Climate Control Acura ZDX I

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A/C Service Tips and Precautions

The air conditioning system uses HFC-134a (R-134a) refrigerant and polyalkyleneglycol (PAG) refrigerant oil.

Use only service equipment that is U.L.-listed and is certified to meet the requirements of SAE J2788 to remove R-134a from the air conditioning system.

If accidental system discharge occurs, ventilate the work area before resuming service.

R-134a service equipment or vehicle air conditioning systems should not be pressure tested or leak tested with compressed air.

Additional health and safety information may be obtained from the refrigerant and lubricant manufacturers.

1. Always disconnect the negative cable from the battery whenever replacing air conditioning parts.
2. Keep moisture and dirt out of the system. When disconnecting any lines, plug or cap the fittings immediately; do not remove the caps or plugs until just before you reconnect each line.
3. Before connecting any hose or line, apply a few drops of refrigerant oil to the O-ring.
4. When tightening or loosening a fitting, use a second wrench to support the matching fitting.
5. When discharging the system, use an R-134a refrigerant recovery/recycling/charging station; do not release refrigerant into the atmosphere.

A/C System Inspection

Note. For A/C system noise, go to the A/C SYSTEM NOISE CHECK (see ).

Before troubleshooting any problem with the air conditioning system, other than noise, do the following

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1. Check that the HVAC air intake plenum at the base of the windshield is not blocked by leaves or debris. Remove any blockage.
2. Check for kinks or sharp bends in the A/C lines and hoses (which can greatly reduce system performance). If any of the A/C lines and hoses are kinked or bent, replace them (see «A/C LINE REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
3. Inspect the A/C components, the pressure lines, and the hoses for stains that may indicate a refrigerant or an A/C compressor oil leak. If there is any indication of leaks, do the Refrigerant Leak Check (see «REFRIGERANT LEAK CHECK»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__refrigerant-leak-check) ) to confirm the leak(s).
4. Inspect the drive belt for physical damage or signs of slippage (see «DRIVE BELT INSPECTION»(/acura/zdx/i-2009-2013/remont/charging-system/#charging-system) ). If the drive belt is damaged or shows signs of slippage, replace it (see «DRIVE BELT REPLACEMENT»(/acura/zdx/i-2009-2013/remont/charging-system/#charging-system__drive-belt-replacement) ) and recheck.
5. Check the A/C condenser (A) for material clogging the fins (dirt, insects, etc.). If the A/C condenser is clogged or restricted, carefully clean any material from the A/C condenser fins with water and detergent. If deeper cleaning is required, clean the fins with HondaBrite cleaner (P/N 08732-0020B). Do not perform pressure test until the A/C condenser is completely dry.
6. Check the A/C condenser for fin damage (bent fins). If any of the A/C condenser fins are bent, try to comb them straight. Do the Refrigerant Leak Check (see «REFRIGERANT LEAK CHECK»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__refrigerant-leak-check) ) to check for leaks if there is visible damage to the A/C condenser. If the A/C condenser is leaking or the fins cannot be straightened, replace the A/C condenser (see «A/C CONDENSER REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
7. Check the dust and pollen filter. If the dust and pollen filter is clogged or restricted, replace it (see «DUST AND POLLEN FILTER REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
8. Check for climate control DTCs using the Self-Diagnostic Function (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ). If there are any DTCs, go to the appropriate troubleshooting (see «CHECKING FOR DTCS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__checking-for-dtcs) ).
9. Start the engine, turn the air conditioning system on, and allow it to run for a few minutes and reach stable operation.
10. Check that the A/C operates at each position of the fan control switch (except OFF). If the A/C does not operate at all fan control switch positions, refer to the symptom troubleshooting.
11. Check that the A/C compressor clutch pressure plate (A) is rotating at the same speed as the pulley and is engaging. If the A/C compressor clutch is not engaging properly, go to the «A/C COMPRESSOR CLUTCH CIRCUIT TROUBLESHOOTING»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__ac-compressor-clutch-circuit-troubleshooting) (see ).
12. Check that the A/C condenser fan (B) and the radiator fan (C) operate when the A/C compressor clutch is engaged and blow air toward the engine compartment. If one or both of the fans is not working properly, refer to the symptom troubleshooting.
13. Check that the engine idle speed is correctly maintained when the A/C is switched on and off, (A/C compressor clutch is engaged and disengaged). If the idle speed increases more than 100 rpm when the A/C compressor engages, confirm that the A/C compressor is the cause of the idle speed increase. Replace the A/C compressor, if necessary.

