body JEEP LIBERTY 2002 KJ / 1.G Workshop Manual

The park lamp relay can be diagnosed using con-
ventional diagnostic tools and methods.
DIAGNOSIS AND TESTING - PARK LAMP
RELAY
The park lamp relay (Fig. 54) is located in the
Junction Block (JB) under the driver side outboard
end of the instrument panel. Refer to the appropriate
wiring information. The wiring information includes
wiring diagrams, proper wire and connector repair
procedures, details of wire harness routing and
retention, connector pin-out information and location
views for the various wire harness connectors, splices
and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.(1) Remove the park lamp relay from the JB.
(Refer to 8 - ELECTRICAL/LAMPS/LIGHTING -
EXTERIOR/PARK LAMP RELAY - REMOVAL).
(2) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
no continuity between terminals 87 and 30. If OK, go
to Step 3. If not OK, replace the faulty relay.
(3) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 75   8 ohms. If OK, go to Step
4. If not OK, replace the faulty relay.
(4) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, reinstall the relay and use a DRBIIIt
scan tool to perform further testing. Refer to the
appropriate diagnostic information.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the steering column opening cover
from the instrument panel. (Refer to 23 - BODY/IN-
STRUMENT PANEL/STEERING COLUMN OPEN-
ING COVER - REMOVAL).
(3) Remove the park lamp relay by grasping it
firmly and pulling it straight out from the receptacle
in the Junction Block (JB) (Fig. 55).
Fig. 54 ISO Micro Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
KJLAMPS8Ls-55
PARK LAMP RELAY (Continued)

INSTALLATION
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.(1) Position the park lamp relay to the proper
receptacle in the Junction Block (JB) (Fig. 55).
(2) Align the park lamp relay terminals with the
terminal cavities in the JB receptacle.
(3) Push firmly and evenly on the top of the park
lamp relay until the terminals are fully seated in the
terminal cavities in the JB receptacle.
(4) Reinstall the steering column opening cover
onto the instrument panel. (Refer to 23 - BODY/IN-
STRUMENT PANEL/STEERING COLUMN OPEN-
ING COVER - INSTALLATION).
(5) Reconnect the battery negative cable.
REAR FOG LAMP RELAY
DESCRIPTION
The rear fog lamp relay is located in the Junction
Block (JB) on the driver side outboard end of the
instrument panel in the passenger compartment of
the vehicle. The rear fog lamp relay is a conventional
International Standards Organization (ISO) micro
relay (Fig. 56). Relays conforming to the ISO specifi-
cations have common physical dimensions, current
capacities, terminal patterns, and terminal functions.
The relay is contained within a small, rectangular,
molded plastic housing and is connected to all of the
required inputs and outputs by five integral male
spade-type terminals that extend from the bottom of
the relay base.
The rear fog lamp relay cannot be adjusted or
repaired and, if faulty or damaged, the unit must be
replaced.
Fig. 55 Junction Block - Inboard Side (LHD Shown -
Rotate 180É for RHD)
1 - PASSENGER DOOR UNLOCK RELAY
2 - JB C3 CONNECTOR RECEPTACLE
3 - LOW BEAM RELAY
4 - CIRCUIT BREAKER #1
5 - CIRCUIT BREAKER #2
6 - CIRCUIT BREAKER #3
7 - DOOR LOCK RELAY
8 - DEFOGGER RELAY
9-SPARE
10 - FRONT FOG LAMP RELAY
11 - HORN RELAY
12 - SPARE
13 - SPARE
14 - REAR FOG LAMP RELAY
15 - PARK LAMP RELAY
16 - DRIVER DOOR UNLOCK RELAY
17 - JB C1 CONNECTOR RECEPTACLE
18 - JB C2 CONNECTOR RECEPTACLE
Fig. 56 ISO Micro Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
8Ls - 56 LAMPSKJ
PARK LAMP RELAY (Continued)

OPERATION
The rear fog lamp relay is an electromechanical
switch that uses a low current input from the Body
Control Module (BCM) to control a high current out-
put to the rear fog lamps. The movable common feed
contact point is held against the fixed normally
closed contact point by spring pressure. When the
relay coil is energized, an electromagnetic field is
produced by the coil windings. This electromagnetic
field draws the movable relay contact point away
from the fixed normally closed contact point, and
holds it against the fixed normally open contact
point. When the relay coil is de-energized, spring
pressure returns the movable contact point back
against the fixed normally closed contact point. A
resistor is connected in parallel with the relay coil in
the relay, and helps to dissipate voltage spikes and
electromagnetic interference that can be generated as
the electromagnetic field of the relay coil collapses.
