve adapter pipe bracket bolts (1). Tighten: Tighten the bolts to 9 N.m (80 lb in).
8. Position the EGR cooler pipe (4).
9. Install the EGR cooler pipe bolt. Tighten: Tighten the bolt to 9 N.m (80 lb in).
10. Install the EGR cooler tube. Refer to «Exhaust Gas Recirculation Valve Cooler Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lmm-introduction-2-of-2) .
11. Perform the turbocharger learn procedure. Refer to «Turbocharger Learn»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lbz-and-lly-introduction-2-of-2__turbocharger-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 turbocharger vane position sensor electrical connector.
3. Remove the turbocharger vane position sensor connector from the bracket on the LH valve cover.
4. Remove the turbocharger vane position sensor thermal reflective shield/tape.
5. Remove the turbocharger vane position sensor from the turbocharger.

1. Install the turbocharger vane position sensor to the turbocharger. Tighten: Tighten the sensor to 28 N.m (21 lb ft).
2. Install the turbocharger vane position sensor connector to the bracket located on the LH valve cover.
3. Connect the turbocharger vane position sensor electrical connector.
4. Install the thermal reflective shield/tape, refer to the following procedure.

Thermal Reflective Shield/Tape Installation

1. Peel off the protective backing from the back side of the thermal reflective shield/tape.
2. With the sticky side of the shield/tape applied against the sensor body, align the bottom edge of the shield/tape with the bottom edge of the hex, and begin wrapping the sensor.
3. Completely wrap the shield/tape around the sensor.
4. Tuck the top of the shield/tape under the head of the brass cable crimp sleeve all around, allowing the shield/tape to fold over and overlap itself at the top.
5. The top of the shield/tape is now shown tucked under the head of the brass cable crimp sleeve all around.
6. Wrap the tie strap around the necked porting of the sensor body just above the hex. Insert the end of the strap in the buckle and tighten by pulling the end with needlenose pliers.
7. Bend the end of the tie strap 180 degrees over the top of the buckle.
8. Cut off the tie strap using side cutters so that the cut end will lie approximately over the center of the buckle. Push down the end of the tie strap over the buckle in order to minimize protrusion of the cut end or any sharp edges.
9. Finished installation is shown.
10. Install the engine cover. Refer to «Engine Cover Replacement»(/chevrolet/chevy-express-h1500/2003-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .
11. Perform the turbocharger learn procedure. Refer to «Turbocharger Learn»(/chevrolet/chevy-express-h1500/2003-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-66l-lbz-and-lly-introduction-2-of-2__turbocharger-learn) .

Turbocharger Learn

The turbocharger (TC) learns the vane positions automatically during each ignition cycle. The engine control module (ECM) performs the turbocharger learn procedure automatically when the engine coolant temperature (ECT) is least 72°C (162°F). After each ignition cycle, and before the enable criteria have been met, the ECM will use the previously learned value. If the ECM does not have a previously learn value, it will default to a stored calibrated value. The ECM will use this value until the enable criteria have been met. It will then perform this procedure to learn the new value. If the ECM attempts to perform the TC Learn procedure and fails, DTCs P003A or P2563 may set.

If a TC Learn is not performed after a related turbocharger repair, the ECM will use a stored vane position value that may be invalid. The ECM may then cause a diagnostic to fail and set an invalid DTC. Certain enable criteria must be met for the ECM to perform this procedure.

The turbocharger learn procedure is required when the following service procedures have been performed

1. TC vane position control solenoid valve replacement
2. TC vane position sensor replacement
3. ECM replacement
4. TC replacement
5. Any service that disturbs the TC components

Learn Procedure

1. The following conditions must be met for the ECM to perform the turbocharger learn procedure: The A/C is OFF. The vehicle is in Park or Neutral. Start and idle the engine. The engine coolant temperature (ECT) is greater than 40°C (104°F).
2. After the enable conditions have been met and the engine idle is stabilized, enter the TC Learn Output function from the Module Setup Menu. Command the TC Learn ON for at least 5 seconds, then command it OFF. The system should have learned the new turbocharger position. The TC Learned parameter should have toggled from No to Yes.

