Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means there's a problem with the system that turns off one of the engine's cylinders to save fuel. It's like when you try to turn off a light but the switch doesn't work properly.
The engine control module (ECM) has detected a low voltage condition in the circuit responsible for deactivating the intake valve of cylinder 12.
The P3491 code is triggered when the ECM detects a low voltage in the cylinder deactivation/intake valve control circuit for cylinder 12. This circuit is part of the system that manages the deactivation of certain cylinders to improve fuel efficiency during light load conditions. A low voltage condition can indicate a problem with the wiring, connectors, or the control solenoid itself.
• Check Engine Light illuminated
• Reduced engine performance
• Poor fuel economy
• Faulty intake valve control solenoid
• Damaged or corroded wiring/connectors
• ECM failure
ECM: Engine Control Module
Solenoid: An electromechanical device used to control a valve or switch
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for damage or corrosion.
• Test the intake valve control solenoid for proper operation.
• Replace damaged wiring or connectors.
• Replace the intake valve control solenoid.
• Reprogram or replace the ECM if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $500
Moderate
• Dodge Ram 1500
• Chrysler 300
• Jeep Grand Cherokee
• Regular maintenance checks
• Timely replacement of worn components
• Keeping electrical connections clean
Engine Performance
• Avoid driving with a heavy load until repaired.
• Monitor fuel consumption for changes.
• Schedule a repair with a qualified mechanic.
Check with your vehicle manufacturer for warranty coverage on engine components.
Cylinder deactivation codes like P3491 have become more common with the advent of fuel-saving technologies in modern engines.
Moderate – It is recommended to address this issue soon to avoid further engine performance problems.
Ignoring this code can lead to increased emissions and potential engine damage.
• Engine running at operating temperature
• Light load conditions
The intake valve control solenoid for cylinder 12 is typically located on the engine block near the cylinder head.
Q: Can I drive with a P3491 code?
A: While you can drive with this code, it's best to have it checked soon to avoid potential engine damage.
Q: Will this code affect my vehicle's fuel efficiency?
A: Yes, a malfunction in the cylinder deactivation system can lead to decreased fuel efficiency.
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