AutoCodes – RAM – P0491 RAM

P0491 RAM Code - Secondary Air Injection System Insufficient Flow Bank 1

Quick Answer

An air pump is used on the vehicle to lower tail pipe emissions on start-up. Common causes include Intake leak, Damaged AIR system components, Faulty AIR Solenoid Valve. 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: P0491 RAM indicates Secondary Air Injection System Insufficient Flow Bank 1.
Common causes: Common causes include Intake leak, Damaged AIR system components, Faulty AIR Solenoid Valve.
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.

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Code Popularity 468

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Apr 25, 2021

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0491 RAM Description

An air pump is used on the vehicle to lower tail pipe emissions on start-up. The Powertrain Control Module (PCM) grounds the Air pump relay control circuit which energizes the Air pump. The PCM also grounds the Air combination valve vacuum control solenoid circuit, which energizes the Air vacuum control solenoid. Vacuum is then applied to both Air combination valve diaphragms which opens the shut off valves. The PCM enables both circuits simultaneously when Air system operations id desired. When the AIR system is active, then Air pump forces fresh air into the exhaust stream in order to accelerate catalyst operation. The AIR combination valves replace the conventional check valves. When the AIR system is inactive the shut off valves prevent air flow in either direction.

OBDII Code P0491 RAM - Secondary Air Injection System Insufficient Flow Bank 1 - AutoCodes.com — P0491 RAM Code - Secondary Air Injection System Insufficient Flow Bank 1

What does this mean?

What are the Possible Causes of the DTC P0491 RAM?

Intake leak
Damaged AIR system components
Faulty AIR Solenoid Valve
Faulty AIR system relay

How to Fix the DTC P0491 RAM?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0491 RAM code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0491 RAM Code

1. What are the common symptoms of OBDII code P0491 related to the Secondary Air Injection System Insufficient Flow Bank 1?

The common symptoms of P0491 may include a check engine light, rough idling, decreased engine performance, and increased fuel consumption.

2. What are the possible causes of OBDII code P0491 indicating an insufficient flow in the Secondary Air Injection System Bank 1?

Potential causes of P0491 include a faulty air pump, damaged air pump relay, clogged air injection hoses, or a malfunctioning air bypass valve.

3. How can I diagnose OBDII code P0491 for the Secondary Air Injection System Insufficient Flow Bank 1?

Diagnosing P0491 usually involves inspecting the air pump, relay, hoses, and valves for any signs of damage or blockages. It may also require using a scan tool to monitor system performance.

4. Can a clogged air filter cause OBDII code P0491 to trigger in the Secondary Air Injection System Bank 1?

Yes, a clogged air filter can restrict airflow and lead to insufficient flow in the secondary air injection system, triggering code P0491.

5. What are some repair tips for addressing OBDII code P0491 related to the Secondary Air Injection System Insufficient Flow Bank 1?

Repair tips for P0491 may include checking and replacing the air pump, relay, hoses, and valves as needed. It's also recommended to clear the code after repairs and monitor the system for any recurring issues.

6. Is it safe to continue driving with OBDII code P0491 for the Secondary Air Injection System Insufficient Flow Bank 1?

While the vehicle may still be operable with code P0491, it's best to address the issue promptly to prevent potential damage to the engine or emissions system.

7. Can extreme weather conditions affect the triggering of OBDII code P0491 in the Secondary Air Injection System Bank 1?

Extreme weather conditions, such as very cold temperatures, can impact the performance of the air injection system and potentially lead to insufficient flow issues triggering code P0491.

8. How long does it typically take to repair OBDII code P0491 associated with the Secondary Air Injection System Insufficient Flow Bank 1?

The repair time for P0491 can vary depending on the specific cause of the issue. Simple fixes like replacing a relay may take less time compared to diagnosing and replacing a faulty air pump.

9. Will resetting the OBDII system clear code P0491 for the Secondary Air Injection System Insufficient Flow Bank 1?

Resetting the OBDII system may temporarily clear the code, but if the underlying issue causing P0491 is not addressed, the code is likely to reappear after driving cycles.

10. Are there any recalls or service bulletins related to OBDII code P0491 and the Secondary Air Injection System Insufficient Flow Bank 1?

It's recommended to check with the vehicle manufacturer or authorized service centers for any recalls or service bulletins related to P0491 to see if there are known issues or remedies available.