C5 98 vette auto trans problems
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C5 98 vette auto trans problems so i have a 98 vette auto trans lost 3&4 gear had it rebuilt at Ammco ( i know) they made it a lil more aggressive said it can handle up to 500hp, so my problem is when manual shifting to 1st gear hitting the gas takes off in 2nd gear til it hits @1000 rpm then drop into 1st.. took back to aamco they could not find the problem after 3 weeks recommended take to chevy dealership, took it there mechanic said that the computer was trying to protect the trans so it jumps into 2nd gear. Any thoughts no codes for any trans problems had a bk2 02 rear sensor has been replaced no codes on computer 189000 miles maybe 4000 on the tranny since rebuild...has anyone had or heard of this happening ?
Last edited by Westcoastwarrior; Nov 24, 2017 at 09:52 PM.
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I don't have a solution for you nor do I recall anyone else reporting such strange behavior.
Two questions"
1. As far as you know, does the PCM have a stock tune in it?
2. Why do you feel the need to ever manually shift into 1st? Unless I'm driving down a nasty gravel road I never use manual 1st or even 2nd.
Two questions"
1. As far as you know, does the PCM have a stock tune in it?
2. Why do you feel the need to ever manually shift into 1st? Unless I'm driving down a nasty gravel road I never use manual 1st or even 2nd.
Last edited by mrvedit; Nov 28, 2017 at 08:31 AM. Reason: Missing word
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1st question the car is stock other than flow master mufflers
2nd question, just shifting through gears manual shifting and found the problem.
Im not a mechanic but even taking off in 1st gear Not PUNCHING it.. it still takes off in 2nd...i let off the gas drops back into 1st..
Thanks for the reply .. so what im getting at is i took the car for the trans 2 weeks later the shifter cable fails (hmmm) ok maybe just bad luck.. 2 months later find this problem out and the check it out and tell me nothing wrong with the car go out and still same problem, make the guy go for a ride says its an adjustment on the cable, they keep the car for 3 weeks tell me they cant find out why this is happening that i need to take to dealer and have the pcm flashed . took to dealer there mech said there is no problem that the pcm is protecting the trans? i have never heard of this EVER... i have a 2013 truck with 32000 miles and when i put it in 1st it stays never moves unless i move it.. i paid alot of money to the AAMCO and i dont think this is right so thats the question im asking if anyone has had this issue? and if not if you have a auto trans try it and see if im wrong i would deffinitly apprieciate it . its still under warranty BUT i dont want these guys touching my car again. BTW this happened last year 12/20/16 nice xmas present 4 grand later
Thank you for your response mrvedit
2nd question, just shifting through gears manual shifting and found the problem.
Im not a mechanic but even taking off in 1st gear Not PUNCHING it.. it still takes off in 2nd...i let off the gas drops back into 1st..
Thanks for the reply .. so what im getting at is i took the car for the trans 2 weeks later the shifter cable fails (hmmm) ok maybe just bad luck.. 2 months later find this problem out and the check it out and tell me nothing wrong with the car go out and still same problem, make the guy go for a ride says its an adjustment on the cable, they keep the car for 3 weeks tell me they cant find out why this is happening that i need to take to dealer and have the pcm flashed . took to dealer there mech said there is no problem that the pcm is protecting the trans? i have never heard of this EVER... i have a 2013 truck with 32000 miles and when i put it in 1st it stays never moves unless i move it.. i paid alot of money to the AAMCO and i dont think this is right so thats the question im asking if anyone has had this issue? and if not if you have a auto trans try it and see if im wrong i would deffinitly apprieciate it . its still under warranty BUT i dont want these guys touching my car again. BTW this happened last year 12/20/16 nice xmas present 4 grand later
Thank you for your response mrvedit
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From: Ann Arbor, MI
Diagnosing this will require connecting a scanner to determine if the PCM is commanding the 2nd gear start (probably) or some extremely strange internal trans problem.
Your talk about the cable adjustment makes me wonder if the Manifold Pressure Switch is defective; this switch tells the PCM which position the shifter is in. Perhaps it is intermittently reporting 2nd gear instead of 1st gear.
There have been a handful of other strange shifting problem reported which turned out to be the Manifold Pressure Switch. It is easy to replace after dropping the pan; you could certainly do it yourself.
Your talk about the cable adjustment makes me wonder if the Manifold Pressure Switch is defective; this switch tells the PCM which position the shifter is in. Perhaps it is intermittently reporting 2nd gear instead of 1st gear.
There have been a handful of other strange shifting problem reported which turned out to be the Manifold Pressure Switch. It is easy to replace after dropping the pan; you could certainly do it yourself.
