How to setup a 4L80E/4L85E with FTManager

March 29, 2020

Step by step ECU setup for 4L80E/4L85E transmission

 

The step by step instruction was built for 4L80E/4L85E transmissions wired as the diagram:

 

 

Enable Transmission Control Feature:

In Engine Settings – Map Options - check the boxes:

- Automatic Transmission Control

- Lockup control

- Gear change detection

 

Inputs:

In Sensors and Calibration - Inputs

- TPS – Calibrated – Input must be selected according with the engine wiring.

- Driveshaft RPM – Needs VR to Hall Converter  (click here to buy) OR use Wheel speed

- Transmission Temperature – Default (GM USA)

- Brake Switch – Default – required only if “deactivate Lockup when brake pedal pressed” feature is desired and there is no brake pressure sensor.

- AT Range Selector – Switch A - Default

- AT Range Selector – Switch B - Default

- AT Range Selector – Switch C - Default

 

Outputs:

In Sensors and Calibration - Outputs

- Select outputs for the Transmission Solenoids (A and B), Blue or Gray outputs can be used. Select according with your available outputs.

- For Lockup solenoid and Line Pressure solenoid select Yellow Outputs.

 

Gear Change Detection:

In Sensors and Calibration – Gear change detection

- Information about the differential and gearbox for Gear Detection.

 

Automatic Transmission Range Selector (lever position):

In Sensors and Calibration – AT range selector

- The settings for the input from the lever position should be as bellow:

- The 4L80E/4L85E transmission sends to the ECU the same signal for Park and Neutral, so it’s the user's choice to select N or P instead.

 

Drive shaft RPM:

In Sensors and Calibration – Drive shaft RPM

- When using the 4L80E/4L85E transmission VSS, set 31 teeth and select your differential ratio and tire size info. Wheel speed sensor can be used instead.

 

Automatic Transmission Control:

In Other Functions – Automatic Transmission Control

- User preferences for transmission control settings.

 

Solenoids:

In Other Functions – Automatic Transmission Control - Solenoids

- Solenoid A and B: 75Hz

- Line pressure solenoid: 293Hz for early versions and 614Hz for late (94 and up)

 

Gear change trigger table uses the same values for Upshift and Downshift:

In Other Functions – Automatic Transmission Control – Gear change trigger table

 

Gear Change Table:

In Other Functions – Automatic Transmission Control – Gear change table

- The values of the picture bellow are just a suggestion to start, do your own research and tell the ECU when to shift gears.

- Do not set the same speed for upshift and downshift for the same TPS position.

- The speed for upshift will always be higher than downshift, at least 2 miles/hour apart to avoid constantly gear shifting.

 

Gearbox Line Pressure Table:

In Other Functions – Automatic Transmission Control – Gear line pressure table

- This table is to adjust the Line pressure for smooth gear shifting and stable engine idle.

- Since the line pressure directly affects the torque converter, the adjustment is needed for a smooth run and will depend on the torque converter installed.

- Line pressure solenoids reduce the line pressure when activated, as so, if not using the output for controlling it, your 4L80E will apply full line pressure at all time.

- To reduce line pressure, you should increase the percentage of duty cycle on the solenoid. Values bellow are suggestive.

 

Line pressure by temperature compensation:

In Other Functions – Automatic Transmission Control – Line pressure by temperature compensation

- ATF’s density and viscosity drastically changes with temperature, that’s one of the reasons why using transmission temperature sensor is important to guarantee smooth operation. To reduce the pressure and maintain a smooth operation of your transmission system you should add more duty cycle on the solenoids, as showed:

 

Gear change line pressure:

In Other Functions – Automatic Transmission Control – Gear change line pressure compensation

- A momentary reduction of line pressure at the gear change, making even smoother gear changing. Suggestive values below.

 

Lockup Control:

In Other Functions – Lockup control

- For early versions of 4L80E the TCC (lockup) is ON/OFF solenoid, so PWM frequency can remain “0 Hz”. For late versions, with PWM TCC solenoid 32Hz for PWM frequency is recommended.

 

Lockup Table:

In Other Functions – Lockup control – Lockup table

- The Lockup Table should follow the same logic as the gear changing table, Lock-up speeds should be higher than Unlock speeds 2mph apart to avoid constantly locking and unlocking the converter.