2006 Envoy Problems...codes, Codes, Codes

Mossyoakglock · January 21, 2010

Ok, so I've been trying to figure this problem out for almost a month on my sister's 2006 Envoy. She needs to get this figured out before she can go through emissions testing, or she won't pass. The following codes and the discription from Autozone are as follows:

P2444 - Secondard Air injection system pump stuck on. The PCM has detected air flow during a non-flow period. Probable cause is air control relay.

P0411 - Secondard Air injection system fault. Probable causes are relay defective or fuse open or air pump defective or hose blocked

P2431 - Secondary air injection system pressure sensor signal performance fault. Sensor is reported air pressure greater or less than expected during the system monitor test. Probable causes are failed air pressure sensor or open/short circuit condition on the AIR pressure sensor circuit.

P2432 - Secondary air injections system pressure sensor circuit low voltage. Te PCM has detected a low voltage condition on the AIR pressure sensor signal curcuit. Probable causes are short circuit condition or failed air pressure sensor.

Sorry for such a long post, but I wanted to make sure I am as detailed as possible. If any of these code descriptions are wrong, please let me know. I'm sure you know how the system works, but it only runs for about 20 sec. on a COLD COLD start. I have disconnected the hoses and I get good pressure out of both hoses (sucking and blowing) and the valve will shut off and close (unrestricted exhaust sound, and then goes away). I have checked all the fuses and the relay at the pump works (tested it with a 9v battery and it clicked) and checked all connections.

I am leaning towards the Check Valve and the sensor that is built into it, but I wanted to get some input and feedback from people on here and see if you guys think it's the same thing.

Again, sorry for the long post, but I wanted to be a thorough as possible and give as much information as I could.