UPDATE:

9/27/15--I found a couple of people who kept getting random codes as I was. It was suggested that I first and foremost try the ignition switch. I was told that they tend to fail and many people end up with the symptoms that I had. I was actually shown an ignition switch that was bad. I spent the $85 for the switch and have put it in. So far, I have had no issues with any codes coming up at all. Granted, this is the third day and time will tell, however, this is the longest that I have gone without a random code showing up. I wanted to put this out there incase others are experiencing the issues I have had. If anyone is ever interested in an update to see if I have had codes return or not, feel free to reach out to me. It was a complete pain to get the part switched out as I had to read different posts from various issues to try to figure out how to get to the part and then get the cylinder out. But once it was all said and done, really wasn't that bad. 2 hour project for me being brand new to the vette and how it's put together and all. Crossing my fingers this was it. I'm not going to actually add the pictures here (of the bad part) as they really will not do you any good. You will have to completely remove the part and take the green back off of the ignition switch to even see if you are getting the carbon buildup. From what I was told, the switch should be a number one suspect if your vehicle is throwing random codes, the ig switch has never been changed and you are 50K miles or over. (I was at 76K and when taking my old ig switch apart, I had tons of carbon build up from all the arching.)




After a couple of people were kind enough to give me instructions on how to actually pull the codes, I pulled the ones in this thread. I cleared those codes and when I checked the following day, I did not have paper to write down the codes, but they were completely different codes. I cleared all of those codes, drove the car for about an hour and checked again. No codes this time. I have driven since Tuesday afternoon with no codes. Yesterday, I ended up with one code under PCM and it did not match my previous P1120H (and unfortunately, I again, did not have a pen on me...that has since changed and I am keeping a pen/small notebook in the car at all times now.). I have cleared that code and no codes today. So, I am wondering if maybe it can be tracked back to the ignition switch? Carbon build up between some contacts maybe and giving me random codes?


Since that is something that is easy (and cheap enough) to fix, I think I will make that my Sunday morning project. Any feedback on ignition switches--such as the local car parts store ig switch is just as good as what I can get from a vette supplier?


Thanks again all!


Hi all,

I'm a newb to the vette. Always loved the cars and finally able to afford one. So, question for techs or DIYers out there who can provide some advice...:

Just bought my C5 (03-50th year) the beginning of August. She has had some mods done (2013) which consist of:

HID--low beams
PRC LS6 ported heads
CORSA exhaust
American Racing 1 7/8 inch long tube headers
DMH dual electric cutouts
Fast 92 intake
ls2 throttle body
LS2 MAF
Custom comp Cam
Monster stage 3 single disc clutch with billet fly wheel
3m front clip clear bra
3m clear bra for both rockers
Replaced 2nd gear syncro in the Tranny
Cats installed to pass emissions




That said, on Monday, 8/24/15, on my way to work (early morning) I received the errors:

• Service ABS
• Service Active Handling

Once to work and parked, I received the message:

• Reduced Engine Power

After work, the messages were gone, however, I had the check engine light on. Took her in for service and got her back on 9/2/15. She was throwing the codes for a knock sensor and throttle body.

Mechanic found that it was the plugs to the throttle body and the harness for the knock sensor and replaced.

Two days later, after running in traffic this evening and giving her some gas to get up to speed on a highway, I received the same messages, in the same order as soon as I pulled into my garage to park.

Need to know why I would be getting the same messages two days after new plugs/harness installed? Am I doing something while driving that would cause this? Any of the mods above that conflict? The mods have been on the car since 2013 and there have been no records of these messages from the previous owner.

I have reached out to a couple of great guys to get some thoughts. First and foremost they asked me to pull the codes (and provided info on how to pull them). Codes I get are:

PCM= P 1120 H
TCS= C 1221 H; C 1222 H; C1227H; C 1248 H; C 1278 H
Radio= V 1064 H; V 1096 H; V 1016 H

I was then told that I should check under the battery for any leakage. Pulled the battery and it's actually very clean (except a bit of dust and dirt). No acid.

I'm so confused and needing some direction. Thanks in advance to anyone who can offer some insight! I feel like she is parked more than I get to enjoy her.

 

Thank you so much! Looks like I have plenty to keep me busy for a bit...


