Chrysler PT Cruiser. Manual — part 490
HEATED SEAT SYSTEM DIAGNOSIS
CONDITION
POSSIBLE CAUSES
CORRECTION
NO HEATED SEAT SWITCH
ILLUMINATION WITH
IGNITION ON
1. Faulty fuse.
1. Check heated seat fuse in Junction Block (JB).
Replace fuse, if required.
2. Wiring faulty.
2. Check fused ignition switch output (run-acc)
circuit from heated seat switch connector to
ignition switch. Repair, if required.
3. Ground faulty.
3. Check for ground at heated seat switch
connector. Repair, if required.
4. Faulty switch.
4. Refer to Heated Seat Switch for the proper
switch diagnosis and testing procedures.
SEATS HEAT, BUT NO
HEATED SEAT SWITCH
INDICATORS
1. Wiring faulty.
1. Check LED driver circuit(s) from heated seat
switch connector to heated seat module
connector. Repair, if required.
2. Faulty switch LED.
2. Replace switch with known good unit. If OK,
discard faulty switch.
3. Faulty module.
3. Refer to Heated Seat Module for the proper
module diagnosis and testing procedures.
Replace, if required.
SEATS DO NOT HEAT AND
NO HEATED SEAT SWITCH
INDICATORS
1. Faulty circuit breaker.
1. Check power seat circuit breaker in Junction
Block (JB). Replace, if required.
2. Faulty relay.
2. Refer to Heated Seat Relay for the proper
relay diagnosis and testing procedures. Replace,
if required.
3. Faulty module.
3. Refer to Heated Seat Module for the proper
module diagnosis and testing procedures.
Replace, if required.
HEATED SEAT SWITCH
INDICATORS FLASHING
1. Faulty sensor.
1. Refer to Heated Seat Sensor for the proper
heated seat system self-diagnostic routine.
Repair, as required.
2. Faulty element.
2. Refer to Heated Seat Element for the proper
heated seat system self-diagnostic routine.
Repair, as required.
SELF-DIAGNOSTICS - HEATED SEAT SYSTEM
The heated seat system is capable of performing
some self-diagnostics. The following table depicts the
various failure modes which will be reported to the
occupant via flashing of the heated seat switch Light-
Emitting Diode (LED) indicators. Flashing LED indi-
cators on the driver side switch indicate that a fault
exists in the driver side of the system and, likewise,
flashing LED indicators on the passenger side switch
indicate a fault exists in the passenger side of the
system. The LED indicators will flash at a rate of
approximately one-half second on, and one-half sec-
ond off for a duration of one minute. This process
will repeat each time an attempt is made to turn the
system on with the heated seat switches until the
problem has been corrected.
8G - 10
HEATED SEAT SYSTEM
PT
HEATED SEAT SYSTEM (Continued)
HEATED SEAT SYSTEM SELF-DIAGNOSTIC TABLE
FAILURE MODE
SWITCH
9
HI
9
LED
INDICATOR
SWITCH
9
LO
9
LED INDICATOR
Shorted Heating Element
Flashing
Flashing
Open Heating Element
Flashing
Off
NTC Sensor Value Out of Range
Off
Flashing
DRIVER HEATED SEAT
SWITCH
DESCRIPTION
The heated seat switches are located on the out-
board cushion side shield of the driver (Fig. 2) and
passenger seats. The two, momentary rocker type
switches provide a resistor multiplexed signal to the
Heated Seat Module (HSM) through separate hard
wired circuits. Each switch contains two light emit-
ting diodes (LED), one for each High and Low setting
to let the occupant know that the seat heater system
is on.
The heated seat switches and their LED’s cannot
be repaired. If either switch is faulty or damaged the
entire switch must be replaced.
OPERATION
There are three modes that can be selected with
each of the heated seat switches: Off, Low, and High.
When the front of the switch rocker is depressed, the
High mode is selected and the high mode LED indi-
cator illuminates. Depressing the front of the switch
rocker a second time will turn the heated seat to Off.
When the rear of the switch rocker is depressed, the
Low mode is selected and the low mode LED indica-
tor illuminates. Depressing the rear of the switch
rocker a second time will also turn the heated seat to
Off. In addition, the heated seats will automatically
return to the Off mode anytime the vehicle ignition
switch is turned Off.
Both switches provide separate resistor multi-
plexed hard wire inputs to the Heated Seat Module
to indicate the selected mode. The Heated Seat Mod-
ule responds to the heated seat switch status mes-
sages by controlling the output to the seat heater
elements of the selected seat. The Low heat position
set point is about 36° C (97° F), and the High heat
position set point is about 41° C (105° F).
DIAGNOSIS AND TESTING - DRIVER HEATED
SEAT SWITCH
For circuit description and diagrams, refer to Wir-
ing Diagrams.
Inspect the Heated Seat Switches for apparent
damage or sticking/binding and replace if required.
Refer to Heated Seat Switch Removal and Installa-
tion in this section.
Using an ohmmeter, check the continuity between
pin 4 and pin 6 of the switch. Measure the resistance
between the two pins while depressing the appropri-
ate button. Refer to (Fig. 3) and the Heated Seat
Switch Pin Call-Out table. If the readings do not cor-
respond to those in the Heated Seat Switch Continu-
ity table, replace the heated seat switch.
