Engine Controls and Fuel - 4.6l - Introduction Cadillac STS I рестайлинг

Temperature Versus Resistance

Altitude Versus Barometric Pressure

Ignition System Specifications

Fastener Tightening Specifications

Scheme 53

Scheme 54

Scheme 55

Scheme 56

Scheme 57

Scheme 58

Scheme 59

Scheme 60

Scheme 61

Scheme 62

Scheme 63

Scheme 64

Scheme 65

Scheme 66

Scheme 67

Diagnostic Starting Point - Engine Controls

Begin the system diagnosis with Diagnostic System Check - Vehicle . The Diagnostic System Check - Vehicle will provide the following information

1. The identification of the control modules which command the system
2. The ability of the control modules to communicate through the serial data circuit
3. The identification of any stored diagnostic trouble codes (DTCs) and the codes' statuses

The use of the Diagnostic System Check - Vehicle will identify the correct procedure for diagnosing the system and where the procedure is located.

DIAGNOSTIC CODE INDEX

DIAGNOSTIC CODE INDEX

Removal Procedure

Note. It is necessary to record the remaining engine oil life. If the replacement module is not programed with the remaining engine oil life, the engine oil life will default to 100 percent. If the replacement module is not programmed with the remaining engine oil life, the engine oil will need to be changed at 5 000 km (3,000 mi) from the last engine oil change.

Note. It is necessary to record the remaining automatic transmission fluid life. If the replacement module is not programed with the remaining automatic transmission fluid life, the automatic transmission fluid life will default to 100 percent. If the replacement module is not programmed with the remaining automatic transmission fluid life, the automatic transmission fluid will need to be changed at 83 000 km (50,000 mi) from the last automatic transmission fluid change.

1. Using a scan tool, retrieve the percentage of remaining engine oil and the remaining automatic transmission fluid life. Record the remaining engine oil and the remaining automatic transmission fluid life.
2. Turn OFF the ignition.
3. Disconnect the battery negative cable. Refer to «Battery Negative Cable Disconnection and Connection (Side Post)»(/cadillac/sts/i-2007-2011/remont/charging-system/#battery-charging-system-and-starting-system) .
4. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/sts/i-2007-2011/remont/hoistjack/#general-information) .
5. Remove the front air deflector. Refer to «Front Air Deflector Replacement»(/cadillac/sts/i-2007-2011/remont/exterior-body-panels/#bumpers-and-fascia) .
6. Disconnect the engine control module (ECM) electrical connectors (1).
7. Remove the ECM mounting nuts (2).
8. Remove the ECM from the vehicle.

Installation Procedure

1. Install the ECM to the vehicle.
2. Install the ECM mounting nuts (2) and tighten to 8 N.m (71 lb in).
3. Connect the ECM electrical connectors (1).
4. Install the front air deflector. Refer to «Front Air Deflector Replacement»(/cadillac/sts/i-2007-2011/remont/exterior-body-panels/#bumpers-and-fascia) .
5. Lower the vehicle.
6. Connect the battery negative cable. Refer to «Battery Negative Cable Disconnection and Connection (Side Post)»(/cadillac/sts/i-2007-2011/remont/charging-system/#battery-charging-system-and-starting-system) .
7. Program the ECM. Refer to «Control Module References»(/cadillac/sts/i-2007-2011/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for programming and setup information.

Crankshaft Position System Variation Learn

1. Install a scan tool.
2. Monitor the ECM for DTCs with a scan tool. If other DTCs are set, except DTC P0315, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/sts/i-2007-2011/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-trouble-code-dtc-list) for the applicable DTC that set.
3. With a scan tool, select the CKP system variation learn procedure within the Module Setup menu and perform the following: Observe the fuel cut-off for the applicable engine. Block the drive wheels. Set the parking brake. Place the vehicle's transmission in Park or Neutral. Turn the air conditioning (A/C) OFF. Cycle the ignition from OFF to ON. Apply and hold the brake pedal for the duration of the procedure. Start and idle the engine. Accelerate to wide open throttle (WOT). The engine should not accelerate beyond the calibrated fuel cut-off RPM value noted in step 3.1. Release the throttle immediately if the value is exceeded. IMPORTANT: While the learn procedure is in progress, release the throttle immediately when the engine starts to decelerate. The engine control is returned to the operator and the engine responds to throttle position after the learn procedure is complete. Release the throttle when fuel cut-off occurs.
4. The scan tool displays Learn Status: Learned this Ignition. If the scan tool indicates that DTC P0315 ran and passed, the CKP variation learn procedure is complete. If the scan tool indicates DTC P0315 failed or did not run, or if any other DTCs set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/sts/i-2007-2011/remont/oem-general-information/#vehicle-diagnostic-information-2-of-2__diagnostic-trouble-code-dtc-list) for the applicable DTC that set.
5. Turn OFF the ignition for 30 seconds after the learn procedure is completed successfully.

1. Turn OFF the ignition
2. Remove the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .
3. Drain the coolant to below the level of the engine coolant temperature (ECT) sensor. Refer to «Cooling System Draining and Filling (GE 47716)»(/cadillac/sts/i-2007-2011/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (Static Fill)»(/cadillac/sts/i-2007-2011/remont/cooling-system-mechanical/#engine-cooling-system) .
4. Disconnect the ECT sensor harness connector.
5. Remove the ECT sensor.

1. Coat the sensor threads with sealer GM P/N 1050805, or equivalent.
2. Install the ECT sensor and tighten to 20 N.m (15 lb ft).
3. Connect the ECT sensor harness connector.
4. Install the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .
5. Refill the coolant system. Refer to «Cooling System Draining and Filling (GE 47716)»(/cadillac/sts/i-2007-2011/remont/cooling-system-mechanical/#engine-cooling-system) or «Cooling System Draining and Filling (Static Fill)»(/cadillac/sts/i-2007-2011/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Disconnect the mass air flow (MAF)/intake air temperature (IAT) sensor electrical connector.
2. Remove the air cleaner outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
3. Remove the MAF/IAT sensor screws.
4. Carefully remove the MAF/IAT sensor from the air cleaner housing cover.
5. Discard the MAF/IAT sensor gasket.

1. Install a NEW MAF/IAT sensor gasket.
2. Carefully install the MAF/IAT sensor into the air cleaner housing cover.
3. Install the MAF/IAT sensor screws and tighten to 4 N.m (35 lb in).
4. Install the air cleaner outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
5. Reconnect the MAF/IAT sensor electrical connector.

1. Turn the ignition OFF.
2. Remove the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .
3. Disconnect the manifold absolute pressure (MAP) sensor electrical connector.
4. Remove the bolt (1) and bracket (2) from the MAP sensor (3).
5. Remove the MAP sensor (3).
6. Inspect the MAP sensor seal for wear or damage. If a problem is found, replace as necessary.

1. Install the MAP sensor (3).
2. Install the bracket (2) and bolt (1) and tighten to 12 N.m (106 lb in).
3. Connect the MAP sensor electrical connector.
4. Install the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .

Note. Bank 1 on the LH2 engine in this vehicle is the right side of the engine while sitting in the driver seat. Sensor 1 is the sensor closest to the engine, or farthest forward toward the front of vehicle. A special anti-seize compound is used on the oxygen sensor threads. New service sensors should already have the compound applied to the threads. Coat the threads of a reused sensor with anti-seize compound P/N 5613695 or equivalent.

1. Remove the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .
2. Disconnect the oxygen sensor electrical connector from the engine wiring harness connector at the rear of the right head.
3. Note the wire routing and attachment points for reassembly.
4. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/sts/i-2007-2011/remont/hoistjack/#general-information) .
5. Remove oxygen sensor from the exhaust manifold.

1. Install the heated oxygen sensor (HO2S) in the exhaust manifold and tighten to 42 N.m (31 lb ft).
2. Lower the vehicle.
3. Route and attach the wiring as noted in disassembly.
4. Connect the oxygen sensor electrical connector to the engine wiring harness connector at the rear of the right head.
5. Install the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .

Note. Bank 1 on the LH2 engine in this vehicle is the right side of the engine while sitting in the driver seat. Sensor 2 is the second sensor down stream from the engine towards the rear of the vehicle. A special anti-seize compound is used on the oxygen sensor threads. New service sensors should already have the compound applied to the threads. Coat the threads of a reused sensor with anti-seize compound P/N 5613695 or equivalent.

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/sts/i-2007-2011/remont/hoistjack/#general-information) .
2. Disconnect the oxygen sensor electrical connector.
3. Note the wire routing and attachment points for reassembly.
4. Remove the oxygen sensor from the exhaust pipe.

1. Install the oxygen sensor (HO2S) to the exhaust pipe and tighten to 42 N.m (31 lb ft).
2. Route and attach the wiring as noted during disassembly.
3. Connect the oxygen sensor electrical connector.
4. Lower the vehicle.

Note. Bank 2 on the LH2 engine in this vehicle is the left side of the engine while sitting in the driver seat. Sensor 1 is the sensor closest to the engine, or farthest towards the front of vehicle. A special anti-seize compound is used on the oxygen sensor threads. New service sensors should already have the compound applied to the threads. Coat the threads of a reused sensor with anti-seize compound P/N 5613695 or equivalent.

1. Remove the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .
2. Disconnect the oxygen sensor electrical connector from the engine wiring harness at the rear of the left head.
3. Note the wire routing and attachment points for reassembly.
4. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/sts/i-2007-2011/remont/hoistjack/#general-information) .
5. Remove the oxygen sensor from the exhaust manifold.

1. Install the heated oxygen sensor (HO2S) to the exhaust manifold and tighten to 42 N.m (31 lb ft).
2. Lower the vehicle.
3. Route and attach the wiring as noted during disassembly.
4. Connect the oxygen sensor electrical connector to the engine wiring harness connector at the rear of the left head.
5. Install the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .

Note. Bank 2 on the LH2 engine in this vehicle is the left side of the engine while sitting in the driver seat. Sensor 2 is the second sensor down stream from the engine towards the rear of the vehicle. A special anti-seize compound is used on the oxygen sensor threads. New service sensors should already have the compound applied to the threads. Coat the threads of a reused sensor with anti-seize compound P/N 5613695 or equivalent.

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/sts/i-2007-2011/remont/hoistjack/#general-information) .
2. Disconnect the oxygen sensor electrical connector.
3. Note the wire routing and attachment points for reassembly.
4. Remove the oxygen sensor from the exhaust pipe.

1. Install the oxygen sensor to the exhaust pipe. Tighten the front heated oxygen sensor (HO2S) to 42 N.m (31 lb ft).
2. Route and attach the wiring as noted during disassembly.
3. Connect the oxygen sensor electrical connector.
4. Lower the vehicle.

1. Remove the closeout/insulator panel from under the dashboard on the drivers side. Refer to «Instrument Panel Insulator Panel Replacement - Left Side»(/cadillac/sts/i-2007-2011/remont/gauges-instrument-panels/#instrument-panel-trim-and-console-trim) or «Instrument Panel Insulator Panel Replacement - Right Side»(/cadillac/sts/i-2007-2011/remont/gauges-instrument-panels/#instrument-panel-trim-and-console-trim) .
2. Disconnect the accelerator pedal position (APP) sensor electrical connector from the accelerator pedal module.
3. Remove the nuts from the APP sensor mounting plate and remove the APP sensor from the front of dash.

1. Install the APP sensor to the front of dash.
2. Install the APP sensor mounting nuts and tighten to 9 N.m (80 lb in).
3. Connect the APP sensor electrical connector.
4. Operate the accelerator pedal and observe the APP angles using a scan tool. The accelerator pedal should operate freely, without binding between closed throttle and wide open throttle.
5. Install the closeout/insulator panel. Refer to «Instrument Panel Insulator Panel Replacement - Left Side»(/cadillac/sts/i-2007-2011/remont/gauges-instrument-panels/#instrument-panel-trim-and-console-trim) or «Instrument Panel Insulator Panel Replacement - Right Side»(/cadillac/sts/i-2007-2011/remont/gauges-instrument-panels/#instrument-panel-trim-and-console-trim) .

1. Remove the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .
2. Remove the air cleaner outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
3. Disconnect the electrical connector from the throttle body assembly.
4. Remove the throttle body assemble mounting bolts.
5. Remove the throttle body and throttle body gasket from the water housing.
6. Discard the throttle body gasket.

