Car might be sick,need some advice.

[Z51JEFF]

The Service Engine Soon light came on while driving the car today and Im trying to figure out why.When this is lite does the power default to Valet Mode?Earlier today I washed the car.Afterwards,I went for a drive and noticed the light on then a few minutes later the car started to lose power.My first thought was I might have gottin water in the gas tank.I havent driven the car much in the last month and know things get funny when a car isnt drivin.I disconnected the battery,twice and the second time the light didnt come back on.I guess the easiest thing to have done would have looked for a stored code before I disconnected the battery.When the car wasnt running right I took it up through the gears and the car definitely wasnt running at full power.

[WVZR-1]

Using this diagnostic tool I'd check for stored codes in the ECM and the CCM and move on from there. There's no need to just start "poking around"! The instructions are very straight forward and there's a good bit of information that's easily accessible

http://tech.corvettecentral.com/2011/01/c4-diagnostic-trouble-codes/

[Paul Workman]

Using this diagnostic tool I'd check for stored codes in the ECM and the CCM and move on from there. There's no need to just start "poking around"! The instructions are very straight forward and there's a good bit of information that's easily accessible

http://tech.corvettecentral.com/2011/01/c4-diagnostic-trouble-codes/

I agree.

Jeff: By far, the best tool I ever bought for the Z. after the Factory Service Manual, is the scanner. Paid for itself many times over, it has. And it has allowed me to keep a little more of my hair!

In the mean time, you can refer to the FSM (you do have a manual, right?). Using a paper clip and the ALDL connector, the FSM can guide you through the procedure for pulling codes from the ECM. In the mean time, what is the voltage across the battery, if I may ask?

Far as loosing power, for sure the secondaries are cut off anytime there is a SYS light on.

P.

[GOLDCYLON]

Yep Jeff pull the codes it will save you time in the long run

[scottfab]

Does the SYS light stay on all the time now or does it go out?
You say you washed the car.
Did you get water on the motor much?
With the ing key on but motor not running, does the pump under
the headlight on the passenger side keep running almost all the time?

[Z51JEFF]

Does the SYS light stay on all the time now or does it go out?
You say you washed the car.
Did you get water on the motor much?
With the ing key on but motor not running, does the pump under
the headlight on the passenger side keep running almost all the time?

No water under the hood,VAC pump is fine.I haven't been driving the car alot lately,maybe its pissed that the other cars been getting all the love.;)

[Z51JEFF]

The saga continues.Drove the car abit Sunday,get in the car after it sat for a few hours and the light comes on and the car was off-on would barely run.I pulled into a parking lot to check for codes and found none,get C12 which I believe is no codes stored.Started the car,light is out and car is running fine.The next day I checked the MAP sensor hose and it was full of oil.I replaced it with an NOS piece I had so far no issues.Ill post up with my findings if it continues.Thanks to all for the suggestions.

[scottfab]

The saga continues.Drove the car abit Sunday,get in the car after it sat for a few hours and the light comes on and the car was off-on would barely run.I pulled into a parking lot to check for codes and found none,get C12 which I believe is no codes stored.Started the car,light is out and car is running fine.The next day I checked the MAP sensor hose and it was full of oil.I replaced it with an NOS piece I had so far no issues.Ill post up with my findings if it continues.Thanks to all for the suggestions.

You may have found it then. Hope so. Oil in there is common and effects drive-ability. I routed mine such that the middle of the hose is the high point to avoid oil in there.

[Z51JEFF]

Problem still persists.After checking for codes I get C12 then about 5 seconds later I get H31.Will a battery acting up cause the SERVICE ENGINE light to come on and cause the stumble?

[Brad Sewell]

Someone with far more knowledge should chime in, but in my limited experience with this car any sub-par power supply can promote any number of challenges -- some non-repeatable.