1. Remove 3 air cleaner cover bolts.
2. Remove the air cleaner cover.
3. Remove the air cleaner element.

1. Install the air cleaner element.
2. Install the air cleaner cover.
3. Install the air cleaner cover bolts. Tighten: Tighten the bolts to 4 N.m (35 lb in).

1. Remove the air cleaner assembly hold down screw.
2. Loosen the air cleaner outlet duct hose clamp.
3. Remove the air cleaner assembly.

1. Install the air cleaner assembly.
2. Tighten the air cleaner outlet duct hose clamp. Tighten: Tighten the air cleaner outlet duct hose clamp to 4 N.m (35 lb in).
3. Install the air cleaner assembly hold down screw.

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-66l-lmm-introduction-2-of-2) .
2. Loosen the air intake duct to turbo clamp.
3. Remove the intake air duct.

1. Install the intake air duct.
2. Tighten the intake air duct to turbo clamp. Tighten: Tighten the intake air duct to turbo clamp to 8 N.m (71 lb in).
3. 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-66l-lmm-introduction-2-of-2) .

Scheme 192

Air Intake Pipe Replacement

Scheme 193

The accelerator pedal position (APP) system along with the vehicle electronics and components is used to calculate and control the amount of acceleration and deceleration via fuel injector control. This eliminates the need for a mechanical cable attachment from the accelerator pedal to a throttle body.

The APP system includes, but is not limited to, the following components

1. The APP sensor assembly
2. The engine control module (ECM)

Accelerator Pedal Position (APP) Sensor

The APP sensor is mounted on the accelerator pedal control assembly. The sensor is made up of 2 individual sensors within one housing. Two separate signal, low reference, and 5-volt reference circuits are used in order to interface the accelerator pedal sensor assembly with the engine control module (ECM). Each sensor has a unique functionality to determine pedal position. The ECM uses the APP sensor to determine the amount of acceleration or deceleration desired by the person driving the vehicle. The APP sensor 1 voltage should increase as the accelerator pedal is depressed, from below 1.0 volt at 0 pedal travel to above 4 volts at 100 percent pedal travel. APP sensor 2 voltage should increase from above 0.43 volts at 0 pedal travel to above 2.0 volts at 100 percent pedal travel.

Exhaust Particulate Filter

The exhaust particulate filter (DPF) captures diesel exhaust gas particulates, preventing their release into the atmosphere. This is accomplished by forcing particulate-laden exhaust through a filter substrate of porous cells which removes the particulates from the exhaust gas. The exhaust gas enters the filter, but because every other cell of the filter is capped at the opposite end, the exhaust particulates cannot exit the cell. Instead, the exhaust gas passes through the porous walls of the cell leaving the particulates trapped on the cell wall. The cleaned exhaust gas exits the filter through the adjacent cell. The DPF is capable of reducing more than 90 percent of particulate matter (PM).

Scheme 194

The exhaust particulate filter (DPF) filters particulate-laden diesel exhaust (1) through a porous cell which traps the particulate matter.

Scheme 195

Diesel Oxidation Catalyst

The diesel oxidation catalyst (DOC) (3) has two functions. One function is to reduce emissions of non methane hydro-carbons (NMHC) and carbon monoxide (CO), from the exhaust gases. The other function is to help start a regeneration event by converting the fuel-rich exhaust gases to heat. The engine control module (ECM) monitors the functionally of the DOC by determining if the exhaust gas temperature (EGT) sensor 1 (6) reaches a predetermined temperature during a regeneration event. The DOC and the exhaust particulate filter (DPF) (4) are downstream of the turbocharger, and are two separate components under the vehicle.

Exhaust Pressure Differential Sensor and Lines

The exhaust pressure differential sensor (2) measures the pressure difference between the inlet and outlet of the exhaust particulate filter (DPF) filter. When pressure difference has increased above a calibrated threshold, a high particulate loading condition is indicated. The engine control module (ECM) will command a regeneration event in order to restore the DPF. If the pressure differential continues to increase across the exhaust filter without a regeneration event the ECM will illuminate a DPF lamp or send a message to the drivers information center (DIC) referring the customer to the owners manual. The owner's manual will instruct the customer to drive the vehicle under the conditions necessary for a regeneration to take place. If these lamps and messages are ignored the ECM will eventually illuminate the MIL and revert to Reduced Engine Power which will require the vehicle to be serviced.

