ESP DODGE RAM SRT-10 2006 Service Repair Manual

3.CHECK FOR NORMAL A/C MODE SWITCH & STATUS INDICATOR FUNCTION
Turn the ignition on.
Turn the blower control on.
Press the A/C mode switch on and off several times while observing the A/C status indicator.
Does the A/C status indicator turn on and off with respect to the switch position?
Ye s>>
Go To 4
No>>
Replace the A/C Heater Control in accordance with the Service Information.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES - STANDARD PROCEDURE).
4.VERIFY THAT DTC B1001–A/C SWITCH REQUEST INPUT CIRCUIT LOW IS STILL ACTIVE
Turn the blower control off.
With the scan tool, erase HVAC DTCs.
Turn the ignition off, wait 10 seconds, and then turn the ignition on. Wait two minutes before proceeding.
With the scan tool, read HVAC DTCs.
Does the scan tool display active: B1001–A/C SWITCH REQUEST INPUT CIRCUITLOW?
Ye s>>
Replace the A/C Heater Control in accordance with the Service Information.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES - STANDARD PROCEDURE).
No>>
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES - STANDARD PROCEDURE).

3.CHECK FOR NORMAL REAR DEFROST MODE SWITCH & STATUS INDICATOR FUNCTION
Turn the ignition on.
Press the Rear Defrost mode switch on and off several times while observingthe status indicator.
Does the Rear Defrost status indicator turn on and off with respect to the switch position?
Ye s>>
Go To 4
No>>
Replace the A/C Heater Control in accordance with the Service Information.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES - STANDARD PROCEDURE).
4.VERIFY THAT DTC B1016–REAR DEFROST SWITCH REQUEST INPUT CIRCUIT LOW IS STILL ACTIVE
With the scan tool, erase HVAC DTCs.
Turn the ignition off, wait 10 seconds, and then turn the ignition on. Wait two minutes before proceeding.
With the scan tool, read HVAC DTCs.
Does the scan tool display active: B1016–REAR DEFROST SWITCH REQUEST INPUT CIRCUIT LOW?
Ye s>>
Replace the A/C Heater Control in accordance with the Service Information.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES - STANDARD PROCEDURE).
No>>
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES - STANDARD PROCEDURE).

B1079–CLIMATE CONTROL COOL DOWN TEST EXCESSIVE TIME (SINGLE-ZONE)
For a complete wiring diagramRefer to Section 8W.
Theory of Operation
The Cooldown Test checks A/C system performance based on Evaporator Temperature Sensor input. The main cri-
teria is to lower evaporator temperature 11.11°C (20°F) within one minute. Before starting the test, the evaporator
temperature must be above 13°C (55°F) and the front blower speed must be setto high speed. When the test is
running, A/C Select and A/C Request will be on and the A/C status indicator will flash. When the test is complete,
the scan tool will display one or more test status messages to indicate the outcome of the Cooldown Test. A Suc-
cessful Cooldown – Test Passed status message indicates that the main testcriteria was met. A DTC Set During
Routine – Test Not Passed status message indicates that the A/C system is unable to lower the evaporator tem-
perature 11.11°C (20°F) within one minute. A Conditions Too Cold – Test NotRun status message indicates that the
evaporator temperature was below 13°C (55°F) when starting the Cooldown Test. A Blowers Not On High – Test Not
Run status message indicates that either the front blower speed was not setto high speed prior to starting the
Cooldown Test or the front blower speed was changed from high speed to another setting after starting the
Cooldown test. A Refrigerant Temperature Sensor Error status message indicates that a fault occurred with the
Evaporator Temperature Sensor/sensor circuits. A No Results Stored/Test Not Complete status message indicates
that the power was cycled while the test was running.
When Monitored:
When the Cooldown Test is executed.
Set Condition:
If the A/C system is unable to lower the evaporator temperature 11.11°C (20°F) within one minute.
Possible Causes
OTHER HVAC SYSTEM FAULTS PRESENT
EVAPORATOR TEMPERATURE SENSOR CIRCUITS
EVAPORATOR TEMPERATURE SENSOR
TOTALLY INTEGRATED POWER MODULE (TIPM) FAULTS PRESENT
POWERTRAIN SYSTEM FAULTS PRESENT
Diagnostic Test
1.DIAGNOSE COOLDOWN TEST STATUS MESSAGES
WereanyofthefollowingstatusmessagespresentafterperformingtheCooldown Test?
Yes, Conditions Too Cold - Test Not Run
If running, turn the A/C compressor off. Verify that the work area ambient temperature is above 15.6°C
(60°F). If not, move the vehicle to a warmer work area. Verify that the evaporator temperature is above
13°C (55°F). If not, set the blower to high speed and allow the blower to run for five minutes. Then, run
the Cooldown Test again.
Yes, Blowers Not On High - Test Not Run
Set the blower speed to high speed and then run the Cooldown Test again.
Yes, No Results Stored/Test Not Complete
Verify that power is not interrupted while rerunning the Cooldown Test.
No>>
Go To 2

