TCU Buddy V1 Prototype


A palm-sized Scanner for your AW-4 Transmission needs!

SKU: tcu-buddy-v1-prototype Categories: ,


NOTE: THIS IS A PROTOTYPE to test the design and market, so only basic protection circuitry is included. The Data Line cannot take more than 3.3v or the device is likely to completely fail so be careful!

– The REM + (V3) and Above can also read in the TCU data stream so keep that in mind when ordering.

Due to public interest, I’ve been brewing up a Transmission Scan Tool that is compatible with a larger range of vehicles so I present the first prototype! *Notice, this cannot easily be used together with an REM*

The TCU Buddy V1 is compatible with the AW-4 Automatic Transmission which was a very common option in 80’s – 00’s Jeeps. This device connects to the TCU/TCM located under the passenger side lower dash panel and can read in the data stream as well as manually sense Solenoids and TPS for custom shift setups. Exact Year Compatibility is unknown until I am able to get feedback, but here is my best guess so far:


1986 – 1990 Renix (100% Plug and Play Compatible)

1991 – 1995.5 HO OBD1 (95% Confident, requires splicing or finding very rare CCD Connector or compatible pins)

1996+ HO OBD2 (5% Confident, Schematics only show SCI Protocol and CCD twisted pair which are likely very different from the older TX UART)


For Renix User (86-90) who only need a basic scan tool, the Renix Adapter is recommended. For Manual Sensing and other years, the Splice Adapter is Recommended.

– For Basic Scan Tool functions only 3 wires are need; Ignition, Ground, and Data.

– For reading Current Gear with Manual Shifters; Solenoid 1, 2, and 3 will need to be manually wired.

– For a full 0 – 100% TPS Scale, the TPS will need to be manually wired.


– TPS Step (0 – 7)

– Transmission RPM

– TCU Brake Switch

– Power/Comfort Mode Switch

– PRNDL Shifter

– Solenoids 1, 2 and 3

– Current Gear

– Solenoid and TPS Error Codes

Bonus Features:

– 2.7″ OLED Screen

– MPH Readout (w/ drivetrain info)

– Speedo Gear Tooth Calculator (w/ drivetrain info)

– Dual Indicator LED for Brake Switch and Error Codes

– Extra Analog Line to read up to 18V

– USB Updatable and Arduino Open Source!

In The Box:

– TCU Buddy V1 Scanner

– Renix Adapter or Manual Splice Adapter

– 10′ Ethernet Cord

– Velcro

Additional information

Weight 3 oz
Dimensions 4 × 1 × 2.5 in


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