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2004 GMC Envoy 4.2L I-6 Check Engine Light Code P0410: How to Fix Secondary Air Injection System Issue Step by Step

Model: 2004 GMC Envoy Fault Code: P0410 Posted: 2015-03-19 08:51

Hi everyone, I recently purchased a 2004 GMC Envoy with 375,000 km on the odometer. It has a remote starter installed, but otherwise runs smoothly with no unusual noises or performance issues. The vehicle now shows a Check Engine Light, and after using a diagnostic reader, I received fault code P0410 — Secondary Air Injection System malfunction. I'm new to car maintenance and am looking for clear, beginner-friendly guidance on how to diagnose and fix this issue. I'd appreciate any step-by-step instructions (preferably with videos or photo-based guides) that walk me through the process in simple terms. If possible, please include information about what to check first and how to verify the system is working. I'm confident I can handle a basic repair if someone provides clear direction. Any advice or resources would be greatly appreciated! Thanks in advance.

Related fault codes
P0410
Comments (3)
Anonymous 2015-03-19 11:55

Start by checking the air pump fuse and relay. Use a diagnostic scanner to command the air pump on — observe whether the solenoid activates and the air pump runs. Then monitor the oxygen sensor's response. Also, check for any P14xx series codes. Make sure your scanner can read all stored codes and supports bi-directional communication (i.e., it can send commands to components).

Anonymous 2015-03-21 07:11

Verify fuses 54 and 56 located in the under-hood fuse box. When you start the truck, do you hear the air pump running? If not, this could indicate a blown fuse or faulty relay.

Anonymous 2015-05-23 14:14

I experienced the same P0410 issue and replaced the air pump — but the problem persisted. Eventually, I found that the relay under the driver's seat was failing due to water ingress and internal burning. It cost me only $7 on Amazon. This is a common fix for 2004 GMC Envoy owners with this code.