View Full Version : Valet key - power key problem
gmofjoint
11-12-2010, 06:46 PM
I just bought my 1990 ZR1. 58K, black on black.
The problem is as follows:
When I turn the Valet key from normal to performance, I do not get a light on the dash. I cannot feel any difference in the power of the car. I put a snap-on scanner on the car and placed it into data and drivablity mode. The scanner indicates that the valet mode is "on". It says this no matter which position the key is in. When I trun the key, with scanner hooked up, it goes from on to off only between the positions and only for a brief second. I cannot even get it to stay off, its that sensative.
So, before I tear into this, i thought i would get some opinions.
Key switch? light bulb in dash out? (this doesnt explain it being on all the time with the scanner) Fuses?
Any ideas? Thanks in advance
Aurora40
11-12-2010, 06:59 PM
Does the light ever come on when wiggling the valet key? If so, the bulb is fine. The bulb is lit by the ECM. So if it is not on, the car is not in full power mode regardless of the key position.
Most likely the key cylinder needs to be tweaked. But possibly there are codes stored that prevent the car from going into full power mode. The key cylinder is a simple switch, you can bend it back to working with some pliers once you open it up.
gmofjoint
11-12-2010, 07:04 PM
The bulb never lights. The scanner indicates it is on while driving. There are no codes. I cleared all codes again just to make sure.
Aurora40
11-12-2010, 07:23 PM
Does the car feel like it's in full power mode? Does it pull strongly past 5,000 RPM?
gmofjoint
11-12-2010, 07:26 PM
yes, but is the first z i have driven. It feels pretty strong. I would think in low power (210hp) it wouldnt feel this strong.
I also own a 2003 C5 convertible, 6-speed. It feels fairly close.
BOB HDZ
11-12-2010, 07:32 PM
here what i did. i bypass the switch by grounding the blue & white wire out of the green ecm connector then the light is always on! switch is then bypassed!:cool:
BOB HDZ
11-13-2010, 08:35 AM
the blue & white wire from the ecm to ground! i ground mine to the frame were the hood release is!
Aurora40
11-13-2010, 09:01 AM
that would make the bulb at the key switch even more suspect, I recon.
There is no bulb at the key switch on a 1990, instead it has the much cooler "Full Engine Power" bulb on the dummy light panel.
If the car pulls hard past 5,000, it sounds like your Full Engine Power bulb is burned out. So you need to fix that. Secondly, if the key switch doesn't turn the engine power down, it sounds like it's been bypassed or something.
Aurora40
11-13-2010, 09:03 AM
yes, but is the first z i have driven. It feels pretty strong. I would think in low power (210hp) it wouldnt feel this strong.
I also own a 2003 C5 convertible, 6-speed. It feels fairly close.
Over 5 grand, there is no doubt. In "normal" mode the engine runs out of breath quickly above that, though it feels good to that point. It is very hard to run it up to much past that.
In "full power" mode, it will really wake up past 3,000 RPM, and continue to pull hard to about 6,500, at which point it gradually drops off. With a few mods, it will charge hard all the way to the rev limiter.
Here is my car on the dyno with the key on vs off (ported intake and headers):
http://aurora40.dyndns.org/Hometown/corvettezr11990/misc/keyoff.jpg
John Boothby
11-13-2010, 11:04 AM
What part of Utah do you live in? If southern part of the state maybe we can get together and I can look at it for you. Did a previous owner upgrade the chip with a "Full Power, full time" chip? Maybe he took out the "Full Power" bulb.
gmofjoint
11-13-2010, 05:29 PM
OK, I tore the dash apart. The bulb was burned out. I replaced the bulb and it now reads out on the dash. The key switch works, but is a little loose. I turn it from normal to power and there is an area on the power side that has a dead spot in it. As it enters power mode it turns the light on. If I continue to "full" on it goes out. If I force the key to the very end, the light comes on. So, I think I am going to need a new switch.
Now for the power. I will go drive it again, but there still doesnt seem to be much difference between the two positions. I dont know if it is programmed to be on all the time. The car came with a spare chip. The one that was not in the ecm was marked AUAH. The one in the ecm just had a sticker on it that said 90 corvette zr1. Hand written. So, I removed the one that was hand written and replaced it with the AUAH. Did not notice a difference.
Does it sound like I am going the right way?
Aurora40
11-13-2010, 05:56 PM
The light is turned on by the ecm. If it toggles with the switch, it's working properly. If the switch is sloppy, it can be taken apart and easily fixed. No need to buy a new one.
The auah prom is not the latest. I would put back whatever you had previously.
gmofjoint
11-13-2010, 07:17 PM
Thanks Bob. I appreciate the help.
gmofjoint
11-13-2010, 07:58 PM
http://http://img585.imageshack.us/i/1000291.jpg/
jrd1990zr1
11-13-2010, 08:10 PM
The contacts in the switch get sloppy over time. Best to leave it in full power all the time anyway. :dancing
Since you have already pulled the panel, take the switch apart and tweek the contacts. Pretty easy fix. When you put it back together you will feel the difference in the stops in the switch.
:cheers:
gmofjoint
11-13-2010, 08:18 PM
Being new to the registry, I am very impressed with the help from everyone.
Thanks to all!
Aurora40
11-14-2010, 08:24 AM
http://img585.imageshack.us/img585/2070/1000291.th.jpg (http://img585.imageshack.us/i/1000291.jpg/)
Uploaded with ImageShack.us (http://imageshack.us)
Fixed your image.
Also, if you aren't noticing a difference when the light is out vs lit, maybe your secondaries have other problems. As I've said, the difference is significant above 5k RPM.
gmofjoint
11-14-2010, 12:17 PM
I am going to drive it for awhile and see if i can tell.
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