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 B-CAN system diagnosis test mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A ).

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1. Make sure the ignition switch is in LOCK (0), or the vehicle ignition is in the OFF mode.
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), or press the engine start/stop button to select the ON mode.
4. Make sure the HDS communicates with the vehicle and the climate control unit. If it does not, go to the DLC circuit troubleshooting (see «DLC CIRCUIT TROUBLESHOOTING»(/acura/zdx/i-2009-2013/remont/communication-devices/#communication-systems-f-can-k-line__dlc-circuit-troubleshooting) ).
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»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) . 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.

How to Use the Self-Diagnostic Function With the HDS

Note. This method is only available if the HDS can communicate with the climate control unit. If there is a communication problem with the HDS, go to B-CAN system diagnosis test mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A ).

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1. Make sure the ignition switch is in LOCK (0), or the vehicle ignition is in the OFF mode.
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), or press the engine start/stop button to select the ON mode.
4. Make sure the HDS communicates with the vehicle and the climate control unit. If it does not, go to the DLC circuit troubleshooting (see «DLC CIRCUIT TROUBLESHOOTING»(/acura/zdx/i-2009-2013/remont/communication-devices/#communication-systems-f-can-k-line__dlc-circuit-troubleshooting) ).
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»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) . 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

The climate control unit has a self-diagnostic function. To run the self-diagnostic function, do the following

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1. Turn the ignition switch to LOCK (0) and then back to ON (II), or press the engine start/stop button to select the OFF mode and then the ON mode.
2. Press and hold the ON/OFF button, then within 10 seconds press and release the REAR WINDOW DEFOGGER/MIRROR DEFOGGER button five times. Release the ON/OFF button, then the self-diagnosis begins. NOTE: The blower motor runs at various speeds regardless of what the panel is displaying. If there is a problem with the system, it will flash AUTO, 88 and AUTO, 88 and WINDSHIELD DEFROST, or 88 and MODE, and one or more of the 14 indicator segments (A through N). Refer to «CHECKING FOR DTCS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__checking-for-dtcs) . If there is more than one DTC, they are displayed one at a time in sequence followed by a pause (all the display indicator segments illuminate) between the DTCs. If there are no problems detected, the segments do not illuminate, and the system appears to be turned off. Canceling the Self-Diagnostic Function
3. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode to cancel the self-diagnostic function. After completing repair work, run the self-diagnostic function again to make sure that there are no other DTCs.

Checking for DTCs

The temperature display indicates single or multiple DTCs. If no DTCs are present, the indicator remains blank.

Note. If the driver's indicator segments A, C, E, G, J, and M with the AUTO indicator, MODE indicator, and the WINDSHIELD DEFROST indicator are on at the same time, there may be an open in the sensor common ground wire.

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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), or press the engine start/stop button to select the ON mode, 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 desired test temperature using the driver's control switch: Press the SYNC button off, the LED turns off. When selecting the test temperature, note these items: "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, 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), or press the engine start/stop button to select the OFF mode.

