anyone have experience converting a 4l80E to full manual?


The Grumpy Grease Monkey mechanical engineer.
Staff member
4L80E Cheap stand alone trans controller using 0411 GM engine PCM


EDIT 9/26/16 - Now I have over 400 miles on this stand alone transmission controller. I also recently turned on the torque converter clutch to activate in overdrive. Everything is working perfectly and shifts just like it should.

As the subject says. This is for those guys who are running MegaSquirt, carb or something other than a factory computer for their engines. This write-up is for OPERATION OF THE 4L80E TRANSMISSION. I (Dale Follett) can write up how to make it work on a 4L60e too if theirs enough interest into it.


I (Dale Follett) was tired of having my LS engine/4L80e transmission wired up for full manual valve body and wanted it to shift itself automatically like a factory unit. This could easily be done by swapping around the entire engine computer and harness back to a factory style PCM, BUT my car is wired up with MegaSquirt 2 and I like its features. A Microsquirt and 4L80e harness is $450.00, but thats a bit much to swing just for automatic transmission control and I wanted a cheaper option. This is what I came up with, only cost 2 HP tuners Licencing credits and a PCM from the junkyard (Total of $125.00) and some of my time.

Required Parts or Tools>

HP tuners interface or someone who has a HP tuners interface.

0411 PCM that was a throttle body drive by cable setup. Does not matter if it was a 4L60E or 4L80E BUT having a computer that ran your transmission from the factory from the junkyard is easier.

All your normal wiring crap. Soldering Iron, wire strippers, electrical tape or if you want to be fancy heat shrink, wire, etc.

All the Transmission electrical connectors, and the Factory PCM electrical connectors, and a OBD2 diagnostics port connector for the HP tuners interface to PCM communications.

As already stated this is for the 4L80E GM transmission WITH THE UPDATED PASS THROUGH TRANSMISSION CONNECTOR.

The only required PCM inputs from the engine is only RPM and throttle position. The rest of the PCM's inputs come from the transmission itself.

Biggest thing here is PCM selection. You need a PCM that runs a 4L80E preferably or 4L60E that also reads the crankshaft position wheel. Example, my firebird setup is running a 4.8L LS gen 3 engine that has the 24X wheel. So for the PCM or tune file, it needed to be out of a vehicle that had the LS 24X crankshaft position sensor wheel so the PCM's RPM input would read accurately. If your running a older style 350 small block chevy you would need a PCM out of a chevy express van and setup the engine for the same crankshaft position sensor and wheel to get the correct RPM input into the PCM.

The next thing is TPS. For us using EFI this is no big deal because we already have a TPS sensor. For those of you who are looking into doing this for your carburated setups, you'll need to fabricate a mount onto your carb for a TPS sensor. This PCM REQUIRES A TPS INPUT in order to function correctly as a transmission control module.

Now on how to wire it in. Their are no pre-made wiring harness' for this so you will have to make your own harness. It is not that hard though and NOTHING compared to building a engine wiring harness. I go by pinout count and connector pin counts to do my wiring harness' because the wiring colors may be different from make and model vehicle your swapping parts around. Just makes life simpler because the wire colors may change from X to X but the PCM's pins and connector pinouts do not change The PCM and wiring diagrams I use are for the 0411 or P01 GM PCM that has the Blue and Red PCM connectors. The Blue connector is referred to as C1 and the Red connector is referred to as C2.

The Non Transmission related inputs needed to the 0411 PCM:


C1 Blue connector Pin 1 & 40

C2 Red Connector Pin 1 & 40

0411 PCM 12VDC Power (20 amp fuse, wired directly to battery positive):

C1 Blue connector Pin 20 & 57

0411 PCM 12VDC Ignition Power (20 amp fuse, wired directly to ignition switch and needs power in both run and crank, this is what turns "on" the 0411 PCM):

C1 Blue connector Pin 19 & 75

If you want a "Check Transmission Light" or more commonly known as a check engine light for your transmission.

The 0411 PCM applies a ground to C2 Pin 46. This could be wired to the ground side of a small light bulb to notify you the 0411 PCM has a code in it for something wrong with transmission function.

0411 PCM Class 2 Data Communication (Data wire to OBD2 connector PIN 2)

C1 Blue Connector Pin 58

0411 PCM TPS "Throttle Position Sensor" Input for EFI equipped vehicles. (This is wired to the SIGNAL wire coming out of the TPS sensor.) For EFI equipped vehicles tap into the SIGNAL ONLY.