Fig. 2 PT Heated Seat Switch Location
1 - HEATED SEAT SWITCH
2 - SEAT CUSHION SIDE SHIELD
PT
HEATED SEAT SYSTEM
8G - 11
HEATED SEAT SYSTEM (Continued)
HEATED SEAT SWITCH PIN CALL-OUT
PIN
FUNCTION
1
LO LED
2
OPEN
3
GROUND
4
IGNITION FEED
5
HI LED
6
REQUEST LINE
TESTING HEATED SEAT SWITCH CONTINUITY
CONTINUITY
BETWEEN
SWITCH
POSITION
READING
PIN 4 AND 6
OFF
2.2 Kilohms
(2200 Ohms)
PIN 4 AND 6
LO
.415 Kilohms
(415 Ohms
PIN 4 AND 6
HI
33 Ohms
REMOVAL
(1) Disconnect and isolate the negative battery
cable remote terminal from the remote battery post.
(2) Remove the appropriate seat cushion side
shield. Refer to the Body section of this manual for
the procedure.
(3) Working from the underside of the switch, gen-
tly rock the switch back and forth out of its mounting
location.
INSTALLATION
(1) Gently rock the switch back and forth in to its
mounting location.
(2) Install the appropriate seat cushion side shield.
Refer to the Body section of this manual for the pro-
cedure.
(3) Connect the remote negative battery cable.
HEATED SEAT ELEMENT
DESCRIPTION
The heated seat system includes two seat heating
elements in each front seat, one for the seat cushion
(Fig. 4) and the other for the seat back. All models
use two carbon fiber mesh heating elements for each
seat that are connected in parallel with the Heated
Seat Module (HSM). The temperature sensor is a
Negative Temperature Coefficient (NTC) thermistor.
One temperature sensor is used for each seat, and it
is located in the seat cushion heating element for all
models.
The seat heating elements are glued onto the seat
and seat back cushions. The heated seat elements
and the temperature sensor cannot be adjusted or
repaired and, if faulty or damaged a new service part
must be installed. Refer to the procedure in this sec-
tion.
Fig. 3 Heated Seat Switch (Rear View)
Fig. 4 Heated Seat Element - Typical
1 - SEAT BACK WIRE HARNESS
2 - HEATED SEAT WIRE HARNESS CONNECTOR
3 - HEATED SEAT CUSHION ELEMENT
8G - 12
HEATED SEAT SYSTEM
PT
DRIVER HEATED SEAT SWITCH (Continued)
OPERATION
The heated seat elements resist the flow of electri-
cal current. When battery current is passed through
the elements, the energy lost by the resistance of the
elements is released in the form of heat. The temper-
ature sensor is a NTC thermistor. The heated seat
module supplies a five-volt current to one side of
each sensor, and monitors the voltage drop through
the sensor on a return circuit. When the temperature
of the seat cushion cover rises, the resistance of the
sensor decreases. The heated seat module uses this
temperature sensor input to monitor the temperature
of the seat, and regulates the current flow to the seat
heating elements accordingly.
DIAGNOSIS AND TESTING - HEATED SEAT
ELEMENT
For complete circuit diagrams, refer to Wiring
Diagrams.
NOTE: When checking heated seat elements for
continuity, be certain to move the heating element
being checked. Moving the element, such as sitting
in the seat will eliminate the possibility of an inter-
mittent open in the element which would only be
evident if the element was in a certain position.
Failure to check the element in various positions
could result in an incomplete test.
(1) Disconnect and isolate the battery negative
cable. Disconnect the heated seat module wire har-
ness connector. Check for continuity between the seat
heater B+ driver circuit cavity and a good ground,
preferably under the seat. There should be continu-
ity, less than 7 ohms. If OK, go to Step 2. If not OK,
replace the heating element assembly.
(2) Check for continuity between the seat heater
B+ driver circuit cavity and the seat back frame.
There should be no continuity. If OK, go to Diagnosis
and Testing the heated Seat Module in the electronic
control modules section of this service manual for
additional diagnostics. If not OK, replace the element
as required.
REMOVAL
Do not attempt to remove the heating element
from the seat or seat back cushion. The original ele-
ment is permanently attached to the seat cushions
and cannot be removed without damaging the cush-
ion. The service replacement (if available) heating
elements are designed to be applied directly over the
original seat heating elements.
(1) Disconnect and isolate the negative battery
cable.
(2) Remove the appropriate seat cushion or seat
back trim cover. Refer to the Body section of the ser-
vice manual for the procedures.
(3) Disconnect the inoperative heated seat cushion
or seat back element electrical connectors.
(4) Locate the wires leading from the inoperative
heating element and cut them off flush with the edge
of the original heating element.
INSTALLATION
(1) Peel off the adhesive backing on the back of the
replacement heating element and stick directly over
the original heating element (Fig. 5).
CAUTION: During the installation of the replace-
ment heating element, be careful not to fold or
crease the element assembly. Folds or creases will
cause premature failure.
(2) Connect the new heating element electrical
connectors (Fig. 6).
(3) Connect the negative battery cable.
(4) Verify heated seat system operation.
(5) Install the appropriate seat cushion or seat
back trim cover. Make certain the seat wire harness
is correctly routed through the seat and seat back.
The excess wire between the cushion and back ele-
ments should be securely tucked between the rear of
the cushion foam and the rear carpet flap of the trim
cover.
Fig. 5 Heated Seat Element Installation
1 - ORIGINAL (INOPERATIVE) HEATING ELEMENT
2 - REPLACEMENT HEATING ELEMENT
PT
HEATED SEAT SYSTEM
8G - 13
HEATED SEAT ELEMENT (Continued)
Нет комментариевНе стесняйтесь поделиться с нами вашим ценным мнением.
Текст