Run the Sensor Input Display Mode

1. Make sure the ignition switch is in LOCK (0), or the vehicle ignition is in the OFF mode.
2. Press and hold both the passenger's AUTO and RECIRCULATION buttons, then start the engine.
3. After the engine starts, release both buttons. The HVAC display flashes the sensor number, 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. NOTE: The sensor values are displayed in degrees Celsius (°C) or an alphanumeric code. Use the charts to convert degrees Fahrenheit (°F), or convert the alphanumeric code to a numerical value. 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 use the climate control unit 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 In-car temperature °C 2 Outside air temperature °C 3 Solar radiation sensor value: dark = 00, flashlight = 04, cloudy = 10, sunny = 65 kcal/m 2 .h 4 Engine coolant temperature °C 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 Passenger's air mix opening (low value indicates cooler air distribution, higher value indicates warmer air distribution) (passenger's side of display) % of opening 7 Vent temperature air out (TAO) °C 8 Vehicle speed (vehicle must be driven to display speed) km/h 9 A/C pressure 10 kPa A Humidity sensor value % rh b Fog margin °C C Solar radiation azimuth (with navigation) 10° d Solar radiation angle of elevation (with navigation) 10° CELSIUS TO FAHRENHEIT CONVERSION TABLE °C °F 0 32 1 34 2 36 3 37 4 39 5 41 6 43 7 45 8 46 9 48 10 50 11 52 12 54 13 55 14 57 15 59 16 61 17 63 18 64 19 66 20 68 21 70 22 72 23 73 24 75 25 77 26 79 27 81 28 82 29 84 30 86 31 88 32 90 33 91 34 93 35 95 36 97 37 99 38 100 39 102 40 104 41 106 42 108 43 109 44 111 45 113 46 115 47 117 48 118 49 120 50 122 51 124 52 126 53 127 54 129 55 131 56 133 57 135 58 136 59 138 60 140 61 142 62 144 63 145 64 147 65 149 66 151 67 153 68 154 69 156 70 158 71 160 72 162 73 163 74 165 75 167 76 169 77 170 78 172 79 174 80 176 81 178 82 180 83 181 84 183 85 185 86 187 87 189 88 190 89 192 90 194 91 196 92 198 93 199 94 201 95 203 96 205 97 207 98 208 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 CO thru C9 -20 thru -29 -4 thru -20 -20 thru -29 DO thru D9 -30 thru -39 -22 thru -38 -30 thru -39 E0 thru E9 -40 thru -49 -40 thru -56 -40 thru -49 F0 thru F9 -50 thru -59 -59 thru -74 + 100 thru +109
5. To cancel the sensor input display mode, press the driver's AUTO button or turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

DTC Troubleshooting Index

CHECKING DTCS WITH HDS

Symptom Troubleshooting Index

System Description

The air conditioning (A/C) system removes heat from the passenger compartment by transferring heat from the ambient air to the evaporator. The A/C system refrigerant expands in the evaporator, and the evaporator becomes very cold and absorbs the heat from the ambient air. The blower fan pushes air across the evaporator where the heat is absorbed, and then it blows the cool air into the passenger compartment.

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This vehicle uses HFC-134a (R-134a) refrigerant, which does not contain chlorofluorocarbons. Pay attention to the following service items

1. Use only the recommended polyalkyleneglycol (PAG) refrigerant oil (DENSO ND-OIL 8) designed for the R-134a A/C compressor. Intermixing the recommended (PAG) refrigerant oil with any other refrigerant oil will result in A/C compressor failure.
2. All A/C system parts (A/C compressor, discharge line, suction line, evaporator, A/C condenser, receiver/dryer, expansion valve, O-rings for joints) are designed for refrigerant R-134a.
3. Use a halogen gas leak detector designed for refrigerant R-134a.
4. Use only a recovery/recycling/charging station that is U.L.-listed and is certified to meet the requirements of SAE J2788 to service the R-134a air conditioning systems.
5. Always recover refrigerant R-134a with an approved recovery/recycling/charging station before disconnecting any A/C fitting.

A/C Pressure Sensor

The A/C pressure sensor converts A/C pressure into electrical signals to the PCM.

The response of the A/C pressure sensor is shown in the graph.

Note. When the refrigerant is below 196 kPa (2.00 kgf/cm 2 , 28.4 psi) or above 3, 138 kPa (32.00 kgf/cm 2 , 455.1 psi), the PCM turns the A/C compressor clutch relay off to protect the A/C compressor. When the refrigerant pressure is above 1, 470 kPa (14.99 kgf/cm 2 , 213.2 psi), the PCM switches the radiator and the A/C condenser fans to high speed.

