AutoCommand Keyless Entry Notes Sheet Without Relays.doc
9/7/2004
Test the chassis connection you are using by touching the other probe to a different point on the cars chassis. The
meter should register continuity, or a "continuous" circuit (zero ohms).
Next, locate the lock/ unlock wires (the ones from the wiring guide) in the car by removing whatever panel or
covering you need to. With one probe from the meter still attached to the cars chassis, use the other probe and
pierce the insulation of the lock wire. If you are on the correct wire, the meter should register continuity when you
press the lock switch. When you check for unlock the meter will register when you press the unlock switch. These
wires will register continuity ONLY when the corresponding lock or unlock switch is pressed. When you have found
the correct wires, connect the DesignTech module according to the diagram above.
POSITIVE TRIGGERED DOOR LOCK SYSTEMS
This circuit is similar to the
negative system except that
instead of a ground pulse to lock
and unlock, the system requires a
+12 volt pulse to lock and unlock
the doors. This type system is
found in most GM cars. When
testing for this system, attach the
black probe from the test meter to
chassis ground and set the meter
on the +12 volt DC scale. Use the
red probe from the meter to check
the wires. The meter will register
12 volts on the lock wire
when you press the lock switch
and the meter will register the
same for the unlock wire when
you press the unlock switch. These
wires will re12 volts ONLY
when the lock or unlock switch is
pressed. When you have located
the correct wires, connect them exactly according to the following diagram.
REVERSE POLARITY DOOR LOCK SYSTEMS
Reverse polarity systems are more complicated. The switch in the vehicle sends +12 volts in one direction while
holding chassis ground on the other direction. This is true for both lock and unlock. Testing for this system requires
to check for continuity to chassis ground on the lock and unlock wires at rest. Just like a positive triggered system,
the lock wire will re12 volts when you press the lock switch, and the unlock wire will re12 volts when
you press the unlock switch. When neither switch is being pressed, these wires will show ground on your meter.
When you have located the correct wires, cut them in half. The switch side will still measure continuity to chassis
ground at rest while mea12 volts when the switch is activated. The motor side will not meausure anything
at either rest or when the switch is activated. Once you have determined which is the switch side and which is the
motor side, connect them to the DesignTech module according to the diagram on the next page using two SPDT
(Single Pole Double Throw) 5 pin relays.
