P3491 Code - Cylinder 12 Deactivation/Intake Valve Control Circuit Low
Quick Answer
The diagnostic trouble code P3491 indicates an issue with the Cylinder 12 Deactivation/Intake Valve Control Circuit being low. Common causes include Faulty intake valve control solenoid, Damaged wiring or connectors in the circuit, Defective engine control module (ECM). Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P3491 indicates Cylinder 12 Deactivation/Intake Valve Control Circuit Low.
- Common causes
- Common causes include Faulty intake valve control solenoid, Damaged wiring or connectors in the circuit, Defective engine control module (ECM).
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
Code P3491 Description
The diagnostic trouble code P3491 indicates an issue with the Cylinder 12 Deactivation/Intake Valve Control Circuit being low. In modern vehicles, cylinder deactivation technology is used to improve fuel efficiency by shutting down specific cylinders when they are not needed, such as during cruising or light load conditions. This code specifically relates to Cylinder 12, which means that the intake valve control circuit for that cylinder is experiencing a low voltage condition.
Common Causes of P3491
- Faulty intake valve control solenoid
- Damaged wiring or connectors in the circuit
- Defective engine control module (ECM)
- Low engine oil level affecting cylinder deactivation system
- Mechanical issue with the intake valve in Cylinder 12
Symptoms of P3491
- Rough engine idle
- Engine misfires
- Loss of power
- Decreased fuel efficiency
- Hesitation or stalling during acceleration
How to Fix P3491
- Begin by conducting a visual inspection of the intake valve control circuit, looking for any damaged wiring or connectors. Repair or replace any damaged components.
- Test the intake valve control solenoid using a multimeter to check for proper voltage and resistance. Replace the solenoid if it is faulty.
- Check the engine oil level and top up if necessary, as low oil levels can affect the cylinder deactivation system.
- If the issue persists, perform a thorough diagnostic scan of the engine control module (ECM) to identify any faults or errors. Replace the ECM if necessary.
- Clear the diagnostic trouble codes from the vehicle's memory using a scan tool, and test drive the vehicle to ensure that the issue has been resolved.
Cost to Fix P3491
The typical repair costs for addressing the P3491 code can vary depending on the specific cause of the issue. In general, replacing a faulty intake valve control solenoid can cost between $150 to $300, while repairing damaged wiring or connectors may range from $100 to $200. If the engine control module (ECM) needs to be replaced, the cost can be higher, ranging from $500 to $1000 or more. Labor rates at auto repair shops can vary between $80 and $150 per hour, so the total cost of repairs will depend on the specific diagnosis and repair process required for the vehicle. It is advisable to consult with a professional mechanic to get an accurate estimate based on the vehicle's make and model, as well as the local labor rates in your area.
Need more information about the P3491 code?
Need more information on how to fix the P3491 code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P3491 code diagnosed by a professional: Find a repair shop in your area
Code P3491 Information for Specific Makes
- P3491 Chrysler — Cylinder 12 Deactivation/Intake Valve Control Circuit Low
- P3491 Dodge — Cylinder 12 Deactivation/Intake Valve Control Circuit Low
- P3491 Jeep — Cylinder 12 Deactivation/Intake Valve Control Circuit Low
Frequently Asked Questions about P3491 Code
1. What does the OBDII code P3491 mean?
P3491 indicates a problem with the cylinder deactivation system for Cylinder 12, specifically that the intake valve control circuit is reading a low voltage.
2. What are the common symptoms of P3491?
Symptoms may include reduced engine performance, rough idling, poor fuel economy, and the Check Engine Light being illuminated.
3. What causes the P3491 code to appear?
Common causes include a faulty intake valve solenoid, damaged wiring or connectors in the circuit, low oil pressure, or issues with the engine control module (ECM).
4. Can low engine oil cause the P3491 code?
Yes, low oil levels or poor oil quality can affect the cylinder deactivation system's performance and trigger this code.
5. How do I diagnose the P3491 code?
Start by checking the oil level and quality, inspecting the wiring and connectors for damage, and testing the intake valve solenoid for proper operation.
6. Can I drive with the P3491 code?
Driving with this code is not recommended, as it can lead to engine performance issues and possible damage over time if left unaddressed.
7. How is the P3491 code typically fixed?
Repairs may include replacing the intake valve solenoid, repairing damaged wiring or connectors, performing an oil change, or reprogramming/replacing the ECM if necessary.
8. Does the P3491 code always mean the intake valve solenoid is bad?
No, while the solenoid is a common culprit, the issue could also stem from wiring problems, low oil pressure, or ECM faults.
9. How much does it cost to repair the P3491 code?
The cost varies depending on the root cause, but intake valve solenoid replacement typically ranges from $150 to $300, including parts and labor.
10. Can a dirty oil filter trigger the P3491 code?
Yes, a clogged or dirty oil filter can restrict oil flow and pressure, potentially causing issues with the cylinder deactivation system.
Discuss the causes and fixes for P3491 OBDII Code
Code P3491 comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.