Jeep WJ Grand Cherokee Climate Controls

By Jeep Experts

Welcome to the in-depth web page on WJ Generation Jeep Grand Cherokee local weather controls. We have organized as a lot info as we may discover right into a useful article under. Is one thing incorrect or lacking? Please get in contact with us and we’ll repair it!

WJ local weather methods

1999-2004 Grand Cherokee fashions characteristic both a Manual Temperature Control (MTC) or Automatic Zone Control (AZC). The Automatic management is on the market solely on Limited or Overland fashions. The handbook temperature management HVAC system makes use of a mixture {of electrical}, and vacuum controls. The Automatic Zone Control HVAC system makes use of solely electrical controls. These controls present the automobile operator with various setting choices to assist management the local weather and luxury inside the automobile. Refer to the proprietor’s handbook within the automobile glove field for extra info on the steered operation and use of those controls.

Both a/c heater management panels are positioned on the instrument panel inboard of the steering column and under the radio. Both management panels comprise rotary-type temperature management knob(s), a rotary kind mode management swap knob, a rotary-type blower motor pace swap knob and an air con compressor push button swap. The rear window defogger push button swap can be positioned on a/c heater management panel. The AZC management panel additionally encompasses a recirculation push button swap and a vacuum fluorescent show space.

AZC operation

The AZC management module makes use of infrared sensing expertise to regulate occupant consolation ranges, not the precise passenger compartment air temperature. Dual infrared sensors mounted within the face of the management unit independently measure the floor temperature to keep up customer-perceived consolation temperature underneath altering situations. Dual Zone temperature management offers vast side-to-side variation in consolation temperature to exceed the wants of both entrance seat occupant. This sensing system replaces inside air temperature and photo voltaic sensors used to approximate direct sensing management by complicated management packages.

The AZC system:

  • Communicates over the Programmable Communication Interface Multiplex System (PCI) Bus.
  • Has twin infrared sensors, mounted within the AZC module face, which independently measure floor temperature to keep up occupant consolation ranges.
  • Has dual-zone temperature-controls to supply a large side-to-side variation in temperature to fulfill the wants of both entrance seat occupant.
  • Can be operated in a handbook mode.
  • Uses engine temperature knowledge, acquired over the PCI Bus, for chilly engine blower lock-out.
  • Uses engine RPM knowledge, acquired over the PCI Bus, for wide-open throttle A/C cut-out.
  • Uses automobile pace knowledge, acquired over the PCI Bus, to find out air-flow over the condenser for optimum cooling efficiency.
  • Uses Ambient Temperature Sensor knowledge, acquired over the PCI Bus, to optimize consolation management.
  • Provides an A/C request to the BCM when compressor operation is desired.
  • Provides a request to the BCM when rear defogger operation is desired.
  • Controls fan pace, offering 10 blower speeds in handbook mode and infinite speeds in automated mode.
  • The Blower Motor Controller offers a 5.0 volt sign to the AZC Module over the Blower Motor Control circuit. The AZC Module offers a variable responsibility cycle floor to the 5.0 volt sign based mostly on enter from the blower swap. When the blower swap is ready to LO pace, the AZC Module offers a brief responsibility cycle (much less time grounding the sign voltage). As greater blower speeds are requested, the AZC Module will increase the responsibility cycle (extra time grounding the sign voltage). When the blower swap reaches HI pace, the responsibility cycle will increase to the place the sign sample is sort of a flat line (with temporary voltage spikes).
  • Controls digital door actuator operation.
    A simplified management system for operation of the mode, recirculation, and temperature management actuators offers optimistic positioning with out the complexity of suggestions from place sensors. The AZC Module is aware of the variety of working actuator revolutions required for full door journey in addition to the variety of actuator commutator pulses per revolution. Using these parameters, the AZC Module runs the actuator for the variety of commutator pulses that correspond to the specified door place. To preserve accuracy, the system recalibrates itself periodically at identified zero and full journey situations.
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AZC system doorways:

  • Two, two-wire digital mix door actuators.
  • One, two-wire digital mode door actuator.
  • One, two-wire digital recirculation door actuator.

