Chrysler Sebring, Stratus sedan, Sebring Convertible. Manual - part 726

trouble codes (DTC’s) are stored in the body control
module (BCM). DTC’s pertaining to A/C compressor
control circuits and radiator fan control circuits are
stored in the powertrain control module (PCM). Both
systems can be diagnosed by either the DRBIII

t scan

tool or by using the vehicles own diagnostic display
system.

NOTE: When using the DRBIII

scan tool, refer to

the DRBIII

menu for DTC listings.

There are three DTC tables shown. These DTC

tables are to be used when diagnosing the ATC and
MTC system using only the vehicles diagnostic dis-
play. The DTC’s cover operation of the climate control
door actuators, ambient temperature sensor, in-car
temperature sensor, and the A/C-heater control head.
The ATC/MTC DTC table contains faults that are
common to both the ATC and the MTC systems. The
ATC DTC table covers DTC’s that only pertain to
only the ATC system and the MTC DTC table has
DTC’s that pertain to only the MTC system.

DIAGNOSTIC TROUBLE CODES (DTC’s)

ATC/MTC DTC’S

CODE

DESCRIPTION

BLEND DOOR ACTUATOR
FEEDBACK FAILURE

MODE DOOR ACTUATOR
FEEDBACK FAILURE

AMBIENT TEMPERATURE SENSOR

RECIRCULATION DOOR ACTUATOR
STALL FAILURE

BLEND DOOR ACTUATOR STALL
FAILURE

MODE DOOR ACTUATOR STALL
FAILURE

EVAPORATOR TEMPERATURE
SENSOR FAILURE

BLEND DOOR ACTUATOR OUTPUT
SHORTED TO BATTERY

BLEND DOOR ACTUATOR OUTPUT
SHORTED TO GROUND

MODE DOOR ACTUATOR OUTPUT
SHORTED TO BATTERY

MODE DOOR ACTUATOR OUTPUT
SHORTED TO GROUND

RECIRCULATION DOOR ACTUATOR
OUPUT SHORTED TO BATTERY

RECIRCULATION DOOR ACTUATOR
OUTPUT SHORTED TO GROUND

CODE

DESCRIPTION

COMMON DOOR OUTPUT
SHORTED TO BATTERY

COMMON DOOR OUTPUT
SHORTED TO GROUND

SYSTEM VOLTAGE TOO LOW FOR
DOOR CALIBRATION

ATC DTC’S

CODE

DESCRIPTION

ATC IN-CAR TEMPERATURE
THERMISTER FAILURE

ATC IN-CAR SENSOR FAILURE

ENGINE TEMPERATURE MESSAGE
NOT RECEIVED

ATC CONTROL COMMUNICATION
FAILURE

MTC DTC’S

CODE

DESCRIPTION

A/C CONTROL BLEND DOOR
INPUT OPEN OR SHORTED TO
GROUND

A/C CONTROL BLEND DOOR
SHORTED TO BATTERY

A/C CONTROL - A/C SWITCH
FAILURE

A/C CONTROL MODE DOOR
INPUT SHORTED TO GROUND

A/C CONTROL MODE DOOR
INPUT SHORTED TO BATTERY

A/C CONTROL ELECTRIC
BACKLITE (EBL) SWITCH FAILURE

Climate Control Preliminary DTC Check

(1) Clear any DTC’s.
(2) Operate all HVAC system controls with the

engine running at normal operating temperature.

(3) Check for any DTC’s and perform the required

diagnostics if the DTC reappears. Refer to the appro-
priate Diagnostic Information.

HEATING & AIR CONDITIONING

24 - 3

HEATING & AIR CONDITIONING (Continued)

CAUTION: DTC 26 can be created if the in-car tem-
perature sensor is disconnected while the BCM is
operating. This can happen by disconnecting con-
nectors from the BCM or the ATC A/C-heater control
with the battery connected (even with the ignition
switch in the OFF position). To correct, clear DTC
26 from the BCM.

NOTE: Removing connections without disconnect-
ing the battery may generate a DTC. The negative
battery cable should always be disconnected prior
to servicing any electrical component.

If a DTC does not reappear using the procedure

above, check the history of the vehicle for a low bat-
tery condition, or ambient temperatures below 4° C
(40° F).

TROUBLE CODES FROM THE ATC CONTROL

The DTC’s can be checked with the ATC control if

a DRBIII

t scan tool is not available. The DTC’s are

stored in the BCM. The A/C-heater control can only
be placed into the diagnostic mode while the engine
is running and the vehicle is not moving. Set the
A/C-heater control to a 24° C (75° F) setting (so there
is no confusion with DTCs 23 - 51) (Fig. 2).