The rear fog lamp relay terminals are connected to
the vehicle electrical system through a connector
receptacle in the Junction Block (JB). The inputs and
outputs of the rear fog lamp relay include:
²Common Feed Terminal- The common feed
terminal (30) receives battery current at all times
from a fuse in the JB through a fused B(+) circuit.
²Coil Ground Terminal- The coil ground termi-
nal (85) is connected to a control output of the pre-
mium Body Control Module (BCM) through a rear
fog lamp relay control circuit. The BCM controls rear
fog lamp operation by controlling a ground path
through this circuit.
²Coil Battery Terminal- The coil battery ter-
minal (86) receives battery current at all times from
a fuse in the JB through a fused B(+) circuit.
²Normally Open Terminal- The normally open
terminal (87) is connected to the rear fog lamps
through a rear fog lamp relay output circuit and pro-
vides battery current to the rear fog lamps whenever
the relay is energized.
²Normally Closed Terminal- The normally
closed terminal (87A) is not connected in this appli-
cation.
The rear fog lamp relay can be diagnosed using
conventional diagnostic tools and methods.
DIAGNOSIS AND TESTING - REAR FOG LAMP
RELAY
The rear fog lamp relay (Fig. 57) is located in the
Junction Block (JB) under the driver side outboard
end of the instrument panel. Refer to the appropriate
wiring information. The wiring information includes
wiring diagrams, proper wire and connector repair
procedures, details of wire harness routing and
retention, connector pin-out information and locationviews for the various wire harness connectors, splices
and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Remove the rear fog lamp relay from the JB.
(Refer to 8 - ELECTRICAL/LAMPS/LIGHTING -
EXTERIOR/REAR FOG LAMP RELAY - REMOVAL).
(2) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
no continuity between terminals 87 and 30. If OK, go
to Step 3. If not OK, replace the faulty relay.
(3) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 75   8 ohms. If OK, go to Step
4. If not OK, replace the faulty relay.
Fig. 57 ISO Micro Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
KJLAMPS8Ls-57
REAR FOG LAMP RELAY (Continued)

(4) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, reinstall the relay and use a DRBIIIt
scan tool to perform further testing. Refer to the
appropriate diagnostic information.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the steering column opening cover
from the instrument panel. (Refer to 23 - BODY/IN-
STRUMENT PANEL/STEERING COLUMN OPEN-
ING COVER - REMOVAL).
(3) Remove the rear fog lamp relay by grasping it
firmly and pulling it straight out from the receptacle
in the Junction Block (JB) (Fig. 58).
INSTALLATION
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.(1) Position the rear fog lamp relay to the proper
receptacle in the Junction Block (JB) (Fig. 58).
(2) Align the rear fog lamp relay terminals with
the terminal cavities in the JB receptacle.
(3) Push firmly and evenly on the top of the rear
fog lamp relay until the terminals are fully seated in
the terminal cavities in the JB receptacle.
(4) Reinstall the steering column opening cover
onto the instrument panel. (Refer to 23 - BODY/IN-
STRUMENT PANEL/STEERING COLUMN OPEN-
ING COVER - INSTALLATION).
(5) Reconnect the battery negative cable.