C2 Red Connector Pin 24

0411 PCM CKP "Crankshaft Position Sensor" Input for EFI equipped vehicles. (This is wired to the SIGNAL wiring coming out of the CKP sensor.) For EFI equipped vehicles tap into the SIGNAL ONLY.

C1 Blue Connector Pin 12


0411 PCM TPS "Throttle Position Sensor"

C2 Red Connector Pin 24 to Signal Wire coming out of TPS Sensor

C1 Blue Connector Pin 46 to 5VDC Power wire for TPS Sensor

C1 Blue Connector Pin 46 to Ground wire for TPS Sensor

0411 PCM CKP "Crankshaft Position Sensor"

C1 Blue Connector Pin 12 to Signal Wire coming out of CKP Sensor

C1 Blue Connector Pin 2 to Power Wire for CKP Sensor

C1 Blue Connector Pin 21 to Ground Wire for CKP Sensor

0411 PCM Brake Switch Input. This is wired/relay'd to the Positive wire coming from your brake pedal switch to your brake lights. This needs relayed to work correctly. C1 Blue Connector Pin 33 needs 12vdc key on power until you press on the brake pedal, which then it needs no power or ground applied to that computer pin to let the computer know it needs to release the torque converter clutch. A bosch single pole double throw relay would work great for this. Ground 85, Wire pin 86 to your 12vdc from your brake switch to your brake light wire. Apply key on 12vdc power to pin 30, then wire C1 Blue Connector Pin 33 to 87a. Boom! Your torque converter clutch should release now with the brakes applied.

The Transmission Related Inputs/Outputs needed to the 0411 PCM:

Because the Transmission connector isnt as clearly marked as the PCM connectors are, heres a diagram. This is looking AT THE CONNECTOR, THE SIDE THAT MATES WITH THE TRANSMISSION.


0411 PCM Torque Converter Clutch Control (Wired to pin S on the transmission connector)

C2 Red Connector Pin 2

0411 PCM 1-2 Shift Valve (Wired to pin A on the transmission connector)

C2 Red Connector Pin 48

0411 PCM 2-3 Shift Valve (Wired to pin B on the transmission connector)

C2 Red Connector Pin 47

0411 PCM Transmission Fluid Pressure Switch Signal A (Wired to pin N on the transmission connector)

C2 Red Connector Pin 63

0411 PCM Transmission Fluid Pressure Switch Signal B (Wired to pin R on the transmission connector)

C1 Blue Connector Pin 17

0411 PCM Transmission Fluid Pressure Switch Signal C (Wired to pin P on the transmission connector)

C1 Blue Connector Pin 18

0411 PCM Transmission Fluid Temperature Sensor Signal (Wired to pin L on the transmission connector)

C2 Red Connector Pin 51

0411 PCM Transmission Pressure Control Solenoid Control Ground (Wired to pin D on the transmission connector)

C2 Red Connector Pin 8

0411 PCM Transmission Pressure Control Solenoid Control Power (Wired to pin C on the transmission connector)

C2 Red Connector Pin 6

0411 PCM Transmission Input Shaft Speed Sensor (This is the sensor right behind the bell-housing of the transmission. The Input/Output shaft speed sensors on the 4L80E transmission are not polarity sensitive, and just simply need wired to the PCM)

C2 Red Connector Pin 22 for one wire and C2 Red Connector Pin 23 for the other wire coming from the Input Shaft Speed Sensor

0411 PCM Transmission Output Shaft Speed Sensor (This is the sensor near the back of the transmission. The Input/Output shaft speed sensors on the 4L80E transmission are not polarity sensitive, and just simply need wired to the PCM)

C2 Red Connector Pin 20 for one wire and C2 Red Connector Pin 21 for the other wire coming from the Output Shaft Speed Sensor

You DO NOT NEED a neutral safety switch on the transmission and wired to the 0411 PCM to make it function. All this switch did in the factory cars/trucks was inform the Instrument Panel what gear its in for its gear selector display and to not allow the engine to start in any gear but park/neutral. It is a nice safety feature, but not required.

Ok now that gets the 0411 PCM wired to the Transmission and brake switch and the RPM/TPS required from the engine.

