4l80E Limp Mode

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Ugliergolem

Junior Member
Joined
May 29, 2021
Posts
5
Reaction score
2
Location
Colorado
First Name
Garrett
Truck Year
1987
Truck Model
V20
Engine Size
5.7
I have an 87 chevy V20 with the 350 and swapped my TH400 for a 4l80E and used the E-Z TCU transmission controller and it worked fine for a small while and now I can start it and it works fine and then after a short time of use it goes into limp mode and wont come out till I turn it off. I have gone through the entire wiring harness and all the wires are good and I even took the pan off the transmission and checked everything in there. I changed the speed sensors and that seemed to fix it for a short time but I am at a complete loss so any help would be appreciated.
 

Frankenchevy

Proverbs 16:18
Joined
Jan 3, 2018
Posts
5,905
Reaction score
7,252
Location
USA
First Name
Jeremy
Truck Year
Square
Truck Model
CUCV
Engine Size
Small
Have you talked to tech support for the controller? Sounds like could be a hardware issue if it’s intermittent.
 

Ugliergolem

Junior Member
Joined
May 29, 2021
Posts
5
Reaction score
2
Location
Colorado
First Name
Garrett
Truck Year
1987
Truck Model
V20
Engine Size
5.7
I have, there is a small blue light on the controller and if it is flashing then there is a problem with a signal somewhere but if it is solid then there is no problem and the transmission and computer are talking fine and I always have a solid light.
 

Vbb199

B-rate Hillbilly Customs
Joined
Jan 12, 2018
Posts
8,871
Reaction score
14,885
Location
Salisbury NC
First Name
Vince
Truck Year
89, 79
Truck Model
89 Suburban R1500, 79 C10
Engine Size
350, 502
Pressure/temp sensor thats mounted on valve body maybe ?
 

Ugliergolem

Junior Member
Joined
May 29, 2021
Posts
5
Reaction score
2
Location
Colorado
First Name
Garrett
Truck Year
1987
Truck Model
V20
Engine Size
5.7
Are you talking about the pressure valve solenoid? If so I just got done testing it and I couldn't get an ohm reading off of it. Are there particular symptoms of a bad or failing pressure valve solenoid?
 

Vbb199

B-rate Hillbilly Customs
Joined
Jan 12, 2018
Posts
8,871
Reaction score
14,885
Location
Salisbury NC
First Name
Vince
Truck Year
89, 79
Truck Model
89 Suburban R1500, 79 C10
Engine Size
350, 502
Are you talking about the pressure valve solenoid? If so I just got done testing it and I couldn't get an ohm reading off of it. Are there particular symptoms of a bad or failing pressure valve solenoid?


On the VB, inside the pan,

You must be registered for see images attach
 

Forum statistics

Threads
41,859
Posts
903,678
Members
33,372
Latest member
83elcowes
Top