The exhaust pressure differential sensor wiring consists of the following circuits

1. A 5-volt reference supplied by the ECM
2. A low reference supplied by the ECM
3. A signal supplied by the differential pressure sensor to the ECM-The voltage is relative to the pressure differential changes in the particulate element. The ECM converts the signal voltage input to a pressure value.

The exhaust differential pressure sensor sample lines (5) are connected before and after the DPF. To provide the pressure sensor with accurate back pressure measurements, the DPS sample lines should have a continuous downward gradient, without sharp bends or kinks.

Normal Regeneration

Regeneration is the process of removing the captured particulates through incineration within the exhaust particulate filer. Elevated temperatures are created in the diesel oxidation catalyst (DOC) through a calibrated strategy in the engine control system.

Regeneration occurs when the engine control module (ECM) calculates that the particulate level in the filter has reached a calibrated threshold using a number of different factors, including engine run time, distance traveled, fuel used since the last regeneration, and the exhaust differential pressure. In general, the vehicle will need to be operate continuously at speeds above 48 km/h (30 mph) for approximately 20-30 minutes for a full and effective regeneration to complete. During regeneration the exhaust gases reach temperatures above 550°C (1,022°F). If a regeneration event is interrupted for any reason, it will continue where it left off, including the next key cycle, when the conditions are met for regeneration. Normal regeneration is transparent to the customer.

Service Regeneration

Note. Due to the elevated engine temperatures created while performing this procedure it is imperative to keep the front of vehicle in an open environment, away from any walls or buildings, this will ensure proper airflow across the radiator.

The Tech 2® is an essential tool that is required for service regeneration. Commanding a service regeneration is accomplished using the output control function. The vehicle will need to be parked outside the facility and away from nearby objects, such as other vehicles and buildings, due to the elevated exhaust gas temperature at the tail pipe during regeneration. The service regeneration can be terminated by pressing the brake pedal, commanding service regeneration OFF using the scan tool or disconnecting the Tech 2® from the vehicle.

Regeneration Process

A number of engine components are required to function together for the regeneration process to be performed. These components are the fuel injectors, turbocharger, intake air valve (IAV), fuel pressure control, and the intake air heater (IAH).

The regeneration process consists of several stages

Warming up the oxidizing converter (DOC) to 350°C (662°F) by performing the following

1. Reducing air flow with the intake air valve
2. Increasing or decreasing boost pressure with the turbocharger, depending on engine load
3. Elevating the engine speed
4. Reduce fuel rail pressure
5. Retard fuel injection timing
6. Add late fuel injection pulses. The added fuel is not combusted but is oxidized by the diesel oxidation catalyst (DOC) and exhaust particulate filter (DPF) to create heat.

Ash Loading

Ash is a non-combustible by product from normal oil consumption. Low Ash content engine oil (CJ-4 API) is required for vehicles with the exhaust particulate filter (DPF) system. Ash accumulation in the DPF will eventually cause a restriction in particulate filter. Regeneration will not burn off the ash, only particulate matter is burned off. To service an ash loaded DPF, the DPF will need to be removed from the vehicle and cleaned or replaced.

Exhaust Temperature Sensor Position 1

The exhaust gas temperature (EGT) sensor 1 (6) is a variable resistor that measures the temperature of the exhaust gases at the inlet of the DPF. The engine control module (ECM) supplies EGT sensor with a bias 5 volts on the signal circuit and a ground on the low reference circuit. When the EGT sensor is cold, the sensor resistance is high, as the temperature increases, the sensor resistance decreases. When sensor resistance is high, the ECM detects a high voltage on the signal circuit. When sensor resistance is low the ECM detects a lower voltage on the signal circuit. Proper exhaust gas temperatures at the inlet of the exhaust particulate filter (DPF) are crucial for proper operation and for initiating the regeneration process. A temperature that is too high in the DPF will cause the DPF substrate to melt or crack. Regeneration will be terminated at temperatures above 800°C (1,472 °F). A temperature that is too low will not completely eliminate the particulates during regeneration. The ECM monitors the temperatures at the DPF inlet and outlet to regulate DPF temperatures.