Note. Do not reuse the old throttle body gasket.

1. Install the NEW gasket to the throttle body assembly.
2. Install the throttle body assembly to the water housing.
3. Install the throttle body assembly mounting bolts and tighten to 10 N.m (89 lb in).
4. Connect the electrical connector to the throttle body assembly.
5. Install the air cleaner outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
6. Install the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .
7. Perform the Throttle Body Learn procedure. Refer to «Throttle Learn»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-44l-introduction__throttle-learn) .

Description

The engine control module (ECM) learns the idle position of the throttle plate to ensure the correct idle. The learned airflow values are stored within the ECM. These values are learned to adjust for production variation and will continuously learn during the life of the vehicle to compensate for reduced airflow due to coking. Anytime the throttle body airflow rate changes, for example due to cleaning or replacing, the values must be relearned.

A vehicle that had a heavily coked throttle body that has been cleaned or replaced may take several drive cycles to learn out the coking. To accelerate the process, the scan tool has the ability to reset all learned values back to zero. A new ECM will also have values set to zero.

The idle may be unstable or a DTC may set if the learned values do not match the actual airflow.

Conditions for Running the Throttle Learn Procedure

With Scan Tool - Reset

1. DTCs P0101, P0102, P0103, P0107, P0108, P0111, P0112, P0113, P0506, and P0507 are not set.
2. Ignition ON, engine OFF.
3. The vehicle speed sensor (VSS) is 0 km/h (0 mph).

Without Scan Tool - Learn

1. DTCs P0101, P0102, P0103, P0107, P0108, P0111, P0112, P0113, P0506, and P0507 are not set.
2. The engine speed is between 450-4,000 RPM.
3. The manifold absolute pressure (MAP) is greater than 5 kPa.
4. The mass air flow (MAF) is greater than 2 g/s.
5. The ignition 1 voltage is greater than 10 volts.

Throttle Learn

With Scan Tool - Reset

1. Ignition ON, engine OFF. With a scan tool, perform the Idle Learn Reset in Module Setup.
2. Start the engine, monitor the TB Idle Airflow Compensation parameter. The TB Idle Airflow Compensation parameter value should equal 0 percent and the engine should be idling at a normal idle speed. If the engine is not idling normally, proceed with the Learn portion of the diagnostic.
3. Clear the DTCs and return to the diagnostic that referred you here.

Without Scan Tool-Learn

1. DTCs P0101, P0102, P0103, P0107, P0108, P0111, P0112, P0113, P0506, and P0507 are not set.
2. The engine speed is between 450-4,000 RPM.
3. The manifold absolute pressure (MAP) is greater than 5 kPa.
4. The mass air flow (MAF) is greater than 2 g/s.
5. The ignition 1 voltage is greater than 10 volts.
6. Start and idle the engine in PARK for 3 minutes.
7. With a scan tool, monitor desired and actual RPM.
8. The ECM will start to learn the new idle cells and Desired RPM should start to decrease.
9. Ignition OFF for 60 seconds.
10. Start and idle the engine in PARK for 3 minutes.
11. After the 3 minute run time the engine should be idling normal. IMPORTANT: During the drive cycle the check engine light may come on with idle speed DTCs. If idle speed codes are set, clear codes so the ECM can continue to learn. If the engine idle speed has not been learned the vehicle will need to be driven at speeds above 70 km/h (44 mph) with several decelerations and extended idles.
12. After the drive cycle, the engine should be idling normally. If the engine idle speed has not been learned, turn OFF the ignition for 60 seconds and repeat step 6.
13. Once the engine speed has returned to normal, clear DTCs.

Throttle Body Inspection and Cleaning

1. Remove the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .
2. Remove the air cleaner outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
3. Inspect the throttle body bore and the throttle body plate for deposits. You will need to open the throttle plate in order to inspect all surfaces.
4. Clean the throttle body bore and the throttle plate using a clean shop towel with GM top engine cleaner, P/N 1052626 (Canadian P/N 993026) or AC Delco Carburetor Tune-up Conditioner, P/N X66P, or equivalent product.
5. Install the air cleaner outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
6. Install the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .
7. Perform the Throttle Body Learn procedure. Refer to «Throttle Learn»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-44l-introduction__throttle-learn) .

Special Tools

CH-48027 Digital Pressure Gage

1. If the fuel system requires repair, prevent fuel spillage by removing the fuel pump fuse. Refer to «Electrical Center Identification Views»(/cadillac/sts/i-2007-2011/remont/electrical-component-locations/#wiring-systems-and-power-management-component-views) .
2. Remove the engine cover, if required.
3. Loosen the fuel fill cap in order to relieve the fuel tank vapor pressure.
4. Remove the fuel rail service port cap.
5. Wrap a shop towel around the fuel rail service port.
6. Connect the CH-48027-3 (4) to the fuel rail service port.
7. Connect the CH-48027-2 (2) to the CH-48027-3 (4).
8. Place the hose on the CH-48027-2 (2) into an approved gasoline container.
9. Open the valve on the CH-48027-2 (2) in order to bleed any fuel from the fuel rail.
10. Close the valve on the CH-48027-2 (2).
11. Remove the hose on the CH-48027-2 (2) from the approved gasoline container.
12. Disconnect the CH-48027-2 (2) from the CH-48027-3 (4).
13. Disconnect the CH-48027-3 (4) from the fuel rail service port.
14. Remove the shop towel from around the fuel rail service port, and place in an approved gasoline container.
15. Install the fuel rail service port cap.
16. Install the engine cover, if required.
17. Tighten the fuel fill cap.

Fuel Pressure Relief (Without CH 48027)

1. If the fuel system requires repair, prevent fuel spillage by removing the fuel pump fuse. Refer to «Electrical Center Identification Views»(/cadillac/sts/i-2007-2011/remont/electrical-component-locations/#wiring-systems-and-power-management-component-views) .
2. Loosen the fuel fill cap in order to relieve the fuel tank vapor pressure.
3. Remove the engine cover, if required.
4. Remove the fuel rail service port cap.
5. Wrap a shop towel around the fuel rail service port and using a small flat-bladed tool, depress (open) the fuel rail test port valve.
6. Remove the shop towel from around the fuel rail service port, and place in an approved gasoline container.
7. Install the fuel rail service port cap.
8. Install the engine cover, if required.
9. Tighten the fuel fill cap.

CH-48027 Digital Pressure Gage

1. Relieve the fuel system pressure. Refer to «Fuel Pressure Relief (With CH 48027)»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) or «Fuel Pressure Relief (Without CH 48027)»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction__fuel-pressure-relief-without-ch-48027) .
2. Connect the CH-48027-1 (1) to the CH-48027-2 (2).
3. Remove the shop towel from around the fuel rail service port, and place in an approved gasoline container.
4. Perform any tests and/or diagnostics as needed. For the proper usage of the CH-48027 , refer to the manufacture's directions.

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

1. J 37088-A Fuel Line Disconnect Tool Set
2. J 44581 Fuel Line Disconnect Tool

1. Relieve the fuel system pressure. Refer to «Fuel Pressure Relief (With CH 48027)»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) or «Fuel Pressure Relief (Without CH 48027)»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction__fuel-pressure-relief-without-ch-48027) .
2. Remove the retainer from the quick-connect fitting.
3. Blow dirt out of the fitting using compressed air.
4. Choose the correct tool for the size and access of the fitting: J 37088-A or J 44581 . Insert the tool into the female connector, then push inward to release the locking tabs.
5. Pull the connection apart.
6. Using a clean shop towel, wipe off the male pipe end.
7. Inspect both ends of the fitting for dirt and burrs. Clean or replace the components as required.

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

1. Relieve the fuel system pressure. Refer to «Fuel Pressure Relief (With CH 48027)»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) or «Fuel Pressure Relief (Without CH 48027)»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction__fuel-pressure-relief-without-ch-48027) .
2. Blow dirt out of the fitting using compressed air.
3. Squeeze the plastic tabs of the male end connector.
4. Pull the connection apart.
5. Wipe off the male pipe end using a clean shop towel.
6. Inspect both ends of the fitting for dirt and burrs.
7. Clean or replace the components as required.

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

1. Relieve the fuel system pressure. Refer to «Fuel Pressure Relief (With CH 48027)»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) or «Fuel Pressure Relief (Without CH 48027)»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction__fuel-pressure-relief-without-ch-48027) .
2. Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/sts/i-2007-2011/remont/hoistjack/#general-information) .
3. Remove the rear suspension bracket. Refer to «Rear Suspension Bracket Replacement»(/cadillac/sts/i-2007-2011/remont/suspension-rear/#rear-suspension-system) .
4. Disconnect the quick-connect fittings (3 and 4) at the fuel filter inlet. Refer to «Metal Collar Quick Connect Fitting Service»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) or «Plastic Collar Quick Connect Fitting Service»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
5. Disconnect the threaded fitting (1) at the fuel filter outlet.
6. Drain any remaining fuel into an approved gasoline container.
7. Remove the fuel filter (2).
8. Remove the fuel pipe O-ring.
9. Discard the fuel filter into an approved container.

1. Remove the protective caps from the new fuel filter.
2. If originally equipped, install new plastic connector retainers on the fuel filter inlets. Install the new retainers in the same position as on the old fuel filter.
3. Lubricate the new fuel pipe O-ring with clean engine oil.
4. Install the fuel pipe O-ring.
5. Slide the fuel filter into place.
6. Connect the quick-connect fittings (3 and 4) to the inlet side of the filter. Refer to «Metal Collar Quick Connect Fitting Service»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) or «Plastic Collar Quick Connect Fitting Service»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
7. Connect the threaded fitting to the fuel filter outlet. Use a back-up wrench in order to prevent the fuel filter from turning. Tighten the fuel filter outlet fitting to 30 N.m (22 lb ft).
8. Install the rear suspension bracket. Refer to «Rear Suspension Bracket Replacement»(/cadillac/sts/i-2007-2011/remont/suspension-rear/#rear-suspension-system) .
9. Lower the vehicle.
10. Ensure that the fuel tank filler cap is installed correctly.
11. Connect the negative battery cable. Refer to «Battery Negative Cable Disconnection and Connection (Side Post)»(/cadillac/sts/i-2007-2011/remont/charging-system/#battery-charging-system-and-starting-system) .
12. Perform the following procedure in order to inspect for leaks: Turn ON the ignition, with the engine OFF for 2 seconds. Turn OFF the ignition for 10 seconds. Turn ON the ignition, with the engine OFF. Inspect for fuel leaks.
13. Install the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .

1. J 36850 Transjel Lubricant
2. J 45004 Fuel Drain Hose

Draining Performance

1. Remove the fuel filler cap.
2. Insert the J 45004 into the fuel tank until the hose reaches the bottom of the fuel tank.
3. Use an air operated pump device in order to drain the fuel into an approved gasoline container. Up to 26 liters (7 gallons) of residual fuel may remain in the secondary side of the fuel tank.
4. Simultaneously twist and pull in order to remove the J 45004 from the fuel tank.

1. Drain the fuel tank. Refer to «Fuel Tank Draining»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-44l-introduction) .
2. Relieve the fuel system pressure. Refer to «Fuel Pressure Relief (With CH 48027)»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) or «Fuel Pressure Relief (Without CH 48027)»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction__fuel-pressure-relief-without-ch-48027) .
3. Remove the exhaust system. Refer to «Exhaust System Replacement»(/cadillac/sts/i-2007-2011/remont/exhaust/#engine-exhaust-system__exhaust-system-replacement) .
4. Remove the propeller shaft. Refer to «Rear Propeller Shaft Replacement (AWD)»(/cadillac/sts/i-2007-2011/remont/driveshaft-universal-joints/#propeller-shaft) or «Rear Propeller Shaft Replacement (RWD)»(/cadillac/sts/i-2007-2011/remont/driveshaft-universal-joints/#propeller-shaft) .
5. Disconnect the filler hose (1) from the fuel tank.
6. Disconnect the filler vent tube (2) from the evaporative emission (EVAP) hose. Refer to «Plastic Collar Quick Connect Fitting Service»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
7. Refer to «Metal Collar Quick Connect Fitting Service»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) or «Plastic Collar Quick Connect Fitting Service»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) in order to disconnect the following from the chassis bundle: The fuel feed hoses (3 and 4) The fuel EVAP hose
8. Disconnect the fuel tank electrical connector.
9. Disconnect the EVAP hoses from the EVAP canister.
10. Pull outward on the retainer tab in order to disengage the retainer from the chassis.
11. Disconnect the electrical connector from the EVAP canister.
12. Raise the lower control arms using a suitable screw jack (3) in order to remove the load from the lower shock bolts (2).
13. Remove the lower shock bolts (2).
14. Remove the screw jack (3).
15. Position the screw jack under the rear frame near the adjuster tie bar, in order to support the front of the rear frame.
16. Remove the 2 front bolts from the rear frame.
17. Lower the screw jack until there is approximately 50 mm (2 in) (a) between the front mounting surface of the rear frame and the chassis. This will allow clearance to access the fuel tank strap bolts.
18. Remove the fuel tank strap bolts.
19. Position the fuel tank straps downward around the rear frame.
20. Carefully bend the fuel tank straps ONLY enough to allow the fuel tank to be removed.
21. With the aid of an assistant, carefully lower the fuel tank from the vehicle.
22. Remove the following components if replacing just the fuel tank: The primary fuel tank module-Refer to «Primary Fuel Tank Module Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) . The secondary fuel tank module-Refer to «Secondary Fuel Tank Module Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) . The fuel tank pressure sensor-Refer to «Fuel Tank Pressure Sensor Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-44l-introduction) .