Fig. 58 Junction Block - Inboard Side (LHD Shown -
Rotate 180É for RHD)
1 - PASSENGER DOOR UNLOCK RELAY
2 - JB C3 CONNECTOR RECEPTACLE
3 - LOW BEAM RELAY
4 - CIRCUIT BREAKER #1
5 - CIRCUIT BREAKER #2
6 - CIRCUIT BREAKER #3
7 - DOOR LOCK RELAY
8 - DEFOGGER RELAY
9-SPARE
10 - FRONT FOG LAMP RELAY
11 - HORN RELAY
12 - SPARE
13 - SPARE
14 - REAR FOG LAMP RELAY
15 - PARK LAMP RELAY
16 - DRIVER DOOR UNLOCK RELAY
17 - JB C1 CONNECTOR RECEPTACLE
18 - JB C2 CONNECTOR RECEPTACLE
8Ls - 58 LAMPSKJ
REAR FOG LAMP RELAY (Continued)

REPEATER LAMP UNIT
REMOVAL
Side repeater lamps are used only on vehicles man-
ufactured for certain markets where these lamps are
required.
(1) Disconnect and isolate the battery negative
cable.
(2) Using a trim stick or another suitable wide
flat-bladed tool, carefully pry at the clearance notch
in the lower edge of the repeater lamp lens to disen-
gage the snap features of the lens from the mounting
hole in the front fender panel (Fig. 62).
(3) Pull the repeater lamp unit out from the front
fender panel far enough to access and disconnect the
repeater lamp wire harness connector from the con-
nector receptacle on the back of the repeater lamp
unit socket.
(4) Remove the repeater lamp unit from the front
fender panel.
INSTALLATION
Side repeater lamps are used only on vehicles man-
ufactured for certain markets where these lamps are
required.
(1) Position the repeater lamp unit to the front
fender panel (Fig. 62).
(2) Reconnect the repeater lamp wire harness con-
nector to the connector receptacle on the back of the
repeater lamp unit socket.
(3) Position the repeater lamp unit into the mount-
ing hole in the front fender panel. Be certain that the
clearance notch on the edge of the repeater lamp lens
is oriented toward the bottom.(4) Using hand pressure, press on the repeater
lamp unit firmly and evenly until the snap features
of the lens are fully engaged in the mounting hole of
the front fender panel.
(5) Reconnect the battery negative cable.
TRAILER TOW CONNECTOR
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the four screws that secure the trailer
tow connector to the bracket on the trailer hitch
receiver (Fig. 63).
(3) Pull the trailer tow connector rearward from
the bracket on the trailer hitch receiver far enough to
access and disconnect the rear body wire harness
connector from the receptacle on the back of the
trailer tow connector.
(4) Remove the trailer tow connector from the
trailer hitch receiver.
INSTALLATION
(1) Position the trailer tow connector to the trailer
hitch receiver (Fig. 63).
(2) Reconnect the rear body wire harness connec-
tor to the receptacle on the back of the trailer tow
connector.
(3) Position the trailer tow connector into the
bracket on the trailer hitch receiver.
(4) Install and tighten the four screws that secure
the trailer tow connector to the bracket on the trailer
hitch receiver. Tighten the screws to 4 N´m (35 in.
lbs.).
(5) Reconnect the battery negative cable.
Fig. 62 Repeater Lamp Unit Remove/Install
1 - REPEATER LAMP UNIT
2 - FRONT FENDER PANEL
3 - INNER FENDER
4 - FRONT FASCIA WIRE HARNESS
Fig. 63 Trailer Tow Connector Remove/Install
1 - HITCH RECEIVER
2 - 7-WAY TRAILER TOW CONNECTOR
3 - SCREW (4)
4 - BRACKET
5 - WIRE HARNESS CONNECTOR
KJLAMPS8Ls-61

TRAILER TOW RELAY
DESCRIPTION
The trailer tow relays are located in a connector
bank above the right rear wheelhouse and behind the
quarter trim panel on vehicles equipped with the
optional factory-installed trailer towing package.