Exhaust Temperature Sensor Position 2

The exhaust gas temperature (EGT) sensor 2 (1) is a variable resistor that measures the temperature of the exhaust gases at the outlet of the DPF. The engine control module (ECM) supplies the EGT sensor with a bias 5 volts on the signal circuit and a ground on the low reference circuit. When the EGT sensor is cold, the sensor resistance is high, as the temperature increases, the sensor resistance decreases. When sensor resistance is high, the ECM detects a high voltage on the signal circuit. When sensor resistance is low the ECM detects a lower voltage on the signal circuit. Temperatures at the outlet of the DPF are crucial to maintaining the integrity of the exhaust particulate filter (DPF) substrate. A temperature that is too high in the DPF outlet will cause the substrate to melt or crack. Regeneration will be terminated at temperatures above 800°C (1,472°F). A temperature that is too low will not completely eliminate the particulates during regeneration. The ECM monitors the temperatures at the DPF inlet and outlet to regulate DPF temperatures.

Engine Control Module Description

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

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 196

Scheme 197

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.

Exhaust Gas Recirculation (EGR) System Description

The Exhaust Gas Recirculation (EGR) System is used to reduce the amount of nitrogen oxide (NOx) emission levels caused by high combustion temperatures. At temperatures above 1 371°C (2,500°F), oxygen and nitrogen combine to form oxides of nitrogen (NOx). Introducing small amounts of exhaust gas back into the combustion chamber displaces the amount of oxygen entering the engine. With less oxygen in the air/fuel mixture, the combustion pressures are reduced, and as a result, combustion temperatures are decreased, restricting the formation of NOx.

The EGR valve motor is a direct current (DC) stepper motor utilizing a worm gear that extends from the motor to push on the EGR valve stem. The worm gear is not attached to the valve stem, and can only force the valve open. A return spring is used to force the valve closed.

The mass air flow (MAF) sensor signal is used by the engine control module (ECM) to detect the proper amount of EGR flow. One EGR flow test is performed per ignition cycle. The ECM will close the EGR valve for 5 seconds, then open the EGR valve to 100 percent for 5 seconds. The ECM will then calculate the MAF difference and determine if the proper EGR flow has been detected.

Scheme 198

The exhaust gas recirculation (EGR) valve is controlled by the engine control module (ECM) through the EGR motor high control and EGR motor low control circuits. The ECM supplies voltage that is near ignition voltage to the high and low control circuits at all times. This voltage is used by the ECM as a reference voltage during non EGR operation in order to detect circuit failures. The ECM will pulse width modulate (PWM) the low control circuit to ground and an increase in amperage on the high control circuit can be observed with a DMM when the EGR valve is commanded open. A lower pulse width will increase the open position of the valve. In order to close the EGR valve, the ECM will PWM the high control circuit to ground.

When the ignition is turned ON, the ECM will drive the EGR motor worm gear out with just enough force to touch the EGR valve stem. The ECM will do this 3 times in quick succession. This action determines the minimum closed position of the valve and only happens once per ignition cycle. If the valve is prevented from closing all of the way after the minimum closed position is learned, the scan tool EGR Position parameter will not reflect this position until the next ignition cycle. The EGR motor worm gear is not connected to the EGR valve stem and can only push the valve open. The valve is returned to the closed position by a return spring.

The ECM uses the EGR position sensor to determine the position of the EGR valve. The ECM sends a reference voltage through the 5-volt reference circuit to the EGR position sensor. The ECM provides a voltage return path for the sensor through the low reference circuit. A variable voltage signal, based on the EGR valve position, is sent from the sensor to the ECM through the EGR position sensor signal circuit.

EGR Valve Control Enabling Conditions.

