On 3/10/06 3:12 PM, in article DYlQf.46898$_c.17549@tornado.tampabay.rr.com,

The light has come on a couple of times on my '02 and it was a false alarm
both times. I would get the code out of it and reset the light.  If it is a
real problem the light will be back on in a couple of weeks and you can go
from there.

There is no "set mileage" feature on the engine light.  It only comes on
when it detects a problem.  You can read the light yourself without a
scanner if you don't want to deal with Autozone.  (this is cut-n-paste from
the FSM).

"How to Switch Diagnostic Test Mode

NOTE:
* It is better to count the time accurately with a clock.
* It is impossible to switch the diagnostic mode when an accelerator pedal
position sensor circuit has a malfunction.
* Always ECM returns to Diagnostic Test Mode I after ignition switch is
turned ³OFF².
How to Set Diagnostic Test Mode II (Self-diagnostic Results)

1. Confirm that accelerator pedal is fully released, turn ignition switch
³ON² and wait 3 seconds.
2. Repeat the following procedure quickly five times within 5 seconds.
  1) Fully depress the accelerator pedal.
  2) Fully release the accelerator pedal.
3. Wait 7 seconds, fully depress the accelerator pedal and keep it for
approx. 10 seconds until the MIL starts blinking.
4. Fully release the accelerator pedal.
ECM has entered to Diagnostic Test Mode II (Self-diagnostic results).

Diagnostic Test Mode II ‹ Self-Diagnostic Results

In this mode, the DTC and 1st trip DTC are indicated by the number of blinks
of the MIL. The DTC and 1st trip DTC are displayed at the same time. If the
MIL does not illuminate in diagnostic test mode I (Malfunction warning), all
displayed items are 1st trip DTCs. If only one code is displayed when the
MIL illuminates in diagnostic test mode II (SELF-DIAGNOSTIC RESULTS), it is
a DTC; if two or more codes are displayed, they may be either DTCs or 1st
trip DTCs. DTC No. is same as that of 1st trip DTC. These unidentified codes
can be identified by using the CONSULT-II or GST. A DTC will be used as an
example for how to read a code.

A particular trouble code can be identified by the number of four-digit
numeral flashes. The ³zero² is indicated by the number of ten flashes. The
length of time the 1,000th-digit numeral flashes on and off is 1.2 seconds
consisting of an ON (0.6-second) - OFF (0.6-second) cycle. The 100th-digit
numeral and lower digit numerals consist of a 0.3-second ON and 0.3-second
OFF cycle. A change from one digit numeral to another occurs at an interval
of 1.0-second OFF. In other words, the later numeral appears on the display
1.3 seconds after the former numeral has disappeared.

A change from one trouble code to another occurs at an interval of
1.8-second OFF. In this way, all the detected malfunctions are classified by
their DTC numbers. The DTC ³0000² refers to no malfunction. (See ³TROUBLE
DIAGNOSIS ‹ INDEX², EC-8.)

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How to Erase Diagnostic Test Mode II (Self-diagnostic Results):

1. Set ECM in Diagnostic Test Mode II (Self-diagnostic results). Refer to
How to Set Diagnostic Test Mode II (Self-diagnostic Results).
2. Fully depress the accelerator pedal and keep it for more than 10 seconds.
The emission-related diagnostic information has been erased from the backup
memory in the ECM.
3. Fully release the accelerator pedal, and confirm the DTC 0000 is
displayed.

* If the battery is disconnected, the DTC will be lost from the backup
memory after approx 24 hours.
* Be careful not to erase the stored memory before starting trouble
diagnoses."

There are only a few possibilities:  fuse, broken wire running between the
door and the truck body, bad switch, bad window motor, wire fell off
somewhere in between, etc.  You'll have to get out the multi-meter and start
probing wires.  Also check the main switch and wiring in the drivers door if
you don't find anything in the back door.