Tapping into the '01-'04 Electronic Time and Alarm Control System (ETACS)

by southpawboston

Important information for all DIYs involving the ETACS:

The 2001-2004 model year Elantras that came from the factory equipped with keyless remote entry & alarm utilize a central control module (the ETACS) that controls the following electrical functions: Door and trunk locking/unlocking; all alarm functions incl. arming/disarming, lights flash; starter kill;  all interior and exterior lighting; electric window motor;  door open chime/warning;  seatbelt chime/warning; windshield wiper motor;  four-way hazard lights; cruise control/tachometer; rear window defogger.

This DIY explains how to gain access to the ETACS, and also to map the pins of each ETACS harness to facilitate tapping into specific ETACS functions. With this information, the car's built-in alarm system can be upgraded with accessories like pagers, shock/motion/intrusion sensors, and status LEDs. In addition, various interior lighting improvements can be made. Lots of other electrical modifications can be done, like making the sunroof work during the "key-out" timed delay feature for the power windows, and making the fog lights work without the parking lights being on. These are described in accompanying DIYs.

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ETACS location, access, and pin mapping

The ETACS is located behind the center dash fascia, immediately behind the HVAC controls, and is connected to the electrical system via three separate harness connectors. It is accessed by removing the dash fascia and the HVAC cluster. Once the fascia and HVAC cluster are removed, you will have easy access to the ETACS and its three harness connectors. See figures below. For each of the separate DIYs that involve splicing into to the ETACS connectors, refer to the ETACS Harness Pin Table for the location and function of each pin, and the color of each respective harness wire (the colors have been verified for '01-'03 Elantras, but NOT for '04s. The pin positions and functions are the same).  It will be helpful to print out a copy of this document when performing any of the ETACS DIYs, so that you can refer to the figures and harness pin table.

Wire splicing guidelines

When splicing into harness wires, you will have to unplug the harness from the ETACS, and carefully peel back the adhesive foam insulation that is wrapped around each harness. For reliable splicing, refer to the steps outlined here, and refer to the figure below. Using wire strippers, strip away about 0.25" of the wire insulation from the harness wire that you want to splice into WITHOUT cutting the actual wire. Next, strip away about 0.25" of insulation from the end of the wire that you want to splice into the harness. Wrap the bare wire around the stripped harness wire, solder the connection, and tape the splice junction. I recommend using Scotch 3M brand electrical tape. Never leave any electrical wires, splice connections, solder joints, or terminals exposed. I also recommend using either nylon snap-ties or electrical tape to secure loose wiring where possible. Avoid using "quick-connect" type connectors for splicing wires into the ETACS harness (e.g., Scotch-locks or T-taps). These connectors are unreliable, and when splicing many wires into the same harness, the connectors' bulky size gets in the way. If you don't have a solder iron or don't know how to solder, then at least splice the wires and tape them according to these guidelines. Even if you skip the soldering step, this splicing method is better than quick-connecters.

Precautions and disclaimer

THE CAR BATTERY MUST BE DISCONNECTED FOR AT LEAST ONE HOUR BEFORE PERFORMING ANY OF THE DIY's INVOLVING THE ETACS, AND MUST REMAIN DISCONNECTED UNTIL THE DIY's ARE COMPLETED. BY NOT DOING SO, YOU RISK PERMANENT DAMAGE TO THE ETACS. ANY DAMAGE CAUSED TO THE ETACS BY PERFORMING ANY OF THE PROCEDURES OUTLINED HERE MAY NOT BE COVERED UNDER WARRANTY. REPLACEMENT COST FOR THE ETACS MAY BE BETWEEN $127 AND $393 USD RETAIL (OR BETWEEN $104 AND $318 DISCOUNTED THROUGH JAY MONTIGNY), DEPENDING ON YEAR AND TRIM LEVEL, BASED ON A QUOTE FROM JAY MONTIGNY AT LIA HYUNDAI.

All information provided here is to be used as a guide only. If you are not experienced or comfortable working with electrical systems, I do not recommend you attempt any of these DIYs. I take no responsibility for damage caused to your vehicle by work that was performed using information provided here. Any modifications you perform to your car are done at your own risk.

 

CONNECTOR A

CONNECTOR B

CONNECTOR C

Splicing into the ETACS harness wires