1. Install the following components if fuel tank replacement was necessary: The primary fuel tank module-Refer to «Primary Fuel Tank Module Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) . The secondary fuel tank module-Refer to «Secondary Fuel Tank Module Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) . The fuel tank pressure sensor-Refer to «Fuel Tank Pressure Sensor Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-44l-introduction) .
2. With the aid of an assistant, carefully raise the fuel tank to the vehicle, aligning the filler neck with the filler hose.
3. Carefully bend the fuel tank straps back to their original form.
4. Position the fuel tank straps around the rear frame and upward into position, aligning the holes in the straps with the threaded holes in the chassis.
5. Install the fuel tank strap bolts and tighten to 50 N.m (37 lb ft).
6. Connect the filler hose (1) to the fuel tank. Tighten the fuel filler tube hose clamp (3) to 3.5 N.m (31 lb in).
7. Connect the filler vent tube (2) to the EVAP hose. Refer to «Plastic Collar Quick Connect Fitting Service»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
8. Connect the EVAP hoses to the EVAP canister.
9. Insert the retainer into the chassis and press inward on the tab to engage.
10. Connect the electrical connector to the EVAP canister.
11. Connect the fuel tank electrical connector.
12. Refer to «Plastic Collar Quick Connect Fitting Service»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) or «Metal Collar Quick Connect Fitting Service»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) in order to connect the following to the chassis bundle: The fuel feed hoses (3 and 4) The fuel EVAP hose
13. Raise the rear frame using the screw jack.
14. Install the 2 front bolts to the rear frame and tighten to 265 N.m (195 lb ft).
15. Remove the screw jack.
16. Position the screw jack (3) under the lower control arm in order to raise the lower control arms (2).
17. Install the lower shock bolts (2) and tighten to 150 N.m (111 lb ft).
18. Remove the screw jack (3).
19. Install the propeller shaft. Refer to «Rear Propeller Shaft Replacement (AWD)»(/cadillac/sts/i-2007-2011/remont/driveshaft-universal-joints/#propeller-shaft) or «Rear Propeller Shaft Replacement (RWD)»(/cadillac/sts/i-2007-2011/remont/driveshaft-universal-joints/#propeller-shaft) .
20. Install the exhaust system. Refer to «Exhaust System Replacement»(/cadillac/sts/i-2007-2011/remont/exhaust/#engine-exhaust-system__exhaust-system-replacement) .
21. Refill the fuel tank.
22. Inspect for fuel leaks.

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/sts/i-2007-2011/remont/hoistjack/#general-information) .
2. Disconnect the fuel tank pressure sensor electrical connector (1).
3. Remove the fuel tank pressure sensor from the evaporative emission (EVAP) canister.

1. Install the fuel tank pressure sensor to the EVAP canister until fully seated.
2. Connect the fuel tank pressure sensor electrical connector (1).
3. Lower the vehicle.

1. Remove the fuel filler cap.
2. Drain the fuel tank below the level of the fuel filler hose. Refer to «Fuel Tank Draining»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-44l-introduction) .
3. Remove the bolts securing the fuel filler tube to the body.
4. Remove the right rear wheel. Refer to «Tire and Wheel Removal and Installation»(/cadillac/sts/i-2007-2011/remont/wheel-tire-system/#tires-and-wheels) .
5. Remove the right rear wheelhouse liner. Refer to «Rear Wheelhouse Panel Liner Replacement»(/cadillac/sts/i-2007-2011/remont/frames-subframes-crossmembers/#frame-and-underbody) .
6. Remove the fuel filler tube brace bolt.
7. Disconnect the fuel filler hose (1) from the fuel tank.
8. Disconnect the filler vent tube (2) from the evaporative emission (EVAP) hose. Refer to «Plastic Collar Quick Connect Fitting Service»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
9. Remove the fuel filler tube from the vehicle.

1. Position the fuel filler tube to the vehicle.
2. Connect the filler hose (1) to the fuel tank. Tighten the fuel filler tube hose clamp (3) to 3.5 N.m (31 lb in).
3. Connect the filler vent tube (2) to the EVAP hose. Refer to «Plastic Collar Quick Connect Fitting Service»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
4. Install the fuel filler tube brace bolt and tighten to 9 N.m (80 lb in).
5. Install the bolts securing the fuel filler tube to the body and tighten to 3.5 N.m (31 lb in).
6. Install the right rear wheelhouse liner. Refer to «Rear Wheelhouse Panel Liner Replacement»(/cadillac/sts/i-2007-2011/remont/frames-subframes-crossmembers/#frame-and-underbody) .
7. Install the right rear wheel. Refer to «Tire and Wheel Removal and Installation»(/cadillac/sts/i-2007-2011/remont/wheel-tire-system/#tires-and-wheels) .
8. Add fuel to the fuel tank.
9. Inspect for fuel leaks.
10. Install the fuel filler cap.

J 45747 Fuel Tank Sender Wrench

1. Remove the fuel tank hoses. Refer to «Fuel Hoses/Pipes Replacement - Filter to Tank»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
2. Disconnect the electrical connector from the primary fuel tank module.
3. Rotate the cam lock ring counterclockwise using the J 45747 .
4. Remove the cam lock ring from the fuel tank.
5. Carefully lift the primary fuel tank module (1) from the fuel tank only enough to access the transfer tube (2).
6. Complete the following in order to disconnect the transfer tube from the primary fuel tank module: Pull the locking mechanism away from the module. Remove the transfer tube from the module.
7. Remove the primary fuel tank module from the fuel tank.
8. Remove the primary fuel tank module seal from the module. Do not reuse the seal.

1. Place the new primary fuel tank module seal (1) over the module (2).
2. Complete the following in order to connect the transfer tube (2) to the primary fuel tank module (1). Grasp the transfer tube (2) from inside the fuel tank. Position the module (1) near the module opening. Connect the transfer tube (2) to the module (1).
3. Carefully insert the primary fuel tank module (1) into the fuel tank.
4. Press the primary fuel tank module (1) downward, aligning the module to the encapsulated ring.
5. Position the cam lock ring to the fuel tank.
6. Rotate the cam lock ring clockwise using the J 45747 until fully seated.
7. Connect the electrical connector to the primary fuel tank module.
8. Install the fuel tank hoses. Refer to «Fuel Hoses/Pipes Replacement - Filter to Tank»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .

J 45747 Fuel Tank Sender Wrench

1. Remove the fuel tank. Refer to «Fuel Tank Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
2. Disconnect the electrical connector from the secondary fuel tank module.
3. Rotate the cam lock ring counterclockwise using the J 45747 .
4. Remove the cam lock ring from the fuel tank.
5. Carefully lift the secondary fuel tank module (2) from the fuel tank only enough to access the transfer tube (1).
6. Complete the following in order to disconnect the transfer tube from the secondary fuel tank module. Pull the locking mechanism away from the module. Remove the transfer tube from the module.
7. Remove the secondary fuel tank module from the fuel tank.
8. Remove the secondary fuel tank module seal from the module. Do not reuse the seal.

1. Place the new secondary fuel tank module seal (1) over the module (2).
2. Complete the following in order to connect the transfer tube (1) to the secondary fuel tank module (2). Grasp the transfer tube (1) from inside the fuel tank. Position the module (2) near the module opening. Connect the transfer tube (1) to the module (2).
3. Carefully insert the secondary fuel tank module (2) into the fuel tank.
4. Press the secondary fuel tank module (2) downward, aligning the module to the encapsulated ring.
5. Position the cam lock ring to the fuel tank.
6. Rotate the cam lock ring clockwise using the J 45747 until fully seated.
7. Connect the electrical connector to the secondary fuel tank module.
8. Install the fuel tank. Refer to «Fuel Tank Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .

1. Remove the primary fuel tank module. Refer to «Primary Fuel Tank Module Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
2. Disconnect the fuel level sensor electrical connector (1) from the module.
3. Complete the following in order to remove the fuel level sensor (1) from the module assembly: Pull the locking tab (2) away from the sensor (1). Slide the sensor (1) away from the module assembly.

1. Complete the following in order to install the fuel level sensor (1) to the module assembly: Align the tabs of the sensor (1) with the slots in the module assembly. Slide the sensor (1) fully into position, ensure the locking tab (2) is engaged.
2. Connect the fuel level sensor electrical connector (1) to the module.
3. Install the primary fuel tank module. Refer to «Primary Fuel Tank Module Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .

1. Remove the fuel tank. Refer to «Fuel Tank Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
2. Disconnect the following from the primary fuel tank module: The pressure hose The return hose
3. Disconnect the hoses from the retaining feature at the fuel tank.

1. Clean any contamination from the male pipe ends of the primary fuel tank module.
2. Connect the hoses to the retaining feature at the fuel tank.
3. Connect the following to the primary fuel tank module: The pressure hose The return hose
4. Install the fuel tank. Refer to «Fuel Tank Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .

The fuel system hose/pipes are serviceable individually or as a complete fuel/brake bundle assembly, the following procedure is servicing the fuel hose/pipes individually.

1. Relieve the fuel system pressure. Refer to «Fuel Pressure Relief (With CH 48027)»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) or «Fuel Pressure Relief (Without CH 48027)»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction__fuel-pressure-relief-without-ch-48027) .
2. Disconnect the feed hose/pipe (1) from the fuel rail. Refer to «Metal Collar Quick Connect Fitting Service»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
3. Plug the open ports to prevent fuel loss and contamination.
4. Disconnect the evaporative emission (EVAP) quick connect fitting (2). Refer to «Plastic Collar Quick Connect Fitting Service»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
5. Open the retainers (1 and 2) located at the rear of the engine and on the front of dash.
6. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/sts/i-2007-2011/remont/hoistjack/#general-information) .
7. Refer to «Plastic Collar Quick Connect Fitting Service»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) and «Metal Collar Quick Connect Fitting Service»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) in order to disconnect the following quick connect fittings from the chassis bundle: The fuel filter (2) The fuel hose The fuel EVAP hose Plug the open outlet ports to prevent fuel loss and contamination.
8. Pull the locking mechanism (1) outward in order to disengage the fuel/brake bundle chassis pipe retainers from the rail.
9. Open the retainers (1) located at the forward portion of the rail in order to remove the chassis hose/pipes.
10. Complete the following in order to remove the chassis hose/pipes from the retainers (2) located at the rearward portion of the rail: Pull the retainers (2) free from the rail. Open the retainers (2) at the top. Remove the chassis hose/pipes from the retainers (2).
11. Pull downward in order to disconnect the fuel/brake bundle chassis pipe retainer from the underbody.
12. Remove the bolt securing the fuel filter bracket to the body.
13. Remove the bolts securing the transmission support to the underbody, from the right side only.
14. Pull the right side transmission support down only enough to allow removal of the chassis fuel hose/pipes.
15. Partially lower the hoist only enough to simultaneously gain access to both the front and rear portions of the chassis fuel hose/pipes.
16. With the aid of an assistant, carefully guide the chassis fuel hose/pipes down through the engine compartment, removing from the bottom.

