Chrysler 1998 Voyager, Service Manual, Page: 1873 / 1938

COOLDOWN TEST ENTRY
TO INITIATE TESTS:
•
Set Blower motor ON HIGH
•
Set Mode position to Panel
•
Open all A/C outlets
•
Set Temperature to Cold (Both slide pots if
equipped)
•
Depress WASH and A/C simultaneously for 5
Seconds
NOTE: Prior to start of test, If the evaporator is
already cold, the system will fail test. To correct,
operate system with A/C OFF and the blower motor
ON high for three minutes prior to starting test.
RESULTS:
•
All LED’s will turn on for 5 Seconds
•
Cooldown Test is running when A/C and
RECIRC. are alternately flashing. If A/C and
RECIRC. are flashing simultaneously, Cooldown has
failed.
CALIBRATION DIAGNOSTICS AND
COOLDOWN ABORT
Test can be aborted by doing one of the following:
•
Depressing Rear Window Defogger, RECIRC and
Rear Wiper buttons.
•
Cycling Ignition OFF and then ON.
•
Control will automatically abort after 15 min-
utes from the time Calibration Diagnostics and
Cooldown was entered.
The HVAC control module will return to normal
operation or may indicate unsuccessful Calibration
Diagnostics or Cooldown test by LED’s flashing
simultaneously.
EEPROM DATA
Calibration Diagnostics, Cooldown Status and
evaporator temperature Fin Sensor values are stored
in an EEPROM memory internal to the control. The
microcomputer within the HVAC control module uses
this information:
•
To determine if Cooldown needs to run
•
For proper position of the Heater-A/C unit
assembly doors
ACTUATOR CALIBRATION AND
DIAGNOSTICS.
NOTE: Do not run actuators unless they are prop-
erly mounted on the HVAC control module.
Actuator end point calibration takes approximately
60 seconds. The REAR WIPER and INTERMITTENT
LED’s will flash alternately during the test. The con-
trol will cycle the Blend actuator(s) to the Heat stop
first then back to Cold. After the Blend actuator(s)
have been calibrated the Mode actuator will be cycled
to Defrost and then to Panel. Successful calibration
is defined as actuator travel falling within their min-
imum and maximum limits.
BLEND/PASSENGER ACTUATOR BACKGROUND
The Blend/Passenger Actuator can move the tem-
perature door in two directions. When the voltage at
Pin 12 of the control module is high, about 11.5 volts,
and the voltage at Pin 17 is low, about 1.5 volts, the
door will move towards the Heat position. When Pin
17 is High and Pin 12 is Low the door will move
towards the Cold position. When both Pins are high
or both Pins are low, the actuator will not move. The
Blend/Passenger feedback signal is a voltage signal
that is supplied by the actuator to the control. The
signal will be about 4.0 volts in the Heat position
and 1.0 volt in the Cold position. As the position of
the Blend/Passenger actuator changes, so will the
feedback signal. The feedback signal is necessary for
the correct positioning of the temperature door.
DRIVER ACTUATOR BACKGROUND
The Driver Actuator can move the temperature
door in two directions. When the voltage at Pin 15 of
the control module is high, about 11.5 volts, and the
voltage at Pin 13 is low, about 1.5 volts the door will
LED’S PASS/FAIL
CORRECTIVE
ACTION
NO LED’S
FLASHING-
NORMAL
OPERATION PASSED
CALIBRATION,
DIAGNOSTICS
AND
COOLDOWN NONE
REAR WIPER
AND
INTERMITTENT
LED’S FLASH
SIMULTANEOUSLY FAILED
CALIBRATION
DIAGNOSTICS RUN
CALIBRATION
TEST
A/C AND RECIRC
LED’S FLASH
SIMULTANEOUSLY FAILED
COOLDOWN RUN
COOLDOWN
TEST
REAR WIPER
AND
INTERMITTENT
LED’S ARE
FLASHING
SIMULTANEOUSLY
A/C AND RECIRC
LED’S ARE
FLASHING
SIMULTANEOUSLY FAILED
CALIBRATION,
DIAGNOSTICS
AND FAILED
COOLDOWN
TEST RUN
CALIBRATION
TEST
NS/GS
HEATING AND AIR CONDITIONING 24 - 7
DIAGNOSIS AND TESTING (Continued)