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.
The Cylinder Deactivation System Performance diagnostic is a test of the internal mechanical condition of the engine, during operation in V4 mode.
The engine control module (ECM) determines the internal mechanical condition of the engine through the actual measured values of the mass
airflow (MAF) sensor, the intake manifold absolute pressure (MAP) sensor, and the throttle position sensor. The actual measured values of the 3
sensors are then compared to the calculated values for V4 mode, stored in the ECM. If the measured values are incorrect for V4 mode, the ECM
will set DTC P3400, and will return to V8 mode operation.
Conditions for Running the DTC
* DTCs P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0119, P0335, and P0336 are not set.
* The engine speed is between 450-6,400 RPM.
* The IAT Sensor parameter is between -7 and +125锟斤拷C (+19 and +257锟斤拷F).
* The ECT Sensor parameter is between 70- 125锟斤拷C (158-257锟斤拷F).
* Time in V8 mode is more than 2 seconds.
* Time in V4 mode is more than 2 seconds.
* This DTC runs continuously within the enabling conditions.
Conditions for Setting the DTC
The ECM detects that the actual measured values from the MAF sensor, MAP sensor, and throttle position sensor, are not within the range of the
calculated values for V4 mode.
Action Taken When the DTC Sets
* DTC P3400 is a Type B DTC.
* The engine will return to V8 mode.
Conditions for Clearing the DTC
DTC P3400 is a Type B DTC.
Diagnostic Aids
* This DTC will not set during engine idling conditions. The vehicle will need to be driven for the DTC to set.
* 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 (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Description and Operation
Cylinder Deactivation (Active Fuel Management) System Description (See: Powertrain Management/Computers and Control Systems/Description
and Operation/Cylinder Deactivation (Active Fuel Management) System Description)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit
Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic
Procedures/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General
Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring
Repairs/Wiring Repairs)
