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I was getting a Check Engine light on my 2004 Z06 a couple of months ago. Changed the gas cap and no more problems. Until yesterday, when I ran it fairly hard at VIR for about 80 miles of track time. On the way home, I stopped for gas. The tank was about 1/4 full, yet almost immediately the gas started gurgling up in the tube and the pump shut off. I reseated it and proceeded to fill it with 10 or 11 gallons. As soon as I started the car up, the Check Engine light came on, and has stayed on since.
The car has Hinson long tube headers, X-pipe, no catalytic converter, and was professionally tuned.
Any ideas? I do not have a way to pull codes, but if someone could suggest a good code reader to buy I'd be interested in getting one.
If you didn't know you can check for "codes" through the DIC...YouTube video on procedure enclosed below...you may have an P0449 stored and it could be your EVAP vent valve that may have been stuck closed (momentarily)...it is normally OPEN !!
Wow, that is outstanding, thanks. I pulled the codes but did not clear them. I am going to try to look them up but here they are in case they mean anything to you:
10PCM PO135 H C
60IPC B1543 H
60IPC U1255 H
AO LDCM U1096 H
A1 RDCM U1096 H
Originally Posted by C5 Diag
If you didn't know you can check for "codes" through the DIC...YouTube video on procedure enclosed below...you may have an P0449 stored and it could be your EVAP vent valve that may have been stuck closed (momentarily)...it is normally OPEN !!
If I'm reading it right, "H" means it is history and has cleared. Three of these codes relate to lost communication, 10PCM PO 135 relates to a heated oxygen sensor, and B1543 says oil temperature circuit open.
I know absolutely nothing about the electronics in this car, but now I'm wondering if this is all related to the incident I had with the traction control system while at the track earlier that day. On my third 25 lap session on a 95 degree day, I got a warning about "Traction Control System warming up" while at speed. I pulled into the paddock and it said "warmed up" and went back to normal. I had turned on the AC and hat was the only time all day the temperature needle budged.
My theory for the moment is that all these issues are all related and if I clear the codes everything will be fine.
The history codes are stored in the engine computer and the only “C” current code you have is the O2 heater circuit...the “U”codes are communication codes so a few of the modules couldn’t communicate with the IPC...I’d write down everything you have and clear the codes...the next ignition cycle see what comes back but before shutting the car down check for those codes...don’t know if you are willing to tackle these issues or just take the car to your local garage...I won’t go through the whole diagnostic process if you are not doing the work yourself !!
Thanks, this is extremely helpful. I do as much of the work as I can myself, so a garage is the last resort. I cleared all the codes, the check engine light went out, and I drove it a few miles and back and turned it off. Then I read this message and checked the codes and have "P0135C".
Originally Posted by C5 Diag
The history codes are stored in the engine computer and the only “C” current code you have is the O2 heater circuit...the “U”codes are communication codes so a few of the modules couldn’t communicate with the IPC...I’d write down everything you have and clear the codes...the next ignition cycle see what comes back but before shutting the car down check for those codes...don’t know if you are willing to tackle these issues or just take the car to your local garage...I won’t go through the whole diagnostic process if you are not doing the work yourself !!
OK, so it looks like we have a Bank 1 Sensor 1 heater circuit issue ( left front)...first get underneath and see if you might have some wiring damage. The brown wire on the harness side is your 12 volt feed and the black wire is a body ground. With an ohm meter and with the sensor cold see if you have 3.5-14 ohms of resistance on the O2 sensor side...if good you need to check power and ground...see if you have 12 volts at the brown feed wire key ON...to check the ground it is best to LOAD the ground circuit...the O2 heater draws around 1.556 amps (on my car anyway pictured) so get yourself a 55 watt headlight bulb with the wires attached (see pic below)
and now attach the power wire of the bulb to the power feed of the sensor harness (brown wire) and the ground lead of the bulb to the black wire of the harness...if the ground can carry the current the headlight bulb will burn bright...if the bulb is dim we will need to look at the ground circuit !!
Excellent instructions but this is more than I can get to before the weekend. Is it safe to drive it like this in the meantime? The check engine light is not currently on. I really appreciate your help, very on point and useful.
p.s. since you are so helpful at this, maybe you can point me in the right direction on this which is from another post I made. "I was at a track day at VIR yesterday, and got a display message that said something like "Traction System Warming Up." right as I was leaving turn 12 and shifting from 3rd to 4th launching onto the long back straight. I was already 20 or so laps in, and it was 95 degrees out, so everything was plenty warmed up. I took it easy for the rest of the lap and pulled into the paddock to check it out. At some point during the lap the message went away, but when I pulled into the paddock it came back on for a few seconds then "Warmed up" appeared. I may have the exact wording wrong since it happened pretty quick."
As I think about it, I realize that this was the only time all day I saw my engine temperature elevate (nowhere near the danger zone, but maybe 10-15 degrees hotter than it had been running all day, and I realized I had left my AC on for the first time all day. As far as I can tell none of the error codes were related to this, but I'm wondering if all these issues might be related, since they all started yesterday.
The TCS warm up message is part of the Stabilitrack system...the system wants to see the car go straight for 100 feet at over 5 or 6 MPH I believe and if it doesn’t see it you’ll get that message...should not effect driveability !!
So I didn't get to the diagnostics over the weekend. I did clear the history, and once I restarted, the Check Engine light came back on. I pulled the codes again and got P0135 C, and B1543 H. I was planning to just go ahead and swap out both the front oxygen sensors since I think they are original (and the tuner who did the engine said that is what he would do), but the B1543 error code popping up again has me a little concerned. Any thoughts on that?
The P1543 is an oil temp DTC so I would remove the EOT connector and with key ON you should have a 5 volt reference voltage on one wire and a reference ground on the other...on a cold engine I would OHM out the sensor and see what you have...sorry but I don’t have the temp vs. resistance chart in front of me...since the sensor is a 2 wire thermistor you can short the 5 volt to the low reference (ground) and you should see high temp on the IP !!
Here's another hopefully easy question I ran into while researching the O2 sensor issue. These pictures show an empty socket near the steering shaft right above the O2 sensor which can't be seen in the picture. Could this be related to the rear O2 sensor which was presumably removed when the long tube headers were put in?
The rear O2 sensor connector is square as in the picture...the front are an elliptical shape I guess you can say...the wire colors for the rear would be tan, purple, black and brown !!
Amazing! How do you know all this stuff? You can probably tell me what this hose and bracket that aren't connected to anything on the passenger side of the engine are too:
Originally Posted by C5 Diag
The rear O2 sensor connector is square as in the picture...the front are an elliptical shape I guess you can say...the wire colors for the rear would be tan, purple, black and brown !!
Check Engine Light