Four individual relays are used, one each for fused
ignition switch output (run), brake lamps, right turn
signal, and left turn signal outputs to a trailer
through the rear body wiring and connectors. The
trailer tow relays are conventional International
Standards Organization (ISO) micro relays (Fig. 64).
Relays conforming to the ISO specifications have
common physical dimensions, current capacities, ter-
minal patterns, and terminal functions. The relay is
contained within a small, rectangular, molded plastic
housing and is connected to all of the required inputs
and outputs by five integral male spade-type termi-
nals that extend from the bottom of the relay base.
The trailer tow relays cannot be adjusted or
repaired and, if faulty or damaged, the inoperative
relay must be replaced.
OPERATION
The trailer tow relays are electromechanical
switches. The relays each use an input from the cir-
cuit that they isolate from the trailer wiring to con-
trol a high current output to the trailer. The movable
common feed contact point is held against the fixed
normally closed contact point by spring pressure.When the relay coil is energized, an electromagnetic
field is produced by the coil windings. This electro-
magnetic field draws the movable relay contact point
away from the fixed normally closed contact point,
and holds it against the fixed normally open contact
point. When the relay coil is de-energized, spring
pressure returns the movable contact point back
against the fixed normally closed contact point. A
resistor is connected in parallel with the relay coil in
the relay, and helps to dissipate voltage spikes and
electromagnetic interference that can be generated as
the electromagnetic field of the relay coil collapses.
The terminals of each trailer tow relay are con-
nected to the vehicle electrical system through a con-
nector bank in the rear lighting wire harness above
the right rear wheelhouse. Refer to the appropriate
wiring information. The wiring information includes
wiring diagrams, proper wire and connector repair
procedures, details of wire harness routing and
retention, connector pin-out information and location
views for the various wire harness connectors, splices
and grounds. The trailer tow relays can be diagnosed
using conventional diagnostic tools and methods.
DIAGNOSIS AND TESTING - TRAILER TOW
RELAY
The trailer tow relays (Fig. 65) are located in a
connector bank above the right rear wheelhouse.
Refer to the appropriate wiring information. The wir-
ing information includes wiring diagrams, proper
wire and connector repair procedures, details of wire
harness routing and retention, connector pin-out
information and location views for the various wire
harness connectors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
Fig. 64 Trailer Tow Relays
1 - RELAY CONNECTOR BANK
2 - REAR BODY WIRE HARNESS
3 - LEFT TURN RELAY
4 - RIGHT TURN RELAY
5 - BRAKE LAMP RELAY
6 - FUSED IGNITION SWITCH OUTPUT (RUN) RELAY
8Ls - 62 LAMPSKJ

(1) Remove the trailer tow relay from the connec-
tor bank. (Refer to 8 - ELECTRICAL/LAMPS/LIGHT-
ING - EXTERIOR/TRAILER TOW RELAY -
REMOVAL).
(2) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
no continuity between terminals 87 and 30. If OK, go
to Step 3. If not OK, replace the faulty relay.
(3) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 75   8 ohms. If OK, go to Step
4. If not OK, replace the faulty relay.
(4) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, test the input and output circuits of
the relay. Refer to the appropriate wiring informa-
tion.
REMOVAL
The trailer tow relay bank contains four relays.
The service procedures for each relay are the same.
Be certain any removed relay is replaced with the
same relay size and type that was removed.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THENWAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the trim from the right side quarter
inner panel. (Refer to 23 - BODY/INTERIOR/QUAR-
TER TRIM PANEL - REMOVAL).
(3) Reach through the access hole in the quarter
inner panel behind the right rear wheelhouse to
locate and retrieve the trailer tow relay connector
bank, which is enveloped in foam rubber and placed
on the top of the right rear wheelhouse between the
quarter inner and outer panels (Fig. 66).
(4) Pull the trailer tow relay connector bank into
the cargo area far enough to access the unit for ser-
vice.
