Check engine light....
Thread Starter
Instructor
Joined: Jun 2008
Posts: 136
Likes: 0
From: Enfield CT
Check engine light....
How can I check for codes on my car. I keep hearing people say "I got this code today", and "I am showing this code...", but how are they seeing the code? In the display?
I have done a few mods recently to my 00. A vararam, cough:cut off cats:cough:, new 3:42's, and a tune. All work was done by a very professional RevXtreme VP (free pimp for Tracy), and I drove the car for three days after the work was done with no issues.
Today I was driving to work, and the glow of the CHECK ENGINE light came on. I pulled over, turned the car off, and prayed to the engine fairies to come and fix it. They never came. So I turned the car on and came to work. The car drives fine, but the light is annoying as all hell, and I am the kind of person who MUST know....
Help?
I have done a few mods recently to my 00. A vararam, cough:cut off cats:cough:, new 3:42's, and a tune. All work was done by a very professional RevXtreme VP (free pimp for Tracy), and I drove the car for three days after the work was done with no issues.
Today I was driving to work, and the glow of the CHECK ENGINE light came on. I pulled over, turned the car off, and prayed to the engine fairies to come and fix it. They never came. So I turned the car on and came to work. The car drives fine, but the light is annoying as all hell, and I am the kind of person who MUST know....
Help?
Le Mans Master
Joined: Nov 2005
Posts: 6,993
Likes: 25
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Your car is trashed and basicly useless. Where do you live? I will haul it off for you so it doesnt become an eye sore. 
Here is something you will like:
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.
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 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.
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 the absolute best C5 Diagnostic Trouble Code (DTC) explanation web sites!!!
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 is another very good site:
http://www.obd-codes.com/trouble_cod...d-ii-codes.php
Make sure to include the H or C suffix!!
I would clear all the DTCs and take her for a drive and see what comes back.
Bill
Here is something you will like:
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.
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 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.
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 the absolute best C5 Diagnostic Trouble Code (DTC) explanation web sites!!!
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 is another very good site:
http://www.obd-codes.com/trouble_cod...d-ii-codes.php
Make sure to include the H or C suffix!!
I would clear all the DTCs and take her for a drive and see what comes back.
Bill
