Circuit/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.
* The ignition voltage is between 9-18 volts.
* DTC P3401, P3425, P3441, and P3449 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 P3401, P3425, P3441, and P3449 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 P3401, P3425, P3441, and P3449 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 (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)
Connector End View Reference
