Jeep XJ. Manual - part 138
SEAT HEAT INTERFACE MODULE
Before testing the seat heat interface module, test
the heated seat switch, the heated seat elements, and
the heated seat sensor as described in the Diagnosis
and Testing section of this group. If testing of the
heated seat switch, elements, and sensor reveals no
problems, proceed as follows. For circuit descriptions
and diagrams, refer to 8W - 63 - Power Seat With
Heated Seats in Group 8W - Wiring Diagrams.
(1) Replace the seat heat interface module with a
known good unit and test the operation of the heated
seats. If OK, discard the faulty seat heat interface
module. If not OK, go to Step 2.
(2) Test each of the circuits from the heated seat
switch, heated seat relay, heated seat elements, and
heated seat sensor to the seat heat interface module.
Repair any short or open circuits as required.
REMOVAL AND INSTALLATION
HEATED SEAT SWITCH
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS,
REFER
TO
GROUP
8M
-
PASSIVE
RESTRAINT SYSTEMS BEFORE ATTEMPTING ANY
STEERING
WHEEL,
STEERING
COLUMN,
OR
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Using a trim stick or another suitable wide
flat-bladed tool, gently pry around the perimeter
edges of the heated switch assembly bezel to release
the assembly from the console. Remove the assembly
from the console.
(3) Pull the switch assembly out from the console
far enough to access and unplug the wire harness
connectors.
(4) Remove the heated seat switch assembly from
the console.
(5) Remove the heated seat switch(es) from the
heated seat switch assembly.
(6) Reverse the removal procedures to install.
SEAT HEAT INTERFACE MODULE
(1) Move the right power seat adjuster to its full
up and full rear stop positions.
(2) Disconnect and isolate the battery negative
cable.
(3) Unhook the seat cushion cover retainer from
the seat cushion frame and pull back the seat cush-
ion cover.
(4) Pull back the seat cushion to allow access to
the Seat Heat Interface Module (SHIM).
(5) Pull the SHIM upward to release the two
mounting fasteners from either the module or the
mounting bracket. Unplug the wire harness connec-
tor from the module (Fig. 2).
WARNING: THERE
ARE
MANY
SHARP
METAL
EDGES ON THE SEAT CUSHION FRAME AND SEAT
ADJUSTER RAILS UNDER THE SEAT. WHEN PER-
FORMING THIS SERVICE, A LONG-SLEEVED SHIRT
AND GLOVES SHOULD BE WORN IN ORDER TO
AVOID UNNECESSARY CUTS AND ABRASIONS TO
EXPOSED SKIN.
(6) Reverse the removal procedures to install. Be
certain that the SHIM terminals are aligned with the
cavities in the wire harness connector before pushing
the module firmly into place.
HEATED SEAT RELAY
(1) Move the right power seat adjuster to its full
up and full rear stop positions.
(2) Disconnect and isolate the battery negative
cable.
(3) Unhook the seat cushion cover retainer from
the seat cushion frame and pull back the seat cush-
ion cover.
(4) Pull back the seat cushion to allow access to
the Heated Seat Relay.
Fig. 2 Seat Heat Interface Module Remove/Install
1 – SEAT CUSHION FRAME
2 – SEAT HEAT INTERFACE MODULE
3 – WIRE HARNESS CONNECTOR
4 – POWER SEAT TRACK FRONT BRACKET
8N - 12
ELECTRICALLY HEATED SYSTEMS
XJ
DIAGNOSIS AND TESTING (Continued)