93civEJ1

I have had my car a few days now finally. Noticed that I am not locked out of 2nd or 3rd when the 1 to 4 shift light comes on. I also do not get a engine light when i turn the car to the on position without starting up.

So, I decided to purchase my own scan tool today and just see what happens.
I had 3 codes. Two were the same.
PO650 - MIL indicator ......hmm would this maybe mean the bulb is missing?
PO803 - 1 to 4 shift.....what do I need to look for? I am thinking maybe I have some sort of something installed causing this. The fuse?

onspeed

IIRC, skip shift can't be deleted by pulling a fuse. Usually it's tuned out or you can buy some relay thing to plug in near the transmission. I've always used HPTuners to remove my skip shift, and have never thrown a code, so I assume your issue is with the second option. That said, I wouldn't worry about it because skip shift is very annoying.

And if the CEL isn't turning on when you initially turn the key to ON, then I'd check the bulb first.

ZeeOSix

Previous owner probably put a skip-shift eliminator on the car. It's located on the wire harness on the transmission ... small module that plugs in series with the harness connector.

http://lmgtfy.com/?q=corvette+skip+shift+eliminator

Hitman227

Just locate a friend with HP Tuners. Easy.

93civEJ1

Im not even sure what HP Tuners is, but i am guessing I need to look into it.

AntonioZ06

also.....you don't need a scanner to read the OBDII codes. You can read, display, and erase codes right in the dash itself

93civEJ1

Oh really? Pretty easily? or do you have to do some kind of jumper trick to put the ecu into a certain mode and count flashes and all that stuff?

It was simple to just plug in to the OBD port and hit 1 button.

AntonioZ06

as always copied and pasted from Bill Curlee:

READING YOUR Engine Diagnostic Trouble Codes (DTC)

This procedure should be carried out any time you experience a problem with your C5. Most inexpensive store bought aftermarket code readers will ONLY read power train DTC’s. Reading the DTC’s with the C5 built in code reader will allow you to read ALL the modules in the vehicle.

The Diagnostic Display Mode is entered with the following procedure:
1) Turn on the ignition but don't start the engine.
2) Press the RESET button to turn off any warning messages. (i.e. door open, trunk open ect)
3) Press and hold the OPTIONS button
4) While holding OPTIONS, press FUEL button four times within a 10 -second period.

Initially, the on-board diagnostics go into an Automatic Mode which will cycle through each module and 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 module. ( 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 types of diagnostic codes, Current and History designated with a letter suffix, “C” or “H”. A current code indicates a malfunction is present 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 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 RESET 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. There are a few body module DTC’s that if set will prevent the module from operating properly. Once the DTC is cleared, the module will return to full function. This is not true for power train DTCs.

If you have never read and cleared your codes, there will probably be a lot of old history DTCs. It is recommended that you clear your codes and see if any come back during a driving cycle. Those are the ones that you need to concentrate on diagnosing.

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.

These are some very good C5 Diagnostic Trouble Code (DTC) explanation web sites!!! They also explain how to read the DTCs

http://www.corvettedoctor.com/Code_Main.html

http://www.corvettedoctor.com/index.html

Go to “technical data base” and then to “Corvette ECM Computer Codes”. Then select your year car. Read the instructions and then scroll down to the "READ MORE" window to view the code definitions.\

Here are some more very good sites:

http://www.gearchatter.com/viewtopic11755.php

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

Make sure to include the H or C suffix when you post your DTCs!!

AntonioZ06

and a video to show that in simple plain english

ZeeOSix

DTC P0803
Skip Shift Solenoid Control Circuit

What I said earlier isn't quite accurate. Installing a skip-ship eliminator shouldn't throw a trouble-code unless there is something wrong with the unit. Best to look down at the transmission and see if there are any obvious connectors unplugged, etc.

93civEJ1

I will do that when I go to jack the car up for the first time. I havent made it to that point yet.