Fireman Walt

I am looking at a 1998 C5 BASE with under 18000 miles on it (2 owner). I have heard that early C5's had computer problems. How much concern should that be?

Route99

Welcome to the forum!
I believe what people are referring to is not that the car will have a computer problem, but that many of the systems within the car are run off of different computerized modules which may be difficult to find and somewhat expensive to buy. In 2001 there were some upgrades to the Vette and the newer modules are a little easier to find and less expensive to buy, but the bottom line is no new parts such as EBCMs are being made for any C5 Corvette. Many members on the C5 forum drive 1997-2000 Corvettes and are very pleased with their cars and have been able to work around issues when they arise.


An important part of buying a Corvette is to check the DIC to see if any codes are shown and what potential issues these codes may identify. Forum Tech Contributor Bill Curlee gave great guidance in doing this several years ago. His information is as follows:
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.

NOTE and a WARNING. You can read the DTCs while the engine is running. I pull mine up all the time while driving.
WARNING. Don’t become distracted while reading DTCs while your driving and cause an accident!!!!! Use common sense and drive safe.

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

Here are some very good sites that explain what DTC mean:

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!!


Also, please read the Stickies at the top of the General and Tech areas of the C5 section of the forum for more great info for anyone looking to purchase a C5 Corvette. https://www.corvetteforum.com/forums...s-1997-2004-2/.
Good luck with your purchase of a C5 Corvette!

Jeff T.

Welcome to the forum Walt! 99 covered plenty of bases!

Vetteman Jack

Welcome to the forum. I'm going to move this over to the C5 General section for some additional answers on your potential purchase.

Jstan2014

Welcome aboard Walt. A 1998 with under 18K miles ! Sounds like a great find to me. Good luck! If you pull the trigger, come back with pictures.

Fireman Walt

I haven't met the owner or seen the car in person yet. Assuming everything he has told me is accurate, any advise on what a good, fair price would be? I live in Spokane WA.

Jstan2014

I’m not certain about your area, but a recent search here shows a price range of about $9,900 to $14,999 depending on overall condition and option packages. Best of luck!

knewblewkorvette

I would say higher as she only has 18K miles and is probably in great condition. I would say $15-19K
P.S. Check the tires to see if they are original. If they are, you will need to replace them ASAP.