NOTE: It is important that no other control knob or
button is pushed until all DTC’s are read. Pushing
any control button except Panel Mode or turning
the blower fan control knob will end the diagnostic
test without showing the rest of the DTC’s. There
also may be other DTC’s stored in the BCM not
related to the climate control system. These DTC’s
can only be found using the DRBIII

scan tool.

To place the ATC system into diagnostic mode,

press and hold the Floor, Mix and Defrost buttons (at
the same time). The ATC control display will begin to
blink. Release the Floor, Mix and Defrost buttons.
Once the A/C-heater control enters the diagnostic
mode, the display on the A/C-heater control will con-
tinue to blink until it completes an error check and a
climate control door calibration. Then it will display
any DTC’s that are present in the BCM related to
the climate control system. If there are no climate
control related DTC’s, the ATC system will return to
its normal operation as indicated by the temperature
symbol (C or F). DTC’s related to the ATC system
will appear on the display in numerical form. The
ATC control can only show one DTC at a time. Under
certain circumstances, more than one DTC could be
in the memory. To scroll through any additional
DTC’s, press the Panel Mode button on the ATC con-
trol.

TROUBLE CODES FROM THE MTC CONTROL

The DTC’s can be checked with the MTC control

and the Odometer Display of the Mechanical Instru-
ment Cluster if a DRBIII

t scan tool is not available.

The MTC control can only be placed into the diagnos-
tic mode while the engine is running and the vehicle
is not moving. To place the system into it’s diagnostic
mode, adjust the MTC control to the following set-
tings: (Fig. 3)

(1) The engine must be running with vehicle not

moving.

(2) The fan speed set to any speed except OFF.
(3) The temperature control knob in full cold (full

counterclockwise position).

(4) The mode control knob must be placed in

Defrost position (full clockwise position).

(5) The A/C button can be On or Off.
(6) Press and hold the rear window defogger (EBL)

button

until

the

mechanical

instrument

cluster

odometer display indicates an “AC00”. The BCM will
chime once and the MTC A/C button LED will begin
blinking.

(7) Release the EBL button and wait until the

MTC A/C button LED stops blinking. This means
that the error check and climate control door calibra-
tion is complete.

Fig. 2 Entering Self-Diagnostic Mode

1 - PRESS BUTTONS SIMULTANEOUSLY

Fig. 3 MTC Control Head

24 - 4

HEATING & AIR CONDITIONING

HEATING & AIR CONDITIONING (Continued)

NOTE: It is important that no other control knob or
button is pushed until all DTC’s are read. Pushing
any button except the A/C button or turning a con-
trol knob will end the diagnostic test without show-
ing the rest of the DTC’s. There also may be other
DTC’s stored in the BCM not related to the climate
control system. These DTC’s can only be found
using the DRBIII

scan tool.

DTC’s related to the MTC control head will appear

on the odometer display in numerical form after the
letters “AC”. The odometer display will return to nor-
mal operation if no DTC’s are found. If a problem is
found, then the odometer will display the letters
“A/C” followed by the DTC number. The odometer
display can only show one DTC at a time. Under cer-
tain circumstances, more than one DTC could be in
the memory. To scroll through any additional DTC’s,
press the A/C button on the MTC control. The BCM
will beep each time the A/C button is pushed. Con-
tinue pushing the A/C button and recording the
DTC’s until the odometer returns to normal opera-
tion (note the letters AC will disappear).

ERASING DIAGNOSTIC TROUBLE CODES (DTC’s)

DTC’s can be cleared from the BCM two ways:
• Using a DRBIIIt scan tool

• Disconnecting the negative battery cable for ten

minutes.

If a DRBIII

t scan tool is to be used, refer to the

appropriate Diagnostic Information.

A/C PERFORMANCE

The A/C system is designed to provide the passen-

ger compartment with low temperature and low
humidity air. The A/C evaporator, located in the
HVAC housing is cooled to temperatures near the
freezing point. As warm damp air passes over the
fins of the A/C evaporator, the air transfers its heat
to the refrigerant in the evaporator coils and the
moisture in the air condenses on the evaporator fins.
During periods of high heat and humidity, an A/C
system will be more effective in the Recirculation
mode (max-A/C). With the system in the Recircula-
tion mode, only air from the passenger compartment
passes through the A/C evaporator. As the passenger
compartment air dehumidifies, the A/C system per-
formance levels rise.

Humidity has an important bearing on the temper-

ature of the air delivered to the interior of the vehi-
cle. It is important to understand the effect that
humidity has on the performance of the A/C system.
When humidity is high, the A/C evaporator has to
perform a double duty. It must lower the air temper-
ature, and it must lower the temperature of the
moisture in the air that condenses on the evaporator
fins. Condensing the moisture in the air transfers

heat energy into the evaporator fins and coils. This
reduces the amount of heat the A/C evaporator can
absorb from the air. High humidity greatly reduces
the ability of the A/C evaporator to lower the temper-
ature of the air.

