Chrysler Sebring, Stratus sedan, Sebring Convertible. Manual - part 319

(8) Install the wire harness connectors to the Junc-

tion Block.

(9) Install the silencer.
(10) Install the left lower instrument panel trim.
(11) Install the power mirror switch bezel, radio

bezel, and small bezel to the right of the steering col-
umn.

(12) Install the left end cover.
(13) Connect the remote battery negative cable to

the remote terminal on the shock tower.

HEATED SEAT MODULE

DESCRIPTION

Two heated seat modules are used on this vehicle,

one for each front seat. The heated seat modules are
located under each front seat cushion frame (Fig. 2).
The heated seat module has a single connector recep-
tacle that allows the module to be connected to all of
the required inputs and outputs through the body
wire harness.

The heated seat module is an electronic micropro-

cessor controlled device designed and programmed to
use inputs from the ignition switch, the heated seat
switch and the heated seat sensor to operate/control
the heated seat elements in each front seat.

The heated seat module cannot be repaired. If the

heated seat module is damaged or faulty, the entire
module must be replaced.

OPERATION

The heated seat module operates on fused battery

current received from the ignition switch. The mod-
ule is grounded at all times through the body har-
ness.

Inputs

the

module

include

resistor

multiplexed heated seat switch request circuit for
each of the two heated seat switches and the heated
seat sensor inputs from the seat cushions of each
front seat. In response to those inputs the heated
seat module controls battery current feeds to the
heated seat elements and sensors.

When a heated seat switch (Driver or Passenger)

request signal is received by the heated seat module,
the module energizes the selected heated seat sensor
circuit and the sensor provides the module with an
input indicating the surface temperature of the
selected seat cushion.

The Low heat set point is about 38° C (100.4° F),

and the High heat set point is about 42° C (107.6° F).
If the seat cushion surface temperature input is
below the temperature set point for the selected tem-
perature setting, the heated seat module energizes
an N-channel Field Effect Transistor (N-FET) within
the module which energizes the heated seat elements
in the selected seat cushion and back. When the sen-
sor input to the module indicates the correct temper-
ature set point has been achieved, the module
de-energizes

the

N-FET

which

de-energizes

the

heated seat elements. The heated seat module will
continue to cycle the N-FET as needed to maintain
the selected temperature set point.

DIAGNOSIS AND TESTING - HEATED SEAT
MODULE

One heated seat module is located under each front

seat. The drivers side module controls the drivers
heated seat and the passenger controls the passenger
heated seat. The first step in the testing procedure is
to locate the suspect module and unsnap it from the
appropriate seat cushion pan. After the module is
visible, disconnect the modules electrical connector.
Perform the following tests, Refer to Wiring for the
location of complete heated seat system wiring dia-
grams.

(1) Check for 12 volts at the Fused B+ terminal of

the heated seat control module electrical connector. If
OK go to Step 2. If not OK, check the heated seat
cut-out relay, located in the Power Distribution Cen-
ter.

(2) Turn the ignition switch “ON” and check for 12

volts at the switched ignition feed terminal of the
heated seat control module electrical connector. If OK
go to Step 3. If not OK, check the ignition feed circuit
for shorts or opens.

(3) Check for continuity between a known good

ground and the ground wire terminal of the heated
seat control module electrical connector. If OK go to
step 4. If not OK, carefully inspect the harness for an
open or short.

(4) Check the heated seat switch input terminal of

the heated seat control module electrical connector

Fig. 2 HEATED SEAT MODULE

1 - HEATED SEAT MODULE
2 - SEAT CUSHION FRAME

ELECTRONIC CONTROL MODULES

8E - 5

BODY CONTROL MODULE (Continued)

for the proper MUX signal (resistance range of 0-500
ohms, refer to the heated seat switch diagnosis and
testing). If OK replace the heated seat module. If not
OK, test the heated seat switch and harness as
described in this section.

REMOVAL

(1) Move the appropriate power seat track to its

uppermost and rearward-most stop position.

(2) Disconnect and isolate the negative battery

cable.