I did make the mistake of using a V instead of a U. They all do start with a U for the Radio codes. I just cannot read my own bad handwriting it appears. As for an aftermarket radio--not yet. Right now, it still has the stock, standard radio that drives me insane. Eventually, I would like to swap it out to the touchscreen, Bluetooth, double din. However, my preference is to get my brat up and running around first. Radio is low on the priority list as I'm perfectly happy listening to her purr.


I will have to grab my pops multi meter and start on the list of 'to-do's you have suggested below.


I really cannot thank you enough and I will definitely be replying to the thread as I find/fix things. You have been a tremendous help!! LOVE THIS CORVETTE COMMUNITY! Thank you for such a great experience!

 

FYI... the stock stereo isn't all that bad... the speakers suck and so does the FM/AM... Cd's are a pretty good quality...but, IF you want to do a simple upgrade Dennis @ Double D mods a Forum vendor has a Kicker plug and play replacements for the speakers and you can very simply add bluetooth, to your stock radio... here are the components. He also sells the adapters and bluetooth receivers...







winds up looking something like this... I just leave the Bluetooth receiver in the console...





Along with some sound deadening is sounds pretty darn good. We love it and only spent about $200.

 

1st of all the codes you are getting for the ABS system or traction control system can be caused by only a few things
IF you have NON stock tire sizes this will create those codes
2nd the most often issue for a T/C or ABS code is a fouled or broken wheel speed sensor-- Those sensors are used by both the TC ( to prevent the wheels from spinning) and the ABS to prevent the wheels from skidding on a hard stop
Now looking at your engine mods--- the addition of a LS2 T-Body and a LS2 MAF always creates tuning issues and crazy codes--- My experience is that the STOCK T-Body and the STOCK MAF is good for approx. 500 crank HP-----There is NO performance advantage by going to a larger MAF or T-Body----Yes you can get them to work but it takes hours and hours of data logging and re-tuning to get them to preform---AND after you do---You may be only gaining at best 5 RWHP---At the cost of drivability and numerous annoying codes----Often ending up in a "reduced power mode"
Your car with heads/cam / and LT's would run the best with the stock T-body and stock MAF-----My 98 car had very similar mods and apprx 400 RWHP-----I still used the stock MAF and T-Body I did have my stock T-Body ported and that is OK as it requies no tuning---Remember the MAF is only an air measuring device--There is minimal airflow loss up to 500 Crank HP---So if you go to a larger MAF the entire MAF table becomes messed up-----An LS2 MAF id calibrated for a 6.0 liter engine and yours is a 5.7-
Unless the previous owner hadhis tuner spend hours and hours to correct the MAF table most likely it is all wrong----Being that yoy are getting T-Body codes and MAF related codes with are both related--I would guess that your ECM is NOT tuned correctly for those changes-----Put the STOCK MAF back on as well as the STOCK t-body and your car will run better than ever--and NO CODES---Your other option is to have it re-tuned by a tuner with HP or EFILIVE but even then you ate looking at a very little performance gain

 

VERY informative and GREAT response...

 

so how are you going to put a stock 3 bolt throttle body on a fast 92?... take your bridge and coupler off and look at your throttle body blade, is it silver or gold?... the gold blade is from an 09+ ls3/7 and can be made to work on a c5 but they are notorious for going into rep mode because it thinks the throttle is opening over 100% which in reality it is not... they also open in the reverse direction of the other throttle bodies... an experienced tuner can fix that issue but the easiest thing would be to get a silver blade throttle body and have the tune tweaked if necessary

 

Off subject,I know.but I would get rid of that batt.and get a red top.you don't want that batt.leaking on your electronics under the batt.box.many treads about this.the out come is not good.

 

Thank you so much for the options!!! I may look at that in the meantime. I really was disappointed that this beautiful car had the same exact radio as my 97 1500 Silverado. The look I'm going for will definitely have to take some time as I will need to replenish the $$ for it. Double D is exactly who I was looking at for the double din bezel mod though. Nice work and thank you so much for the info! I didn't know of this other option.


Have a great day!

 

All, thank you for all the things to look into. I have eliminated a power from the battery to the fuses issue. Battery tested good under the load test as well as the starter/alternator. Looks like there is plenty to look into here. I will post things I check and the ultimate fix (hopefully that will happen!!). Thanks again all!