Key set limp mode?

[adamcortell]

My wife dorve the truck this morning. She said it was reving up 3300 rpm (40 mph) without a shift. Limp mode in other words. She reported a similar problem months ago. I drive the truck 99% of the time and have never had this problem. I was wracking my brain trying to come up with an explanation. She thought perhaps she was missing some anatomy that the truck prefered... It struck me that I use the original key and she uses a hardware store remake. Is there any way a poor fitting key could set the truck in limp mode? Tomorrow morning I will start the truck cold with her key and see what happens. Any thoughts??

[JohnC]

Since the key doesn't directly operate the switch, I'd say no on the key. The switch is often the culpret, though. First thing to do is read the codes

[Barry Nave]

This takes me back many years ago after needing a trans rebuild. New rebuild would not get out of #2 gear untill warm. Even then it was really slow going to #3. Trans shop was stumped also. They went as far as to pull trans back out and found nothing wrong. The only cure came to be a product that JK sells called an Interceptor.
This was back before I became a member. Been using it sence with no problem.(at that time)
GM Dealer put blame on the shop. They(dealer) could not figure it out :rolleyes: This same shop has done this for 20+ years.
Way did this work :confused:
What if I would of went all through the grounds,cleaned all conectors. Who Knows now?
Don't use it now(interceptor) with the chip change. Did leave it on for a while but the shifts were to hard.
Try a good cleaning. May help ;)
BTW This was 90K miles ago.
Wow how the miles fly by :D

[adamcortell]

I tried my wife's key two times on a cold start and the truck started fine and shifted normally for me (of course). I knew the key thing was a long shot, but it is about the only variable I could think of other than seat position. She is not blond (I am) and she wasn't making it up.

My wife said she never saw the SES light come on. I pulled codes tonight and got #87 High Ratio Error. Same code came up last summer and was cleared after a new VSSB from stealership. No other codes and SES light has not come on. Also ignition switch was replaced by stealership at about 92k. Runs and shifts fine for me. I guess I will have to wait and see if this problem comes up again. Not sure if my wife will want to drive the truck anymore though!

[JohnC]

high ratio error means the PCM thought it was in a different gear than commanded. Could be a speed sensor or a slow shift. I'd try changing the fluid and filter if it hasn't been done recently.