Exhaust gas recirculation (EGR) valve control will only be enabled during idle and cruising conditions while the following conditions are met

1. The intake air temperature (IAT) is more than 5.25°C (41.5°F). EGR valve control will remain enabled until the IAT is less than 0°C (32°F) and will not enable again until the IAT is more than 5.25°C (41.5°F).
2. The engine coolant temperature (ECT) is between 60-96.75°C (140-206.15°F). EGR valve control will remain enabled until the ECT is less than 57°C (134.6°F) or more than 99.75°C (211.55°F) and will not enable again until the ECT is between 60-96.75°C (140-206.15°F).
3. The barometric pressure (BARO) is more than 74 kPa. EGR valve control will remain enabled until the BARO is less than 72 kPa and will not enable again until 74 kPa.

Fuel System Description

The fuel tank (6) stores the fuel supply. A mechanical fuel injection pump (10), located below the engine intake, includes the fuel supply pump and the high-pressure pump. Fuel is drawn through the diesel fuel conditioning module (DFCM) (7), which combines a water separator, an electric fuel prime pump, a fuel heater element, and a filter element. Fuel passes through a second screw on the fuel filter (8), then to the fuel injection pump. The fuel pump output is controlled by the engine control module (ECM) and provides fuel at the pressure needed by the fuel injectors (3). The fuel injectors supply fuel directly to the combustion chambers of the engine. A separate pipe returns unused fuel through a fuel cooler (5) to the fuel tank.

Scheme 199

The fuel tanks store the fuel supply. The primary fuel tank (2) is located on the left side of the vehicle. The fuel tanks are each held in place by 2 metal straps that attach to the frame. The fuel tanks are molded from high density polyethylene.

Scheme 200

The fuel filler cap has a torque-limiting device that prevents the cap from being over tightened. To install, turn the cap clockwise until you hear audible clicks. This indicates that the cap is fully seated.

Scheme 201

The fuel sender consists of the following major components

1. The fuel level sensor (1)
2. The fuel strainer (2)

Fuel Level Sensor

The fuel level sensor consists of a float, a wire float arm, and a ceramic resistor card. The position of the float arm indicates the fuel level. The fuel level sensor contains a variable resistor which changes resistance in correspondence with the amount of fuel in the fuel tank. The engine control module (ECM) sends the fuel level information via the class 2 circuit to the instrument panel cluster (IPC). This information is used for the instrument panel (I/P) fuel gage and the low fuel warning indicator, if applicable. The ECM also monitors the fuel level input for various diagnostics.

Fuel Strainer

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

Scheme 202

An electric fuel prime pump supplies fuel to low pressure fuel system. The fuel pump is used to prime the fuel system after changing the fuel filter or servicing the fuel system. This fuel pump is powered by the fuel pump relay that is controlled by the engine control module (ECM). The pump is part of the diesel fuel conditioning module (DFCM) (2) assembly. The module assembly is located under the vehicle forward of the fuel tank.

Scheme 203

The fuel injection pump is a mechanical high pressure pump. The fuel injection pump is located below the intake manifold. Fuel is pumped to the fuel rails at a specified pressure. Fuel pressure is regulated by a valve on the inlet of the fuel pump, controlled by the engine control module (ECM). Excess fuel from the fuel injection pump returns to the fuel tank through the fuel return pipe and a fuel cooler.

Fuel Filter

There are 2 fuel filters, a cartridge style located in the diesel fuel conditioning module (DFCM) (2) and a screw-on style fuel filter (1). The paper filter element traps particles in the fuel that may damage the fuel injection system. Both filters are located under the vehicle forward of the fuel tank.

Fuel Feed and Return Pipes

The fuel feed pipe carries fuel from the fuel tank to the fuel injector control module. The fuel return pipe carries fuel from the fuel rail assemblies back to the fuel tank. The fuel pipes consist of 2 sections

1. The rear fuel pipe assemblies are located from the top of the fuel tank to the chassis fuel pipes. The rear fuel pipes are constructed of steel with sections of rubber hose covered with braiding.
2. The chassis fuel pipes are located under the vehicle and connect the rear fuel pipes to the fuel rail pipes. These pipes are constructed of steel with sections of rubber hose covered with braiding.

Quick-Connect Fittings

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

Fuel Pipe O-Rings

O-rings seal the 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 204

The left and right fuel rail assemblies attach to the cylinder heads. The fuel rail assemblies distribute pressurized fuel to the fuel injectors through the fuel lines.