1. Clean any of the contamination from the male line ends and apply a few drops of clean engine oil.
2. With the aid of an assistant, carefully guide the chassis fuel hose/pipes up through the engine compartment into position.
3. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/sts/i-2007-2011/remont/hoistjack/#general-information) .
4. Pull the right side transmission support down only enough to allow installation of the chassis fuel hose/pipes.
5. Install the bolts securing the transmission support to the underbody and tighten to 60 N.m (44 lb ft).
6. Install the bolt securing the fuel filter bracket to the body and tighten to 9 N.m (80 lb in).
7. Push upward in order to connect the fuel/brake bundle chassis pipe retainer to the underbody.
8. Complete the following in order to install the chassis hose/pipes to the retainers (2) located at the rearward portion of the rail: Install the chassis hose/pipes into the retainers (2). Close the retainers (2) at the top. Insert the retainers (2) into the rail.
9. Install the chassis hose/pipes into the retainers (1) located at the forward portion of the rail.
10. Close the retainers.
11. Push the locking mechanism (1) inward in order to engage the fuel/brake bundle chassis pipe retainers to the rail.
12. Refer to «Plastic Collar Quick Connect Fitting Service»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) and «Metal Collar Quick Connect Fitting Service»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) in order to connect the following quick connect fittings to the chassis bundle: The fuel filter (2) The fuel hose The fuel EVAP hose
13. Lower the vehicle.
14. Insert the chassis hose/pipes into the retainers (1 and 2) located at the rear of the engine and the front of dash.
15. Close the retainers.
16. Connect the EVAP quick connect fitting (2). Refer to «Plastic Collar Quick Connect Fitting Service»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
17. Connect the fuel feed pipe (1) to the fuel rail. Refer to «Metal Collar Quick Connect Fitting Service»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
18. Check the fuel system for leaks.
19. Install the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .

Fuel System Cleaning

The following procedure covers the disassembly and the inspection of the complete fuel supply system. If the fuel system is contaminated, the fuel system can be cleaned. You can usually determine the extent of the fuel system contamination during the disassembly.

1. Remove the in-line fuel filter. Refer to «Fuel Filter Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
2. Inspect the fuel system for contamination of the in-line fuel filter. Replace the filter after cleaning the fuel lines if the filter is plugged or contaminated.
3. Remove the fuel module assemblies. Refer to «Primary Fuel Tank Module Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) and «Secondary Fuel Tank Module Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
4. Locate the tank in a suitable work area away from any heat, any flame, or any other source of ignition.
5. Perform the following procedures: Inspect the fuel sender strainer. Replace the primary fuel tank module if the strainer is contaminated. Inspect the secondary fuel tank module for debris. Clean the secondary fuel tank module if debris is found. WARNING: Wear safety glasses when using compressed air, as flying dirt particles may cause eye injury. Use compressed air in order to apply air pressure to the transfer tube.
6. Flush the fuel tank with running hot water for at least five minutes. Pour the water out of the fuel sender assembly opening. Rock the tank in order to ensure that the removal of the water from the tank is complete.
7. Disconnect the fuel feed hose/pipe from the fuel rail. Refer to «Metal Collar Quick Connect Fitting Service»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
8. Use compressed air in order to apply air pressure to the fuel lines in the opposite direction from the normal fuel flow.
9. Remove the fuel injectors and fuel rail. Refer to «Fuel Injector and Fuel Rail Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
10. Clean and inspect the fuel injectors and fuel rail.

Assemble the fuel system as follows

1. Install the fuel injectors and fuel rail. Refer to «Fuel Injector and Fuel Rail Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
2. Install the fuel module assemblies. Refer to «Primary Fuel Tank Module Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) and «Secondary Fuel Tank Module Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
3. Install the fuel filter. Refer to «Fuel Filter Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
4. Connect the fuel line to the fuel rail. Refer to «Metal Collar Quick Connect Fitting Service»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .

1. Relieve the fuel system pressure. Refer to «Fuel Pressure Relief (With CH 48027)»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) or «Fuel Pressure Relief (Without CH 48027)»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction__fuel-pressure-relief-without-ch-48027) .
2. Remove the cross vehicle brace. Refer to «Cross Vehicle Brace Replacement»(/cadillac/sts/i-2007-2011/remont/exterior-body-panels/#bolted-exterior-body-panels-and-closures) .
3. Clean the fuel rail assembly with a spray type engine cleaner, GM X-30A or equivalent, if necessary. Follow the package instructions. Do not soak the fuel rail in liquid cleaning solvent.
4. Disconnect the fuel feed hose/pipe (1) from the fuel rail. Refer to «Metal Collar Quick Connect Fitting Service»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
5. Remove the positive crankcase ventilation (PCV) dirty air hose.
6. Disconnect the evaporative emission (EVAP) quick connect fitting (2). Refer to «Plastic Collar Quick Connect Fitting Service»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
7. Open the retainers (1 and 2) located at the right side rear of the engine and the front of dash. Position the lines aside.
8. Disconnect the left side fuel injector wiring harness connectors (1) from the fuel injectors (2).
9. Disconnect the right side fuel injector wiring harness connectors (1) from the fuel injectors (2).
10. Remove the fuel injector sight shield bracket.
11. Remove the fuel rail attaching studs.
12. Remove the fuel rail assembly.
13. Remove the injector lower O-ring seal from the spray tip end of each injector.
14. Discard the O-ring seals.
15. Remove the retainers from the fuel injectors.
16. Remove the fuel injectors from the fuel rail.
17. Remove the O-ring seals from the fuel injectors. Discard the O-ring seals.

1. Lubricate the new fuel injector O-ring seals with clean engine oil.
2. Install the new fuel injector O-ring seals on to the fuel injectors.
3. Install the fuel injectors to the fuel rail using new retainer clips.
4. Ensure that the injectors are aligned by orientating the electrical connectors perpendicular to the crankshaft centerline.
5. Lubricate and install the new O-ring seals on the spray tip end of each injector.
6. Align the fuel injectors and fuel rail to the intake manifold.
7. Carefully press the fuel rail assembly downward until fully seated against the intake manifold.
8. Install the fuel rail attaching studs and tighten to 10 N.m (89 lb in).
9. Install the fuel injector sight shield bracket nuts and tighten to 10 N.m (89 lb in).
10. Connect the right side fuel injector electrical connectors (1) to each fuel injector (2).
11. Connect the left side fuel injector electrical connectors (1) to each fuel injector (2).
12. Install the fuel feed and EVAP lines to the retaining clips (1 and 2) at the right side rear of the engine and at the front of dash.
13. Install the EVAP quick connect fitting (2) to the purge valve. Refer to «Plastic Collar Quick Connect Fitting Service»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
14. Install the positive crankcase ventilation (PCV) dirty air hose.
15. Connect the fuel feed hose/pipe to the fuel rail (1). Refer to «Metal Collar Quick Connect Fitting Service»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
16. Install the cross vehicle brace. Refer to «Cross Vehicle Brace Replacement»(/cadillac/sts/i-2007-2011/remont/exterior-body-panels/#bolted-exterior-body-panels-and-closures) .
17. Connect the negative battery cable. Refer to «Battery Negative Cable Disconnection and Connection (Side Post)»(/cadillac/sts/i-2007-2011/remont/charging-system/#battery-charging-system-and-starting-system) .
18. Inspect for fuel leaks using the following procedure: Turn ON the ignition, with the engine OFF for 2 seconds. Turn OFF the ignition for 10 seconds. Turn ON the ignition, with the engine OFF. Inspect for fuel leaks.
19. Install the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .

1. Loosen the fuel cap in order to relieve the system pressure.
2. Remove the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .
3. Disconnect the evaporative emission (EVAP) canister purge valve electrical connector (1).
4. Disconnect the EVAP purge pipe (2) from the EVAP canister purge valve.
5. Remove the EVAP canister purge valve retaining bolt.
6. Remove the EVAP canister purge valve from the water housing.

1. Lubricate the O-ring with clean engine oil.
2. Install the EVAP canister purge valve to the water housing.
3. Install the EVAP canister purge valve retaining bolt and tighten to 12 N.m (106 lb in).
4. Connect the EVAP purge pipe (2) to the EVAP canister purge valve.
5. Connect the EVAP canister purge valve electrical connector (1).
6. Install the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .

1. Remove the evaporative emission (EVAP) canister. Refer to «Evaporative Emission Canister Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
2. Clean away any debris that may be present around the EVAP canister vent valve.
3. Twist the EVAP canister vent valve counter-clockwise.
4. Pull the EVAP canister vent valve from the EVAP canister.

1. Insert the EVAP canister vent valve into the EVAP canister.
2. Twist the EVAP canister vent valve clockwise into the locked position.
3. Install the EVAP canister. Refer to «Evaporative Emission Canister Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .

1. Remove the fuel tank. Refer to «Fuel Tank Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
2. Remove the chassis to canister evaporative emission (EVAP) hose from the following: The body retainer (1) The 3 retaining features (2) on the fuel tank The retainer clip (3)
3. Remove the EVAP hose from the fuel tank.

1. Position the EVAP hose to the fuel tank.
2. Install the chassis to canister evaporative emission (EVAP) hose to the following: The body retainer (1) The 3 retaining features (2) on the fuel tank The retainer clip (3)
3. Install the fuel tank. Refer to «Fuel Tank Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .

1. Remove the rear frame. Refer to «Rear Frame Replacement»(/cadillac/sts/i-2007-2011/remont/frames-subframes-crossmembers/#frame-and-underbody) .
2. Disconnect the evaporative emission (EVAP) hoses from the EVAP canister.
3. Disconnect the electrical connector from the EVAP canister.
4. Remove the EVAP canister retaining nuts.
5. Complete the following in order to remove the EVAP canister: Lower the rear of the canister enough to clear the 2 weld studs. Slide the canister rearward from the body brace.

1. Complete the following in order to install the EVAP canister: Insert the fresh air tube and tab on the canister forward into the body brace. Rotate the rear of the canister up over the 2 weld studs on the floor pan.
2. Install the EVAP canister retaining nuts and tighten to 6 N.m (53 lb in).
3. Connect the EVAP hoses to the EVAP canister.
4. Connect the electrical connector to the EVAP canister.
5. Install the rear frame. Refer to «Rear Frame Replacement»(/cadillac/sts/i-2007-2011/remont/frames-subframes-crossmembers/#frame-and-underbody) .

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/sts/i-2007-2011/remont/hoistjack/#general-information) .
2. Using a 90 degree pick, disengage the lower filter cover clips.
3. Insert a flat-bladed tool between the filter cover and canister, and push up to disengage the upper clips.
4. Remove and discard the evaporative emission (EVAP) canister filter cover.
5. Remove and discard the EVAP canister filter.
6. Clean the inside of the EVAP canister filter housing with a clean shop towel.

1. Insert a NEW EVAP canister filter into the EVAP canister.
2. Install a NEW EVAP canister filter cover seal to a EVAP NEW canister cover.
3. Snap the EVAP canister filter cover onto the EVAP canister.
4. Lower the vehicle.

J 41413 EVAP Pressure and Purge Station

Inspection Procedure

1. Turn OFF the ignition.
2. Remove the EVAP canister purge valve. Refer to «Evaporative Emission Canister Purge Solenoid Valve Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
3. Lightly tap the EVAP canister purge valve on a hard surface.
4. Inspect for carbon particles exiting either of the vacuum ports. If no carbon particles were detected, but a blockage was detected during a diagnostic procedure, install the original EVAP canister purge valve. Continue with the cleaning procedure. If carbon particles are found during the inspection procedure, continue with the cleaning procedure. If a diagnostic procedure directed you to replace the EVAP canister purge valve and no carbon particles were detected, replace the EVAP canister purge valve. Return to the published service procedure.

Cleaning Procedure

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/sts/i-2007-2011/remont/hoistjack/#general-information) .
2. Remove the EVAP canister. Refer to «Evaporative Emission Canister Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
3. Turn OFF the main valve on the J 41413 .
4. Disconnect the hose from the diagnostic station pressure regulator.
5. Using a section of vacuum hose, connect one end onto the EVAP pressure/purge diagnostic station pressure regulator.
6. Connect the other end of the vacuum hose to the canister side of the purge pipe.
7. Turn ON the main nitrogen cylinder valve and continue to discharge nitrogen for 15 seconds.
8. If the nitrogen does not clear the blockage, replace the purge pipe.
9. Return the EVAP pressure/purge diagnostic station to the stations original condition.
10. Install a new EVAP canister. Refer to «Evaporative Emission Canister Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
11. Lower the vehicle.
12. Install a new EVAP canister purge valve. Refer to «Evaporative Emission Canister Purge Solenoid Valve Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
13. Return to the diagnostic table that sent you here.

