Identifying The Door Lock System - Directed Electronics 446 Series Installation Manual

Door Lock Harness Wire Connection Guide

Identifying the Door Lock System

The easiest way to determine which type of door lock system you are working with is to remove the
master locking switch itself, which is usually on the driver's door or on the center console. Once you
have determined which type of factory door lock circuit you are working with, and the color codes
of the switch wires to be used, you can usually simplify the installation by locating the same wires
in the vehicle's kick panel.
NOTE: Always retest the kick panel wires to make sure they work the same as the wires on the
switch.
There are five different types of common door lock circuits found in GM vehicles (some vehicles
use more unusual systems). The five most common systems are:
T T y y p p e e A A - Three-wire (+) pulse controlling factory lock relays. This system is most commonly
found in GM four-door trucks, SUVs and sedans.
T T y y p p e e B B - Three-wire (-) pulse controlling factory lock relays. This system is found in some late
model GM vehicles.
T T y y p p e e C C - Direct-wired reversing-polarity switches. The switches are wired directly to the motors.
This type of door lock system has no factory relays. This system is most commonly found in
two-door GM cars and trucks.
T T y y p p e e D D - These include slave systems without an actuator in the driver's door, but with factory
actuators in all the other doors. Type D also includes cars without power locks, which are having
actuators added. All Saab before 1994, all Volvo except 850i, all Subaru, most Isuzu, and many
Mazda. Some mid-eighties Nissans, pre-1985 Mercedes-Benz and Audi.
T T y y p p e e E E - The vehicle must have a vacuum actuator in each door. Make sure that locking the doors
from the driver's or passenger side using the key activates all the actuators in the vehicle. This
requires a slight modification to the door lock harness. Mercedes-Benz and Audi 1985 and newer.
T T y y p p e e F F - This system is found in the late-model Nissan Sentra, some Nissan 240SX, and Nissan
300ZX 1992-up. It is also found in older Mitsubishi, and some early Mazda MPV's.
T T y y p p e e G G - Positive (+) multiplex. A Resistor Interface Module (GM P/N 12496739) may be used
for this type of door locking system. This system is found in the 2001 and newer GM Aztek.
T T y y p p e e H H - Negative (-) multiplex. A Resistor Interface Module (GM P/N 12496739) may be
used for this type of door locking system. This system is found in 1999 and newer Grand Am
and Alero models, as well as 2000 and newer Impala and Monte Carlo models.
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Directed Electronics, Inc.