The fuel rail assemblies consists of the following components

1. The fuel rail pressure sensor in the right fuel rail
2. The fuel pressure relief valve in the left fuel rail

The fuel rail pressure sensor gives the engine control module (ECM) an indication of fuel pressure. The ECM uses this information to regulate fuel pressure, by commanding the fuel pressure regulator open or closed on the inlet of the fuel injection pump.

The fuel pressure relief valve opens only to prevent excessive pressure in the event of a malfunction. Fuel from the fuel pressure relief valve is returned to the fuel tank.

Scheme 205

Scheme 206

A fuel injector is a solenoid device controlled by the ECM that meters pressurized fuel to a single engine cylinder. Fuel pressure is released from above the fuel injector pintle, and is returned to the fuel tank through the fuel return lines. The difference in fuel pressure above and below the pintle causes the pintle to open. Fuel from the fuel injector tip is sprayed directly into the combustion chamber on the compression stroke of the engine.

The control functions for the fuel injection system are integrated in the engine control module (ECM). During the manufacturing process, each injector's flow rate is measured and recorded as injection quantity adjustment (IQA) flow rate data. The flow rate data is then etched as a hexadecimal number on the body of the injector. This data, together with the injector's cylinder position, is stored in the memory of both the glow plug control module (GPCM) and the ECM. When the ignition is turned ON, both the GPCM and the ECM monitor to ensure that the fuel injection flow rate numbers are present. If any of the injector flow rate numbers are missing, the diagnostic for that control module will set the appropriate DTC.

Scheme 207

The fuel system cooler (1) is located in front of the primary fuel tank. The fuel system cooler cools the fuel before it is returned to the fuel tank.

Glow Plug System Description

In the diesel engine, air alone is compressed in the cylinder. Then, after the air has been compressed, a charge of fuel is sprayed into the cylinder and ignition occurs, due to the heat of compression. Eight glow plugs are used as an aid to starting.

Control of the instant start system (ISS) glow plugs is accomplished by a glow control module unit and 4.7 volt glow plugs, requiring 2 seconds to heat up to 1,000°C (1,832°F). The temperature and the power consumption is controlled between the engine control module (ECM) and the controller within a wide range to suit the engine's pre-heating requirements. Each glow plug is energized individually. This capability yields more optimum heat times for the glow plugs, thus pre-glow times can be kept to a minimum for short wait to crank times and maximum glow plug durability. A DTC will set if there is a glow plug system fault.

A normal functioning system operates as follows

1. Turn the ignition ON with the engine OFF, and at room temperature.
2. The glow plugs turn ON and heat up in 2 seconds and then are pulse-width modulated (PWM) for another 2 seconds.
3. The glow plug wait lamp is ON for 1 second during cold start.
4. The glow plug wait lamp may not illuminate during a warm engine start.
5. If the engine is cranked during or after the above sequence, the glow plugs may cycle ON and OFF after the ignition switch is returned from the start position, whether the engine starts or not. The engine does not have to be running to terminate the glow plug cycling.

The glow plug initial ON time will vary based on the system voltage and temperature. Lower temperatures cause longer ON times.

The ECM provides glow plug operation after starting a cold engine. This post-start operation is initiated when the ignition switch is returned to Run, from the Start position. This function helps clean up excessive white smoke and/or poor idle quality after starting.

Glow Plugs

The glow plugs are 4.7 volt heaters in each of the cylinders that turn ON, then pulse-width modulated when the ignition switch is turned to the RUN position prior to starting the engine. They remain pulsing a short time after starting, then they are turned OFF.

A Wait to Start lamp on the instrument panel provides information on engine starting conditions. The Wait to Start lamp will not illuminate during post-start glow plug operation.

Glow Plug/Controller

The glow plug controller is a solid state device which operates the glow plugs. The glow plug controller is connected to the following circuits

1. The fuel heater ignition 1 voltage circuit
2. The battery voltage circuit
3. The CAN communication circuit located between the engine control module (ECM) and the glow plug controller
4. The engine ground circuit
5. The glow plug supply voltage circuits located between the glow plug controller and the glow plugs.

The glow plug diagnostic circuits are directly monitored individually by using a separate transistor to control current to each glow plug. Individual diagnosis is thus possible for every glow plug.