*HVAC SYSTEM TEST
For a complete wiring diagramRefer to Section 8W.
Theory of Operation
The HVAC System Test provides a starting point in the diagnostic process byidentifying the appropriate diagnostic
procedure or system test to perform when diagnosing a given symptom, condition, or DTC. It also provides a means
for testing the entire HVAC system byutilizing the A/C-heater control’s On-Board System Tests. The On-Board Sys-
tem Tests can also assist in diagnosing stored DTCs. (Refer to 24 - HEATING &AIR CONDITIONING - DIAGNOSIS
AND TESTING) for additional information about on-board diagnostics.
Diagnostic Test
1.HVAC SYSTEM TEST
NOTE: Diagnose and repair all active DTCs before diagnosing and repairingstored DTCs.
Make a selection based on the symptom, condition, or DTC that you want to diagnose.
For Any Active DTC
Refer to the Table of Contents in this Section for a complete list of HVAC related symptoms.
Scan Tool Indicates HVAC Not Active On Bus
(Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING) for no
response related diagnostic procedures.
Blower Motor Inoperative
Refer to *Blower Motor Inoperative in this Section.
Complete HVAC System Test
Go To 2
A/C System Performance Test
Go To 2
Mode Switch & Door Actuator Ckt Test
Go To 3
Actuator DTC Detection Test
Go To 4
Actuator Calibration Test
Go To 5
2.A/C SYSTEM PERFORMANCE TEST
NOTE: The following are prerequisites of the Cooldown Test. Verify each ofthe following before running the
test:
If active, diagnose and repair Evaporator Temperature Sensor related DTCs before proceeding. Refer to
the Table of Contents in this Section for a complete list of HVAC related symptoms.
Verify that the refrigerant system has an adequate charge. Check and repair as necessary before pro-
ceeding. (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - DIAGNOSIS ANDTESTING).
Verify that the blower motor operates correctly in all speeds. Diagnose and repair all blower related faults
before proceeding.
Verify that the work area ambient temperature is above 15.6°C (60°F) before proceeding. Move the vehicle
to a warmer work area if necessary.
Verify that the evaporator temperature is above 13°C (55°F) before proceeding.
Verify that the Mode Select control is set to the panel position.
Verify that the A/C compressor is not running. If the compressor is running, turn the A/C off and allow the
evaporator to warm up before proceeding.
NOTE: Running the AC Cooldown test will cause the A/C status indicator to flash.
NOTE: One or more status messages will display on the scan tool after running the Cooldown Test. These
messages will clear after paging back out of this test function. Therefore, it is important to note all mes-
sages before doing so.
Start the engine.
Turn the Blower control to the high speed position.

ACTUATOR-BLEND DOOR
DESCRIPTION
The blend door actuators are reversible, 12-volt direct
current (DC), servo motors. Models with the single
zone heating-A/C system have a single blend-air door,
which is controlled by a single blend door actuator.
Models with the dual zone system have two blend-air
doors, which are controlled by two blend door actua-
tors.
The blend door actuator (1) for the single zone heat-
ing-A/C system is located near the center of the HVAC
housing (2), close to the dash panel.
For the dual zone heating-A/C system, the same
blend door actuator used for the single zone system
becomes the driver side blend door actuator, which is
mechanically connected to only the driver side blend-
air door. A second separate blend door actuator (3)
located on the top of the HVAC housing is mechani-
cally connected to the passenger side blend-air door.
All actuators (1) are interchangeable with each other.
Each actuator is contained within an identical black
molded plastic housing with an integral wire connector
receptacle (2). Each actuator also has an identical
output shaft with splines (3) that connect it to its
respective door linkage and three integral mounting
tabs (4) that allow the actuator to be secured to the
HVAC housing. The blend door actuators do not
require mechanical indexing to the blend-air doors, as
they are electronically calibrated by the A/C-heater
control.
OPERATION
The blend door actuators are connected to the A/C-heater control through the vehicle electrical system by a dedi-
cated two-wire lead and connector of the HVAC wire harness. The blend door actuator(s) can move the blend-air
door(s) in two directions. When the A/C-heater control pulls the voltage on one side of the motor connection high
and the other connection low, the blend-air door will move in one direction. When the A/C-heater control reverses
the polarity of the voltage to the motor, the blend-air door moves in the opposite direction.
When the A/C-heater control makes the voltage to both connections high or both connections low, the blend-air door
stops and will not move. The A/C-heater control uses a pulse-count positioning system to monitor the operation and
relative position of the blend door actuator(s) and the blend-air door(s). The A/C-heater control learns the blend-air
door stop positions during the calibration procedure and will store a diagnostic trouble code (DTC) for any problems
it detects in the blend door actuator circuits.