Next is the Tune File

The tune file in the PCM must be setup for the engine or crankshaft position sensor wheel currently equipped on the engine in order for it to get a proper RPM signal input. The RPM signal input is required for the WOT shift tables.

The 0411 PCM WILL REQUIRE A TUNE/FLASH FOR IT TO OPERATE CORRECTLY. If you run it just as is from a junkyard, It will A: go into anti-theft mode because VATS is still enabled, B: go into transmission limp mode and C: possibly not work at all depending what application you pulled your computer out of.

On my setup, I had a PCM tune file out of a 01 GMC 1500 with a 4.8L and a 4L60e in the control module. I had to get another tune file with the same OS (operating system) my 0411 PCM has that had a 4L80e transmission originally so I could segment swap the transmission and transmission diagnostics segments over to my tune file. IF YOU GET A PCM FROM A VEHICLE EQUIPPED WITH A 4L60E FACTORY AND YOUR RUNNING IT ON A 4L80E OR VICE VERSA THIS SEGMENT SWAP IS REQUIRED FOR THE TRANSMISSION TO FUNCTION! "Ask me how I know".

All Engine Related DTC's must be turned off EXCEPT for the TPS and CKP DTC's Number P0121, P0122, P0123, P0335 & P0336.

Leave all Transmission Related DTC's under the Engine Diagnostics>DTC's turned ON that are factory turned on with a PCM thats equipped with a 4L80E EXCEPT P0705 & P0706, these two codes must be turned off if you are not using the Neutral Safety Switch. Leaving the rest of the Transmission DTC's on will allow the 0411 PCM to turn on the MIL light or store a MIL code if there is a issue with the Transmission and will also allow the PCM to go into transmission Limp Mode.

Under System>General, change the PRNDL equipped to none.


Under Trans>Auto Shift Properties>General> Perf Option, select No Switch. This is the tow haul switch, which was hooked to the BCM (Body Control Module) and signalled over the Class 2 Data network to turn on the feature in the PCM. I currently have not found a work around to be able to use this feature. If I do find a way, I will update this wiki page.

Those are the required settings that need changed over in order for the 0411 PCM to function as a stand alone transmission controller and actually shift the 4L80E transmission correctly. The last of the settings will be dependent on your particular setup. These settings are:

Gear Ratio and Tire Height (Found under the Edit tab>Gear/Tire Wizard)

Auto Shift Properties>All tables (modify for the way your transmission is built, wanted transmission characteristics, etc)

Auto Shit Speed> All tables. These are the ones you'll need to modify for your particular setup to make the transmission shift at the right speed and MPH.


My TPS input at idle is at 25% in the 0411 PCM. This isnt a big issue because you can work around it in the Shift Speed tables. I believe I need to also tap my TPS sensor ground from the 0411 PCM to my MegaSquirt 2's TPS ground, which I believe will fix it. I will update this wiki when this is diagnosed and corrected.

EDIT 9/26/16 - I found the TPS Issue. Its actually working as its supposed to. I am not running a IAC valve and modified my throttle body for a adjustable idle screw. Anyhow the thottle blades were literally opened between 20-23% for the engine to idle, well it was due to carbon buildup on the throttle body. I cleaned off the carbon and this percentage fell to around 13-15% for the same RPM idle. So its working correctly.

Below is my R&D and proof of concept video playlist on Youtube:

Proof of Concept Video
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The Grumpy Grease Monkey mechanical engineer.
Staff member


reading these links and sub links will help

-6 x 1/4NPS is the correct size for GM turbo 350, Turbo 400, 700R4, 4L60E and many other GM transmissions. These have a straight thread and seal on the gasket.
The case thread size is 1/4 in.-18 NPSM (straight thread)

but there are adapter fittings allowing larger line sizes, that flow with less restriction

trust me my personal goal has been for several years,
to collect the parts required and knowledge to produce and install a larger displacement, EFI BBC engine,
connected to a 4l80E transmission i a personally owned c4 corvette,
modified with full manual control 4l80e trans in a C4 corvette with a dana 60 rear differential, I personally own,
I've helped 8 other people do similar engine swaps over the last 21 years, installing, chevy big block engines in their personal C4 corvettes ,
so I know what's involved, but I personally just never yet, have had the spare cash, to build my corvette the way I want to build it,
and since I refuse to compromise and slap something inferior, or sub-standard together,
its still a project I'm working on completing.
with the rapidly approaching future move its once more being delayed
if your going to do something I've learned you either do it correctly or wait until you can do so, or you'll always regret the results