Scheme 208

Scheme 209

The intake air heater (IAH) is located in the air inlet tube and is used to warm the incoming air to aid in starting the engine and for proper cylinder combustion. The glow plug control module (GPCM) will command the IAH on when the engine coolant temperature is below 40°C (104°F).

The IAH is commanded ON by the GPCM through the command 1 circuit and the command 2 circuits. The command 1 signal is ON or OFF from the GPCM to the IAH. The command 2 circuits are digital signal from the GPCM to the IAH. Without both signals the IAH will not operate. The feedback signal is digital and informs the GPCM of the status of IAH. The temperature, current, and voltage circuits are analog signals from the IAH to the GPCM.

The IAH will be commanded to 100 percent when the engine coolant temperature is below 5°C (41°F) for 180 seconds after key up, then it will ramp down to 42 percent after 180-300 seconds and will hold it there until 300-500 seconds. After 500-600 seconds the IAH will ramp down to 0 percent. When the engine coolant is 10-40°C (50-104°F) the IAH is 100 percent for 30 seconds after key up then ramps down to 42 percent after 30-90 seconds and holds it there for up to 500 seconds, then it ramps down to 0 percent from 500-600 seconds.

High Idle System

The diesel engine has a high idle system to improve the warm-up time of the engine in cold weather conditions. This system allows the engine control module (ECM) to increase the idle speed above the normal calibrated value. The ECM increases the idle speed using the following adjustments

1. The fuel injection timing is changed.
2. The fuel injection quantity is changed.
3. The turbocharger vane position is commanded closed. The vane position will be farther closed than any other normal operating condition.

The instrument panel will indicate the high idle system is active one of two ways

1. The driver information center (DIC) will indicate an active high idle system on light duty trucks.
2. An indicator lamp will flash on medium duty trucks.
3. The manual high idle feature comes enabled from the factory. The Elevated Idle function in the scan tool will disable or enable this feature. If the engine does not increase to the calibrated high idle speed after the procedure is performed, use the scan tool to verify the Elevated Idle speed feature is enabled.

High Idle Speed Enable and Disable

To enable or disable the high idle system perform the following procedure

1. Turn the ignition ON, with the engine OFF.
2. Depress the accelerator pedal to the floor and hold down.
3. While the accelerator pedal is depressed, depress the brake pedal 3 times in less than 8 seconds.
4. Release the accelerator pedal.
5. Start the engine.

When the procedure is followed the engine idle speed will slowly increased to the calibrated high idle speed. This is 1,200 RPM for light duty, and 1,500 RPM for medium duty trucks.

The idle speed will return to normal if any of the following conditions occur

1. There is brake, clutch, or throttle input from the driver.
2. The automatic transmission is shifted out of Park or Neutral.
3. The air temperature is more than 7°C (45°F).
4. The engine coolant temperature (ECT) is more than 68°C (154°F).
5. The vehicle speed exceeds 0 km/h (0 mph).

The high idle system will reactivate automatically when the following conditions occur

1. The engine has been idling for more than 30 seconds.
2. The transmission is placed in Park or Neutral.
3. The vehicle speed is 0 km/h (0 mph).
4. The ambient air temperature is less than 3°C (37°F).
5. The ECT is less than 68°C (154°F).
6. The brake, clutch and throttle pedals are not depressed.

Scheme 210

The turbocharger increases engine power by pumping compressed air into the combustion chambers, allowing a greater quantity of fuel to combust at the optimal air/fuel ratio. In a conventional turbo, the turbine (4) spins as exhaust gas flows out of the engine and over the turbine blades. This spins the compressor wheel at the other end of the turbine shaft, pumping more air into the intake system.

The turbocharger for this system has vane position control by the engine control module (ECM). The vanes (5) are controlled to vary the amount of boost pressure. Thus, the boost pressure can be controlled independent of engine speed. There are 9 controllable vanes in this turbocharger. The vanes mount to a unison ring (3) that can be rotated to change the vane angle. The ECM will vary the boost dependent upon the load requirements of the engine.

