[Z06] Check Engine light on, but no current codes? Huh?
Thread Starter
Drifting
Joined: Oct 1999
Posts: 1,311
Likes: 0
From: Near Philly PA
Check Engine light on, but no current codes? Huh?
Hey all,
The Check Engine light just reappeared in my '01 (it's been on and off the past month). This time out, the idle felt shakey, the power was down, and the exhaust kind of "puttered." It felt to me (and my untrained sensors) that it wasn't running on all cylinders. I've got a Corsa Ti exhaust on it (with no mufflers), and so it gurgles A LOT on deceleration -- but this last time out I got a couple full-on backfires on deceleration.
All of this, and there are no "current" codes. I have some "history" codes (which I can't seem to clear, incidentally), but no current. Is this normal?
The one "newer" of the H codes is P0200.
Any thoughts on the matter? (I'm thinking I'm going to have to take this to the good Corvette service center I normally go to, but it's not close to me, and so I thought I'd try some at-home diagnostics first.)
Thanks, folks!
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The Check Engine light just reappeared in my '01 (it's been on and off the past month). This time out, the idle felt shakey, the power was down, and the exhaust kind of "puttered." It felt to me (and my untrained sensors) that it wasn't running on all cylinders. I've got a Corsa Ti exhaust on it (with no mufflers), and so it gurgles A LOT on deceleration -- but this last time out I got a couple full-on backfires on deceleration.
All of this, and there are no "current" codes. I have some "history" codes (which I can't seem to clear, incidentally), but no current. Is this normal?
The one "newer" of the H codes is P0200.
Any thoughts on the matter? (I'm thinking I'm going to have to take this to the good Corvette service center I normally go to, but it's not close to me, and so I thought I'd try some at-home diagnostics first.)
Thanks, folks!
/< / /2 /<
Safety Car
Joined: Aug 2000
Posts: 4,933
Likes: 30
From: San Rafael CA
P0200 is the PCM detecting an incorrect voltage on a fuel injector control circuit. On first failure no CEL is illuminated, but data is stored under "Failed Last Test"
On second failure the CEL is illuminated and a HISTORY P0200 is stored. You'll never see a CURRENT P0200 listed.
If you have a scan tool that can display stored Diagnostic data that can help isolate which particular injector is having the problem.
This is most likely a wiring issue to the fuel injectors. I'd look carefully at the wiring to them to see if you have a loose or broken wire.
If that doesn't isolate it, remove wies from injector on #1 cylinder and then run engine. If it runs worse, injector #1 is OK. Move on to #2 and repeat until you find the injector that, when you pull its wiring, doesn't change how the engine is running. Check the wiring for that injector. If not a wiring problem, the injector most likely needs replacing.
HTH
On second failure the CEL is illuminated and a HISTORY P0200 is stored. You'll never see a CURRENT P0200 listed.
If you have a scan tool that can display stored Diagnostic data that can help isolate which particular injector is having the problem.
This is most likely a wiring issue to the fuel injectors. I'd look carefully at the wiring to them to see if you have a loose or broken wire.
If that doesn't isolate it, remove wies from injector on #1 cylinder and then run engine. If it runs worse, injector #1 is OK. Move on to #2 and repeat until you find the injector that, when you pull its wiring, doesn't change how the engine is running. Check the wiring for that injector. If not a wiring problem, the injector most likely needs replacing.
HTH
Thread Starter
Drifting
Joined: Oct 1999
Posts: 1,311
Likes: 0
From: Near Philly PA
Thanks for the reply.
Nando -- I'm back now. Going to take the car to the dealer that does all of my warranty work. I'm not going to mess with it -- I'll let a pro diagnose and fix it.
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