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

- Code Popularity: 20,619 Views
- Repair Importance Level: 1/3
- Repair Difficulty Level: 2/3
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What are the Possible Causes of the DTC P0491 Ford?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Secondary air pump with no or low air flow
  • Secondary air bypass solenoid leaking /blocked or stuck open /closed
  • Secondary AIR air hose restricted
  • Secondary air vacuum hoses restricted or leaking
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How to Fix the DTC P0491 Ford?

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

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What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0491 Ford code, it typically requires 1.0 hour of labor. The specific diagnosis time and labor rates at auto repair shops can differ based on factors such as the location, make and model of the vehicle, and even the engine type. It is common for most auto repair shops to charge between $75 and $150 per hour.

What are Code Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)

Code P0491 Ford 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 Ford - Secondary Air Injection System Insufficient Flow Bank 1 - AutoCodes.com
P0491 Ford Code - Secondary Air Injection System Insufficient Flow Bank 1

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Code P0491 Ford comments

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