1. Remove the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .
2. Remove the ignition coil cover from the cam cover by lifting straight up.
3. Disconnect the ignition coil wiring harness electrical connector from the coil that needs to be replaced.
4. Remove the ignition coil retaining bolt.
5. Carefully remove the ignition coil.

1. Install the ignition coil.
2. Install the ignition coil retaining bolt and tighten to 10 N.m (89 lb in).
3. Reconnect the ignition coil electrical connector.
4. Install the ignition coil cover to the cam cover.
5. Install the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .

1. Remove the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .
2. Remove the ignition coil cover from the cam cover by lifting straight up.
3. Disconnect the ignition coil wiring harness electrical connector from the coil that needs to be replaced.
4. Remove the ignition coil retaining bolt.
5. Carefully remove the ignition coil assembly.

1. Install the ignition coil.
2. Install the ignition coil retaining bolt and tighten to 10 N.m (89 lb in).
3. Reconnect the ignition coil electrical connector.
4. Install the ignition coil cover to the cam cover.
5. Install the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .

Spark Plug Operation

Worn or dirty spark plugs may operate well at idle speeds, but frequently fail at higher load. Bad spark plugs are often responsible for the following conditions

1. Power loss
2. Poor fuel economy
3. Loss of speed
4. Hard starting
5. Poor engine performance

Normal spark plug operation results in brown to grayish tan deposits on the area of the spark plug that enters the cylinder. A small amount of reddish brown, yellow, and white powdery residue may also be present on the insulator tip around the center electrode. These deposits are normal combustion by-products of fuels and lubricating oils which contain additives.

Misfiring is a general term that applies to a poor running engine. With misfiring, the ignition spark is not igniting the air/fuel mixture at the proper time. While other possible causes must be investigated, the spark plugs should be inspected first. Spark voltage should not reach ground before jumping across the gap at the tip of the spark plug. This leaves the air/fuel mixture unburned, causing misfiring. Pre-ignition misfiring occurs when the spark plug tip overheats, igniting the mixture before the spark jumps.

Carbon fouling of the spark plug is indicated by dry carbon deposits on the portion of the spark plug inside of the cylinder. Excess idling and driving at slower speeds under light engine loads can keep the spark plug temperatures so low that these deposits are not burned off. Rich fuels or poor ignition system output may also cause carbon fouling.

Oil fouling of the spark plug appears as wet oily deposits on the portion of the spark plug inside of the cylinder. This may be caused by the following conditions

1. Oil getting past worn piston rings
2. Breaking in a new or recently overhauled engine

Deposit fouling of the spark plug occurs when the normal reddish brown, yellow, or white deposits of combustion by-products become sufficient enough to cause misfiring. In some cases, these deposits melt and form a shiny glaze on the insulator around the center electrode. If the fouling is found only in one or two of the cylinders, valve stem clearances or the intake valve seals may be allowing excess lubricating oil to enter the cylinder, particularly if the deposits are heavier on the intake valve side of the spark plug.

Excess gap means that the air space between the center and side electrodes at the bottom of the spark plug is too wide for consistent firing. This may be due to improper gap adjustment or to excess wear of the electrodes during use. A gap that is too small may cause idling instability. Excess gap wear might indicate vehicle operation at continual high speeds or with high engine loads. This causes the spark plugs to run too hot. Excessively lean fuel may also cause the wear.

Improper torque or seating can cause a spark plug to run hot, eventually leading to excess gap wear. In extreme cases, an overtightened or under-tightened spark plug can cause exhaust blow-by. The cylinder head seats must make good contact for sufficient heat transfer and spark plug cooling. Dirty or damaged threads in the head or on the spark plug can keep the spark plug from seating even though the proper torque is applied. Once the spark plugs are properly seated, tighten the spark plugs properly.

Cracked or broken insulators and insulator tips may be the result of improper installation or heat shock. Heat shock is a rapid increase in the insulator tip temperature which causes the insulator material to crack. The upper insulators can be broken when a poorly-fitting tool is used during servicing, or when the spark plug is hit from the outside. Cracks in the upper insulator may be inside the shell or invisible. The breakage may not cause problems until oil or water penetrates the crack later. Heat shock breakage in the lower insulator tip generally occurs during severe engine operating conditions such as higher RPM or heavy loading. Over advanced timing or low grade fuels may also cause heat shock breakage. Always replace spark plugs with broken or cracked insulators.

Damage during gapping can occur when the tool is pushed against the center electrode or the surrounding insulator, causing the insulator to crack. When gapping a spark plug, bend only the outside electrode. Keep tools free of any other parts.

Spark plugs with less than the recommended amount of service can sometimes be cleaned and regapped, then returned to service. If there is any doubt about the serviceability of a spark plug, replace the spark plug.

1. Remove the ignition coils. Refer to «Ignition Coil Replacement - Bank 1»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) and/or «Ignition Coil Replacement - Bank 2»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
2. Clean the spark plug recess area with low pressure air.
3. Remove the spark plugs from the cylinder heads.
4. Inspect the spark plugs. Refer to «Spark Plug Inspection»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-44l-introduction) .

1. Measure the spark plug gap on the spark plugs to be installed. Compare the measurement to the gap specifications. Refer to «Ignition System Specifications»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction__ignition-system-specifications) , correct as necessary.
2. Install the spark plugs to the cylinder heads and tighten to 20 N.m (15 lb ft).
3. Install the ignition coils. Refer to «Ignition Coil Replacement - Bank 1»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) and/or «Ignition Coil Replacement - Bank 2»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .

1. Remove the intake manifold. Refer to «Intake Manifold Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .
2. Disconnect the crankshaft position sensor electrical connector.
3. Remove the crankshaft sensor retaining bolt.
4. Remove the crankshaft sensor.

1. Lubricate the crankshaft sensor O-ring with clean engine oil.
2. Install the crankshaft sensor and the retaining bolt and tighten to 10 N.m (89 lb in).
3. Connect the crankshaft position sensor electrical connector.
4. Install the intake manifold. Refer to «Intake Manifold Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .
5. Perform the «Crankshaft Position System Variation Learn»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-44l-introduction__crankshaft-position-system-variation-learn) .

1. Remove the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .
2. Disconnect the electrical connector from the left bank exhaust camshaft position sensor (2).
3. Remove the camshaft sensor retaining bolt.
4. Remove the left bank exhaust camshaft sensor (4).

1. Lubricate the camshaft sensor O-ring with engine oil.
2. Install the left bank exhaust camshaft position sensor (4) and retaining bolt and tighten to 10 N.m (89 lb in).
3. Reconnect the camshaft sensor electrical connector (2).
4. Install the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .
5. Operate the engine and inspect the camshaft sensor for engine oil leaks.

1. Remove the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .
2. Disconnect the electrical connector from the left bank intake camshaft position sensor (1).
3. Remove the camshaft sensor retaining bolt.
4. Remove the left bank intake camshaft sensor (3).

1. Lubricate the camshaft sensor O-ring with engine oil.
2. Install the left bank intake camshaft position sensor (3) and retaining bolt. Tighten: Tighten the retaining bolt to 10 N.m (89 lb in).
3. Reconnect the camshaft sensor electrical connector (1).
4. Install the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .
5. Operate the engine and inspect the camshaft sensor for engine oil leaks.

1. Remove the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .
2. Disconnect the electrical connector from the right bank exhaust camshaft position sensor (2).
3. Remove the camshaft sensor retaining bolt.
4. Remove the right bank exhaust camshaft sensor (1).

1. Lubricate the camshaft sensor O-ring with engine oil.
2. Install the right bank exhaust camshaft position sensor (1) and retaining bolt and tighten to 10 N.m (89 lb in).
3. Reconnect the camshaft sensor electrical connector (2).
4. Install the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .
5. Operate the engine and inspect the camshaft sensor for engine oil leaks.

1. Remove the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .
2. Disconnect the electrical connector from the right bank intake camshaft position sensor (1).
3. Remove the camshaft sensor retaining bolt.
4. Remove the right bank intake camshaft sensor (2).

1. Lubricate the camshaft sensor O-ring with engine oil.
2. Install the right bank intake camshaft position sensor (2) and retaining bolt and tighten to 10 N.m (89 lb in).
3. Reconnect the camshaft sensor electrical connector (1).
4. Install the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .
5. Operate the engine and inspect the camshaft sensor for engine oil leaks.

1. Remove the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .
2. Disconnect the actuator solenoid electrical connector.
3. Remove the right intake camshaft position (CMP) actuator solenoid bolts.
4. Remove the right intake CMP actuator solenoid.

Note. The CMP actuator solenoid must be precisely aligned to the CMP actuator oil control valve on the end of the camshaft. This is accomplished with an alignment pin. Failure to align the CMP actuator solenoid to the CMP actuator oil control valve can lead to poor engine performance.

To allow for CMP actuator solenoid to CMP actuator oil control valve alignment, DO NOT install the NEW CMP actuator solenoid alignment plugs at this time.

Camshaft Position Actuator Solenoid Alignment Procedure

1. Make an alignment pin from drill rod 15/64 inch diameter and at least 50 mm (1.97 in) long.
2. If necessary remove the black alignment plug on the actuator and verify that the alignment pin will pass through the CMP actuator solenoid alignment hole.
3. Verify that the alignment pin will fit into the alignment hole in the CMP actuator oil control valve.
4. Apply a 2 mm (0.079 in) bead of RTV GM P/N 12378521 (Canadian P/N 88901148) around the flange of the CMP actuator solenoid.
5. Install the CMP actuator solenoid over the oil control valve.
6. Install the alignment pin through the solenoid alignment hole and into the oil control valve alignment hole.
7. With the alignment pin in place, install the CMP actuator solenoid bolts and tighten to 8 N.m (71 lb in).
8. Remove the alignment pin.
9. Install a NEW CMP actuator solenoid plug.
10. Connect the electrical connector to the actuator solenoid.
11. Install the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .

1. Remove the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .
2. Disconnect the actuator solenoid electrical connector.
3. Remove the right exhaust camshaft position (CMP) actuator solenoid bolts.
4. Remove the right exhaust CMP actuator solenoid.

Note. The CMP actuator solenoid must be precisely aligned to the CMP actuator oil control valve on the end of the camshaft. This is accomplished with an alignment pin. Failure to align the CMP actuator solenoid to the CMP actuator oil control valve can lead to poor engine performance.

To allow for CMP actuator solenoid to CMP actuator oil control valve alignment, DO NOT install the NEW CMP actuator solenoid alignment plugs at this time.

1. Make an alignment pin from drill rod 15/64 inch diameter and at least 50 mm (1.97 in) long.
2. If necessary remove the black alignment plug on the actuator and verify that the alignment pin will pass through the CMP actuator solenoid alignment hole.
3. Verify that the alignment pin will fit into the alignment hole in the CMP actuator oil control valve.
4. Apply a 2 mm (0.079 in) bead of RTV GM P/N 12378521 (Canadian P/N 88901148) around the flange of the CMP actuator solenoid.
5. Install the CMP actuator solenoid over the oil control valve.
6. Install the alignment pin through the solenoid alignment hole and into the oil control valve alignment hole.
7. With the alignment pin in place, install the CMP actuator solenoid bolts and tighten to 8 N.m (71 lb in).
8. Remove the alignment pin.
9. Install a NEW CMP actuator solenoid plug.
10. Connect the electrical connector to the actuator solenoid.
11. Install the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .

1. Remove the remote power steering reservoir. Refer to «Remote Power Steering Fluid Reservoir Replacement (LH2)»(/cadillac/sts/i-2007-2011/remont/manual-power-steering/#power-steering-system) .
2. Disconnect the actuator solenoid electrical connector.
3. Remove the left intake camshaft position (CMP) actuator solenoid bolts.
4. Remove the left intake CMP actuator solenoid.

Note. The CMP actuator solenoid must be precisely aligned to the CMP actuator oil control valve on the end of the camshaft. This is accomplished with an alignment pin. Failure to align the CMP actuator solenoid to the CMP actuator oil control valve can lead to poor engine performance.