(5) Carefully remove the trailer tow relay connec-
tor bank from the foam wrap.
(6) Remove the trailer tow relay by grasping it
firmly and pulling it straight out from the connector
bank (Fig. 67).
INSTALLATION
The trailer tow relay bank contains four relays.
The service procedures for each relay are the same.
Be certain any removed relay is replaced with the
same relay size and type that was removed.
Fig. 65 ISO Micro Relay
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
Fig. 66 Trailer Tow Relay Wrap
1 - FOAM WRAP
2 - REAR BODY WIRE HARNESS
KJLAMPS8Ls-63
TRAILER TOW RELAY (Continued)

WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Position the trailer tow relay to the proper con-
nector in the connector bank (Fig. 67).
(2) Align the trailer tow relay terminals with the
terminal cavities in the connector.
(3) Push firmly and evenly on the top of the trailer
tow relay until the terminals are fully seated in the
terminal cavities in the connector.
(4) Carefully restore the foam wrap around the
trailer tow relay connector bank (Fig. 66).
(5) Reach through the access hole in the quarter
inner panel behind the right rear wheelhouse to
place the trailer tow relay connector bank on the top
of the right rear wheelhouse between the quarter
inner and outer panels.(6) Reinstall the trim onto the right side quarter
inner panel. (Refer to 23 - BODY/INTERIOR/QUAR-
TER TRIM PANEL - INSTALLATION).
(7) Reconnect the battery negative cable.
TRAILER TOW WIRING
DESCRIPTION
Vehicles equipped with an optional factory-in-
stalled (not dealer-installed or port-installed) trailer
towing package have a rear body wire harness that
includes an integral trailer tow wiring take out that
connects to a heavy duty, sealed, 7-pin trailer tow
connector located on a bracket on the trailer hitch
receiver (Fig. 68). This harness includes a second
take out with a trailer tow relay connector bank and
four trailer tow relays that isolate the right turn sig-
nal, left turn signal, and brake lamp circuits of the
vehicle from the electrical system of the trailer. The
fourth relay in the connector bank provides a fused
ignition switch output (run) source of battery current
to the trailer tow connector through a trailer tow
relay output circuit. The package also includes an
adapter harness (stored beneath the left rear seat
cushion of the vehicle when it is shipped from the
factory) that adapts the 7-pin trailer tow connector to
a standard, light-duty, 4-pin trailer tow connector.
Refer to the appropriate wiring information. The wir-
ing information includes wiring diagrams, proper
wire and connector repair procedures, further details
on wire harness routing and retention, as well as
pin-out and location views for the various wire har-
ness connectors, splices and grounds.
Fig. 67 Trailer Tow Relay Remove/Install
1 - RELAY CONNECTOR BANK
2 - REAR BODY WIRE HARNESS
3 - LEFT TURN RELAY
4 - RIGHT TURN RELAY
5 - BRAKE LAMP RELAY
6 - FUSED IGNITION SWITCH OUTPUT (RUN) RELAY
Fig. 68 Trailer Tow Wiring
1 - RETAINER CLIP (4)
2 - REAR BODY HARNESS (TRAILER TOW TAKE OUT)
3 - RETAINER CLIP (2)
4 - WIRE HARNESS CONNECTOR
8Ls - 64 LAMPSKJ
TRAILER TOW RELAY (Continued)

The CMTC may also be integrated with the Uni-
versal Transmitter. If so, your CMTC module will
have three buttons centered together between the
outer four buttons. Below the three buttons are cor-
responding dots to indicate which button you are
using.
The Compass Mini-Trip Computer includes the fol-
lowing display options:
²Compass and thermometer- provides the out-
side temperature and one of eight compass readings
to indicate the direction the vehicle is facing.
²Average fuel economy- shows the average
fuel economy since the last trip computer reset.
²Distance to empty- shows the estimated dis-
tance that can be travelled with the fuel remaining
in the fuel tank. This estimated distance is computed
using the average miles-per-gallon from the last 30
gallons of fuel used.
