Tach Emulator


1996-2010 Jeeps

GM to Jeep Tachometer Interface

Module, crank position emulator for CAN Bus Jeep tachometers with GM engine conversions, #E-TX

In 1996, Chrysler Jeep rolled out a more advanced version of their in-vehicle network called the Controller Area Network Bus, or CAN Bus system, over which data is shared between various electronic modules in the Jeep. One of those modules is the Jeep gauge cluster which uses a microcontroller to run the gauges.

One largely successful strategy in retaining the factory gauges has been to keep the Jeep Powertrain Control Module (PCM) connected to the network as nothing more than a gauge mule, which is good for every gauge in the cluster except the tachometer, until now...

The Tachometer Emulator Module

Novak has developed this innovative emulator module that receives the tachometer output from a GM Generation III/IV PCM. It then outputs the correct Crank Position (CKP) pulses to the Jeep PCM which then calculates the engine RPM's to be transmitted on the CAN bus to the Jeep gauge module.

This emulator module is built using an industrial duty processor making thousands of calculations per second to properly mimic the pulsetrain needed by the Jeep PCM to calculate and relay engine speed.

Additional Cruise Control Functionality

The Jeeps 5 Cruise Control buttons talk to the Jeep PCM via complex resistive multiplexing, making integration to the GM system seemingly impossible. Novak's E-TXCC module can take those complex signals and translate them to the GM system for seamless Cruise Control compatibility with your GM engine conversion. Select the E-TXCC Emulator for Tachometer and Cruise Control Emulation on all 1997-2006 XJ, TJ, and LJ Jeeps with a GM Gen III conversion. This E-TXCC module is not compatible with Jeep JK models.

Applications & Compatibility


The #E-TX series are all compatible with most Gen III & IV GM engine swaps.

Holly ECM's are not supported. This emulator is specifically designed for use with stock GM PCM's.

The E-TXCC is compatible with all 1997-2006 XJ, TJ, and LJ's, and only Gen III (1999-2007) GM engine swaps. When using a 1999-2001 GM engine, the stock cruise control module must be retained.

Related Products

GM PCM Mount Bracket
Speed Signal Interface Module
GM to Jeep wiring harness
GM speed sensors for Jeeps

Installation Requirements


Installation requires that the installer be able to competently join the wire leads to the existing Jeep wiring harness as directed in the instructions. This is best done with solder and thermal shrink wrap, followed up by wire loom. Physical installation into the Jeep engine bay is easy using the mounting tabs on the case of the module. Drilling is required.

Pull-up Resistor

A pull-up resistor is often required for tachometer applications. However, the Novak tach emulator circuitry already includes this.

Also See