HVAC System Troubleshooting & Testing: Other Honda CR-V IV

How to Check for DTCs With the HDS

Note. There are three methods used to check for DTCs. The recommended method is to use the Honda Diagnostic System (HDS) with the appropriate software, plugged into the data link connector (DLC). The second method is to run the self-diagnostic function built into the climate control unit. The third method is to use the B-CAN SYSTEM DIAGNOSIS TEST MODE A .

Scheme 144

1. Make sure the ignition switch is in LOCK (0).
2. Connect the HDS to the DLC (A) located under the driver's side of the dashboard.
3. Turn the ignition switch to ON (II).
4. Make sure the HDS communicates with the vehicle and the climate control unit. If it does not, go to the «DLC CIRCUIT TROUBLESHOOTING»(ref-595375-S01818375202014013100000) .
5. Select HVAC/Climate Control in the BODY ELECTRICAL menu.
6. Select DTCs in the HVAC/Climate Control Mode 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, do all system scan, then 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.

Checking for DTCs

The driver's temperature indicator indicates single or multiple DTCs. If no DTCs are present, the indicator will flashes no.

Note. If the driver's temperature indicator segments 05, 07, 09, 40, 43, 49, 55, and 89 indicator are on at the same time, there may be an open in the sensor common ground wire.

Scheme 145

Displaying Sensor Inputs at the Climate Control Unit

The climate control unit has a mode that displays the 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.

Checks Before Using the Sensor Input Display Mode

1. Turn the ignition switch to 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 dial to the desired test temperature: "Lo" temperature setting will default to MAX COOL, VENT, and RECIRC (A/C on) or FRESH (A/C off). "Hi" temperature setting will default to MAX HOT, HEAT or HEAT/DEF, and FRESH. 58 through 86 °F (14 through 30 °C) settings will use the automatic climate control logic.
3. Turn the ignition switch to LOCK (0).

Scheme 146

1. Turn the ignition switch to LOCK (0), and then back to ON (II).
2. Press and hold both the AUTO and RECIRCULATION buttons, then start the engine.
3. After the engine starts, release both buttons. The climate 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 REAR WINDOW DEFOGGER/MIRROR DEFOGGER* button. *: With mirror defogger NOTE: The sensor values will be displayed in degrees Celsius (°C) or an alphanumeric code. Use the chart to convert the value to degree 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, o use the climate control self-diagnostic function. If necessary, compare the sensor input display to a known-good vehicle under the same test conditions. If the sensor displayed value is out of the normal range, refer to the sensor test or substitute a known-good sensor, and recheck. Sensor Item Displayed Value 1 Mode positioning % 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/m 2 .h 5 Evaporator outlet air temperature °C 6 Driver's air mix opening (low value indicates cooler air distribution, higher value indicates warmer air distribution) % of opening 7 Passenger's air mix opening (low value indicates cooler air distribution, higher value indicates warmer air distribution) % of opening 8 Recirculation control opening % of opening 9 Vehicle speed (vehicle must be driven to display speed) 10 km/h A Engine coolant temperature °C b Vent temperature air out (TAO) (driver's) °C C Humidity sensor value % d Illumination duty Step e Software version ----- CELSIUS TO FAHRENHEIT CONVERSION °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 54 129 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 67 153 77 170 87 189 97 207 58 136 68 154 78 172 88 190 98 208 59 138 69 156 79 174 89 192 99 210 ALPHANUMERIC CONVERSION Display Reading (Alphanumeric) °C °F % A1 thru A9 -1 thru -9 30 thru 16 -1 thru -10 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 -56 -40 thru -49 E9 -50 or less -58 or less -50 or less ALPHANUMERIC CONVERSION (MODE POSITIONING) Display Reading (Alphanumeric) Mode Position 0 VENT 18 HEAT/VENT-1 32 HEAT/VENT-2 54 HEAT 69 HEAT/DEF-1 84 HEAT/DEF-2 F0 DEF

Procedure

Note. To test the outside air temperature sensor, refer to the outside air temperature sensor test procedure.

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1. Outside Air Temperature Indicator - Calibration Description The outside air temperature sensor is located behind the center of the front bumper. The gauge control module uses measurements from this sensor, plus analog with data provided by the climate control unit via the B-CAN communication line, to display the outside air temperature. Because of the location of the sensor, it may be affected by heat reflection from the road, engine and radiator or hot exhaust from surrounding traffic. These conditions can soak the outside air temperature sensor in heat and cause inaccurate readings. Logic has been written into the gauge control module to help prevent abnormal or fluctuating outside air temperature indicator readings. Outside Air Temperature Indicator Logic Initial outside air temperature is indicated after the ignition switch is turned ON (II): Engine coolant temperature is 140 °F (60 °C) or higher: If the engine coolant temperature is 140 °F (60 °C) or higher when the ignition switch is turned ON (II), the outside air temperature indicated the last time the key was turned off is displayed regardless of the current temperature measured by the outside air temperature sensor. Engine coolant temperature is 138 °F (59 °C) or lower: If the engine coolant temperature is 138 °F (59 °C) or lower when the ignition switch is turned ON (II), the current temperature measured by the outside air temperature sensor is indicated. Information Update to the Outside Air Temperature Indicator While Driving Engine coolant temperature is 140 °F (60 °C) or higher: If the temperature measured by the outside air temperature sensor is greater than the temperature on the outside air temperature indicator, the outside air temperature indicator increases by 1 °F (1 °C) per minute after vehicle speed is greater than 19 mph (30 km/h) for more than 33 seconds (one minute). It continues to increase until the current outside air temperature is indicated. So, the first change to the outside air temperature indicator is 33 seconds (one minute) after vehicle speed is greater than 19 mph (30 km/h). If the vehicle speed drops below 19 mph (30 km/h), the indicator does not update again until the vehicle speed has increased to 19 mph (30 km/h) or more for more than 33 seconds (one minute) again. Engine coolant temperature is 138 °F (59 °C) or lower: If the outside air temperature is less than the indicated temperature, the temperature decreases 1 °F (1 °C) every 2 seconds until the current outside air temperature is indicated regardless of vehicle speed. Troubleshooting If the indicator displays - - - °F for more than 2 seconds after selecting the outside air temperature display mode, the gauge control module is not receiving outside temperature data from the climate control unit via the B-CAN. Check for and resolve all B-CAN related DTCs, then check the climate control system or multiplex integrated control system for DTCs. (see B-CAN System Diagnosis Test Mode A) Fahrenheit: Celsius: Calibration NOTE: The outside air temperature indicator's displayed temperature can be recalibrated 5 °F (3 °C) to meet the customer's expectations. Turn the ignition switch to ON (II). Select the odometer/trip A or odometer/trip B display. Select the outside air temperature display and press and hold the SELECT/RESET knob for 10 seconds. While you continue to hold the button, the display will scroll through temperature setting from +5 °F (+3 °C) to -5 °F (-3 °C) as shown. Fahrenheit: Celsius: When the desired correction value appears on the display, release the button, and the recalibrated outside air temperature will be displayed. NOTE: The recalibration temperature is not the value the sensor detects. Therefore the temperature can only be adjusted 5 °F (3 °C) from sensors reading. Example: Incorrect value = 68 °F (20 °C) Desired correction value = +2 °F (+1 °C) Correct value = 70 °F (21 °C) Desired correction value = -2 °F (-1 °C) Correct value = 66 °F (19 °C) NOTE: To recalibrate the display to the true temperature, remove the outside air temperature sensor (A), but leave it connected. Submerge the sensor and a thermometer (B) in a container of ice water (C). Select the calibration mode as described above, then recalibrate the display to the true temperature.