[Z06] "Reduced Engine Power" code this morning
Thread Starter
Drifting
Joined: Nov 2011
Posts: 1,279
Likes: 18
From: Oklahoma
"Reduced Engine Power" code this morning
So I just drove the car to a show and back on Saturday and everything was normal. It's a nearly bone stock 2003 Z06 with only a SLP Blackwing CAI and has only 17k miles. I've owned it since March and did have absfixer.com repair the ECBM. I've driven it about 1,000 miles since then with no issues. I get in this morning and it begins showing this warning so I turn it off and restart. Goes away so I leave for work. Then driving in the neighborhood it appears again. I noticed that most of my gauges are dead. It starts saying low fuel and shows empty on the gauge when I know there's half a tank in there. The temp and oil pres gauges are also dead. Yet the car seems to run fine. I turn around and go home for the truck. What's the deal? Could my CAI be loose somewhere and throwing off the airflow to the TB causing this? I read another thread on here but the guy's car was heavily modified. I just drove this car on a five hour round trip in early August with no issues.
Instructor
Joined: Jan 2017
Posts: 233
Likes: 41
From: Clarksville Tennessee
battery issue
First thing Id do is pull the battery and have it tested. If the battery is good, I'd start testing the grounds. These cars are very sensitive to voltage fluctuations. The CAI is not the cause of all these problems. It could cause a reduced engine power and kill the engine for safety reasons, but it would not cause the gauges to go dead.
If the battery is not bad, I'll find a pick of all the ground locations for you.
If the battery is not bad, I'll find a pick of all the ground locations for you.
Safety Car
Joined: Oct 2000
Posts: 4,080
Likes: 565
From: Allen TX
As Proletariat said... I suspect it is the battery.
I've owned my '02Z since new... these cars (and the C6s are even worse) do crazy things as far as throwing codes, acting strange with electronics and relays, etc if the battery is weak or dying.
I've owned my '02Z since new... these cars (and the C6s are even worse) do crazy things as far as throwing codes, acting strange with electronics and relays, etc if the battery is weak or dying.
Thread Starter
Drifting
Joined: Nov 2011
Posts: 1,279
Likes: 18
From: Oklahoma
First thing Id do is pull the battery and have it tested. If the battery is good, I'd start testing the grounds. These cars are very sensitive to voltage fluctuations. The CAI is not the cause of all these problems. It could cause a reduced engine power and kill the engine for safety reasons, but it would not cause the gauges to go dead.
If the battery is not bad, I'll find a pick of all the ground locations for you.
If the battery is not bad, I'll find a pick of all the ground locations for you.
Safety Car
Joined: Oct 2003
Posts: 3,699
Likes: 16
From: Sun City- Menifee Calif.
wiggle the wires in the accordion on the driver`s side door. This is a common problem of the symptoms you have. If that fixes it you need to take the acc. off and pull the connectors out from the body side and check them for good connections. Check the electrical sticky at top by Bill Curlee. The exact same thing has happened to me, and that was the problem if your battery is good. It should read at least 12 volts with engine off and key on. Bill Curlee is a genious with elec. problems. 
Melting Slicks
Joined: May 2005
Posts: 2,152
Likes: 33
From: Folsom Ca
So I just drove the car to a show and back on Saturday and everything was normal. It's a nearly bone stock 2003 Z06 with only a SLP Blackwing CAI and has only 17k miles. I've owned it since March and did have absfixer.com repair the ECBM. I've driven it about 1,000 miles since then with no issues. I get in this morning and it begins showing this warning so I turn it off and restart. Goes away so I leave for work. Then driving in the neighborhood it appears again. I noticed that most of my gauges are dead. It starts saying low fuel and shows empty on the gauge when I know there's half a tank in there. The temp and oil pres gauges are also dead. Yet the car seems to run fine. I turn around and go home for the truck. What's the deal? Could my CAI be loose somewhere and throwing off the airflow to the TB causing this? I read another thread on here but the guy's car was heavily modified. I just drove this car on a five hour round trip in early August with no issues.
Last edited by ETM; Sep 12, 2017 at 07:16 PM.
Thread Starter
Drifting
Joined: Nov 2011
Posts: 1,279
Likes: 18
From: Oklahoma
wiggle the wires in the accordion on the driver`s side door. This is a common problem of the symptoms you have. If that fixes it you need to take the acc. off and pull the connectors out from the body side and check them for good connections. Check the electrical sticky at top by Bill Curlee. The exact same thing has happened to me, and that was the problem if your battery is good. It should read at least 12 volts with engine off and key on. Bill Curlee is a genious with elec. problems.
What kind of gas do you run in it? The reason I`m asking is that I had a similar issue with an `02 ZO6. The gauges went dead and then it eventually corrected itself. It had to do with the gas gauge and the gas tank. There is a reflector or a mirror in your tank that gets clouded. It happened twice to my ZO6
Safety Car
Joined: Oct 2003
Posts: 3,699
Likes: 16
From: Sun City- Menifee Calif.
Interesting you point this out as I just replaced the drivers side window motor two months ago. In the process I cracked the switch panel and just put a new one in two weeks ago. That switch panel wasn't working nor was the truck release switch when all of the warnings began flashing two days ago. Sounds like this is what it is. When you say i "need to take the acc. off and pull the connectors from the body side", where are you speaking of?
91 octane ethanol free
91 octane ethanol free
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Thread Starter
Drifting
Joined: Nov 2011
Posts: 1,279
Likes: 18
From: Oklahoma
The driver`s side. The connectors are inside the body under the dash. You can pull them out but not too far. Look at Bill Curlee`s electrical sticky on the C 5 tech. There will be pictures of them pulled out. They can cause lots of weird things to happen . Hope this helps you!
Safety Car
Joined: Oct 2003
Posts: 3,699
Likes: 16
From: Sun City- Menifee Calif.
I really appreciate it. I haven't been able to locate his sticky on here yet but I'll keep looking. BTW the battery did test a bit low at 11.96 volts and should be between 12.4-12.6 so I put it on a trickle charger last night. I'll see if that changes anything this weekend. Sure would like to drive the car in this nice weather!
Last edited by Dennis Wilson; Sep 15, 2017 at 03:36 PM. Reason: mis spelling
Thread Starter
Drifting
Joined: Nov 2011
Posts: 1,279
Likes: 18
From: Oklahoma
I found it shortly after I responded but the pics were no longer available. However get this. I charged up the battery this weekend and put it back in today and still same problem. However the driver's side window switches still weren't working so I popped them out of the door panel and accidentally hit one of the buttons and it worked. I made sure the wire harness connectors were tight and popped it back in. Started up the car and no issues. Must have been a bad connection but hard to believe that I had driven it several times since installing a new switch panel with no issues. Also hard to believe that one little thing like that can trigger so many multiple issues. Reminds me why i hate all GM products and am at heart a Ford guy...