How to Set Up a 4L80E or 4L85E Transmission with FTManager

August 29, 2024

Setting up your 4L80E or 4L85E transmission with FTMANAGER delivers precise and reliable transmission control. In this guide, we’ll walk you through the necessary steps to configure your FuelTech ECU for seamless integration with these powerful GM transmissions. Whether you’re fine-tuning shift points, optimizing torque converter lockup, or adjusting other transmission parameters, FTMANAGER offers the flexibility and control you need. Follow our detailed instructions to ensure your 4L80E or 4L85E transmission operates at peak performance with your FuelTech system.

The step-by-step instruction are for 4L80E and 4L85E transmissions that have been wired according to the transmission wiring diagrams below:

Enable Transmission Control Feature:

Under Engine Settings – Map Options check the following boxes:
- Automatic Transmission Control
- Lockup Control
- Gear Change Detection

Inputs:

Under Sensors and Calibration - Select Inputs

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

- Driveshaft RPM – Requires VR to Hall Converter OR Wheel Speed Sensor

- 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:

Under Sensors and Calibration - Outputs:

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

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

Gear Change Detection:

Under Sensors and Calibration – Gear Change Detection:

- Under Gear Detection, enter differential and gearbox information.

- Select Detection Type: “By Automatic Transmission Control”

Automatic Transmission Range Selector (lever position):

Under Sensors and Calibration – Automatic Transmission Range Selector

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

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

Drive Shaft RPM:

Under Sensors and Calibration – Drive Shaft RPM

- When using the 4L80E or 4L85E transmission VSS: set 31 teeth, enter your differential ratio, select tire type, and enter tire size. A wheel speed sensor may be used instead.

Automatic Transmission Control:

Under Other Functions – Automatic Transmission Control:

- User preferences for transmission control settings.

Solenoids:

Under Other Functions – Automatic Transmission Control - Solenoids:

- Solenoid A and B: 75Hz

- Line Pressure Solenoid: 293Hz for 1993 and earlier versions and 614Hz for 1994 and later versions. 

Gear Change Trigger Table uses the same values for Upshift and Downshift:

Under Other Functions – Automatic Transmission Control – Gear Change Trigger Table

Gear Change Table:

Under Other Functions – Automatic Transmission Control – Gear Change Table

- The values in the table shown below are suggestions designed to give you settings to start from. Do your own research or consult with a professional tuner if you are unsure of your preferred setting preferences for gear shift settings.

- Do not set the same speed for upshift and downshift in the same TPS position (column).

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

Gearbox Line Pressure Table:

Under Other Functions – Automatic Transmission Control – Gear Line Pressure Table

- This table allows you to adjust the gearbox line pressure for smooth gear shifting and stable engine idle.

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

- Line pressure solenoids reduce the line pressure when activated. If you are not using an output to control the line pressure solenoid, your 4L80E/4L85E will apply full line pressure at all times.

- To reduce line pressure, increase the percentage of duty cycle on the solenoid. The values shown below are an example.

Line Pressure by Temperature Compensation:

Under Other Functions – Automatic Transmission Control – Line Pressure by Temperature Compensation:

- Automatic transmission fluid's density and viscosity changes drastically with temperature fluctuations, which is one of the reasons why a transmission temperature sensor is important for smooth operation. To reduce pressure and maintain smooth transmission operation you may add more duty cycle on the solenoids, as shown:

Gear Change Line Pressure:

Under Other Functions – Automatic Transmission Control – Gear Change Line Pressure Compensation:

- A momentary reduction in line pressure at the gear change provides an even smoother gear change. Suggested values are shown below.

Lockup Control:

Under Other Functions – Lockup Control

- For early versions of 4L80E or 4L85E the TCC (lockup) is an ON/OFF solenoid, so PWM frequency may remain “0 Hz”. For later versions, 32Hz for PWM frequency is recommended.

Lockup Table:

Under Other Functions – Lockup Control – Lockup Table:

- The Lockup Table should follow the same logic as the Gear Changing Table. Lock-up speeds should be 2 MPH higher than Unlock speeds to avoid constant or excessive locking and unlocking.

 By properly setting up your 4L80E or 4L85E transmission with FTMANAGER, you’ll ensure that your transmission operates smoothly and efficiently, providing the reliability and performance you expect from your vehicle. This configuration not only enhances shift quality and overall drivability but also maximizes the lifespan of your transmission. Should you need further assistance or have any questions, FuelTech’s expert tech support team is always ready to help. Optimize your setup today and experience the full potential of your 4L80E or 4L85E transmission with FuelTech.

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