This morning I adjusted the parking brake shoes (adjusted the little "clicker" wheels on the rear hubs) and replaced the brake fluid in the master (I sucked the old brake fluid out of the master and refilled it ... am going to do a full bleed when SS lines arrive). Nothing else. No rain, no washing the car, etc.

Now, when I get to 30MPH I get hit will these 3 warnings:
- Reduced Engine Power
- Service Active Handling System
- Service Traction Control System

The only two codes that are showing up are:
PCM - P2101
TCS - C1278

I can clear the PCM code with HPTuners but as soon as I get back to 30MPH the system goes crazy again. Engine cranks and idles fine. Throttle responds fine (as long as I'm not at/abot 30mph).

 

Check and see if you accidentally disconnected one of the wheel sensors, that's how the PCM knows the tires are spinning/car is out of control. If it gets no/bad input from one or more wheels it will throw an active handling code.

 

PROBLEM SOLVED! THANKS!

Turned out it was my throttle body. With you guys directing me towards the TAC and PCM, it made me process through logically with the easiest step being "see if the throttle plate moves when the gas pedal is pushed." Sure enough, no throttle movement. I tried to "push" the throttle blade by hand and found it locked up solid. When I took the throttle body apart, I found that the bearings in the intermediate gear (the one that works between the motor and the throttle shaft) were frozen up. I noted that the gasket was dry and cracked up, so I can only assume that it got moisture in the gear box and over time froze up the bearings. I cleaned it all up, greased the bearings, got it all working smoothly and now everything is working as it should again.

So again, thanks for putting me on the path to solving the problem!

P.S. sorry for not putting the relevant vehicle info. Back when I had my 01 F-body, an LS1 F-body was an LS1 F-body... still transitioning to Y-body mentality.

 

Glad you were able to get her fixed.. Good Job!!

You need to learn how to read the DTCs using the DIC..

Check this out.. YOU dont need any stinking HP Tuners.

READING YOUR Engine Diagnostic Codes



The Diagnostic Display Mode is entered with the following procedure:

1) Turn on the ignition but don't start the engine.
NOTE! You can read the DTCs with the engine running and or driving down the road but it can distract you. BE careful! Some DTCs clear themselves when you turn the ignition OFF!
I always read my DTCs prior to turning OFF the ignition switch. If you have any messages on the DIC,, PRESS RESET until they are gone!

2) Press the RESET button to turn off any warning messages. (i.e. door open, trunk open ect.)
3) Press and hold OPTIONS
4) While holding OPTIONS, press FUEL four times within a 10-second period.


Initially, on-board diagnostics go into an Automatic Mode which shows diagnostic codes in a pre-set sequence: PCM - TCS - RTD - BCM - IPC - RADIO - HVAC - LDCM - RDCM - SCM - RFA. All codes will be displayed for each. ( i.e. PCM = 4 codes) If none are present in a given module, you will see No More Codes on the display.
There are two kinds of diagnostic codes, Current and History designated with a letter suffix, "C" or "H". A current C code indicates a malfunction is present and active in the module displaying data. A history code indicates a problem existed sometime in the last 40 or 50 ignition cycles. When not accompanied by a current code of the same number, it's potential evidence of a previous problem, now resolved, that was not removed by clearing the codes.
More likely it's an indication of an intermittent malfunction.
Intermittent codes are the most challenging of the diagnostics. An intermittent code may have happened once, may have happened more than once but is inconsistent or may be happening on a regular basis but not at the time the codes are displayed. History codes can also be caused by a current malfunction in a system that is not operating at the time codes are displayed. An example is the rear window defogger which doesn't operate until the Body Control Module detects engine rpm. For history codes set by a module that does not operate with the key on and engine off, a special diagnostic tool called a Scan Tester is necessary to properly diagnose the malfunction.
Once the system has displayed all modules, it goes into the manual mode which allows selection of each module using combinations of Driver Information Center buttons. Manual mode can also be entered during the automatic sequence by pressing any button except English/Metric (E/M). Once the display shows Manual Diagnostics, select a module by pressing the OPTIONS button to go forward or the TRIP button to go back. Once a module is selected, a code is displayed, and if more than one are present; press GAGES to go forward or FUEL to go back.
To exit the diagnostic mode at any time, press E/M. If you want to erase codes in a given module, press and hold the RESET button To reset the codes once in manual mode, press and hold RESET until it displays NO CODES Press OPTIONS to go to the next module. Repeat the steps until you have reset the codes in all the computer modules.
NOTE!! Only reset the codes IF you want to - it is NOT necessary to do this. Clearing a code does not repair a problem. You are simply erasing the evidence of it in the module's memory. If you clear the code/s, and extinguish the Check Engine Light, your emissions status ready will NOT allow you to pass an emissions test until you have completed the required driving cycles.
Once you have the codes, the next question is: What to do with the information?
First, consult the factory service manual. Any serious C5 Do-It-Yourself owner should invest in the Corvette Service Manual of the appropriate model year. The Service Manual is really a requirement if you want to understand and work on your C5. You can GOOGLE the DTC and also find information on it.




Here is very good site that explains the DTCs:


http://www.corvette-web-central.com/C5DTCcode.html


http://www.obd-codes.com/trouble_cod...d-ii-codes.php



Make sure to include the H or C suffix!!