(3) Reach under the front of the seat cushion and

separate the heated seat module from the seat cush-
ion frame (Fig. 2).

(4) Disconnect the wire harness connector from the

connector receptacle on the back of the heated seat
module.

(5) Remove the heated seat module from the vehi-

cle.

INSTALLATION

(1) Position the heated seat module under the

seat.

(2) Connect the wire harness connector on the

back of the heated seat module.

(3) Reposition the drivers power seat track.
(4) Connect the negative battery cable.

POWERTRAIN CONTROL
MODULE

DESCRIPTION

OPERATION

The Powertrain Control Module (PCM) is a digital

computer containing a microprocessor (Fig. 3). The
PCM receives input signals from various switches
and sensors referred to as Powertrain Control Mod-
ule Inputs. Based on these inputs, the PCM adjusts
various

engine

and

vehicle

operations

through

devices referred to as Powertrain Control Module
Outputs.

NOTE: PCM Inputs:

• Air Conditioning Pressure Transducer

• ASD Relay

• Battery Voltage

• Brake Switch

• Camshaft Position Sensor

• Crankshaft Position Sensor

• Distance Sensor (from transmission control mod-

ule)

• EGR Position Feedback (if equipped)

• Engine Coolant Temperature Sensor

• Heated Oxygen Sensors

• Ignition sense

• Inlet Air Temperature Sensor

• Knock Sensor

• Leak Detection Pump Feedback

• Manifold Absolute Pressure (MAP) Sensor

• Park/Neutral (from trans range sensor)

• PCI Bus

• Power Steering Pressure Switch

• Proportional Purge Sense

• SCI Receive

• Speed Control

• Throttle Position Sensor

• Transmission Control Relay (Switched B+)

• Transmission Pressure Switches

• Transmission Temperature Sensor

• Transmission Input Shaft Speed Sensor

• Transmission Output Shaft Speed Sensor

• Vehicle Speed

NOTE: PCM Outputs:

• Air Conditioning Clutch Relay

• Automatic Shut Down (ASD) and Fuel Pump

Relays

• Data Link Connector (PCI and SCI Transmit)

• Double Start Override

• EGR Solenoid (if equipped)

• Fuel Injectors

• Generator Field

• High Speed Fan Relay

• Idle Air Control Motor

• Ignition Coils

• Leak Detection Pump

• Natural Vacuum Leak Detection

Fig. 3 NGC CONTROLLER

8E - 6

ELECTRONIC CONTROL MODULES

HEATED SEAT MODULE (Continued)

• Low Speed Fan Relay

• MTV Actuator

• Proportional Purge Solenoid

• SRV Valve

• Speed Control Relay

• Speed Control Vent Relay

• Speed Control Vacuum Relay

• Torque Reduction Request

• Transmission Control Relay

• Transmission Solenoids

• 5 Volt Output
Based on inputs it receives, the powertrain control

module (PCM) adjusts fuel injector pulse width, idle
speed, ignition timing, and canister purge operation
and EGR if equipped. The PCM regulates the cooling
fans, air conditioning and speed control systems. The
PCM changes generator charge rate by adjusting the
generator field.

The PCM adjusts injector pulse width (air-fuel

ratio) based on the following inputs.

• Manifold Absolute Pressure

• Engine Speed (crankshaft position sensor)

• Battery Voltage

• Inlet Air Temperature Sensor

• Engine Coolant Temperature

• Exhaust Gas Oxygen Content (heated oxygen

sensors)

• Throttle Position
The PCM adjusts engine idle speed through the

idle air control motor based on the following inputs.

• Brake Switch

• Engine Coolant Temperature

• Engine Speed (crankshaft position sensor)

• Park/Neutral

• Transaxle Gear Engagement

• Throttle Position

• Vehicle Speed (from Transmission Control Mod-

ule)

The PCM adjusts ignition timing based on the fol-

lowing inputs.

• Inlet Air Temperature

• Engine Coolant Temperature

• Engine Speed (crankshaft position sensor)

• Knock Sensor

• Manifold Absolute Pressure

• Park/Neutral (from trans range sensor)

• Transaxle Gear Engagement

• Throttle Position
The automatic shut down (ASD) and fuel pump

relays are mounted externally, but turned on and off
by the powertrain control module.