²Instant fuel economy- shows the present fuel
economy based upon the current vehicle distance and
fuel used information.
²Trip odometer- shows the distance travelled
since the last trip computer reset.
²Elapsed time- shows the accumulated igni-
tion-on time since the last trip computer reset.
²Blank screen- the CMTC compass/thermome-
ter/trip computer VFD is turned off.
If the vehicle is equipped with the optional Univer-
sal Transmitter transceiver, the CMTC will also dis-
play messages and an icon indicating when the
Universal Transmitter is being trained, which of the
three transmitter buttons is transmitting, and when
the transceiver is cleared.
Data input for all CMTC functions, including VFD
dimming level, is received through PCI data bus
messages. The CMTC module uses its internal pro-
gramming and all of its data inputs to calculate and
display the requested data. If the data displayed is
incorrect, perform the self-diagnostic tests as
described in this group. If these tests prove inconclu-
sive, the use of a DRBIIItscan tool and the proper
Diagnostic Procedures manual are recommended for
further testing of the CMTC module and the PCI
data bus.
The CMTC module cannot be repaired, and is
available for service only as a unit. This unit
includes the push button switches and the plastic
module and display lens. If any of these components
is faulty or damaged, the complete CMTC module
must be replaced. The incandescent bulbs used for
CMTC push button back-lighting are available for
service replacement.
DESCRIPTION - COMPASS
While in the compass/thermometer mode, the com-
pass will display the direction in which the vehicle ispointed using the eight major compass headings
(Examples: north is N, northeast is NE). The self-cal-
ibrating compass unit requires no adjusting in nor-
mal use. The only calibration that may prove
necessary is to drive the vehicle in three complete
circles at 5 to 8 kilometers-per-hour (3 to 5 miles-per-
hour), on level ground, in not less than forty-eight
seconds. This will reorient the compass unit to its
vehicle.
The compass unit also will compensate for magne-
tism the body of the vehicle may acquire during nor-
mal use. However, avoid placing anything magnetic
directly on the roof of the vehicle. Magnetic mounts
for an antenna, a repair order hat, or a funeral pro-
cession flag can exceed the compensating ability of
the compass unit if placed on the roof panel. Mag-
netic bit drivers used on the fasteners that hold the
overhead console assembly to the roof header can
also affect compass operation. If the vehicle roof
should become magnetized, the demagnetizing and
calibration procedures found in this group may be
required to restore proper compass operation.
DESCRIPTION - THERMOMETER
The thermometer displays the outside ambient
temperature in whole degrees. The temperature dis-
play can be toggled from Fahrenheit to Celsius by
using the U.S./Metric button. The displayed temper-
ature is not an instant reading of conditions, but an
average temperature. It may take the thermometer
display several minutes to respond to a major tem-
perature change, such as driving out of a heated
garage into winter temperatures.
When the ignition switch is turned to the Off posi-
tion, the last displayed temperature reading stays in
the Body Control Module (BCM) unit memory. When
the ignition switch is turned to the On position
again, the CMTC will display the memory tempera-
ture for one minute; then update the display to the
current average temperature reading within five
minutes.
The thermometer function is supported by an
ambient temperature sensor. The sensor is mounted
outside the passenger compartment near the front
and center of the vehicle, and is hard wired to the
Body Control Module (BCM). The BCM sends tem-
perature status messages to the CMTC module over
the PCI data bus network. The ambient temperature
sensor is available as a separate service item, refer to
additional information later in this section.
OPERATION
The compass mini-trip computer operates when the
ignition is in the ON position. The VFD will display
the last display before ignition was turned OFF. The
four outer buttons operate:
KJMESSAGE SYSTEMS 8M - 5
COMPASS/MINI-TRIP COMPUTER (Continued)

²STEP
²C/T - Compass/Temperature
²US/M - English/Metric
²RESET
1. STEP BUTTON
Pressing the STEP button selects one of the follow-
ing 6 displays:
²Average fuel economy
²Distance to empty
²Instantaneous fuel economy
²Trip odometer
²Elapsed time
²Blank Screen
2. C/T (COMPASS/TEMPERATURE)
BUTTON
Pressing the C/T button selects the Compass/Tem-
perature display.