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Dual Mode Control System

All modes (except defroster) can be controlled independently.

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The i-Dual climate control system automatically controls the temperature and the air direction to the driver and passenger's side depending on the angle of the sun and the direction of the vehicle. It calculates information such as date, time, longitude, and latitude from the navigation system, as well as the radiant strength of the sun from the sunlight sensor, to determine the appropriate mode position and temperature to be directed to each side.

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In the event that the navigation system malfunctions, or when driving in areas where the navigation system cannot determine the vehicle position (non-coverage areas, tunnels, etc.), the climate control system will operate the same as a vehicle without navigation.

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CONNECTOR A

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CONNECTOR B

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CONNECTOR C

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Note. If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A ).

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1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode.
3. Do the Self-Diagnostic Function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC U0155 indicated? YES -Go to step 5. NO -The system is OK at this time. Check for loose wires or poor connections on the B-CAN lines between the gauge control module and the climate control unit.
5. Select B-CAN Control Units Information in the BODY ELECTRICAL menu.
6. Select Check Connected Control Units in the B-CAN Control Units Information menu. Is the gauge control module detected? YES -Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). NO -Go to step 7.
7. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
8. Disconnect gauge control module connector A (32P).
9. Disconnect climate control unit connector C (20P).
10. Check for continuity between the following terminals of gauge control module connector A (32P) and climate control unit connector C (20P). 32P: 20P: No. 29 No. 7 No. 30 No. 8 Is there continuity? YES -Go to the gauge control module input test (see «GAUGE CONTROL MODULE INPUT TEST»(/acura/zdx/i-2009-2013/remont/gauges-instrument-panels/#gauges__gauge-control-module-input-test) ). NO -Repair an open in the wire(s) between the climate control unit and the gauge control module.

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1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode.
3. Do the Self-Diagnostic Function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B1215 or J and MODE indicated? YES -Go to step 5. NO -Intermittent failure. Check for loose wires or poor connections on the recirculation control motor circuit.
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
6. Test the recirculation control motor (see «RECIRCULATION CONTROL MOTOR TEST»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__recirculation-control-motor-test) ). Is the recirculation control motor OK? YES -Go to step 7. NO -Replace the recirculation control motor (see «RECIRCULATION CONTROL MOTOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
7. Disconnect the recirculation control motor 7P connector.
8. Disconnect climate control unit connector C (20P).
9. Check for continuity between the following terminals of climate control unit connector C (20P) and the recirculation control motor 7P connector. 20P: 7P: No. 1 No. 7 No. 18 No. 5 No. 19 No. 4 No. 20 No. 3 Is there continuity? YES -Go to step 10. NO -Repair an open in the wire(s) between the climate control unit and the recirculation control motor.
10. Check for continuity between body ground and climate control unit connector C (20P) terminals No. 18, No. 19, and No. 20 individually. Is there continuity? YES -Repair a short to body ground in the wire(s) between the climate control unit and the recirculation control motor. NO -Go to step 11.
11. Check for continuity between climate control unit connector C (20P) terminals as follows. From terminal To terminals 18 19, 20 19 20 Is there continuity between any of the terminals? YES -Repair a short in the wire(s) between the climate control unit and the recirculation control motor. NO -Go to step 12.
12. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between body ground and climate control unit connector C (20P) terminals No. 18, No. 19, and No. 20 individually. Is there any voltage? YES -Repair a short to power in the wire(s) between the climate control unit and the recirculation control motor. This short may also damage the climate control unit. Repair a short to power before replacing the climate control unit. NO -Check for loose wires or poor connections at climate control unit connector C (20P) and at the recirculation control motor 7P connector. If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

