What are the possible causes of the P3497 Dodge code?
- Low oil pressure
- Restricted oil passage
- Mechanical condition of the engine
- Failure of the Multiple Displacement System (MDS) solenoid
How to fix the P3497 Dodge code?
Start by checking the “Possible Causes” listed above. Visually inspect the wiring harness and associated connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.
When is the P3497 Dodge code detected?
The Engine Control Module (ECM) detected a lean condition on bank 2 in 4-cylinder mode
What are the possible symptoms of the P3497 Dodge Code?
- Check engine light on (or Service Engine Soon warning light)
What does the P3497 Dodge code mean?
To provide maximum fuel economy under low load driving conditions, the Engine Control Module (ECM) will command the cylinder deactivation system ON to disable cylinders 1 and 7 on the left bank and cylinders 4 and 6 on the right bank, switching to V4 mode. The engine will operate on 8 cylinders, or V8 mode, during engine starting, engine idle, and medium to heavy acceleration applications. When commanded ON, the ECM will determine which cylinder is firing and begin deactivation on the next closest deactivated cylinder in the firing order sequence. The Gen IV engine has a firing order of 1-8-7-2-6-5-4-3. If cylinder number 1 is on its combustion event when cylinder deactivation is commanded ON, the next cylinder in the firing order sequence that can be deactivated is cylinder number 7. If cylinder number 5 is on its combustion event when cylinder deactivation is commanded ON, then the next cylinder in the firing order sequence that can be deactivated is cylinder number 4. Cylinder deactivation is accomplished by not allowing the intake and exhaust valves to open on selected cylinders using special valve lifters. The deactivation lifters contain spring-loaded locking pins that connect the lifter’s inner pin housing to the outer housing. The pin housing contains the lifter piston and pushrod seat that interfaces with the pushrod. The outer housing contacts the camshaft lobe via a roller. In V8 mode, the locking pins are pushed outward by spring force, locking the pin housing and outer housing together, causing the lifter to function as a normal lifter. When V4 mode is activated, the locking pins are pushed inward with engine oil pressure directed from the Valve Lifter Oil Manifold (VLOM) assembly solenoids. When the lifter pin housing is unlocked from the outer housing, the inner pin housing will remain stationary, while the outer housing will move with the camshaft lobe profile, causing the valve to remain closed. A VLOM solenoid controls both intake and exhaust valves for each deactivation cylinder. There are 2 separate oil passages going to each cylinder deactivation lifter bore, one for the lifter lash hydraulic adjustment function and one to control the locking pins used for cylinder deactivation. Although the intake and exhaust valve lifters are controlled by the same solenoid in the VLOM, the intake and exhaust valves are not deactivated at the same time. Cylinder deactivation is timed so that the cylinder is on an intake event. During an intake event, the intake cam lobe pushes the valve lifter upward to open the intake valve against the valve spring force. The force exerted by the valve spring acts on the side of the lifter locking pins, preventing them from moving until the intake valve has closed. When the intake valve lifter reaches the base circle of the camshaft lobe, the valve spring force is reduced, allowing the locking pins to move, deactivating the intake valve. However, when cylinder deactivation is commanded ON, the exhaust valve of the deactivated cylinder is in the closed position. By deactivating the exhaust valve first, this allows the trapping of a burned air/fuel charge or exhaust gas charge in the combustion chamber. Trapping exhaust gases in the combustion chamber will contribute to reduced oil consumption, noise and vibration levels, and exhaust emissions during V4 mode operation. During the transition from V8 mode to V4 mode, the fuel injectors will be turned off on the deactivated cylinders. The secondary voltage or spark from the ignition system is still present at the spark plug electrodes on the deactivated cylinders. If all activation conditions are met and maintained for cylinder deactivation operation, the ECM calibrations will limit cylinder deactivation to a 10-minute cycle time in V4 mode, then return to V8 mode for 1 minute. Switching between V8 and V4 modes takes less than 250 milliseconds, making transitions smooth and seamless for the vehicle driver. The 250 milliseconds includes the time required for the ECM to sequence the transitions, the response time for VLOM solenoid activation, and the time for valve lifter deactivation, all within 2 engine crankshaft revolutions.
