View Full Version : 4T80E Electronically controlled torque converter clutch

01-30-12, 05:20 AM
Some say the '05+ 4T80Es got the electronically controlled torque converter, is this true? Would all '05 have this?

Is there an RPO code that I could look at to tell if it has electronically controlled torque converter? Or any other special designations?

01-30-12, 11:46 AM
It has an electronically controlled torque converter clutch. Is there any such thing as an electronically controlled torque converter?

Hydra-Matic 4T80-E Transaxle


Type: four speed front-wheel drive, electronically controlled, automatic overdrive transaxle with electronically controlled torque converter clutch.

Max Gearbox Torque: 461 lb.-ft.

Weight: 295 lbs.

Engine Range: 4.6L

Assembly Site: Ypsilanti, Michigan

Applications: Cadillac DTS; Buick Lucerne


01-30-12, 05:44 PM
Yeah, like I said on the title I meant the electronically controlled TCC, not TC. Thanks for pointing that out. Sorry about making a confusion.

I am looking at some '05 Devilles, I wonder if all of the '05 models have this feature instead of viscous TCC.

01-30-12, 10:12 PM
I believe they do. I think the viscous TCC is history, BUT in looking at the link I posted, most of them say "electronically controlled torque converter clutch", but a few say "electronically controlled automatic overdrive transmission with torque converter clutch". Makes me wonder what the difference is.

01-31-12, 03:23 AM
I found this from a 2005 bulletins:

#PIP3341: TCC Replacement - keywords 4T80E ECCC EC3 converter torque valve body spacer plate DTC MIL P0741 PCM calibration code SES - (Feb 17, 2005)


TCC Replacement



The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in the PI.

4T80E Transmission Torque Converter Assembly design change in 2005 model Cadillac DeVille and Pontiac Bonneville.

Vehicles with the Vehicle Identification Numbers (VIN), listed below, are built with automatic transmissions that have a new broadcast code and transmission assembly part number. These transmissions are built with an Electronically Controlled Capacity Clutch (ECCC or EC3), a new upper control valve body assembly, a new upper control valve body spacer plate, and a new powertrain control module calibration. They will not have a viscous fluid converter.

VIN / Model / Trans Serial No.
...and so on (there's a list of cars with N*)

Use the current MY 2005 service information and diagnostics procedures for any transmission service requirements. All warranty labor codes and time allowances remain the same.

IMPORTANT: When ordering parts for these vehicles, the vehicle VIN, the transmission broadcast code and the transmission assembly part number must be used.

Reman torque converter part # for trans code 5ABN, 3.11 axle ratio is 12491371.

Reman torque converter part # for trans code 5MMN, 3.71 axle ratio is 12491372.

Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.


(2005 Cadillac DeVille) and (2005 Pontiac Bonneville)

I think this somewhat answers my question (and I think by the "viscous fluid converter" they meant the viscous TCC.) - at least the cars after the VIN 5U189290 Deville should have the updated 4T80E with the new TC/TCC.

Don't know why I was curious about this yesterday... even with a "Electronically Controlled Capacity Clutch - ECCC/EC3" it would still be controlled with a TCC PWM solenoid. anyways thank you Ranger!