How to Troubleshoot the Climate Control

How to Check for DTCs with the HDS

1.	Make sure the ignition switch is OFF.

2.	Connect the HDS to the data link connector (DLC) (A) located under the driver's side of the dashboard.

3.	Turn the ignition switch ON (II).

4.	Make sure the HDS communicates with the vehicle and the climate control unit. If it doesn't, troubleshoot the DLC circuit, except K20Z2 engine, K20Z2 engine.

5.	Select HVAC/CLIMATE CONTROL in the BODY ELECTRICAL menu.

6.	Select DTCs in the HVAC/CLIMATE CONTROL menu.

7.

Check for DTCs. If any DTCs are indicated, write down the DTCs, then go to the indicated DTC troubleshooting. If no DTCs are indicated, refer to symptom troubleshooting. NOTE: After troubleshooting, clear the DTCs with the HDS. For specific operations, refer to the user's manual that came with the HDS.

How to Use the Self-diagnostic Function with the HDS

1.	Make sure the ignition switch is OFF.

2.	Connect the HDS to the data link connector (DLC).

3.	Turn the ignition switch ON (II).

4.	Make sure the HDS communicates with the vehicle and the climate control unit. If it doesn't, troubleshoot the DLC circuit, except K20Z2 engine, K20Z2 engine.

5.	Select HVAC/CLIMATE CONTROL in the BODY ELECTRICAL menu.

6.	Select INSPECTION in the HVAC/CLIMATE CONTROL menu.

7.	Select CLIMATE CONTROL SELF TEST in the INSPECTION menu.

8.	Check for DTCs. If any DTCs are indicated, write down the DTCs, then go to the indicated DTC troubleshooting. NOTE: After troubleshooting, clear the DTCs with the HDS. For specific operations, refer to the user's manual that came with the HDS.

How to Use the Self-diagnostic Function without the HDS

1.	Turn the ignition switch OFF.

2.	Press and hold the AUTO and recirculation buttons, and turn the ignition switch ON (II).

3.

ALL LCD segments turn on for 2 seconds, then self-diagnostic function begins. NOTE: The blower motor will run at any speed regardless of what the panel is displaying. If there is any problem in the system, the temperature indicator will light up the segment (A through P) and AUTO indicator corresponding to the error. The temperature indicator will then alternate every second between displaying ‘‘88'' (all segments lit) and the error code segment (A through P) and AUTO indicator. To determine the meaning of the DTC, refer to checking for DTCs. If there are no problems detected, the segments will not illuminate, and the system will appear to be turned off.

Clear the DTCs

1.	Turn the ignition switch OFF.

2.	Press and hold the AUTO and windshield defrost buttons, turn the ignition switch ON (II).

3.	Windshield defrost indicator blinks for 5 seconds, then DTCs clear.

Checking for DTCs

The temperature display indicates single or multiple DTCs. If indicator segments A, C, E, G, J, M, and AUTO are on at the same time, there may be an open in the common ground wire. If no DTCs are present, the indicator remains blank.

DTC (Temperature Indicator Segment and AUTO Indicator)	Detection Item
A	An open in the in-car temperature sensor circuit
B	A short in the in-car temperature sensor circuit
C	An open in the outside air temperature sensor circuit
D	A short in the outside air temperature sensor circuit
E	An open in the sunlight sensor circuit
F	A short in the sunlight sensor circuit
G	An open in the evaporator temperature sensor circuit
H	A short in the evaporator temperature sensor circuit
J	An open in the air mix control motor circuit
K	A short in the air mix control motor circuit
L	A problem in the air mix control linkage, door, or motor
M	An open or short in the mode control motor circuit
N	A problem in the mode control linkage, doors, or motor
P	A problem in the blower motor circuit
A and AUTO	An open in the recirculation control motor circuit
B and AUTO	A problem in the recirculation control linkage, door, or motor
C and AUTO	Climate control unit internal error
D and AUTO	Climate control unit lost communication with gauge control module (ILLUMI message)
E and AUTO	A short in the recirculation control motor circuit
F and AUTO	Climate control unit lost communication with gauge control module (ECT message)
J and AUTO	Climate control unit lost communication with gauge control module (VSP message)
K and AUTO	Communication bus line error
L and AUTO	Climate control unit lost communication with gauge control module (NE message)

Displaying Sensor Inputs at the Climate Control Unit

Check these items before using the sensor input display mode

1.	Turn the ignition switch ON (II), and check the recirculation door function; press the recirculation button to switch from FRESH to RECIRC. The air volume and sound should change slightly.

