I have a 95 Camaro z28, and the smog pump went bad, i had a code of 29, which I thought meant that the smog pump was bad. The ses light comes on and off as i drive, when i stop it goes off, when i take off from a stop light it comes back on. I had the dealership replace the smog pump and the light still goes on and off, i checked the fuse, it looked good, not blown, any ideas?? Also, i went to check the code at Auto Zone and they only had an OBD 2 scanner and I didnt know it would affect the car, after it said it couldnt read the computer, the security light came on and i could not start the car for about 5 mins., when i turned the key nothing happened, just the security light was on. I was p.o. waited 5 min and tried to start the car and it fired right up, security light hasnt been on since, so i think everything is okay? Any Ideas and thoughts would be much appreciated!

 

Anybody??

 

Code 29 is for the AIR pump circuit. It doesn't necessarily, as you found, mean the pump is bad. Check the wired for damaged wiring and the connectors for breaks or corrosion. Try running the car with the AIR pump disconnected to see if the symptoms are the same.

Understand that the codes the computer gives are not necessarily the answer in themselves. They are a response to feedback from a sensor or circuit that was not what the computer expected. Sometimes it's clearly the sensor, other times it's not. There are two good resources for you:

http://shbox.com/1/Dtcs.htm This is part of Rob's larger site which is just full of detailed information. The page I've linked to here is just his trouble code page.

http://www.injuneer.com/ScanMast.html This is part of Fred's larger site and is a great guide to what the scanner is telling you.


Good luck!

 

DTC 29 sets based on the circuit that goes to the control side of the relay. Could be the fuse, the wiring to the relay or the relay itself. There is no check in OBD-I for the power circuit to the AIR pump itself. In fact you can unplug the AIR pump and remove it from the vehicle (OBD-I only), and DTC will not set as long as the fuse/relay control circuit is healthy.

There was a recall on the AIR pump (95-97 models). The dealer should have replaced it for free, and made several modifications to the system.

 

Thanks for the replies, the dealer did replace it for free, a few wks back, my mechanic and I tried to change the fuse for the air pump, thinking that may have been what was wrong and took the relay out and I forgot about it, when I went to the dealer they said the relay was missing, it was in my center console the whole time I put the relay in and whala, no more ses