The turbocharger vanes are normally open when the engine is not under load. However, the ECM will often close the turbocharger vanes to create back pressure to drive exhaust gas through the exhaust gas recirculation (EGR) valve as required. At extreme cold temperatures, the ECM may close the vanes at low load conditions in order to accelerate engine coolant heating. The ECM may also close the turbocharger vanes under exhaust braking conditions, only with RPO K40.

During regeneration, the ECM will vary the turbocharger vanes to assist with the exhaust system warm-up, and to maintain proper engine exhaust temperatures needed to properly regenerate the exhaust particulate filter (DPF).

The turbocharger control system utilizes the following components

Turbocharger Vane Position Control Solenoid Valve

The vane position control solenoid valve (2) works in conjunction with oil pressure to control the turbocharger vanes. The solenoid valve has two circuits; a low control circuit and a high control circuit. The engine control module (ECM) uses a pulse width modulation on both control circuits to control the solenoid valve. The ECM will control the solenoid valve to allow the engine oil pressure (EOP) to move a piston (6). This piston rotates the unison ring, thus controlling the engine boost dependant upon engine load.

Turbocharger Vane Position Sensor

The vane position sensor (1) uses 3 circuits: a 5-volt reference circuit, a low reference circuit, and a signal circuit. The engine control module (ECM) provides the sensor with 5 volts on the 5-volt reference circuit and a ground on the low reference circuit. Movement of the vanes provides the ECM with a signal voltage from the Turbocharger (TC) sensor through the position sensor signal circuit. The voltage is low when the TC vanes are open, and high when the TC vanes are closed.

Engine Control Module (ECM)

The engine control module (ECM) controls all turbocharger control functions. The ECM monitors information from various sensor inputs that include the following

1. The accelerator pedal position (APP) 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 manifold absolute pressure (MAP) sensor

Special Tools

Special Tools Illustration Tool Number/Description CH-48027 Digital Pressure Gage EN-47909 Injector Bore and Sleeve Cleaning Kit EN-47969 Fuel Supply Diagnostic Hose EN-48565 EGR Test Harness J-28428-E High Intensity Black Light Kit J-34730-405 Injector Test Lamp J-35555 Metal MityVac J-35616-200 Test Light - Probe Kit J-36169-A Fused Jumper Wire J-38641-B Diesel Fuel Quality Tester J-43178 Fuel Line Disconnect Tool J-43244 Relay Puller Pliers J-44581 Fuel Line Disconnect Tool J-45004 Fuel Tank Drain Hose J-45722 Fuel Sender Lock Ring Wrench J-45873 Fuel Return Volume Test Kit J-45873-30 Injector Flow Test Adapter J-46091 Charge Air Cooler Tester J-46091-10 Charge Air Cooler Tester Adapter J-46594 Fuel Injector Remover

Scheme 211

Scheme 212

Scheme 213

Scheme 214

Scheme 215

Scheme 216

Scheme 217

Scheme 218

Scheme 219

Scheme 220

Scheme 221

Scheme 222

Scheme 223

Scheme 224

Scheme 225

Scheme 226

Scheme 227

See also:
• DTC P0016
• DTC P029D, P02A1, P02A5, P02A9, P02AD, P02B1, P02B5, or P02B9
• DTC P154A
• DTC P2564 or P2565
• Control Module References
• Battery Negative Cable Disconnection and Connection
• Washer Solvent Container Replacement
• Turbocharger Learn
• Diagnostic Trouble Code (DTC) List - Vehicle
• Symptoms - Vehicle
• Intake Manifold Tube Replacement (LLY, LBZ)
• Draining and Filling Cooling System (Static Fill)
• Draining and Filling Cooling System (Vac N Fill)
• Fastener Notice
• Safety Glasses Caution
• Fuel Pipe Fitting Caution
• Lifting and Jacking the Vehicle
• Engine Cover Replacement
• Compressor Replacement (6.6L)
• Tire and Wheel Removal and Installation
• Wheelhouse Splash Shield Replacement
• Fan Clutch Replacement
• Exhaust Pipe Replacement - Right Side (6.6L (LBZ/LLY))
• Air Intake Pipe Replacement
• Water-in-Fuel Draining
• Fuel System Priming
• Fuel Tank Draining
• Metal Collar Quick Connect Fitting Service