ACTUATOR-MODE DOOR
DESCRIPTION
The mode door actuators are reversible, 12-volt direct
current (DC) servo motors.The heating-A/C systems
on this vehicle use two mode door actuators. One for
the panel/floor-air door and one for the defrost-air
door.
Both the panel/floor door actuator (1) and the defrost
door actuator (2) are located on the driver side end of
the HVAC housing (3), close to the dash panel.
All actuators (1) are interchangeable with each other.
Each actuator is contained within an identical black
molded plastic housing with an integral wire connector
receptacle (2). Each actuator also has an identical
output shaft with splines (3) that connects it to its
respective door linkage and three integral mounting
tabs (4) that allow the actuator to be secured to the
HVAC housing. The mode door actuators do not
require mechanical indexing to the mode-air doors, as
they are electronically calibrated by the A/C-heater
control.
OPERATION
The mode door actuators are connectedto the A/C-heater control through the vehicle electrical system by dedicated
two-wire leads and connectors of the HVAC wire harness. The mode door actuators can move the defrost-air door
and the panel/floor-air door in two directions. When the A/C-heater control pulls the voltage on one side of the motor
connection high and the other connection low, the mode-air door will move in one direction. When the A/C-heater
control reverses the polarity of the voltage to the motor, the mode-air door moves in the opposite direction.
When the A/C-heater control makes the voltage to both connections high or both connections low, the mode-air door
stops and will not move. The A/C-heater control uses a pulse-count positioning system to monitor the operation and
relative position of the mode door actuators and the mode-air doors. The A/C-heater control learns the mode-air
door stop positions during the calibration procedure and will store a diagnostic trouble code (DTC) for any problems
it detects in the mode door actuator circuits.
The mode door actuators are diagnosed using using a scan tool (Refer to 24 - HEATING & AIR CONDITIONING -
DIAGNOSIS AND TESTING and to 24 - HVAC Electrical Diagnostics for more information).

ACTUATOR-RECIRCULATION DOOR
DESCRIPTION
The recirculation door actuator (1) is a reversible
12-volt direct current (DC)servo motor. The single
recirculation door actuator is located on the passenger
side end of the HVAC housing (2), on the top of the
air inlet housing.
All actuators (1) are interchangeable with each other.
Each actuator is contained within an identical black
molded plastic housing with an integral wire connector
receptacle (2). Each actuator also has an identical
output shaft with splines (3) that connects it to its
respective door linkage and three integral mounting
tabs (4) that allow the actuator to be secured to the
HVAC housing. The recirculation door actuator does
not require mechanical indexing to the recirculation-air
door, as it is electronically calibrated by the A/C-heater
control.
OPERATION
The recirculation door actuator is connected to the heater-A/C control module through the vehicle electrical system
by a dedicated two-wire lead and connector of the HVAC wire harness. The recirculation door actuator can move
the recirculation-air door in two directions. When the A/C-heater control pulls the voltage on one side of the motor
connection high and the other connection low, the recirculation-air doorwill move in one direction.
When the A/C-heater control makes the voltage to both connections high or both connections low, the recirculation-
air door stops and will not move. The A/C-heater control uses a pulse-countpositioning system to monitor the oper-
ation and relative position of the recirculation door actuator and the recirculation-air door. The A/C-heater control
learns the recirculation-air door stop positions during the calibrationprocedure and will store a diagnostic trouble
code (DTC) for any problems it detects in the recirculation door actuator circuits.
The recirculation door actuator is diagnosed using a scan tool (Refer to 24- HEATING & AIR CONDITIONING -
DIAGNOSIS AND TESTING and to 24 - HVAC Electrical Diagnostics for more information).
The recirculation door actuator cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.