3. US/M (ENGLISH/METRIC
MEASUREMENT) BUTTON
Pressing the US/M button switches the display
units between English and Metric readings.
4. RESET BUTTON
Pressing the RESET button resets the function on
the display, provided that function can be reset. The
functions which can be reset are Average fuel econ-
omy, Trip odometer and Elapsed time.
Global ResetThis feature allows all three dis-
plays (Average fuel economy, Trip odometer and
Elapsed time) to be reset easily, by pressing the
RESET button twice within three seconds with any
of the screens in display. This eliminates the need to
reset each display individually.
The RESET button is also used to set the variance
and/or calibrate the compass. Refer to the Variance
Procedure and Calibration Procedure in this section.
For more information on the features, control func-
tions and setting procedures for the CMTC module,
see the owner's manual in the vehicle glove box.
DIAGNOSIS AND TESTING - COMPASS
MINI-TRIP COMPUTER
The following diagnostic procedure can be used if
the compass mini-trip computer is not operational in
any way. If the problem is specific to a individual
CMTC display, go to the appropriate display title
noted below and diagnose using the information pro-
vided on how these displays are generated.
(1) Remove the overhead console from the head-
liner (Refer to 8 - ELECTRICAL/OVERHEAD CON-
SOLE - REMOVAL).
(2) Using a ohmmeter, check the ground circuit
cavity of the compass mini-trip computer electricalconnector for proper continuity to ground. Continuity
should be present, If OK go to Step 3, If not OK
repair the open or shorted ground circuit as required.
NOTE: Connect the negative battery cable before
proceeding.
(3) Using a voltmeter, check the fused (B+) circuit
cavity of the compass mini-trip computer electrical
connector for 12v. Voltage should be present, If OK go
to Step 4, If not OK repair the open or shorted fused
(B+) circuit as required.
(4) Using a voltmeter, check the fused ignition
switch output circuit cavity of the compass mini-trip
computer electrical connector for 12v with Key ON.
Voltage should be present, If OK, replace the inoper-
ative CMTC module, If not OK repair the open or
shorted fused ignition switch output circuit as
required.
TEMPERATURE
The compass mini-trip computer receives Program-
mable Communications Interface bus (PCI bus) mes-
sages from the Body Control Module (BCM) for all
displayed information except the compass display. If
a dash (-) is displayed, the compass mini-trip com-
puter is not receiving a PCI bus message from the
BCM. To check out the PCI bus line and the BCM,
use the DRB llltscan tool and proper Body Diagnos-
tic Procedure Manual.
If the compass mini-trip computer displays a tem-
perature more than 54É C (130É F), check for a short
circuit between the temperature sensor and the
BCM.
If the compass mini-trip computer displays a tem-
perature less than -40É C (-67É F), check for an open
circuit between the temperature sensor and the
BCM.
AVERAGE FUEL ECONOMY
The compass mini-trip computer receives average
fuel economy information from the BCM over the PCI
bus line. If the compass mini-trip computer displays
-.- instead of an average fuel economy value, it is not
receiving a PCI bus message for the average fuel
economy from the BCM. To check out the PCI bus
line and the BCM use the DRB llltscan tool and
proper Body Diagnostic Procedure Manual.
DISTANCE TO EMPTY
The compass mini-trip computer receives distance
to empty information from the BCM over the PCI bus
line. If compass mini-trip computer displays a dash
(-) instead of a distance to empty value, it is not
receiving a PCI bus message for the distance to
empty from the BCM. To check out the PCI bus line
8M - 6 MESSAGE SYSTEMSKJ
COMPASS/MINI-TRIP COMPUTER (Continued)