Performance upgrade?Check engine
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Instructor
Joined: Nov 2008
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Performance upgrade?Check engine
I have a stock C-5 Vert and just finished putting on a ZO-6 intake, Vortex B-2 rammer, high flow MAF housing, Upgraded MAS sensor, Ported Throttle body and Zo-6 TI exhaust. Ran real good but when I went to WOT the engine got check engine light, service active handling message and engine cut out. It ran great all the way to work and when the light went green I went WOT and all hell broke loose. Any ideas?
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Joined: Mar 2011
Posts: 40
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Is it an auto? Did you do an idle relearn/reset? I think the procedure is a little different for an auto, but for mine I just pulled the battery terminal. If you didn't do any of those things, you are getting the wrong fuel mixture because your PCM remembers the old air flow.
You need to retrain the car at varying RPMs for 50-100 miles. Going WOT immediately after your upgrades will cause all sorts of unexpected things to happen.
The only part that would worry me is the Active Handling light. If that came on before your engine cut out, that's something electrical or EBCM related. However, if I had to guess, it kicked on when your engine stalled? Right? (which is fine if that's the case)
Check your Vararam connections and make sure you aren't leaking air. This will cause bucking and/or surging. You also said you upgraded the MAF. Make sure you didn't damage any of the tiny wires inside. Make sure it's actually working. Make sure the electric connector is clean (no corrosion or junk) and seated properly. Also, did you relocate the MAF near the throttle body? I have heard of more people having issues with aftermarket MAF near the throttle body (usually throwing codes)
You also mentioned exhaust. Make sure everything is tight and secure. Make sure your O2 sensors are connected and operable.
Also, pull the codes. Get in the car, turn it to ON, (You don't have to start it) close the door and HOLD down the OPTIONS button while pressing the FUEL button 4 times. You can let it scroll through or you can manually scroll through them. Write down the codes and post your findings here.
Is your check engine stuck on? Does it go away if you start the car?
Again, check all your wires. Including any you disconnected when installing the Vararam. There are at least 2 I know of near the radiator shroud you need to check.
Like always, more information is really helpful! Good luck!
You need to retrain the car at varying RPMs for 50-100 miles. Going WOT immediately after your upgrades will cause all sorts of unexpected things to happen.
The only part that would worry me is the Active Handling light. If that came on before your engine cut out, that's something electrical or EBCM related. However, if I had to guess, it kicked on when your engine stalled? Right? (which is fine if that's the case)
Check your Vararam connections and make sure you aren't leaking air. This will cause bucking and/or surging. You also said you upgraded the MAF. Make sure you didn't damage any of the tiny wires inside. Make sure it's actually working. Make sure the electric connector is clean (no corrosion or junk) and seated properly. Also, did you relocate the MAF near the throttle body? I have heard of more people having issues with aftermarket MAF near the throttle body (usually throwing codes)
You also mentioned exhaust. Make sure everything is tight and secure. Make sure your O2 sensors are connected and operable.
Also, pull the codes. Get in the car, turn it to ON, (You don't have to start it) close the door and HOLD down the OPTIONS button while pressing the FUEL button 4 times. You can let it scroll through or you can manually scroll through them. Write down the codes and post your findings here.
Is your check engine stuck on? Does it go away if you start the car?
Again, check all your wires. Including any you disconnected when installing the Vararam. There are at least 2 I know of near the radiator shroud you need to check.
Like always, more information is really helpful! Good luck!
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
READ AND POST THE DTDs!!!!!!!!!!!!!!
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!
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!!
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!
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!!