To allow for CMP actuator solenoid to CMP actuator oil control valve alignment, DO NOT install the NEW camshaft position actuator solenoid alignment plugs at this time.

1. Make an alignment pin from drill rod 15/64 inch diameter and at least 50 mm (1.97 in) long.
2. If necessary remove the black alignment plug on the actuator and verify that the alignment pin will pass through the CMP actuator solenoid alignment hole.
3. Verify that the alignment pin will fit into the alignment hole in the CMP actuator oil control valve.
4. Apply a 2 mm (0.079 in) bead of RTV GM P/N 12378521 (Canadian P/N 88901148) around the flange of the CMP actuator solenoid.
5. Install the CMP actuator solenoid over the oil control valve.
6. Install the alignment pin through the solenoid alignment hole and into the oil control valve alignment hole.
7. With the alignment pin in place, install the CMP actuator solenoid bolts and tighten to 8 N.m (71 lb in).
8. Remove the alignment pin.
9. Install a NEW CMP actuator solenoid plug.
10. Connect the electrical connector to the actuator solenoid.
11. Install the remote power steering reservoir. Refer to «Remote Power Steering Fluid Reservoir Replacement (LH2)»(/cadillac/sts/i-2007-2011/remont/manual-power-steering/#power-steering-system) .

1. Remove the remote power steering reservoir. Refer to «Remote Power Steering Fluid Reservoir Replacement (LH2)»(/cadillac/sts/i-2007-2011/remont/manual-power-steering/#power-steering-system) .
2. Disconnect the actuator solenoid electrical connector.
3. Remove the left exhaust camshaft position (CMP) actuator solenoid bolts.
4. Remove the left exhaust CMP actuator solenoid.

Note. The CMP actuator solenoid must be precisely aligned to the CMP actuator oil control valve on the end of the camshaft. This is accomplished with an alignment pin. Failure to align the CMP actuator solenoid to the CMP actuator oil control valve can lead to poor engine performance.

To allow for CMP actuator solenoid to CMP actuator oil control valve alignment, DO NOT install the NEW CMP actuator solenoid alignment plugs at this time.

1. Make an alignment pin from drill rod 15/64 inch diameter and at least 50 mm (1.97 in) long.
2. If necessary remove the black alignment plug on the actuator and verify that the alignment pin will pass through the CMP actuator solenoid alignment hole.
3. Verify that the alignment pin will fit into the alignment hole in the CMP actuator oil control valve.
4. Apply a 2 mm (0.079 in) bead of RTV GM P/N 12378521 (Canadian P/N 88901148) around the flange of the CMP actuator solenoid.
5. Install the CMP actuator solenoid over the oil control valve.
6. Install the alignment pin through the solenoid alignment hole and into the oil control valve alignment hole.
7. With the alignment pin in place, install the CMP actuator solenoid bolts and tighten to 8 N.m (71 lb in).
8. Remove the alignment pin.
9. Install a NEW CMP actuator solenoid plug.
10. Connect the electrical connector to the actuator solenoid.
11. Install the air conditioning, power steering and water pump drive belt tensioner. Refer to «Drive Belt Tensioner Replacement - Air Conditioning, Power Steering, and Water Pump»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .
12. Install the remote power steering reservoir. Refer to «Remote Power Steering Fluid Reservoir Replacement (LH2)»(/cadillac/sts/i-2007-2011/remont/manual-power-steering/#power-steering-system) .

1. Remove the intake manifold. Refer to «Intake Manifold Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .
2. Disconnect the knock sensor (KS) electrical connector (2).
3. Remove the KS bolt.
4. Remove the KS (1).

1. Thoroughly clean the mating surfaces of the KS and the engine block. The entire contact surface of the KS must lie directly on the engine block.
2. Install the KS (1) and tighten bolt to 20 N.m (15 lb ft).
3. Ensure that the wiring harness is installed correctly.
4. Connect the KS electrical connector (2).
5. Install the intake manifold. Refer to «Intake Manifold Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .

1. Remove the intake manifold. Refer to «Intake Manifold Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .
2. Disconnect the knock sensor (KS) electrical connector (3).
3. Remove the KS bolt.
4. Remove the KS (4).

1. Thoroughly clean the mating surfaces of the KS and the engine block. The entire contact surface of the KS must lie directly on the engine block.
2. Install the KS (4) and tighten bolt to 20 N.m (15 lb ft).
3. Ensure that the wiring harness is installed correctly.
4. Connect the KS electrical connector (3).
5. Install the intake manifold. Refer to «Intake Manifold Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .

1. Remove the air cleaner outlet duct from the vehicle. Refer to «Air Cleaner Outlet Duct Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
2. Remove the air cleaner housing screws.
3. Open the air cleaner housing.
4. Remove the air cleaner element.
5. Remove any loose debris that may be found laying in the base of the air cleaner.

1. Install the new air filter element.
2. Close the air cleaner housing.
3. Install the air cleaner housing screws and tighten to 3 N.m (27 lb in).
4. Install the air cleaner outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .

1. Remove the air cleaner outlet duct from the vehicle. Refer to «Air Cleaner Outlet Duct Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
2. Disconnect the mass air flow (MAF)/intake air temperature (IAT) sensor electrical connector.
3. Remove the MAF/IAT sensor if necessary. Refer to «Mass Airflow Sensor/Intake Air Temperature Sensor Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
4. Remove the coolant hose from the retaining feature on the top of the air cleaner assembly. Position the hose aside.
5. Remove the screws securing the air cleaner assembly to the vehicle and remove the assembly.

Note. An improperly installed air cleaner or a distorted or missing intake air duct may cause a diagnostic trouble code (DTC) to set. Ensure that the air cleaner assembly and intake air duct is installed correctly and that there are no kinks or folds in the intake air duct. Debris in the air cleaner assembly or MAF sensor inlet screen, that may distort air flow can set a DTC.

1. Install the air cleaner assembly into the vehicle.
2. Install the air cleaner assembly screws and tighten to 10 N.m (89 lb in).
3. Install the coolant hose into the retaining feature on the top of the air cleaner assembly.
4. Install the MAF/IAT sensor if previously removed. Refer to «Mass Airflow Sensor/Intake Air Temperature Sensor Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .
5. Connect the MAF/IAT sensor electrical connector.
6. Install the air cleaner outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(/cadillac/sts/i-2007-2011/remont/testing-diagnostics/#engine-controls-and-fuel-46l-introduction) .

1. Remove the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .
2. Disconnect the positive crankcase ventilation (PCV) tube from the air cleaner duct.
3. Loosen the air duct clamp at the throttle body.
4. Loosen the air duct clamp at the mass air flow (MAF)/intake air temperature (IAT) sensor.
5. Remove the air cleaner duct from the vehicle.

1. Install the air cleaner duct to the vehicle.
2. Tighten the air cleaner duct clamps at the throttle body and the MAF/IAT sensor to 3 N.m (27 lb in).
3. Connect the PCV tube to the air cleaner duct.
4. Install the fuel injector sight shield. Refer to «Fuel Injector Sight Shield Replacement»(/cadillac/sts/i-2007-2011/remont/mechanical/#engine-mechanical-46l-2-of-6) .

Engine Control Module Description

The engine control module (ECM) interacts with many emission related components and systems, and monitors the emission related components and systems for deterioration. OBD II diagnostics monitor the system performance and a diagnostic trouble code (DTC) sets if the system performance degrades.

The malfunction indicator lamp (MIL) operation and the DTC storage are dictated by the DTC type. A DTC is ranked as a Type A or Type B if the DTC is emissions related. Type C is a non-emissions related DTC.

The ECM is in the engine compartment. The ECM is the control center of the engine controls system. The ECM controls the following components

1. The fuel injection system
2. The ignition system
3. The emission control systems
4. The on-board diagnostics
5. The A/C and fan systems
6. The throttle actuation control (TAC) system

The ECM constantly monitors the information from various sensors and other inputs, and controls the systems that affect the vehicle performance and the emissions. The ECM also performs diagnostic tests on various parts of the system. The ECM can recognize operational problems and alert the driver via the MIL. When the ECM detects a malfunction, the ECM stores a DTC. The condition area is identified by the particular DTC that is set. This aids the technician in making repairs.

ECM Function

The engine control module (ECM) can supply 5 volts or 12 volts to the various sensors or switches. This is done through pull-up resistors to the regulated power supplies within the ECM. In some cases, even an ordinary shop voltmeter will not give an accurate reading because the resistance is too low. Therefore, a DMM with at least 10 megaohms input impedance is required in order to ensure accurate voltage readings.

The ECM controls the output circuits by controlling the ground or the power feed circuit through the transistors or a device called an output driver module.

EEPROM

The electronically erasable programmable read only memory (EEPROM) is a permanent memory that is physically part of the engine control module (ECM). The EEPROM contains program and calibration information that the ECM needs in order to control the powertrain operation.

Special equipment, as well as the correct program and calibration for the vehicle, are required in order to reprogram the ECM.

Data Link Connector (DLC)

The data link connector (DLC) is a 16-pin connector that provides the technician a means of accessing serial data for aid in the diagnosis. This connector allows the technician to use a scan tool in order to monitor the various serial data parameters, and display the DTC information. The DLC is located inside of the drivers compartment, underneath the dash.

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 68

Scheme 69

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.

ECM Service Precautions

The engine control module (ECM), by design, can withstand the normal current draws that are associated with the vehicle operations. However, care must be used in order to avoid overloading any of these circuits. When testing for opens or shorts, do not ground or apply voltage to any of the ECM circuits unless the diagnostic procedure instructs you to do so. These circuits should only be tested with a DMM.

Emissions Diagnosis For State I/M Programs

This OBD II equipped vehicle is designed to diagnose any conditions that could lead to excessive levels of the following emissions

1. Hydrocarbons (HC)
2. Carbon monoxide (CO)
3. Oxides of nitrogen (NOx)
4. Evaporative emission (EVAP) system losses

Should this vehicles on-board diagnostic system (ECM) detect a condition that could result in excessive emissions, the ECM turns ON the malfunction indicator lamp (MIL) and stores a DTC that is associated with the condition.

Aftermarket (Add-On) Electrical And Vacuum Equipment

Aftermarket, add-on, electrical and vacuum equipment is defined as any equipment installed on a vehicle after leaving the factory that connects to the vehicles electrical or vacuum systems. No allowances have been made in the vehicle design for this type of equipment.

Add-on electrical equipment, even when installed to these strict guidelines, may still cause the powertrain system to malfunction. This may also include equipment not connected to the vehicle electrical system, such as portable telephones and radios. Therefore, the first step in diagnosing any powertrain condition is to eliminate all of the aftermarket electrical equipment from the vehicle. After this is done, if the problem still exists, the problem may be diagnosed in the normal manner.

Electrostatic Discharge (ESD) Damage

Note. In order to prevent possible electrostatic discharge damage to the engine control module (ECM), DO NOT touch the connector pins on the ECM.

The electronic components that are used in the control systems are often designed to carry very low voltage. The electronic components are susceptible to damage caused by electrostatic discharge. Less than 100 volts of static electricity can cause damage to some electronic components.

There are several ways for a person to become statically charged. The most common methods of charging are by friction and by induction. An example of charging by friction is a person sliding across a car seat.

Charging by induction occurs when a person with well insulated shoes stands near a highly charged object and momentarily touches ground. Charges of the same polarity are drained off leaving the person highly charged with the opposite polarity. Static charges can cause damage, therefore, it is important to use care when handling and testing electronic components.

Emissions Control Information Label

The underhood Vehicle Emissions Control Information Label contains important emission specifications and setting procedures. In the upper left corner is the exhaust emission information. This identifies the year, the manufacturing division of the engine, the displacement of the engine in liters, the class of the vehicle, and type of fuel metering system. There is also an illustrated emission components and vacuum hose schematic.

This label is located in the engine compartment of every General Motors vehicle. If the label has been removed, it can be ordered from GM service parts operations (GMSPO).

Underhood Inspection

Note. This inspection is very important and must be done carefully and thoroughly.

