loss of od & tc lockup in 4t60e

Joined
Oct 16, 2007
Messages
2
Likes
0
Points
0
#1
My 1995 Olds Cutlass Ciera (3.1 engine & 4t60e trans) shifts out great, but as soon as it reaches normal operating temperature I lose OD & TC lockup. No check engine light but there is a PO740 history code. Fluid is very clean, & no trash in pan, or TC shudder. Need direction as what to do next. Please help.
 

Transman

Receptionist & Complaint Dept.
Joined
Nov 14, 2006
Messages
2,953
Likes
0
Points
0
Location
New Jersey
Website
www.edsofvineland.com
#2
P0740 is the code for TCC not functioning. The fact that you are losing 4th when it warms up is a concern. The factors that can effect this would be temp over ride. What does the computer think the engine temp is when the vehicle acts up? Is it actually overheating? Check the basics... Grounds especially at the battery, look for corrosion and inside connectors too. Check ALL your fuses not just the ones you think would be in the circuit. Are the cooling fans running when they are supposed to? What mileage is on this vehicle? Any add ons? Post back, Transman
 
Joined
Oct 16, 2007
Messages
2
Likes
0
Points
0
#3
Thankyou for the reply! I forgot to mention this transmission came out of a 96 cutlass supreme. (mine is a 95 Cutlass Ciera) Car has 110,000 miles & transmission has about the same. Ciera's come stock with 14" tires. I am running 15" tires and wheels off off a later model van. At one time I thought this might be the problem & I went back to 14" tires & there was no change. So I put the 15" back on as they look & ride better.( I had to swap range selector switch when installing transmission as wiring was different & I feel good about adjustment) Engine cooling fan comes on at 223 to 224 degrees, & turns off after normal cool down period. I have replaced altenator, coolant temp sensor & thermostat recently and all systems are functioning normal. All fuses, under hood wiring, connectors, battery, cables, & all grounds are intact. I even tried a speed sensor & there was no change. At one time the center brake light bulb above the rear deck was blown. Replacing this fixed the brake light, turned off the abs light, & the cruise control started working. Is there a temperature sensor inside trans. that can give this problem? What about a lockup solenoid? Thanks again, Tommy.
 

Transman

Receptionist & Complaint Dept.
Joined
Nov 14, 2006
Messages
2,953
Likes
0
Points
0
Location
New Jersey
Website
www.edsofvineland.com
#4
Tommy, This is a problem with info, You give what you feel is needed and sometimes that is not enough. Your trans swap most likely is the big factor. The computers change from model to model & year to year as does the wiring even sometimes among the same year, make & model. Obviously, it sort of works but my bet is that it won't for long. Transman
 
Joined
Feb 4, 2008
Messages
10
Likes
0
Points
0
#5
My 94 Cutlass seems to have exact same problem. When cold it shifts fine and will go into OD and run until it warms up. Then it drops to 3rd and won't up-shift back to OD. I can get onto highway in morning and get OD, then when temp gauge gets up around 160 no OD. Also when warmed up I get a slip from 1st to 2ND and then a harsh 2ND gear engagement. It pulls just shy of 18in vacuum at idle cold to warm. The line from the manifold to the modulator is dry. When I put a vacuum (mighty vac) on the modulator and plugged the port on intake I could hear a difference in sound coming from the trans as I pulled more vacuum on it, it also didn't indicate a climb or leakdown. I don't have a pressure gauge to check line pressure so I can't post that right now. The car is all original and was purchased from 1st owner, who also gave me the service records.
 
Joined
Nov 14, 2006
Messages
2,079
Likes
0
Points
36
#6
Welcome to Bat.

On your problem please start a new post and give all info.

Saves on hyjacking the info from this post. :)
Crunch