TRANMISSION TUNING - DODGE/CHRYSLER/JEEP

Dodge · Chrysler · Jeep · Ram · Durango | ZF 8HP Series Automatic (TCU/TCM) | A licensed module inside the GPEC2A Tuner

Custom Tunez now supports transmission (TCU) tuning for the ZF 8HP series — in Dodge, Chrysler, Jeep and Ram vehicles — using our own in-house tool. No third-party software, no shipping anything out.

Transmission tuning lives right inside the GPEC2A Tuner you already use for your engine. A transmission license unlocks the module, and you read, back up, and flash your transmission calibration over the same OBD cable.

A transmission tune transforms how the vehicle drives: firmer, faster shifts, smarter shift logic, and a calibration built to work with your engine tune instead of against it.

Currently in beta — available to early-access customers at a discounted price, with additional vehicles and software versions rolling out as coverage expands.

WHY TUNE YOUR TRANSMISSION

• Firmer, more aggressive shifts — crisp, positive gear changes you can feel

• Faster shift speeds — less time between gears for quicker acceleration

• Raised shift points — hold each gear longer and stay in the power

• Reduced torque management — less power cut during shifts, so more of your engine's power reaches the ground

• Higher torque handling — the transmission is set up to handle a modified engine instead of fighting it

• Firmer torque-converter lockup — a tighter, more connected feel

• Smarter shift logic — less gear hunting in everyday driving

• Aggressive sport/manual behavior — holds gears and responds like a performance transmission should

• Pairs with your engine tune — engine and transmission calibrated to work together

Firmer, more controlled shifts can also reduce clutch slip and heat on modified setups — helping your build live a better life.

WHAT YOU CAN DO

Activate Your Module

Transmission tuning unlocks as its own licensed module inside the GPEC2A Tuner. Your license is tied to your specific transmission controller, so you're set up for your vehicle.

Read Your Transmission

Read your supported TCU calibration directly through the vehicle's OBD connection. Every read is integrity-checked before it's accepted, helping prevent an incomplete or corrupted read from being used for a flash.

Automatic Stock Backup

Your original transmission calibration is retained when the vehicle is first read, so you can always return to stock.

Request Your Custom Calibration

Send your read to Custom Tunez with your vehicle and modification details. We develop a transmission calibration appropriate for your supported vehicle and intended use, and send it back ready to flash.

Flash Your Calibration

Load the calibration we send you and write it to the transmission controller through the application, over the same cable. The platform verifies controller information and calibration data, and is built to stop safely before making a change if anything doesn't line up.

Restore Stock Anytime

Need to go back? Select your original backup and flash it back to the transmission controller.

Instant Identification

Quickly identify your transmission controller before making any changes — VIN, part number, hardware number, serial number, and software version. Know exactly what you're working with.

HOW IT WORKS

1. Activate your license to unlock the Transmission module

2. Back up your transmission (read your stock file)

3. Send us the read

4. Flash the custom calibration we send back

Same cable you already use for the engine. Back it up, flash your tune — no shipping anything out.

COMPATIBILITY

Designed for supported Dodge, Chrysler, Jeep and Ram vehicles equipped with a ZF 8HP series automatic transmission (8HP45 / 8HP70 / 8HP75 / 8HP90 family).

Applications may include:

• Ram 1500

• Dodge Charger

• Dodge Challenger

• Dodge Durango

• Jeep Grand Cherokee

• Chrysler 300

• Other supported ZF 8HP vehicles

Beta coverage note: Support is validated on real hardware and added one software version at a time. Your exact controller is confirmed by its software version — not simply by vehicle year and model. Contact Custom Tunez with your year, make, model, and engine to confirm your vehicle, or to request that it be added.

ACCESS REQUIREMENTS

• Same hardware as the GPEC2A Tuner — if you already have the cable, you're ready.

• A transmission license to unlock the module (sold separately from the engine license).

• 2018+ vehicles: certain applications require an appropriate security-gateway / bypass solution for authorized programming. Contact Custom Tunez if you're unsure.

WHAT'S INCLUDED

• Transmission (TCU) module inside the GPEC2A Tuner

• Transmission read, integrity check, and automatic stock backup

• Custom calibration request-and-flash workflow

• Stock backup / restore

• Instant transmission identification

• Uses your existing GPEC2A Tuner OBD cable

A transmission license is required to activate the module and is sold separately from the engine (GPEC2A) license.

IMPORTANT SAFETY & LEGAL NOTICE

The 8HP Transmission Tuner is a vehicle calibration and programming platform. Transmission programming carries inherent risk; always keep a verified backup and a stable power supply during any flash. Custom Tunez is not responsible for damage resulting from interrupted programming, unsupported hardware, or use outside supported applications.

This platform is not intended to bypass, defeat, disable, or render inoperative any emissions-control system required by law. Users are responsible for ensuring that vehicle modifications and calibrations comply with all laws and regulations applicable to the vehicle and its location. Certain features may be restricted to applications where their use is lawful.