The camshaft and crankshaft signals are sent to

the powertrain control module. If the PCM does not
receive both signals within approximately one second
of engine cranking, it deactivates the ASD and fuel
pump relays. When these relays are deactivated,

power is shut off to the fuel injectors, ignition coils,
fuel pump and the heating element in each oxygen
sensor.

The

PCM

contains

voltage

converter

that

changes battery voltage to a regulated 5.0 volts. The
5.0 volts power the camshaft position sensor, and
crankshaft position sensor. The PCM also provides a
regulated 5.0 volts supply for the, manifold absolute
pressure sensor, throttle position sensor and EGR (if
equipped).

The PCM engine control strategy prevents reduced

idle speeds until after the engine operates for 320 km
(200 miles). If the PCM is replaced after 320 km (200
miles) of usage, update the mileage in new PCM. Use
the scan tool to change the mileage in the PCM.
Refer to the appropriate Powertrain Diagnostic Man-
ual and the scan tool. If equipped with SKIM, must
use SKIM function to program VIN number in new
PCM.

TRANSMISSION CONTROL

CVI CALCULATION

An important function of the PCM is to monitor

Clutch Volume Index (CVI). CVIs represent the vol-
ume of fluid needed to compress a clutch pack.

The PCM monitors gear ratio changes by monitor-

ing the Input and Output Speed Sensors. The Input,
or Turbine Speed Sensor sends an electrical signal to
the PCM that represents input shaft rpm. The Out-
put Speed Sensor provides the PCM with output
shaft speed information.

By comparing the two inputs, the PCM can deter-

mine transaxle gear ratio. This is important to the
CVI calculation because the PCM determines CVIs
by monitoring how long it takes for a gear change to
occur (Fig. 4).

Gear ratios can be determined by using the scan

tool and reading the Input/Output Speed Sensor val-
ues in the “Monitors” display. Gear ratio can be
obtained by dividing the Input Speed Sensor value by
the Output Speed Sensor value.

For example, if the input shaft is rotating at 1000

rpm and the output shaft is rotating at 500 rpm,
then the PCM can determine that the gear ratio is
2:1. In direct drive (3rd gear), the gear ratio changes
to 1:1. The gear ratio changes as clutches are applied
and released. By monitoring the length of time it
takes for the gear ratio to change following a shift
request, the PCM can determine the volume of fluid
used to apply or release a friction element.

The volume of transmission fluid needed to apply

the friction elements are continuously updated for
adaptive controls. As friction material wears, the vol-
ume of fluid need to apply the element increases.

ELECTRONIC CONTROL MODULES

8E - 7

POWERTRAIN CONTROL MODULE (Continued)

Certain mechanical problems within the clutch

assemblies (broken return springs, out of position
snap rings, excessive clutch pack clearance, improper
assembly, etc.) can cause inadequate or out-of-range
clutch volumes. Also, defective Input/Output Speed
Sensors and wiring can cause these conditions. The
following chart identifies the appropriate clutch vol-
umes and when they are monitored/updated:

CLUTCH VOLUMES

Clutch

When Updated

Proper Clutch

Volume

Shift Sequence

Oil Temperature

Throttle Angle

L/R

2-1 or 3-1 coast

downshift

> 70°

< 5°

35 to 83

2/4

1-2 shift

> 110°

5 - 54°

20 to 77

2-3 shift

48 to 150

4-3 or 4-2 shift

> 5°

24 to 70

Fig. 4 Example of CVI Calculation

1 - OUTPUT SPEED SENSOR
2 - OUTPUT SHAFT
3 - CLUTCH PACK
4 - SEPARATOR PLATE
5 - FRICTION DISCS
6 - INPUT SHAFT
7 - INPUT SPEED SENSOR
8 - PISTON AND SEAL

8E - 8

ELECTRONIC CONTROL MODULES

POWERTRAIN CONTROL MODULE (Continued)

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