SENSOR-EVAPORATOR TEMPERATURE
DESCRIPTION
The evaporator temperature sensor is a two-wire tem-
perature sensing element located at the coldest point
on the face of the A/C evaporator. The probe (1) for
evaporator temperature sensor is attached to the
evaporator coil fins. The wire lead (2) for evaporator
temperature sensor is routed through an opening at
the back of the HVAC housing and the connector (3)
is attached to the HVAC wire harness.
OPERATION
The evaporator temperature sensor monitors the surface temperature of A/C evaporator and supplies an input signal
to the A/C-heater control. The A/C-heater control uses the evaporator temperature sensor input signal to optimize
A/C system performance and to protect the A/C system from evaporator freezing. The evaporator temperature sen-
sor will change its internal resistance in response to the temperatures itmonitors and is connected to the A/C-heater
control through sensor ground circuit and a 5-volt reference signal circuit. As the temperature of the A/C evaporator
decreases, the internal resistance of the evaporator temperature sensordecreases.
The A/C-heater control uses the monitored voltage reading as an indication of evaporator temperature. The A/C-
heater control is programmed to respond to this input by requesting the powertrain control module (PCM) or the
engine control module (ECM) (depending on engine application) to cycle the A/C compressor clutch as necessary to
optimize A/C system performance and to protect the A/C system from evaporatorfreezing(Referto24-HEATING
& AIR CONDITIONING/CONTROLS/COIL-A/C COMPRESSOR CLUTCH - OPERATION formore information).
The evaporator temperature sensor is diagnosed using a scan tool (Refer to24 - HEATING & AIR CONDITIONING
- DIAGNOSIS AND TESTING and to 24 - HVAC Electrical Diagnostics for more information).
The evaporator temperature sensor cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.

TRANSDUCER-A/C PRESSURE
DESCRIPTION
The A/C pressure transducer (1) is a switch that is
installed on a fitting located on the A/C discharge line.
An internally threaded fitting on the A/C pressure
transducer connects it to the externally threaded
Schrader-type fitting on the A/C discharge line. A rub-
ber O-ring seals the connection between the A/C pres-
sure transducer and the discharge line fitting. The A/C
pressure transducer is connected to the vehicle elec-
trical system by a molded plastic connector with three
terminals.
OPERATION
The A/C pressure transducer monitors the pressures in the high side of the refrigerant system through its connection
to a fitting on the A/C discharge line. The A/C pressure transducer will change its internal resistance in response to
the pressures it monitors. A Schrader-type valve in the A/C discharge linefitting permits the A/C pressure transducer
to be removed or installed without disturbing the refrigerant in the A/C system.
The A/C pressure transducer will change its internal resistance in response to the pressures it monitors. The pow-
ertrain control module (PCM) or the engine control module (ECM) (depending on engine application) provides a five
volt reference signal and a sensor ground to the A/C pressure transducer, then monitors the output voltage of the
transducer on a sensor return circuit to determine refrigerant pressure.The PCM/ECM is programmed to respond to
this and other sensor inputs by controlling the operation of the A/C compressor clutch and the radiator cooling fan
to help optimize A/C system performance and to protect the system components from damage. The PCM will dis-
engagetheA/Ccompressorclutchwhenhighsidepressurerisesabove3172kPa (460 psi) and re-engage the
clutch when high side pressure drops below 1999 kPa (290 psi). The A/C pressure transducer will also disengage
the A/C compressor clutch if the high side pressure drops below 193 kPa (28 psi) and will re-engage the clutch
when the high side pressure rises above 234 kPa (34 psi). If the refrigerantpressure rises above 1655 kPa (240
psi), the PCM will actuate the cooling fan. The A/C pressure transducer signal to the PCM/ECM will also prevent the
A/C compressor clutch from engaging when ambient temperatures are below about 10° C (50° F) due to the pres-
sure/temperature relationship of the refrigerant. The A/C pressure transducer input to the PCM/ECM will also pre-
vent the A/C compressor clutch from engaging when ambient temperatures are below about 10° C (50° F) due to
the pressure/temperature relationship of the refrigerant.
The A/C pressure transducer is diagnosed using a scan tool. Refer to 9 - Engine Electrical Diagnostics for more
information.
The A/C pressure transducer cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.
REMOVAL
NOTE: It is not necessary to discharge the refrigerant system to replace the A/C pressure transducer.

1. Disconnect and isolate the negative battery cable.
2. Disconnect the wire harness connector (1) from the
A/C pressure transducer (2) located on the A/C dis-
charge line (3).
3. Remove the A/C pressure transducer from the fit-
ting on the A/C discharge line and remove and dis-
card the O-ring seal.
INSTALLATION
NOTE:UseonlythespecifiedO-ringasitismadeofspecialmaterialforR-134a. Use only refrigerant oil of
the type required for the A/C compressor.
1. Lubricate a new rubber O-ring seal (4) with clean
refrigerant oil and install it onto the discharge line
fitting (3).
2. Install the A/C pressure transducer (2) onto the A/C
discharge line. Tighten the A/C pressure transducer
securely.
3. Connect the wire harness connector (1) to the A/C
pressure transducer.
4. Reconnect the negative battery cable.