System revisons

The 2003-2004 mannequin 12 months AZC Module is NOT interchangeable with 1999-2002 AZC Modules attributable to revised management software program.

AZC fault codes

Fault codes are two-digit numbers that establish a circuit that’s malfunctioning. The Automatic Zone Control (AZC) management module has a system self-diagnostic mode which repeatedly displays varied parameters throughout regular system operation. If a system fault is detected, a present and historic fault is recorded. When the present fault is cleared, the historic fault stays till reset (manually or mechanically). Both the present and historic fault codes might be accessed by both the entrance panel, or over the Programmable Communications Interface (PCI) bus utilizing a DRBIII scan device, and the suitable diagnostic info.

The two completely different sorts of fault codes are:

1. Current Fault Codes – Current means the fault is current proper now. There are two sorts of present faults: enter faults, and system defects.

2. Historical Fault Codes – Historical or saved signifies that the fault occurred beforehand, however will not be current proper now. A majority of historic fault codes are attributable to intermittent wire harness or wire harness connector issues.

AZC self-diagnostic mode:

1. To enter the self-diagnostic mode, depress the a/c and recirc buttons on the identical time and maintain. Rotate the left temperature management knob clockwise (CW) one detent.

2. If you proceed to maintain the a/c and recirc buttons depressed, the AZC management module will carry out a Segment Test of the Vacuum Fluorescent (VF) show. In the Segment Test you must see the entire show segments illuminate so long as each buttons are held. If a show phase fails to light up, the vacuum fluorescent show is defective and the a/c heater management should be changed.

3. After viewing the Segment Test, launch the A/C and Recirc buttons and the show will clear momentarily. If there aren’t any fault codes, the “00” show worth will stay within the VF window. Should there be any codes, every might be displayed for one second in ascending numerical sequence (observe: no effort is made to show faults within the order they occurred). The left facet set temperature show might be blanked and the appropriate facet set temperature show will point out present and historic codes (8 historic max) presently energetic.

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Once all codes have been displayed, the system will repeat the fault code numbers. This will proceed till the left facet set temperature management is moved a minimum of one detent place in both route, by urgent each the A/C and Recirc buttons on the identical time, or the ignition is turned off. Record the entire fault codes, then see the Current and Historical Fault Code charts under for the descriptions.

Clearing fault codes

Current faults can’t be electronically cleared. Repair should be made to the system to get rid of the fault inflicting code. Historical fault codes might be cleared manually, or mechanically. To clear a historic fault manually, depress and maintain both the A/C or Recirc button for a minimum of three seconds whereas the show is within the fault code mode of operation. Historical fault codes are cleared mechanically when the corresponding present fault code has been cleared, and has remained cleared for 72 ignition cycles. The faults have been cleared when two horizontal bars seem within the Test Selector show.

