Rear Heater-A/C Control System
How to Retrieve a Diagnostic Trouble Codes
The climate control unit has a self-diagnostic function. To run the self-diagnostic function, do the following
Scheme 89
Scheme 90
- Turn the ignition switch ON (II).
- Turn the temperature control knob to LO for about 20 seconds, then HI for about 20 seconds.
- Press the OFF button, then press the recirculation control button to select Recirculation (recirculation indicator comes on).
- Press and hold the recirculation control button to select Fresh (recirculation indicator goes off). Continue to hold the button. The recirculation indicator comes on for 2 seconds, and then goes off. If the system is OK, the recirculation indicator stays off. If any trouble is found, the recirculation indicator blinks the diagnostic trouble code (DTC) to indicate a faulty circuit or component.
- After recording the DTC, release the recirculation control button. To determine the meaning of the DTC, refer to the DTC troubleshooting index for rear heater-A/C control system. Example of DTC Indicator Pattern (DTC 2)
- Turn the ignition switch OFF to cancel the self-diagnostic function. After completing repair work, run the self-diagnostic function again to make sure that there are no other malfunctions.
| DTC (Recirculation Indicator Blinks) | Detection Item | Reference |
|---|---|---|
| 1 | A problem in the rear blower motor circuit | (see DTC 1: A Problem in the Rear Blower Motor Circuit ) |
| 2 | A problem in the rear air mix control linkage, door, or motor | (see DTC 2: A Problem in the Rear Air Mix Control Linkage, Door, or Motor ) |
| 3 | A short in the rear air mix control motor circuit | (see DTC 3: A Short in the Rear Air Mix Control Motor Circuit ) |
| 4 | An open in the rear air mix control motor circuit | (see DTC 4: An Open in the Rear Air Mix Control Motor Circuit ) |
DETECTION ITEMS AND REFERENCE
In case of multiple problems, the recirculation indicator will indicate only the DTC with the least number of blinks.
In case of an intermittent failure, the climate control unit will store the DTC until the ignition switch is turned off.
The climate control unit has a mode that displays sensor inputs it receives. This mode shows you what the climate control unit is receiving from each of the sensors, one at a time, and it can help you determine if a sensor is faulty.
Check these items before using the sensor input display mode
- 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.
- Set the temperature control knob to the desired test temperature. When selecting the test temperatures, 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. 58 through 86°F settings will use the automatic climate control logic.
- Turn the ignition switch OFF.
To run the sensor input display mode, follow these steps
- Turn the ignition switch OFF.
- Press and hold both the AUTO and RECIRC buttons, then start the engine.
- After the engine starts, release the buttons. The climate control display will flash the sensor number and then the value for that sensor. Record the value displayed.
- To advance to the next sensor, press the rear window defogger button. ITEMS DISPLAYED VALUE REFERENCE Sensor Item Displayed Value 1 In-car Temperature Sensor °C 2 Outside Air Temperature Sensor °C 3 Solar Radiation Sensor Value: Dark = 00, Flashlight = 04, Cloudy = 10, Sunny = 65 10 kcal/m 2 .h 4 Engine Coolant Temperature °C 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 Vent Temperature Air Out (TAO) °C 8 Vehicle Speed (Vehicle must be driven to display speed) km/h NOTE: The sensor values will be displayed in degrees Celsius (°C) or an alphanumeric code. Use «CELSIUS TO FAHRENHEIT CONVERSION TABLE»(ref-243355-S13804908532006082300000) 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. Run the self-diagnostic function to check for a DTC. 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 the sensor with a known-good sensor, and recheck.
- To cancel the sensor input display mode, press the AUTO button, or turn the ignition OFF. Celsius to Fahrenheit Conversion Table 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 Celsius to Fahrenheit Conversion Table CELSIUS TO FAHRENHEIT CONVERSION TABLE °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 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 - F0 thru F9 -50 thru -59 -58 thru -74 +100 thru +109