RaceTowin

I need help with this one. I have a 99 Suburban 1500 4x4 5.7L. I am on my second air pump.

About a year ago I threw the same P0410 check engine light. I replaced the air pump and all was good. The code stayed away. Fast forward a year. Code comes back. I've read a lot about this issue over the last month or so. I realize that these pumps seem to go bad for whatever reason. Keep in mind I live in San Jose California. It's not humid here, it doesn't snow and rarely rains.

So, I did as much testing of the system as I could. I checked the pump (out of the vehicle) it would not turn on. I had one bad check valve on the passenger side.

So I replaced both check valves, I replaced the gaskets on the metal hoses connected to the exhaust manifold. I replaced the stop valve (even though it's discontinued) with one from another GM 5.7L motor (AC Delco PN # 214-1938). I wanted to replace the relay, but when I went to buy it, the item the dealer had was a shielded model. It would not work in the fuse box in the engine bay. So, there is a relay somewhere, but NOT in the fuse box. I checked, there isn't one there. Air Pump Relay that's shielded

The code came back on after 3 days of being off. I have no idea where to go from here. I cannot locate the air pump relay. There is only one other part I can find to the system, it's where the two wire for the air pump plug plugs into, I think it's some type of actuator. It has two tiny air tubes connected to it. One of the air tubes connects to the stop valve.

I am at my wits end with this. I have no idea what to check next. I am crap with a multimeter. Any help from here would save me gray hair and hundreds of dollars at the dealer.

Thanks, Christian

RaceTowin

I just confirmed the pump IS activating/turning on. I turned on the truck, walked to the front and felt suction on the inlet tube. So I am letting the ECU discharge and see if that works. I had orginally reset the ECU with a scan tool. We'll see I guess.

I still don't understand why these pumps keep failing when the stop valve is functioning.

Christian

Leigh Chancey

Having same issue. My mechanic told me to tap on the top of the relay That's under the hood if it stays running again. I read a post by a certified Chev technician who added that a bad ground wire to the relay can also cause intermittent problems & you would need to trace the wire back from the relay to the air pump until you located the source of the bad ground. Said the wire was brown in color. Hoping you solved it because it's smog time & not looking forward to trying to clear the code & getting in drive cycles so it will pass.