I posted a message last night about a problem I had while driving my car. Unfortunately I also mentioned that I went over the speed limit by 25mph and that there was a car following me and the moderators in their infinite ability to miss the point closed the thread as a street racing 'kill story' thread rather than a request for help on a technical issue on my C5 ZO6 ( I feel I should put that in so they don't lock the thread as not being about the right car for this section).

original thread: http://forums.corvetteforum.com/show....php?t=1972061

The couple of responses I got before the thread was locked said it sounded like a flaky Steering Wheel Position Sensor. They also said to read the codes out and post them. I have only had this car a few months and while I have a scan tool for my old C4, and of course you could just jumper the ALDL to get the codes on those cars, I have no idea how to do that on a C5. I have the factory manuals for the car but they just say 'plug in the scan tool' and go from there. As you would expect as they are for a dealership that would have the tool.

So how do I go about reading a DTC on this car? I have a copy of LS1edit but I don't see anywhere in it's manual about reading trouble codes, although I could have missed it as I skimmed it. Will LS1edit work or do I need to buy some aftermarket scan tool? I have an AutoX-Ray unit I bought for my C4 but it must be ten years old now so I wouldn't imagine it would work. I would like to find out if it is the SWPS because having the car suddenly veer to the side like someone grabbed the wheel is terrifying. Thanks for any help guys.

 

Some info here;

http://www.corvettedoctor.com/2004_DTC_Codes.html

I suppose someone will give you more info in time.

Dave.

 

Ok, read out the codes with that. No clue how old some of them are. There where 9 codes that where basically

UXXXXH- Loss of communication with XXX.

I assume these came when the new battery was put in or some of the other mods, no clue how old they are. Cleared them out. They are spread out over 3 different systems, the IPC, the radio and the A1-RDCM. Some of the codes are not listed under that topic but since its the same code I am assuming it means the same thing.

There was one code that stood out as different from the rest as it actually pertained to something other than losing communication with a Control Module. It was.

28 - TCS: C1282H -Yaw Rate Sensor Bias Circuit Malfunction

So I am now looking through the factory manuals to try to figure out what exactly that means as far as fixing it. I know what it does, but not how to diagnose whether it was a freak accident or if a ground is bad or what. Not even sure where the Yaw sensor is. The factory manual layout can be labrynthine sometimes so I will continue to dig. Suprisingly did not see the C1281 which I believe is the SWPS error message. Although the Vette Doctors list has it as VSES not SWPS, no clue what VSES means. Learning as I go. Veering into a wall is a great motivator for learning. Thanks again for the help guys.

P.S. Oh quick question. If the Active Handling had just come on and saved me from a slide or something if there actually had been one would I have gotten the same message on the DIC? Or would it have just flashed the little Glyph on the IP and said "Active Handling" on the DIC. Only had it go off once and didn't look. Thanks. Just trying to see if the fashion in which it displayed is normal for AH intrusion or was an error.

 

I'll take a guess at this, but it is only a guess. The Yaw sensor would control the braking in the car as it will try to correct an incorrect attitude in the vehicle. So, if you are driving straight but the computer thinks you are going sideways it will apply the brakes to try and correct this. I doubt the steering wheel would move as that would require an input that just doesn't exist on this car, but the brakes being applied is very doable since it is there.
VSES is the Vehicle Speed E System - E might be Electronic. I guess I can look it up in the manuals as well just to be certain.

The loss of communications is typical of a bad ground system so look for the ground wire closest to those systems being affected by the loss of comms.

 

...just skimming this thread - but I will say that the system applying the brakes on on side of the front and not the other will result in a steering wheel position change. Further, the system applying the brakes on one side of the vehicle and not the other can cause a completely unwanted lane change (been there).

 

Looks like you have got to the codes ... but here's another write-up ...

https://www.corvetteforum.com/techti...D=26&TopicID=1

It is in the Service Manual .... Go to the Instrument Panel, Gauges and Console .... early in that section ... right after the "Sacan Tool Data Definitions" is a discussion of how to displaty the DTC on the DIC.




To take your last question first ... a "normal" engagement of either Traction Control or Active Handling will cause the DIC to dispaly TRACTION CONTROL ACTIVE or AH ACTIVE and you get a chime when they engage. The warnng lamp will NOT illuminate for a normal activation.

If the "glyph" (the skidding rear of the car) illuminates, that indicates a "problem" with eithr AH or TC (or both). It will stay illuminated until the next ignition cycle.

Using the factory manuals .... they are pretty daunting at first, but after a while they do "kinda" make sense.

Let's take as an example your C1282 and use that to "decode" what is happening.

So let's suppose we have NO CLUE what a C1282 means ... go to the index of any of the three manuals and in the last few pages (under DTC) you will see a long list of the DTC codes .... find the C1282 and then go to that page ..... 5-161 in my 2001 Manual.

First is a description of the particular system this code relates to. Notice right away you find out what VSES stands for .... . You also get a fair description of how the various sensors work together to make VSES function. If, at the end of this description (and this is true of any section in the manaual ... at the very end of each section (DISC BRAKES is one section - ANTI-LOCK BRAKES is another section) there is an overview of that entire system called "Description and Operation" (page 5-203 in mine) which helps when, for example, you're not sure how VSES and TC interact, or if they do.

OK so back to the DTC C1282 page .... after the description of the system come descriptions of what tests are performed that can set the DTC, what conditions can set the DTC, and what the effect of the DTC being set (in this case AH is turned OFF, the warning lamp is lit, the DIC displays a message, and it even tells you that with this DTC both ABS and TC remain ON.

After that is the "Diagnostic Aids section ... the numbers refer to the table below and help explain what certain steps are looking for. Then the Diagnostic Table ..... just step through it as best you can (it assumes everyone has a Tech2 scanner ... mostly only dealers and some larger shops have them.)

Finally ... a few other pointers ... take the start of the ANTI-LOCK BRAKE SYSTEM section (page 5-112 in mine) ... all sections are laid out in the same format .... Tables for Torrque setting for the section, fluids and lubricants and capacities for this section, then the electrical diagrams for this section. Following that is data the Tech2 can display .... while this might not seem useful at first, often times just looking at the data the computer can work with (who knew the EBCM calculates the RF and LF rotor temperatures ????) can give you ideas about problems. Following this is How to diagnose a problem ... mainly in this section oriented around DTC diags ... but in other sections there may be diagnostic trees for problems like "Bad smell inside car". After the diag section is the "mechanical section ... how to actually go in and remove/replace componenets in this section.

If you just take Manual #1 and skim through it for a half hour ... see how each section is laid out the same ???? Usually a DTC will take you to the right section and get you started, but remember that there is also in the diagnostic sections more generic problems not related to a DTC (rattles, smells, vibrates, noises ..... whatever).

Hope this helps.