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The Grumpy Grease Monkey mechanical engineer.
Staff member
he 4L80E is essentially a TH400 with an overdrive gear added.
They are both legendary for their bulletproof reliability straight from the factory.
Their specs are similar, although the 4L80E is a few inches longer,
and a couple inches wider at a few points, making a trans swap or the trans fit ,
in some cars trans tunnels a bit more difficult

which means you’ll need to get a new driveshaft if you were to swap one for the other
They both have the same forward gear ratios, only the 4L80E gets the overdrive gear of course.
That overdrive gear is not as aggressive as the overdrive on the 4L60E.
It is a very heavy transmission. In fact, it’s 27 pounds heavier than the 4L60E.

4L80E Transmission Specs

Manufacturer: General Motors
Production: 1991-2005
Type: 4 Speed Automatic, 6.2 quart capacity (standard models)
Gear Ratios:

  • First- 2.48
  • Second- 1.48
  • Third- 1.00
  • Fourth-0.75:1
  • Reverse- 2.07:1
Input Shaft: 32 spline
Torque Converter Lock: Yes
Overdrive: Yes
Case Length: 32″Different applications had different lengths due to different tail shafts/transfer cases. Use this diagram to help you.
Outer Case Material: Aluminum
Controlled by Computer: Yes
Weight: 187 pounds without the converter


this is the golden era for horsepower. But that added power puts even more pressure on the rest of the driveline, and no more so than on the transmission. The good news for GM fans is that when it comes to automatic transmissions, there are multiple options. The trans we think has been overlooked is the 4L80E Transmission. This cryptic description is GM's way of saying this is an automatic transmission with four forward speeds designed for longitudinal (i.e. RWD) use. The "80" references higher torque capacity (compared with a 60, for example), while the "E" defines this as an electronically controlled transmission. We did some research on some of the more important aspects of performance uses for this transmission.

You can think of this trans as basically a TH400 with a 25 percent overdrive tacked on. The 4L80E transmission was mostly used in 34- and 1-ton trucks and larger SUV applications beginning in 1991. The "E" means that it must use an electronic ECU for control, as it will not function without it. The trans has experienced multiple minor upgrades over the years, with the newer boxes being a bit more attractive, but all the versions can be made to work well in a performance application. The addition of electronic control and overdrive adds roughly 50 pounds and a slight amount of width over a TH400, but for the most part, any floorpan that can accommodate a TH400 can also fit a 4L80E. Also, the 4L80E transmission is typically about 4 inches longer than a TH400 (depending on the length of the extension housing), but the trans mount is located roughly 112 inches rearward.

Most of the concerns about rL80E transmission revolve around the need for electronic control. Car Craft did an extensive review of five aftermarket controllers in the Mar. '12 issue, evaluating units from Powertrain Control Systems (PCS), TCI, Chevrolet Performance (GM), CompuShift, and Painless. Be aware that if your car is carburetor-equipped, an aftermarket conversion will also require a throttle-position sensor (TPS) adapter to the carburetor throttle linkage. Holley and most of the companies that sell the controllers also offer a TPS adapter. The price (between $600 and $1,000) and function of these controllers vary, so a review of our story is advised to help you decide which one would be best.

So while the 4L80E is affordable, there is some expense involved with converting it into an earlier chassis. If you've been adding up the costs in your head during this story, it wouldn't be surprising if the cost exceeded $2,000, even if you find a used 4L80E for around $500. But isn't half the battle knowing how deep the water is before you dive in headfirst? The advantage here is a trans that is even stronger than the original TH400 and offers an excellent 25 percent overdrive.

4L80E Transmission Specs
Dimensions (inches) A B C
TH400 28-3/4 27-1/4 2-1/2
4L80E 32 30-1/2 4-3/8
Gear Ratio
First 2.48
Second 1.48
Third 1.00
Parts List
Description PN Source Price
70434 Summit Racing $849.95
TCI Saturday Night Special 242900 Summit Racing 530.95
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B&R Racing

solid fixture here in the forum
Jake's Performance is the guy to call for 4L80E to get advice or work with him and purchase parts for 4L80E.
It has become so specialized and hard to understand even for myself.

Also Coan Performance in Indiana. Coan will be Pro Mod Full Drag Race 4L80E for some street use.