C6 engine codes and service traction control...help needed please
03-24-2019, 09:15 AM
#1
Instructor
Thread Starter
C6 engine codes and service traction control...help needed please
I have a 2012 grand sport with engine light on. It is showing lean on bank 1 and bank 2. Also random misfire code, along with MAP code. As a result of all this the service traction control light is on as well.
I have replaced the plugs and wires, replaced the mass air flow sensor, replaced MAP sensor. We also switched around some fuel injectors with no change, and checked for good spark at coils. Cannot get things corrected. When first started up it will run fine for maybe a minute. Then teach jumps around just a bit and engine and traction control lights come on and you can hear it miss.
Any suggestions? In general car runs great. Just need to find the culprit here and correct.
I have replaced the plugs and wires, replaced the mass air flow sensor, replaced MAP sensor. We also switched around some fuel injectors with no change, and checked for good spark at coils. Cannot get things corrected. When first started up it will run fine for maybe a minute. Then teach jumps around just a bit and engine and traction control lights come on and you can hear it miss.
Any suggestions? In general car runs great. Just need to find the culprit here and correct.
03-24-2019, 12:59 PM
#2
Race Car Tech
Initially, the wires and spark plugs came to mind, but since you have replaced these, with other components as well, I'd be looking at something that has been known to cause some of the issues that you mention. This may not be the cause, but it's another place to check.
The passenger footwell fuse panel connectors (blue ones) can become shifted if a passenger was pushing on the footboard too hard. This makes the footwell board panel come in contact with the connectors, and that can shift them a bit so that some of the connector pins are fretting.
Disconnect your battery, remove the connectorts and check for bent pins, etc. on the connectors. If OK, then replace the connectors, maybe adding a bit of dielectric grease of the pins. Reconnect the battery, and see if those issues are still there. If the issues are gone, then use some pencil erasers between the floorbord and the fuse boxes so that the floorboard can no longer be pushed against the connectors.
If the issues are still there, you will have to continue to troubleshoot, looking at the main ground connection from the battery, etc. etc.
Good Luck
Here is a PDF of the fuse panel connectors.
The passenger footwell fuse panel connectors (blue ones) can become shifted if a passenger was pushing on the footboard too hard. This makes the footwell board panel come in contact with the connectors, and that can shift them a bit so that some of the connector pins are fretting.
Disconnect your battery, remove the connectorts and check for bent pins, etc. on the connectors. If OK, then replace the connectors, maybe adding a bit of dielectric grease of the pins. Reconnect the battery, and see if those issues are still there. If the issues are gone, then use some pencil erasers between the floorbord and the fuse boxes so that the floorboard can no longer be pushed against the connectors.
If the issues are still there, you will have to continue to troubleshoot, looking at the main ground connection from the battery, etc. etc.
Good Luck
Here is a PDF of the fuse panel connectors.
Last edited by 4SUMERZ; 03-24-2019 at 01:00 PM.
03-24-2019, 03:55 PM
#4
Lean on both bank is screaming air leak at the intake manifold, or you changed the air filter system and the Maf is not reading the amount of air coming into the intake correctly instead.
So if you changed the intake manifold, pull it and will bank that one or more of the O rings came unseated as you where moving the intake past the back crowling before it was dropped in place. If you changed the air filter system, then will need to check the tune to make sure that Maf is reading correctly as well. Hell, could be one of the bad OEM Maf's in play as well.
If oem stock, then check for a air line on the intake manifold that become unplugged, or problems with the fuel pump not supplied enough pressure to the injectors/one or more of injectors clogged instead. Hence on start up, car is going to run fat since it running in start up loop, but as soon as it starts to heat up, motor is trying to hold the AFR to 14.1. So codes is after initial warm up, motor is running leaner than 14.1 both banks in closed loop, motor can not compensate to bring it back down to 14.1, and why you are getting the codes. Hence either air leak, or injectors not able to spray enough fuel to bring the AFR back down.
So if you changed the intake manifold, pull it and will bank that one or more of the O rings came unseated as you where moving the intake past the back crowling before it was dropped in place. If you changed the air filter system, then will need to check the tune to make sure that Maf is reading correctly as well. Hell, could be one of the bad OEM Maf's in play as well.
If oem stock, then check for a air line on the intake manifold that become unplugged, or problems with the fuel pump not supplied enough pressure to the injectors/one or more of injectors clogged instead. Hence on start up, car is going to run fat since it running in start up loop, but as soon as it starts to heat up, motor is trying to hold the AFR to 14.1. So codes is after initial warm up, motor is running leaner than 14.1 both banks in closed loop, motor can not compensate to bring it back down to 14.1, and why you are getting the codes. Hence either air leak, or injectors not able to spray enough fuel to bring the AFR back down.
Last edited by Dano523; 03-24-2019 at 03:56 PM.
03-24-2019, 04:04 PM
#5
Instructor
Thread Starter
Intake and air cleaner are stock. Checked for air leaks or something unplugged. Nothing. Unhooked injectors and swapped around to see If the miss followed it but injectors all seem fine. Makes sense what you are saying about startup, as it runs good for 30 seconds to a minute then the idle gets a little erratic and slowly drops down . That's when the lights will come back on.
03-24-2019, 04:50 PM
#7
Can you do a quick data log on the O2 sensors to see if they are the problem to start with?
Also, quick check on the injector duty cycles as well.
Lastly, put a manual gauge on the injector rail and make sure that the rail is holding at least 45psi at all times.
Again, problem is either too much air past the Maf that is not being sensed correctly, injectors not able to spray enough fuel to bring the motor back down from above 14.1, or pre 02 sensors not reading correctly in the first place.
Also, quick check on the injector duty cycles as well.
Lastly, put a manual gauge on the injector rail and make sure that the rail is holding at least 45psi at all times.
Again, problem is either too much air past the Maf that is not being sensed correctly, injectors not able to spray enough fuel to bring the motor back down from above 14.1, or pre 02 sensors not reading correctly in the first place.