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1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode.
3. Do the Self-Diagnostic Function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B1225 or A and AUTO indicated? YES -Go to step 5. NO -Intermittent failure. Check for loose wires or poor connections on the in-car temperature sensor circuit.
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
6. Remove the humidity/in-car temperature sensor (see «HUMIDITY/IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ), and test it (see «HUMIDITY/IN-CAR TEMPERATURE SENSOR TEST»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). Is the in-car temperature sensor OK? YES -With the humidity/in-car temperature sensor disconnected, go to step 7. NO -Replace the humidity/in-car temperature sensor (see «HUMIDITY/IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
7. Disconnect climate control unit connector C (20P).
8. Check for continuity between climate control unit connector C (20P) terminal No. 15 and humidity/in-car temperature sensor 4P connector terminal No. 4. Is there continuity? YES -Go to step 9. NO -Repair an open in the wire between the climate control unit and the in-car temperature sensor.
9. Check for continuity between climate control unit connector C (20P) terminal No. 1 and humidity/in-car temperature sensor 4P connector terminal No. 3. Is there continuity? YES -Check for loose wires or poor connections at climate control unit connector C (20P) and at the humidity/in-car temperature sensor 4P connector. If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). NO -Repair an open in the wire between the climate control unit and the in-car temperature sensor.

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1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode.
3. Do the Self-Diagnostic Function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B1226 or B and AUTO indicated? YES -Go to step 5. NO -Intermittent failure. Check for loose wires or poor connections on the in-car temperature sensor circuit.
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
6. Remove the humidity/in-car temperature sensor (see «HUMIDITY/IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ), and test it (see «HUMIDITY/IN-CAR TEMPERATURE SENSOR TEST»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). Is the in-car temperature sensor OK? YES -With the humidity/in-car temperature sensor disconnected, go to step 7. NO -Replace the humidity/in-car temperature sensor (see «HUMIDITY/IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
7. Disconnect climate control unit connector C (20P).
8. Check for continuity between climate control unit connector C (20P) terminal No. 15 and body ground. Is there continuity? YES -Repair a short to body ground in the wire between the climate control unit and the in-car temperature sensor. NO -Go to step 9.
9. Check for continuity between climate control unit connector C (20P) terminals No. 1 and No. 15. Is there continuity? YES -Repair a short in the wires between the climate control unit and the in-car temperature sensor. NO -Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

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1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode.
3. Do the Self-Diagnostic Function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B1227 or C and AUTO indicated? YES -Go to step 5. NO -Intermittent failure. Check for loose wires or poor connections on the outside air temperature sensor circuit.
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
6. Remove the outside air temperature sensor (see «OUTSIDE AIR TEMPERATURE SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ), and test it (see «IN-CAR TEMPERATURE SENSOR TEST»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__in-car-temperature-sensor-test) ). Is the outside air temperature sensor OK? YES -With the outside air temperature sensor disconnected, go to step 7. NO -Replace the outside air temperature sensor (see «OUTSIDE AIR TEMPERATURE SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
7. Disconnect climate control unit connector C (20P).
8. Check for continuity between climate control unit connector C (20P) terminal No. 17 and outside air temperature sensor 2P connector terminal No. 2. Is there continuity? YES -Go to step 9. NO -Repair an open in the wire between the climate control unit and the outside air temperature sensor.
9. Check for continuity between climate control unit connector C (20P) terminal No. 1 and outside air temperature sensor 2P connector terminal No. 1. Is there continuity? YES -Check for loose wires or poor connections at climate control unit connector C (20P) and at the outside air temperature sensor 2P connector. If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). NO -Repair an open in the wire between the climate control unit and the outside air temperature sensor.