2.

Set the temperature control knob to the desired test temperature. When selecting the test temperature, note these items: ‘‘Lo'' temperature setting will default to MAX COOL, VENT, and RECIRC. ‘‘Hi'' temperature setting will default to MAX HOT, FLOOR, and FRESH. 19 through 31 °C settings will use the automatic climate control logic.

3.	Turn the ignition switch OFF.

To run the sensor input display mode, follow these steps

1.	Turn the ignition switch OFF.

2.	Press and hold both the AUTO and MODE buttons, then start the engine.

3.	After the engine starts, release both buttons. The display panel control unit will flash the sensor number and then the value for that sensor. Record the value displayed.

4.

To advance to the next sensor, press the A/C button. Sensor  Item  Displayed Value  1  Mode Positioning  BIT  2  In-car Temperature  °C  3  Outside Air Temperature  °C  4  Solar Radiation Sensor Value: Dark = 00, Flashlight = 04, Cloudy =10, Sunny =65  10 kcal/m2·h  5  Evaporator Outlet Air Temperature  °C  6  Air Mix Opening (Low value indicates cooler air distribution, higher value indicates warmer air distribution)  % of opening  7  Recirculation Opening  % of opening  8  Vehicle Speed (Vehicle must be driven to display speed)  km/h  9  Engine Coolant Temperature  °C  A  Vent Temperature Air Out (TAO)  °C  NOTE: The sensor values will be displayed in degrees Celsius (°C) or an alphanumeric code. Use the chart to convert the value to degrees Fahrenheit (°F). If the sensor value displays ‘‘Er'' this indicates there is an open or short in the circuit or sensor. Check for DTCs using the HDS, or refer to checking DTCs by DTC indication to check for DTCs. If necessary, compare the sensor input display to an alike, known-good vehicle under the same test conditions. If the sensor is out of the normal range, refer to the sensor test or substitute a known-good sensor, and recheck.

5.

To cancel the sensor input display mode, press the AUTO button or turn the ignition switch OFF. Celsius to Fahrenheit Conversion Table °C  °F  °C  °F  °C  °F  °C  °F  °C  °F  0  32  10  50  20  68  30  86  40  104  1  34  11  52  21  70  31  88  41  106  2  36  12  54  22  72  32  90  42  108  3  37  13  55  23  73  33  91  43  109  4  39  14  57  24  75  34  93  44  111  5  41  15  59  25  77  35  95  45  113  6  43  16  61  26  79  36  97  46  115  7  45  17  63  27  81  37  99  47  117  8  46  18  64  28  82  38  100  48  118  9  48  19  66  29  84  39  102  49  120  °C  °F  °C  °F  °C  °F  °C  °F  °C  °F  50  122  60  140  70  158  80  176  90  194  51  124  61  142  71  160  81  178  91  196  52  126  62  144  72  162  82  180  92  198  53  127  63  145  73  163  83  181  93  199  54  128  64  147  74  165  84  183  94  201  55  131  65  149  75  167  85  185  95  203  56  133  66  151  76  169  86  187  96  205  57  135  67  152  77  170  87  188  97  207  58  136  68  154  78  172  88  190  98  208  59  139  69  158  79  174  89  192  99  210  Alphanumeric Conversion Table Display Reading (Alphanumeric)  °C  °F  %  A1 thru A9  -1 thru -9  30 thru 16  -1 thru -9  B0 thru B9  -10 thru -19    14 thru -2  -10 thru -19  C0 thru C9  -20 thru -29   -4 thru -20  -20 thru -29  D0 thru D9  -30 thru -39  -22 thru -38  -30 thru -39  E0 thru E9  -40 thru -49  -40 thru -58  -40 thru -49  F0 thru F9  ———  ———  +100 thru +109  Alphanumeric Conversion Table (Mode Positioning) Display Reading (Alphanumeric)  Mode Position  2  OVER VENT  A  VENT  8  VENT-HEAT/VENT  c  HEAT/VENT  d  HEAT/VENT-VENT  9  HEAT  b  HEAT-HEAT/DEF  3  HEAT/DEF  7  HEAT/DEF-DEF  6  DEF  E  OVER DEF