AZC fault codes

Input faults 01 = IR thermister circuit open
02 = IR thermister circuit shorted
03 = Fan pot shorted
04 = Fan pot open
05 = Mode pot shorted
06 = Mode pot open
07 = IR sensor delta too giant
08 = Reserved
09 = Reserved
10 = One of 4 motor drivers has drive “A” shorted to floor
11 = Engine air consumption temperature bus message lacking
12 = Country code bus message lacking
System faults 13 = Mode motor not responding
14 = AI (Recirc) motor not responding
15 = Left temperature door not responding
16 = Right temperature door not responding
17 = Mode door journey vary too small
18 = Mode door journey vary too giant
19 = AI (Recirc) door journey too small
20 = AI (Recirc) door journey too giant
21 = Left temperature door journey too small
22 = Left temperature door journey too giant
23 = Right temperature door journey too small
24 = Right temperature door journey too giant
25 = Calibration verify sum error
26 = Engine coolant temp bus message lacking
27 = Vehicle pace bus message lacking
28 = Engine RPM bus message lacking
29 = OAT bus message lacking
30 = Display depth bus message lacking
31 = VIN quantity bus message lacking
32 = Raw OAT buss message lacking
Input faults 33 = IR thermister circuit was open
34 = IR thermister circuit was shorted
35 = Fan pot was shorted
36 = Fan pot was open
37 = Mode pot was shorted
38 = Mode pot was open
39 = IR sensor delta was too giant
40 = Reserved
41 = Reserved
42 = One of 4 motor drivers had drive 9A9 shorted to floor
43 = Engine air consumption temperature bus message lacking
44 = Country code buss message lacking
System faults 45 = Mode motor was not responding
46 = AI (Recirc) motor was not responding
47 = Left temperature door was not responding
48 = Right temperature door was not responding
49 = Mode door journey vary too small
50 = Mode door journey vary too giant
51 = AI (Recirc) door journey vary too small
52 = AI (Recirc) door journey vary too giant
53 = Left temperature door journey too small
54 = Left temperature door journey too giant
55 = Right temperature door journey too small
56 = Right temperature door journey too giant
57 = Calibration verify sum error
58 = Engine coolant temp bus message lacking
59 = Vehicle pace bus message lacking
60 = Engine RPM bus message lacking
61 = OAT bus message lacking
62 = Display depth bus message lacking
63 = VIN quantity bus message lacking
64 = Raw OAT bus message was lacking
65 = Reserved
66 = Reserved
67 = Reserved
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Calibrating AZC door actuators

Calibrate the door actuators after making any repairs to the AZC system. To calibrate the door actuators proceed as follows:

1. Turn the ignition on.
2. Set the AZC to automated.
3. Turn the ignition off.
4. Remove the IOD fuse from the Power Distribution Center. Wait a number of seconds, after which set up the IOD fuse.
5. Turn the ignition on. Do not contact any of the AZC controls for a minimum of one minute to permit the calibration operate to run to completion.

Every 20 key cycles the AZC head initiates a re-calibration routine which identifies pulse counts required to realize full door journey. Also throughout this routine all modes and features are validated as useful. When the self calibration routine is full, the management head resets itself to its final settings.

The air con compressor will have interaction in sure modes to chill and take away moisture from air getting into the passenger compartment. The AZC management, when it isn’t set within the auto mode, at all times defaults to A/C enabled. The LED illuminates when the management requests A/C. The buyer should toggle A/C off by miserable the button each time he turns to handbook mode or the A/C is enabled. Additionally, when the automobile is off for a “calibratable” period of time, automated A/C is once more enabled and the shopper should once more drive it off by miserable the button.


See additionally  Blower motor

Change in outlet temperature from desired setting – 1999-2001 fashions (see TSB # 2400701)

Cold air leaking into passenger compartment foot effectively – 1999-2000 fashions (see TSB #242599)

Condensation on exterior of heater housing – 1999-2000 fashions (see TSB #240699A)

Heater A/C system altering to defrost mode when accelerating – 1999-2000 fashions (see TSB # 242499)

Reduced airflow from middle retailers – 1999 fashions (see TSB # 240799)

Temperature coming from the HVAC system blows chilly air solely. – Air temperature stays chilly whatever the place of the temperature knob. Observe the temp door actuators on the HVAC housing whereas rotating the temp knob. If the actuators rotate, however the air temp doesn’t change, the issue might be a damaged temp door or temp door cease. Blend doorways and doorstops can be found by the Mopar Parts. The half variety of the doorstop is 05012711AA.

Temperature fluctuation within the automated mode – 1999 fashions (see TSB #241699. Involves AZC module recalibration. Also addresses having to set the temperature too excessive or low to keep up a cushty passenger compartment, consistently having to regulate the temperature setting when in automated mode and temperature overshoot in automated mode).

Water drips onto the passenger flooring when air con is on – Ensure the condensation drain is freed from restriction. High temperature and humidity will promote condensation buildup on the outside of the HVAC housing. Self adhesive foam tape is on the market that can assist take up water droplets that will kind on the HVAC housing. Dry the areas the place water condensation is probably the most. Carefully set up self adhesive foam tape Part # 05015245AA.

Whistling sound from heater blower – 1999 fashions (see TSB # 240899)

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