Perform a careful underhood inspection when performing any diagnostic procedure or diagnosing the cause of an emission test failure. This can often lead to repairing a condition without further steps. Use the following guidelines when performing an inspection

1. Inspect all of the vacuum hoses for correct routing, pinches, cuts, or disconnects.
2. Inspect any hoses that are difficult to see.
3. Inspect all of the wires in the engine compartment for the following conditions: Burned or chafed spots Pinched wires Contact with sharp edges Contact with hot exhaust manifolds

Scheme 70

The engine control module (ECM) is the control center for the throttle actuator control (TAC) system. The ECM determines the driver's intent based on input form the accelerator pedal position sensors, then calculates the appropriate throttle response based on the throttle position sensors. The ECM achieves throttle positioning by providing a pulse width modulated voltage to the throttle actuator motor. The throttle blade is spring loaded in both directions, and the default position is slightly open.

Normal Mode

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

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

Reduced Engine Power Mode

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

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

Camshaft Actuator System Description

The camshaft position (CMP) actuator system is used for a variety of engine performance enhancements. The CMP actuator system accomplishes this by controlling the amount of intake and exhaust valve overlap. These enhancements include the following

1. Lower emission output through exhaust gas recirculation (EGR) control
2. A wider engine torque range
3. Improved gas mileage
4. Improved engine idle stability

The CMP actuator system is comprised of the following components

1. Four CMP actuator solenoids
2. Four oil control valves
3. Four vane style CMP actuators
4. Four CMP sensors

The CMP actuator system requires a very complex electrical signal from the engine control module (ECM) in order to control the position of the CMP actuators. The electrical signal requires use of an un-fixed pulse width modulation (PWM) signal as well as 2 different operating frequencies of 150 and 500 Hz. Changes in the PWM can happen every 100 milliseconds and thus makes it difficult to measure the correct PWM or frequency with a DMM during CMP actuator control. At idle, the ECM commands a consistent 7 percent duty cycle at 150 Hz. The ECM uses this signal in order to sense certain circuit failures.

Scheme 71

The CMP actuator solenoids, or electromagnets, are located on the front of the engine and are mounted to their corresponding bank CMP actuator housing.

The oil control valves are threaded, and attach the CMP actuators to the front of the camshafts. The oil control valve meters the oil flow to the CMP actuator through the advancing and retarding oil ports. With no command fro the ECM, all of the oil is ported to the advancing chambers of the exhaust CMP actuators and to the retarding chambers of the intake CMP actuators. With full command from the ECM, all of the oil is ported to the retarding chambers of the exhaust CMP actuators and to the advancing chambers of the intake CMP actuators. When the intake or exhaust camshafts reach a desired position, above 0 degrees on the scan tool, the ECM will apply an electrical signal to the solenoids in order to hold the CMP actuators in the desired position. The oil control valves will port engine oil evenly to the advancing and retarding chambers of the CMP actuators in order to hold the camshafts in the desired position. The oil control valves will allow enough engine oil to flow to compensate for any leakage past the CMP actuators in order to hold the camshafts in a steady position.

The CMP actuators interface the timing chain to the camshafts, and are able to change the camshaft timing in relation to the crankshaft. The intake CMP actuators have the ability to move the intake camshafts a total of 40 degrees from the parked position. The exhaust CMP actuators have the ability to move the exhaust camshafts a total of 50 degrees from the parked position. With the engine OFF or with the CMP actuators not commanded, the exhaust CMP actuators are parked at the full advance position of 133 degrees ATDC and the intake CMP actuators are parked at the full retard position of 117 degrees before top dead center (BTDC). The CMP Angle parameters on the scan tool will indicate 0 degrees with the engine running and the CMP actuators in the parked position for both exhaust and intake camshafts.

A locking pin keeps the CMP actuators in the parked position in order to avoid valve train noise upon engine start-up. The locking pin will release the actuator after the engine oil pressure is sufficient to overcome the locking pin spring pressure. The exhaust CMP actuators have return springs. The return springs are necessary to assist the CMP actuators to return to the parked position due to the rotational inertia of the valve train components upon engine shutdown.

An oil outlet tube is used to transfer oil from a dedicated oil galley in the engine block, from the replaceable oil filter, up to each head and is located in the timing chain area. The oil outlet tube incorporates a non-replaceable 40 micron oil filter. If the filter becomes clogged with contamination and can not be cleaned, the tube and filter must be replaced as an assembly. Engine oil pressure, level, viscosity, and temperature can have an adverse affect on the CMP actuator performance.

The CMP sensors are used by the ECM to monitor the position of the camshafts. The intake cam sensor wheels have 4X targets. The exhaust cam sensor wheels have a 4X target. The ECM can detect a camshaft position variance as small as 4 degrees. The variance is the difference between the actual camshaft position and the desired camshaft position. A CMP actuator performance DTC will set if the ECM detects the camshaft position has a 4 degree to 11 degree variance. A 4 degree variance takes more time for the ECM to detect than an 11 degree variance. A crankshaft to camshaft correlation DTC will set if the ECM detects a 12 degree variance or more.

If a CMP actuator system DTC is present, the ECM will disable the CMP actuator system control for that ignition cycle.

CMP Actuator System Operation

The engine control module (ECM) sends an electrical signal to the camshaft position (CMP) actuator solenoids through the control circuits when a camshaft timing change is desired. The ground circuit of the CMP actuator solenoid is used as a return. The CMP actuator solenoid uses electromagnetic force to pull on the plunger of the oil control valve. The oil control valve will port the pressurized engine oil to either the advancing or retarding chambers of the CMP actuator. The CMP actuator, in turn, changes the camshaft position relative to crankshaft position. The ECM uses the CMP sensors to determine the position of the camshafts.

The ECM calculates the optimum CMP through the following inputs

1. Engine speed
2. Throttle position indicated angle
3. Crankshaft position (CKP)
4. CMP
5. Engine load
6. Barometric pressure (BARO)
7. Intake air temperature (IAT)

The ECM monitors the following inputs before assuming control of the CMP actuator system

1. Engine coolant temperature (ECT)
2. Loop status
3. Calculated engine oil temperature (EOT)
4. Engine oil pressure (EOP)
5. Engine oil level
6. Crankshaft/camshaft correlation
7. Ignition 1 signal voltage
8. Barometric pressure (BARO)

Fuel Tank

The fuel storage tank is made of high density polyethylene. The fuel storage tank is held in place by 2 metal straps that are attached to the underbody of the vehicle. The tank shape includes a sump in order to maintain a constant supply of fuel around the fuel pump strainer during low fuel conditions or during aggressive maneuvers.

The fuel tank also contains a fuel vapor vent valve with a roll-over protection. The vent valve also features a 2-phase vent calibration which increases the fuel vapor flow to the canister when the operating temperatures increase the tank pressure beyond an established threshold.

On-Board Refueling Vapor Recovery (ORVR) System

The on-board refueling vapor recovery (ORVR) system is an on-board vehicle system to recover fuel vapors during the vehicle refueling operation. The flow of liquid fuel down to the fuel tank filler neck provides a liquid seal. The purpose of ORVR is to prevent refueling vapor from exiting the fuel tank filler neck.

Fuel Tank Filler Pipe

In order to prevent refueling with leaded fuel, the fuel filler pipe has a built-in restrictor and a deflector. The opening in the restrictor will accept only the smaller unleaded gasoline fuel nozzle which must be fully inserted in order to bypass the deflector. The tank is vented during filling by an internal vent tube inside of the filler pipe.

Scheme 72

The fuel tank filler pipe is equipped with a turn to vent screw on the type cap which incorporates a ratchet action in order to prevent over-tightening.

The turn to vent feature allows the fuel tank pressure relief prior to removal. Instructions for proper use are imprinted on the cap cover. A vacuum safety relief valve is incorporated into this cap.

Scheme 73

The modular fuel sender assembly mounts to the threaded opening of the plastic fuel tank with a multi-lipped seal and a threaded retainer (nut). The reservoir, containing the exterior inlet strainer, the electric fuel pump, and the pump strainer, maintains contact with the tank bottom. This design provides

1. Optimum fuel level in the integral fuel reservoir during all fuel tank levels and during driving conditions
2. An improved tank fuel level measuring accuracy
3. An improved coarse straining and added pump inlet filtering
4. More extensive internal fuel pump isolation for noiseless operation

The modular fuel sender assembly maintains an optimum fuel level in the reservoir (bucket). The fuel entering the reservoir is drawn in by the following components

1. The first stage of the fuel pump through the external strainer AND/OR
2. The secondary umbrella valve OR
3. The return fuel line, whenever the level of fuel is below the top of the reservoir

Fuel Pump

The electric fuel pump is a turbine pump which is located inside of the modular fuel sender. The electric fuel pump operation is controlled by the engine control module (ECM) through the fuel pump relay.

Fuel Sender Strainers

The strainers act as a coarse filter to perform the following functions

1. Filter contaminants
2. Separate water from fuel
3. Provide a wicking action that helps draw fuel into the fuel pump

Fuel stoppage at the strainer indicates that the fuel tank contains an abnormal amount of sediment or water. Therefore, the fuel tank will need to be removed and cleaned, and the filter strainer should be replaced.

Scheme 74

The fuel filter is located on the fuel feed pipe, between the fuel pump and the fuel rail. The electric fuel pump supplies fuel through the in-line fuel filter to the fuel injection system. The fuel pressure regulator keeps the fuel available to the fuel injectors at a regulated pressure. Unused fuel is returned from the fuel filter to the fuel tank by a separate fuel return pipe. The paper filter element (2) traps particles in the fuel that may damage the fuel injection system. The filter housing (1) is made to withstand maximum fuel system pressure, exposure to fuel additives, and changes in temperature. There is no service interval for fuel filter replacement. Replace a restricted fuel filter.

EVAP Lines and Hoses

The evaporative emission (EVAP) line extends from the fuel tank vent valve to the EVAP canister and into the engine compartment. The EVAP line is made of nylon and connects to the EVAP canister with a fuel resistant rubber hose and quick connect fittings.

Scheme 75

The fuel pressure regulator attaches to the fuel return pipe on the fuel sender assembly. The fuel pressure regulator is a diaphragm-operated relief valve. A software bias compensates the injector on-time because the fuel pressure regulator is not referenced to manifold vacuum. The injector pulse width varies with the signal from the mass air flow/intake air temperature (MAF/IAT) sensor.

With the engine running at idle, the system fuel pressure at the pressure test connection should be between 380-410 kPa (55-60 psi). With the system pressurized and the pump OFF, the pressure should stabilize and hold. If the pressure regulator supplies a fuel pressure which is too low or too high, a driveability condition will result.

Fuel Rail

The fuel rail consists of 3 parts

1. The pipe that carries fuel to each injector
2. The fuel pressure test port
3. Eight individual fuel injectors

The fuel rail is mounted on the intake manifold and distributes the fuel to each cylinder through the individual injectors.

Fuel Injectors

The fuel injector is a solenoid device that is controlled by the engine control module (ECM). When the ECM energizes the injector coil, a normally closed ball valve opens, allowing the fuel to flow past a director plate to the injector outlet. The director plate has holes that control the fuel flow, generating a dual conical spray pattern of finely atomized fuel at the injector outlet. The fuel from the outlet is directed at both of the intake valves, causing the fuel to become further vaporized before entering the combustion chamber.

The fuel injectors will cause various driveability conditions if the following conditions occur

1. If the injectors will not open
2. If the injectors are stuck open
3. If the injectors are leaking
4. If the injectors have a low coil resistance

Engine Fueling

The engine is fueled by 8 individual injectors, one for each cylinder, that are controlled by the engine control module (ECM). The ECM controls each injector by energizing the injector coil for a brief period once every other engine revolution. The length of this brief period, or pulse, is carefully calculated by the ECM to deliver the correct amount of fuel for proper driveability and emissions control. The period of time when the injector is energized is called the pulse width and is measured in milliseconds, thousandths of a second.

While the engine is running, the ECM is constantly monitoring the inputs and recalculating the appropriate pulse width for each injector. The pulse width calculation is based on the injector flow rate, mass of fuel the energized injector will pass per unit of time, the desired air/fuel ratio, and actual air mass in each cylinder and is adjusted for battery voltage, short term, and long term fuel trim (FT). The calculated pulse is timed to occur as each cylinders intake valves are closing to attain largest duration and most vaporization.

Fueling during a crank is slightly different than fueling during an engine run. As the engine begins to turn, a prime pulse may be injected to speed starting. As soon as the ECM can determine where in the firing order the engine is, the ECM begins pulsing the injectors. The pulse width during the crank is based on the coolant temperature and the engine load.

