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1999 Z28 service engine soon lamp on

01-20-2004, 10:38 PM
I recently had scan tool diagnostics completed on my 1999 Z28 which is running well. In fact the only reason the vehicle was brought in for service was due to the ses indicator light being on. The folowing codes were displayed: P0161, P0172, P0327, P0410, P0412, P0418, P1416( no rf8air sat this time). The ses light was then cleared and came back on almost immediately after clearing. What part do you think is responsible for these codes being displayed.

01-20-2004, 11:16 PM
dunno, ill see if i can look it up tomorrow for ya at work, and get back to ya. got kinda a busy day tomorrow (see "Define stupidity" thread) but ill see if i can fit ya in.

01-21-2004, 04:37 PM
I had the same thing happen to me. I had it checked out, and it was all fine. Just hold in the trip meter stick/button thingy in for about 10 seconds. I belive their was another thread on the same topic with someone elses 02 Camaro.

01-21-2004, 05:42 PM
If u had skip shift and disconected it or the pulg slipped loose from the tranny that can cause the light to stay on so i'd check that. and if u havent disconected it DO IT it sucks it tries to make you shift from 1 to 4 not all the time just when it feels like it u can get directions from a haynes manual

01-21-2004, 10:11 PM
um, i wouldnt reccomend clearing the codes and ignoring the problem, codes are set because something is going wrong. i didnt get a chance to look up the codes today, too busy getting my ass chewed at work, but ill see about doing it tomorrow.

01-22-2004, 06:37 PM
ok darren, i think i know what your problem is, 7 codes, 30 pages of diagnostic info, four wiring schematics, and a system description later......... you have a blown fuse. the 25amp AIR PUMP fuse in the underhood fuse block to be exact. here are the codes
P0161 = Heated O2 sensor performance bank2 sensor2
P0172 = Rich mix bank 1 (sure its not P0174??? that would be bank 2 which is where the problem is i think)
P0327 = Knock sensor circuit
P0410 = secondary AIR system
P0412 = Secondary AIR solenoid relay control circuit
P0418 = secondary AIR Pump relay control circuit
P1416 = secondary AIR system bank 2.

all of the system wiring goes back to that one fuse. the reason you are getting the check engine light is because it is also hooked to the PCM, because there is no power to the AIR system, the PCM has no communications with it, and sets codes. the purpose of the AIR in case you dont know, is emmissions. it pumps air into the exhaust, to burn excess fuel, and help the cats heat up to optimum operating temp faster. what has probly happend is that the fuse blew, for whatever reason. and the AIR stopped working. this would cause more fuel than normal to make it to the cats,(aka a rich condition) and therefore the O2 sensor. chances are you have burned up that O2 sensor, but i would replace the fuse, clear the code and drive it for a while to see if the check engine light comes on again, if not your ok. if it does come back then replace the O2 sensor. that code points to the one on the passenger side behind the cat. could be anywhere from 60-120 bucks i think. dont quote me on that. anyway, check that fuse, chances are its blown and is causing all your problems. good luck.

01-22-2004, 06:39 PM
oh and the skip shift, dont just unplug it, they sell skip shift eliminators that fit in between the plugs, so that the computer thinks its working but it isnt, and it wont set a code. although, it is there for better gas mileage, so i personally would leave it, you can shift through it if you really want to. so it dosnt really have an impact on performance.

01-22-2004, 06:45 PM
Nicely done 89IROC&RS...very nice.

01-22-2004, 07:09 PM
why thank you *takes a bow* its what i do :) also helps to be a chevy tech assistant that specializes in electrical problems, and therefore has access to all the service information :)

01-22-2004, 07:42 PM
Yeah, we have a program called Alldata. I dont know if you've heard or know about it. But you look up the year, make, model of the car. Then select what catagory and....poof, what you need when you need it.

01-22-2004, 08:01 PM
yeah same thing, we call ours SI its the GM vehicle database. all the info for diagnosis, wireing diagrams, sysetm operations, repair procedures. everything. very very handy

01-22-2004, 08:10 PM
Ours is for all cars from 81 and up. Has most of the stuff you need. Because cant look up stuff older than that.

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