Scheme 37

Scheme 38

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode.
3. Do the Self-Diagnostic Function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B1228 or D and AUTO indicated? YES -Go to step 5. NO -Intermittent failure. Check for loose wires or poor connections on the outside air temperature sensor circuit.
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
6. Remove the outside air temperature sensor (see «OUTSIDE AIR TEMPERATURE SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ), and test it (see «IN-CAR TEMPERATURE SENSOR TEST»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__in-car-temperature-sensor-test) ). Is the outside air temperature sensor OK? YES -With the outside air temperature sensor disconnected, go to step 7. NO -Replace the outside air temperature sensor (see «OUTSIDE AIR TEMPERATURE SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
7. Disconnect climate control unit connector C (20P).
8. Check for continuity between climate control unit connector C (20P) terminal No. 17 and body ground. Is there continuity? YES -Repair a short to body ground in the wire between the climate control unit and the outside air temperature sensor. NO -Go to step 9.
9. Check for continuity between climate control unit connector C (20P) terminals No. 1 and No. 17. Is there continuity? YES -Repair a short in the wires between the climate control unit and the outside air temperature sensor. NO -Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

Scheme 39

Scheme 40

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode.
3. Do the Self-Diagnostic Function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B1229 or E and AUTO indicated? YES -Go to step 5. NO -Intermittent failure. Check for loose wires or poor connections on the sunlight sensor circuit.
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
6. Disconnect the sunlight sensor 5P connector.
7. Disconnect climate control unit connector C (20P).
8. Check for continuity between climate control unit connector C (20P) terminal No. 14 and sunlight sensor 5P connector terminal No. 4. Is there continuity? YES -Go to step 9. NO -Repair an open in the wire between the climate control unit and the sunlight sensor.
9. Check for continuity between climate control unit connector C (20P) terminal No. 1 and sunlight sensor 5P connector terminal No. 2. Is there continuity? YES -Go to step 10. NO -Repair an open in the wire between the climate control unit and the sunlight sensor.
10. Reconnect the sunlight sensor 5P connector.
11. Reconnect climate control unit connector C (20P).
12. Test the sunlight sensor (see «SUNLIGHT SENSOR TEST»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__sunlight-sensor-test) ). Is the sunlight sensor OK? YES -Check for loose wires or poor connections at climate control unit connector C (20P) and at the sunlight sensor 5P connector. If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). NO -Replace the sunlight sensor (see «SUNLIGHT SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

Scheme 41

Scheme 42

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode.
3. Do the Self-Diagnostic Function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B1230 or F and AUTO indicated? YES -Go to step 5. NO -Intermittent failure. Check for loose wires or poor connections on the sunlight sensor circuit.
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
6. Disconnect the sunlight sensor 5P connector.
7. Disconnect climate control unit connector C (20P).
8. Check for continuity between climate control unit connector C (20P) terminal No. 14 and body ground. Is there continuity? YES -Repair a short to body ground in the wire between the climate control unit and the sunlight sensor. NO -Go to step 9.
9. Check for continuity between climate control unit connector C (20P) terminals No. 1 and No. 14. Is there continuity? YES -Repair a short in the wires between the climate control unit and the sunlight sensor. NO -Go to step 10.
10. Reconnect the sunlight sensor 5P connector.
11. Reconnect climate control unit connector C (20P).
12. Test the sunlight sensor (see «SUNLIGHT SENSOR TEST»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__sunlight-sensor-test) ). Is the sunlight sensor OK? YES -Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). NO -Replace the sunlight sensor (see «SUNLIGHT SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

Scheme 43

Scheme 44

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode.
3. Do the Self-Diagnostic Function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B1231 or G and AUTO indicated? YES -Go to step 5. NO -Intermittent failure. Check for loose wires or poor connections on the evaporator temperature sensor circuit.
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
6. Disconnect climate control unit connector C (20P).
7. Disconnect the evaporator temperature sensor 2P connector.
8. Check for continuity between climate control unit connector C (20P) terminal No. 16 and evaporator temperature sensor 2P connector terminal No. 1. Is there continuity? YES -Go to step 9. NO -Repair an open in the wire between the climate control unit and the evaporator temperature sensor.
9. Check for continuity between climate control unit connector C (20P) terminal No. 1 and evaporator temperature sensor 2P connector terminal No. 2. Is there continuity? YES -Go to step 10. NO -Repair an open in the wire between the climate control unit and the evaporator temperature sensor.
10. Remove the evaporator temperature sensor (see «EVAPORATOR TEMPERATURE SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ), and test it (see «SUNLIGHT SENSOR TEST»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__sunlight-sensor-test) ). Is the evaporator temperature sensor OK? YES -Check for loose wires or poor connections at climate control unit connector C (20P) and at the evaporator temperature sensor 2P connector. If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). NO -Replace the evaporator temperature sensor (see «EVAPORATOR TEMPERATURE SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