The fueling system has several automatic adjustments in order to compensate for the differences in the fuel system hardware, the driving conditions, the fuel used, and the vehicle aging. The basis for the fuel control is the pulse width calculation that is described above. Included in this calculation are an adjustment for the battery voltage, the short term FT, and the long term FT. The battery voltage adjustment is necessary since the changes in the voltage across the injector affect the injector flow rate.

Fuel Trim

The engine control module (ECM) controls the air/fuel metering system in order to provide the best possible combination of driveability, fuel economy, and emission control. The ECM monitors the heated oxygen sensor (HO2S) signal voltage while fuel injectors based on this signal. The ideal fuel trim (FT) values are around 0 percent for both short term and long term FT. A positive FT value indicates the ECM is adding fuel in order to compensate for a lean condition by increasing the pulse width. A negative FT value indicates that the ECM is reducing the amount of fuel in order to compensate for a rich condition by decreasing the pulse width. A change made to the fuel delivery changes the short term and long term FT values. The short term FT values change rapidly in response to the HO2S signal voltage. These changes fine tune the engine fueling. The long term FT makes coarse adjustments to fueling in order to re-center and restore control to short term FT. A scan tool can be used to monitor the short term and long term FT values. A block of cells contain information arranged in combinations of engine RPM and load for a full range of vehicle operating conditions. The long term FT diagnostic is based on an average of cells currently being used. If the powertrain control module (PCM) detects an excessive lean or rich condition, the ECM will set a FT DTC.

Sequential Fuel Injection (SFI)

The engine control module (ECM) controls the fuel injectors based on information that the ECM receives from several information sensors. Each injector is fired individually in the engine firing order, which is called sequential fuel injection. This allows precise fuel metering to each cylinder and improves the driveability under all of the driving conditions.

The ECM has several operating modes for fuel control, depending on the information that has been received from the sensors.

Starting Mode

When the engine control module (ECM) detects reference pulses from the crankshaft position (CKP) sensor, the ECM will enable the fuel pump. The fuel pump runs and builds up pressure in the fuel system. The ECM then monitors the mass air flow (MAF), intake air temperature (IAT), engine coolant temperature (ECT), and the throttle position (TP) sensor signal in order to determine the required injector pulse width for starting.

Clear Flood Mode

If the engine is flooded with fuel during starting and will not start, the Clear Flood Mode can be manually selected. To select Clear Flood Mode, push the accelerator to wide open throttle (WOT). With this signal, the engine control module (ECM) will completely turn OFF the injectors and will maintain this stage as long as the ECM indicates a WOT condition with engine speed below 1,000 RPM.

Run Mode

The Run Mode has 2 conditions: Open Loop operation and Closed Loop operation. When the engine is first started and the engine speed is above 480 RPM, the system goes into an Open Loop operation. In an Open Loop operation, the engine control module (ECM) ignores the signals from the oxygen sensors and calculates the required injector pulse width based primarily on inputs from the mass air flow (MAF), intake air temperature (IAT), and engine coolant temperatures (ECT) sensors.

In a Closed Loop, the ECM adjusts the calculated injector pulse width for each bank of injectors based on the signals from each oxygen sensor.

Acceleration Mode

The engine control module (ECM) monitors the changes in the throttle position (TP) and the mass air flow (MAF) sensor signals in order to determine when the vehicle is being accelerated. The ECM will then increase the injector pulse width in order to provide more fuel for improved driveability.

Deceleration Mode

The engine control module (ECM) monitors changes in the throttle position (TP) and the mass air flow (MAF) sensor signals to determine when the vehicle is being decelerated. The ECM will then decrease injector pulse width or even shut OFF injectors for short periods to reduce exhaust emissions.

Battery Voltage Correction Mode

The engine control module (ECM) can compensate in order to maintain acceptable vehicle driveability when the ECM sees a low battery voltage condition. The ECM compensates by performing the following functions

1. Increasing the injector pulse width in order to maintain the proper amount of fuel being delivered
2. Increasing the idle speed to increase the generator output

Fuel Shut-Off Mode

The engine control module (ECM) has the ability to completely turn OFF all of the injectors or selectively turn OFF some of the injectors when certain conditions are met. These fuel shut-off modes allow the ECM to protect the engine from damage and also to improve the vehicles driveability.

The ECM will disable all injectors under the following conditions

1. Ignition OFF-Prevents engine run-on
2. Ignition ON but no ignition reference signal-Prevents flooding or backfiring
3. A high engine speed-Above the red line
4. A high vehicle speed-Above the rated tire speed
5. The extended high speed closed throttle coastdown-Reduces the emissions and increases engine braking

The ECM will selectively disable the injectors under the following conditions

1. The torque management enabled-Transmission shifts or abusive maneuvers
2. The traction control enabled-In conjunction with the front brakes applying

EVAP System Operation

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

Large Leak Test

This tests for large leaks and restrictions to the purge path in the evaporative emission (EVAP) system. When the enabling criteria has been met, the control module commands the EVAP vent solenoid valve ON and the EVAP purge solenoid valve ON, allowing vacuum into the EVAP system. The control module monitors the fuel tank pressure (FTP) sensor voltage to verify that the system is able to reach a predetermined level of vacuum within a set amount of time.

Small Leak Test

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

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

The EONV diagnostic is designed to detect leaks as small as 0.51 mm (0.020 in). The diagnostic can determine if a small leak is present based on vacuum or pressure readings in the EVAP system. When the system is sealed, a finite amount of pressure or vacuum will be observed. When a 0.51 mm (0.020 in) leak is present, often little or no pressure or vacuum is observed. If the test reports a failing value, DTC P0442 will set.

Canister Vent Restriction Test

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

Purge Solenoid Valve Leak Test

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

Check Gas Cap Message

The control module sends a class 2 message to the driver information center (DIC) illuminating the Check Gas Cap message when a malfunction in the evaporative emission (EVAP) system and a large leak test fails.

EVAP System Components

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

EVAP Canister

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

EVAP Purge Solenoid Valve

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

EVAP Vent Solenoid Valve

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

Fuel Tank Pressure Sensor

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

Electronic Ignition (EI) System Operation

The electronic ignition (EI) system produces and controls the high energy secondary spark. This spark ignites the compressed air/fuel mixture at precisely the correct time, providing optimal performance, fuel economy, and control of exhaust emissions. The engine control module (ECM) primarily collects information from the crankshaft position (CKP) and camshaft position (CMP) sensors to control the sequence, dwell, and timing of the spark.

Crankshaft Position (CKP) Sensor

The crankshaft position (CKP) sensor circuits consist of an engine control module (ECM) supplied 5-volt reference circuit, low reference circuit and an output signal circuit. The CKP sensor is an internally magnetic biased digital output integrated circuit sensing device. The sensor detects magnetic flux changes of the teeth and slots of a 58-tooth reluctor wheel on the crankshaft. Each tooth on the reluctor wheel is spaced at 60-tooth spacing, with 2 missing teeth for the reference gap. The CKP sensor produces an ON/OFF DC voltage of varying frequency, with 58 output pulses per crankshaft revolution. The frequency of the CKP sensor output depends on the velocity of the crankshaft. The CKP sensor sends a digital signal, which represents an image of the crankshaft reluctor wheel, to the ECM as each tooth on the wheel rotates past the CKP sensor. The ECM uses each CKP signal pulse to determine crankshaft speed and decodes the crankshaft reluctor wheel reference gap to identify crankshaft position. This information is then used to determine the optimum ignition and injection points of the engine. The ECM also uses CKP sensor output information to determine the camshaft relative position to the crankshaft, to control camshaft phasing, and to detect cylinder misfire.

Crankshaft Reluctor Wheel

The crankshaft reluctor wheel is part of the crankshaft. The reluctor wheel contains a pattern around the circumference of the wheel consisting of 58 teeth and a reference gap. Each tooth on the reluctor wheel is spaced at 60 tooth spacing, or 6 degrees apart from each other with 2 missing teeth for the reference gap. The engine control module (ECM) uses the teeth and reference gap to determine the crankshaft position (CKP) and speed.

Camshaft Position (CMP) Sensor

Each camshaft position (CMP) sensor is a 3-wire sensor that provides a digital output signal. The wire circuits consist of an engine control module (ECM) supplied 5-volt reference circuit, a low reference circuit between the CMP sensor and the ECM, and an output signal circuit from the CMP sensor to the ECM. The CMP sensor detects magnetic flux changes between the teeth and slots on the reluctor wheel. The CMP sensor provides a digital ON/OFF DC voltage of varying frequency width output pulses per each camshaft revolution. The frequency of the CMP sensor output signal depends on the speed of the camshaft. The ECM will recognize the narrow and wide tooth patterns to identify camshaft position, or which cylinder is in compression and which is in exhaust. The information is then used to determine the correct time and sequence for fuel injection and ignition spark events. The ECM also uses the CMP sensor output signal to determine the camshaft relative position to the crankshaft position.

Camshaft Reluctor Wheel

The CMP sensors are used by the ECM to monitor the position of the camshafts. The intake cam sensor wheels have 4X targets. The exhaust cam sensor wheels have a 4X target. The ECM can detect a camshaft position variance as small as 4 degrees. The variance is the difference between the actual camshaft position and the desired camshaft position.

Knock Sensor (KS)

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

The KS system uses 2 flat response 2-wire sensors. The sensor uses piezo-electric crystal technology that produces an AC voltage signal of varying amplitude and frequency based on the engine vibration or noise level. The amplitude and frequency are dependant upon the level of knock that the KS detects. The control module receives the KS signal through the signal circuit.

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

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

Ignition Coils

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

Engine Control Module (ECM)

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

1. The throttle actuator control (TAC) system
2. The engine coolant temperature (ECT) sensor
3. The mass airflow (MAF) sensor
4. The intake air temperature (IAT) sensor
5. The vehicle speed sensor (VSS)
6. The transmission gear position or range information sensors
7. The engine knock sensor (KS)

Illustration Tool Number/ Description CH-47976 Active Fuel Injector Tester (AFIT) CH-48027 Digital Pressure Gage CH-48096 EVAP Service Access Port Tool GE-41415-50 Fuel Tank Cap Adapter J-22610 Keystone Clamp Pliers J-26792 HEI Spark Tester J-34730-1A Fuel Pressure Gage J-34730-405 Injector Test Lamp J-35555 Metal Mityvac J-35616 GM-Approved Terminal Test Kit J-36850 Transjel Lubricant J-37088-A Fuel Line Disconnect Tool Set J-37287 Fuel Line Shut-Off Adapters J-38522 Variable Signal Generator J-39021 Fuel Injector Coil and Balance Tester J-39765-A Fuel Sender Lock Ring Tool J-41413-200 Evaporative Emissions System Tester (EEST) J-41413-SPT High Intensity White Light J-42960-2 Fuel Flapper Door Holder J-43094 Spark Plug Boot Puller J-43244 Relay Puller Pliers J-44175 Fuel Composition Tester J-44581 Fuel Line Disconnect Tool J-44602 Injector Test Adapter J-45004 Fuel Tank Drain Hose J-45747 Fuel Tank Sender Wrench

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See also:
• Diagnostic System Check - Vehicle
• DTC P0010, P0013, P0020, or P0023
• DTC P0335
• Battery Negative Cable Disconnection and Connection (Side Post)
• Lifting and Jacking the Vehicle
• Front Air Deflector Replacement
• Fastener Caution
• Control Module References
• Diagnostic Trouble Code (DTC) List - Vehicle
• Fuel Injector Sight Shield Replacement
• Cooling System Draining and Filling (GE 47716)
• Oxygen Sensor Caution
• Instrument Panel Insulator Panel Replacement - Left Side
• Throttle Learn
• Gasoline/Gasoline Vapors Warning
• Electrical Center Identification Views
• Rear Suspension Bracket Replacement
• Fuel Tank Draining
• Exhaust System Replacement
• Rear Propeller Shaft Replacement (AWD)
• Tire and Wheel Removal and Installation
• Rear Wheelhouse Panel Liner Replacement
• Cross Vehicle Brace Replacement
• Crankshaft Position System Variation Learn
• Remote Power Steering Fluid Reservoir Replacement (LH2)
• Air Cleaner Outlet Duct Replacement
• Fuel Pressure Relief (Without CH 48027)
• Ignition System Specifications