I just got a 1999 LT 4-Door 4WD 4.3L which needs inspection and now shows the P0410 plus it lists it twice with a p/d tag. I reviewed posts from the last year or so involving a P0410 code. Some people don't seem concerned about it and others indicate it might lead to poor gas mileage and ruining the cat. The weather has been real cold and I get terrible mileage just driving around town. Good on a long trip though.

Regardless I need to fix it for inspection. I'm going to start with the diagnosis procedure from the forum, but I thought I'd post first anticipating further help. I doubt my code reader can turn the secondary air injection pump relay on and off.

The diagnosis procedure calls for the AIR fuse to be in the underhood fuse block cover. The truck's manual shows no fuse there. Some posts show the location of the relay and 30amp maxi fuse in the fender next to the battery. It was blown, but replacing it had no effect on the blower. I'm already stuck as whatever caused the fuse to go in the first place hasn't been fixed, yet the fuse is still good after driving a bit.

I believe the p/d tag means pending, but all the monitors have already been checked.

 

I was reading the wrong diagnostics chart. There is a 10 amp IGN E fuse in the underhood fuse block and it's good. As stated, the 30 amp fuse was replaced and the other 10 amp fuse in the AIR fuse block is also good.

Without a scan tool to command the pump on/off, I applied 12v to the connector between the AIR fuse block and the control module. I proceeded through diagnostics as best I could and found the relay and pump to be working OK. After reconnecting the control module circuit and turn the key to RUN position, the pump doesn't work. Next I disconnected the blue connector from the PCM/VCM and one by one jumped all the terminals to ground and one of them started the AIR pump. So my PCM/VCM is bad. Can this be fixed by a reprogram, or do I have to replace it?

I called my local Chevy service and they weren't sure a reprogram can fix this. Does anyone know for sure? It will be $99 just for the dealer to look at it.