Page 1 of 5 2008 Chevrolet Avalanche - 4WD Avalanche, Escalade, Suburban, Tahoe, Yukon VIN C/K Service Manual Document ID: 1914310 DTC,,, or Diagnostic Instructions Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Review Strategy Based Diagnosis for an overview of the diagnostic approach. Diagnostic Procedure Instructions provides an overview of each diagnostic category. DTC Descriptors DTC Cylinder 1 Deactivation Solenoid Control DTC Cylinder 4 Deactivation Solenoid Control DTC Cylinder 6 Deactivation Solenoid Control DTC Cylinder 7 Deactivation Solenoid Control Diagnostic Fault Information Open/High Resistance Signal Performance Ignition 1 P0102, P0443,,,,,,, Cylinder 1 Deactivation Solenoid Control 1 Cylinder 4 Deactivation Solenoid Control 2 Cylinder 6 Deactivation Solenoid Control 3 Cylinder 7 Deactivation Solenoid Control 4 2015 General Motors. All rights reserved.
Page 2 of 5 Typical Scan Tool Data Cylinder 1, 4, 6, or 7 Deactivation Solenoid Valve Control Test Status Component Commanded OFF Open Operating Conditions: Component Commanded OFF Parameter Normal Range: The following illustrates the normal parameter state with no circuit conditions: Component OFF OK for Open/ Gnd Test and Not Run for Volts Test Component ON Not Run for Open/ Gnd Test and OK for Volts Test Ignition Fault Fault Cylinder 1, 4, 6, or 7 Deactivation Solenoid Control Fault Fault Not Run Cylinder 1, 4, 6, or 7 Deactivation Solenoid Valve Control Test Status Component Commanded ON Open Operating Conditions: Component Commanded ON Parameter Normal Range: The following illustrates the normal parameter state with no circuit conditions: Component OFF OK for Open/ Gnd Test and Not Run for Volts Test Component ON Not Run for Open/ Gnd Test and OK for Volts Test Ignition Not Run Not Run Cylinder 1, 4, 6, or 7 Deactivation Solenoid Control Not Run Not Run Fault /System Description The cylinder deactivation system is used to deactivate 4 cylinders of the engine under light load driving conditions. The engine control module (ECM) commands the cylinder deactivation solenoids ON to deactivate engine cylinders 1, 7, 6, and 4, switching to 4 cylinders or V4 mode. The cylinder deactivation solenoids controls the oil flow to the appropriate valve lifters. The engine operates on 8 cylinders or V8 mode, during engine starting, engine idling, and medium to heavy throttle conditions. Ignition voltage is supplied directly to the 4 cylinder deactivation solenoids. The engine control module (ECM) controls the 4 cylinder deactivation solenoids by grounding the control circuit with a solid state device called a driver. Conditions for Running the DTC The engine speed is greater than 400 RPM.
Page 3 of 5 The ignition voltage is between 9 18 volts. DTC,,, and runs continuously when the above conditions are met. Conditions for Setting the DTC The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for greater than 5 s. Action Taken When the DTC Sets DTC,,, and are Type B DTCs. The engine will return to V8 mode. The fuel injector will turn OFF for the cylinder that has a cylinder deactivation DTC set, resulting in an engine misfire. Conditions for Clearing the DTC DTC,,, and are Type B DTCs. Diagnostic Aids The valve lifter oil manifold solenoids are assigned to the following engine cylinders: Solenoid #1 = Cylinder #1 Solenoid #2 = Cylinder #4 Solenoid #3 = Cylinder #6 Solenoid #4 = Cylinder #7 Reference Information Schematic Reference Engine Controls Schematics Connector End View Reference Component Connector End Views Description and Operation Cylinder Deactivation (Active Fuel Management) System Description Electrical Information Reference Testing Connector Repairs Testing for Intermittent Conditions and Poor Connections Wiring Repairs DTC Type Reference Powertrain Diagnostic Trouble Code (DTC) Type Definitions Scan Tool Reference Control Module References for scan tool information Special Tools
Page 4 of 5 EN-46999 Displacement On Demand Tester For equivalent regional tools, refer to Special Tools. /System Verification Note: DTC,,, and sets with an open ignition circuit fuse. 1. Ignition ON, command the appropriate cylinder deactivation solenoid ON and OFF while observing the following status parameters with a scan tool: Cyl. 1, 4, 6, or 7 Deact. Sol. Ckt Open Test Status Cyl. 1, 4, 6, or 7 Deact. Sol. Ckt Short Gnd Test Status Cyl. 1, 4, 6, or 7 Deact. Sol. Ckt Short Volts Test Status Each parameter should display OK or Not Run 2. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data. /System Testing Note: If any of the scan tool circuit status parameters displayed Fault during the /System Verification, inspect the wiring harness for signs of binding, chaffing or pinching before intake manifold removal. 1. Ignition OFF, remove the intake manifold. Refer to Intake Manifold Replacement. 2. Disconnect the harness connector at the valve lifter oil manifold assembly. 3. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal E and ground. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test all the components connected to the ignition circuit and replace as necessary. 4. Verify that a test lamp does not illuminate between the ignition circuit terminal E and the appropriate cylinder deactivation solenoid control circuit terminal listed below. If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM. 5. Verify that a test lamp does not illuminate between ground and the appropriate cylinder deactivation solenoid control circuit terminal listed below. If the test lamp illuminates, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM. 6. Connect a test lamp between the ignition circuit terminal E and the appropriate cylinder deactivation solenoid control circuit terminal listed below.
Page 5 of 5 7. Command the appropriate cylinder deactivation solenoid ON with a scan tool. Verify the test lamp illuminates with each command. If the test lamp does not illuminate, test the control circuit for an open/high resistance. If the circuit tests normal, replace the ECM. 8. If all the circuits test normal, test or replace the valve lifter oil manifold assembly. Component Testing Static Test 1. Ignition OFF, disconnect the harness connector at the valve lifter oil manifold assembly. 2. Connect the harness that is labeled resistance from the displacement on demand (DOD) tester to the valve lifter oil manifold connector. 3. Connect the power leads from the DOD tester to B+ and ground. Test for 11 18 Ω on each valve lifter oil manifold solenoid. If not within the specified range for each solenoid, replace the valve lifter oil manifold assembly. 4. Test for infinite resistance between each valve lifter oil manifold circuit terminal and the valve lifter oil manifold housing. If less than infinite resistance, replace the valve lifter oil manifold assembly. Dynamic Test 1. Ignition OFF, disconnect the harness connector at the valve lifter oil manifold assembly. 2. Connect the cable that is labeled power from the displacement on demand DOD tester to the connector. 3. Connect the power leads from the DOD tester to B+ and ground. 4. Command each valve lifter oil manifold solenoid ON and OFF using the DOD tester. You should be able to hear each solenoid turn ON and OFF. If the function does not perform as specified, replace the valve lifter oil manifold assembly. Repair Instructions Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Valve Lifter Oil Manifold Replacement Control Module References for ECM replacement, setup, and programming