I have lost my over drive but only when warm FIXED!!!!!!!! - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


1992-1999 Series I L27 (1992-1994 SE,SLE, SSE) & Series II L36 (1995-1999 SE, SSE, SLE) and common problems for the Series I and II L67 (all supercharged models 92-99) Including Olds 88's, Olds LSS's and Buick Lesabres Please use General Chat for non-mechanical issues, and Performance and Brainstorming for improvements.

Reply
 
 
 
Thread Tools Search this Thread
Old 04-14-2004, 10:18 AM   #1
Member
Posts like a V-Tak
Thread Starter
 
Join Date: Apr 2004
Location: Osceola, WI
Posts: 34
Thanks: 0
Thanked 0 Times in 0 Posts
doo700 is on a distinguished road
Default I have lost my over drive but only when warm FIXED!!!!!!!!

Hello all I am new here and I have a transmission issue.

I have a 1994 Bonn. in which I have transplanted the drive train of 1994 Buick Lasaber.
The new drive train has 47000 miles on it. The engine runs fine but the transmission has to be cold to shift into overdrive after 7-10 miles it will no longer shift into overdrive or lock up the torque converter. At 60 mph the rpmí* when in OD and TC locked are about 1500-1600. When not in OD it is 2500-2600. I have replaced the vacuum modulator and changed the tranny fluid. I donít know of any differences between the Buick and the Pontiac to cause this. I have read on this web sight about wiring troubles and shift solenoids. How do you test for a wiring problem or a solenoid problem? I really need to fix this soon so any help is greatly appreciated.
doo700 is offline   Reply With Quote
Old 04-14-2004, 11:59 AM   #2
Junior Member
Posts like a Ricer Type-R
 
Join Date: Aug 2002
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
willwren is on a distinguished road
Default

I think the first thing you need to do is hook up a scantool, and go for a drive. You need to see if the PCM is even commanding TC lockup, and if it is, to see the slip RPM'*.
willwren is offline   Reply With Quote
Old 04-14-2004, 12:49 PM   #3
Member
Posts like a V-Tak
Thread Starter
 
Join Date: Apr 2004
Location: Osceola, WI
Posts: 34
Thanks: 0
Thanked 0 Times in 0 Posts
doo700 is on a distinguished road
Default

Thanks for the reply willwren.
I will get it on a scan tool as soon as I can.
When it shifts it shifts fine then it just stops. I donít understand why it only works when cold. Why would that make a difference?
doo700 is offline   Reply With Quote
Old 04-14-2004, 06:49 PM   #4
Senior Member
True Car Nut
 
Join Date: Oct 2002
Location: Groton, CT _NEBF 05, 06, 07_
Posts: 2,703
Thanks: 0
Thanked 0 Times in 0 Posts
markwb is on a distinguished road
Default

It sounds as if reverse logic is being applied here. The PCM normally won't allow TCC engagement until it receives input from the ECT sensor that the engine is warmed to a specific temperature.
markwb is offline   Reply With Quote
Old 04-14-2004, 08:57 PM   #5
Member
Posts like a V-Tak
Thread Starter
 
Join Date: Apr 2004
Location: Osceola, WI
Posts: 34
Thanks: 0
Thanked 0 Times in 0 Posts
doo700 is on a distinguished road
Default

Thanks markwb
Not sure, what an ECT is or were it is located.
Is it possible I wired it up backwards?
I had to swap the engine wiring harnesses and a couple of sensors because the Buick was all idiot lights and of course, the Bonn, is all gauges. Iím not an idiot I just donít have all the lingo down yet

Thanks again for the help.
doo700 is offline   Reply With Quote
Old 04-14-2004, 08:59 PM   #6
Junior Member
Posts like a Ricer Type-R
 
Join Date: Aug 2002
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
willwren is on a distinguished road
Default

I'll be home in a couple hours. I'll dig in the factory service manuals and see what I can figure out.
willwren is offline   Reply With Quote
Old 04-14-2004, 09:54 PM   #7
Member
Posts like a V-Tak
Thread Starter
 
Join Date: Apr 2004
Location: Osceola, WI
Posts: 34
Thanks: 0
Thanked 0 Times in 0 Posts
doo700 is on a distinguished road
Default


I really appreciate that willwren
Ití* nice to finally find a site with this kind of expertise
doo700 is offline   Reply With Quote
Old 04-15-2004, 12:28 AM   #8
Junior Member
Posts like a Ricer Type-R
 
Join Date: Aug 2002
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
willwren is on a distinguished road
Default

I'm still researching, but you should start by looking at the schematics on my website here:

http://www.williamwren.com/Bonnevill...umba/page1.htm

Note some minor differences. You should be able to find which wires/pins the thermistor is located on. I'm betting something was slightly different in wiring between the transaxles of the two cars. It should be simple, and maybe as simple as simply reversing two wires. Keep this thread going to keep us updated.
willwren is offline   Reply With Quote
Old 04-15-2004, 06:48 AM   #9
Senior Member
True Car Nut
 
Join Date: Oct 2002
Location: Groton, CT _NEBF 05, 06, 07_
Posts: 2,703
Thanks: 0
Thanked 0 Times in 0 Posts
markwb is on a distinguished road
Default

Quote:
Not sure, what an ECT is or were it is located
Engine Coolant Temperature. Should be located in close proximity to thermostat. housing. But I'm not necessarily saying there is a fault with the ECT, only the way in which the PCM interprets the signal for purposes of TCC engagement. Like Bill said, it could be as simple as two leads reversed there.
markwb is offline   Reply With Quote
Old 04-15-2004, 11:13 AM   #10
Junior Member
Posts like a Ricer Type-R
 
Join Date: Aug 2002
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
willwren is on a distinguished road
Default

Memory coming back to me here.....we had a new member in the last 3 or 4 months that did a swap, and found a wiring difference. Anyone remember where that thread is?
willwren is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
No warm air at heater until I drive for a while Bob Jones GMC/Chevrolet Truck/SUV 7 09-22-2013 09:59 PM
STALLING IN REVERSE only when engine warm aminoacid Pontiac 8 07-15-2012 11:35 AM
But, but, my engine wont turn over. Danthurs General GM Chat 4 02-10-2011 04:15 PM
Help! Weird Sputtering on 2000; only when warm. baldeville 2000-2005 40 11-24-2010 12:50 PM
97 Bonneville SE stalls when warm, only at idle ninjaman 1992-1999 9 10-01-2009 12:39 AM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 08:40 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.