However, evaporator capacity used to reduce the

amount of moisture in the air is not wasted. Wring-
ing some of the moisture out of the air entering the
vehicle adds to the comfort of the passengers.
Although, an owner may expect too much from their
A/C system on humid days. A performance test is the
best way to determine whether the system is per-
forming up to design standards. This test also pro-
vides valuable clues as to the possible cause of
trouble with the A/C system. The ambient air tem-
perature of the vehicle and the location where the
vehicle will be tested must be a minimum of 21° C
(70° F) for this test. Also the evaporator temperature
sensor probe (located between the evaporator fins)
must be a minimum of 18° C (65° F) for this test as
well.

PERFORMANCE TEST PROCEDURE

WARNING: Refer to the applicable warnings and
cautions for this system before performing the fol-
lowing operation (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - WARNINGS) and (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
CAUTIONS). Failure to follow the warnings and cau-
tions could result in possible personal injury or
death.

NOTE: When connecting the service equipment
coupling to the line fitting, verify that the valve of
the coupling is fully closed. This will reduce the
amount of effort required to make the connection.

(1) Perform the Heating and A/C System Self

Diagnostics (Refer to 24 - HEATING & AIR CONDI-
TIONING - DIAGNOSIS AND TESTING - HEATING
AND A/C SELF DIAGNOSTICS). If no diagnostic
trouble codes (DTCs) are found in the body control
module (BCM) or the powertrain control module
(PCM), go to Step 2. If any DTCs are found, repair as
required, then proceed to Step 2.

(2) Connect a tachometer and a manifold gauge set

and adjust the heating-A/C controls as outlined
below.

HEATING & AIR CONDITIONING

24 - 5

HEATING & AIR CONDITIONING (Continued)

NOTE: The ambient air temperature of the vehicle
and the location where the vehicle will be tested
must be a minimum of 21° C (70° F) before perform-
ing this test. Also the evaporator temperature sen-
sor must be a minimum of 18° C (65° F) for this test
as well. If the vehicle has been sitting in the sun
prior to testing, place the vehicle in the testing area
until the temperature within the vehicle reaches a
minimum of 18° C (65° F).

Manual Temperature Control (MTC) System

• Blower motor control to the highest speed posi-

tion.

• Temperature control to the full cool position.

• Mode control to the Recirculation (max-A/C)

position.

• A/C control to the ON position.

Automatic Temperature Control (ATC) System

• Blower motor control to the highest speed posi-

tion.

• Temperature control to the LO position.

• Recirculation control ON (A/C and RECIRC sym-

bols should be lit).

• Mode control to PANEL position.

NOTE: The word MANUAL should appear in the ATC
display, confirming that the system is set manually.

(3) Start the engine and hold the idle at 1,000 rpm

with the compressor clutch engaged. If the A/C com-
pressor does not engage, see the A/C Pressure Diag-
nosis chart.

(4) The engine should be warmed to operating

temperature with the doors closed and windows
open.

(5) Insert a thermometer in the driver side center

panel outlet and operate the A/C system until it sta-
bilizes.

(6) Start the engine and hold the idle at 1,000 rpm

with the compressor clutch engaged. If the A/C com-
pressor does not engage, see the A/C Diagnosis chart.

(7) With the A/C compressor clutch engaged, com-

pare the air temperature at the center panel outlet
and the compressor discharge pressure (high side) to
the A/C Performance and Pressure chart. The com-
pressor clutch may cycle, depending upon the ambi-
ent temperature and humidity. If the clutch cycles,
use the readings obtained before the clutch disen-
gaged.

A/C PERFORMANCE TEMPERATURE AND PRESSURE

AMBIENT TEMPERATURE

21°C

(70°F)

26.5°C

(80°F)

32.5°C

(90°F)

37°C

(100°F)

43°C

(110°F)

MAXIMUM ALLOWABLE AIR
TEMPERATURE AT CENTER
LEFT PANEL OUTLET

6°C

(42°F)

7°C

(45°F)

10°C

(50°F)

12°C

(54°F)

15°C

(59°F)

COMPRESSOR DISCHARGE
PRESSURE

1379–1585

kPa

(200–230

psi)

1448–1723

kPa

(210–250

psi)

1654–1930

kPa

(240–280

psi)

1930–2206

kPa

(280–320

psi)

2206–2516

kPa

(320–365 psi)

COMPRESSOR SUCTION
PRESSURE

103–172 kPa

(15–25 psi)

139–208 kPa

(20–30 psi)

172–241 kPa

(25–35 psi)

208–276 kPa

(30–40 psi)

241–310 kPa

(35–45 psi)

24 - 6

HEATING & AIR CONDITIONING

HEATING & AIR CONDITIONING (Continued)

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