Pacifica V6-3.8L VIN L (2005)
SYSTEM CONTROLS
The A/C Heater Control:
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is fully addressable with the DRBIII(R).
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communicates on the Programmable Communication Interface Multiplex System (PCI) Bus.
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broadcasts an A/C request on the PCI Bus to the Powertrain Control Module (PCM) when compressor operation is desired.
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uses input from the evaporator temperature sensor to prevent evaporator freeze up while maintaining optimum cooling performance.
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has dual-zone temperature control to provide a wide side-to-side variation in temperature to meet the needs of the driver and the front seat
passenger.
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broadcasts a blower relay on request on the PCI Bus to the Integrated Power Module (IPM) at power up (power switch on).
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controls EBL operation.
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controls blower operating speed, providing four speed settings (Low, M1, M2 and High).
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controls the electric door actuators' operation.
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A simplified control system for operation of the mode, recirculation, and temperature control actuators provides positive positioning without
the complexity of feedback from position sensors. The A/C Heater Control knows the number of operating actuator revolutions required for
full door travel as well as the number of actuator commutator pulses per revolution. Using these parameters, the A/C Heater Control runs the
actuator for the number of commutator pulses that correspond to the desired door position. To maintain accuracy, the system recalibrates itself
periodically at known zero and full travel conditions.
The Dual-Zone HVAC system uses:
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two, two-wire electric blend door actuators.
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one, two-wire electric mode door actuator.
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one, two-wire electric recirculation door actuator.
System Relays
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The Integrated Power Module (IPM) houses and provides power to the A/C Clutch Relay, EBL Relay, and the Front Blower Motor Relay.
SYSTEM DIAGNOSTICS
Fault detection is through active and stored Diagnostic Trouble Codes (DTCs)
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DTCs are displayed by the DRBIII(R).
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Active DTCs are those which currently exist in the system. The condition causing the fault must be repaired in order to clear this type of DTC.
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Stored DTCs are those which occurred in the system since the A/C Heater Control received the last "dear diagnostic info" message.
The A/C Cooldown Test:
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is actuated with the DRBIII(R).
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checks A/C system performance based on evaporator temperature sensor input.
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will not run if ambient temperature is below 12.7° C(55° F).
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will pass if the evaporator temperature drops 6.7° C(20° F) within two minutes of starting the test.
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faults display on the DRBIII(R) as test messages only after running the test.
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faults will not display on the DRBIII(R) as Diagnostic Trouble Codes.
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will cause the PWR and A/C status indicators on the A/C Heater Control to flash alternately while the test is running.
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The A/C status indicator will flash twice per second to indicate that the A/C Cooldown Test needs to be run. The A/C status indicator will stop
flashing twice per second if either the A/C Cooldown Test returns passed, or if any button on the control is pressed, or if the ignition is cycled and
the odometer shows greater than eight miles.
The HVAC Door Recalibration function:
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is actuated with the DRBIII(R).
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After completing HVAC Door Recalibration, the DRBIII(R) stores the total span and the status of each door actuator. Selecting HVAC Door
Cal Monitor in the System Tests will display this information.
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homes and repositions door actuators.
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monitors for door span faults on the actuator circuits.
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faults display on the DRBIII(R) as test messages only after running the test.
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faults will not display on the DRBIII(R) as Diagnostic Trouble Codes.
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will cause the PWR and RECIRC status indicators on the A/C Heater Control to flash alternately while the test is running.
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The RECIRC status indicator will flash twice per second to indicate that the HVAC Door Recalibration Test needs to be run. The RECIRC status
indicator will stop flashing twice per second if either the HVAC Door Recirculation Test returns passed, or if any button on the control is pressed,
or if the ignition is cycled and the odometer shows greater than eight miles.
The Actuator Circuit Test:
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is actuated with the DRBIII(R).
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monitors for shorted actuator circuits.
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allows service to easily diagnose and troubleshoot up to three simultaneous shorts.
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supplements the continuous diagnostics on the actuator drive system.