Scheme 45

Scheme 46

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode.
3. Do the Self-Diagnostic Function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B1232 or H and AUTO indicated? YES -Go to step 5. NO -Intermittent failure. Check for loose wires or poor connections on the evaporator temperature sensor circuit.
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
6. Disconnect climate control unit connector C (20P).
7. Disconnect the evaporator temperature sensor 2P connector.
8. Check for continuity between climate control unit connector C(20P) terminal No. 16 and body ground. Is there continuity? YES -Repair a short to body ground in the wire between the climate control unit and the evaporator temperature sensor. NO -Go to step 9.
9. Check for continuity between climate control unit connector C(20P) terminals No. 1 and No. 16. Is there continuity? YES -Repair a short in the wires between the climate control unit and the evaporator temperature sensor. NO -Go to step 10.
10. Remove the evaporator temperature sensor (see «EVAPORATOR TEMPERATURE SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ), and test it (see «SUNLIGHT SENSOR TEST»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__sunlight-sensor-test) ). Is the evaporator temperature sensor OK? YES -Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). NO -Replace the evaporator temperature sensor (see «EVAPORATOR TEMPERATURE SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

Scheme 47

Scheme 48

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode.
3. Do the Self-Diagnostic Function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B1233 or J and AUTO indicated? YES -Go to step 5. NO -Intermittent failure. Check for loose wires or poor connections on the driver's air mix control motor circuit.
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
6. Test the driver's air mix control motor (see «DRIVER'S AIR MIX CONTROL MOTOR TEST»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__drivers-air-mix-control-motor-test) ). Is the driver's air mix control motor OK? YES -Go to step 7. NO -Replace the driver's air mix control motor (see «DRIVER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
7. Disconnect the driver's air mix control motor 7P connector.
8. Disconnect climate control unit connectors A (32P) and C (20P).
9. Check for continuity between the following terminals of climate control unit connectors A (32P), C (20P), and the driver's air mix control motor 7P connector. 32P: 7P: No. 25 No. 3 20P: 7P: No. 1 No. 5 No. 2 No. 7 Is there continuity between any of the terminals? YES -Check for loose wires or poor connections at climate control unit connectors A (32P), C (20P), and at the driver's air mix control motor 7P connector. If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). NO -Repair an open in the wire(s) between the climate control unit and the driver's air mix control motor.

Scheme 49

Scheme 50

Scheme 51

Scheme 52

Scheme 53

Scheme 54

Scheme 55

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode.
3. Do the Self-Diagnostic Function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B1234 or K and AUTO indicated? YES -Go to step 5. NO -Intermittent failure. Check for loose or poor connection on the driver's air mix control motor circuit.
5. Check for DTCs. Are these DTCs also present; B1237 or N and AUTO, and/or B2968 or B and WINDSHIELD DEFROST, and/or B2980 or F and WINDSHIELD DEFROST? YES -Go to step 13 . NO -Go to step 6.
6. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
7. Test the driver's air mix control motor (see «DRIVER'S AIR MIX CONTROL MOTOR TEST»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__drivers-air-mix-control-motor-test) ). Is the driver's air mix control motor OK? YES -Go to step 8. NO -Replace the driver's air mix control motor (see «DRIVER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
8. Disconnect the driver's air mix control motor 7P connector.
9. Disconnect climate control unit connectors A (32P) and C (20P).
10. Check for continuity between climate control unit connector A (32P) terminal No. 25 and body ground. Is there continuity? YES -Repair a short to body ground in the wire between the climate control unit and the driver's air mix control motor. NO -Go to step 11.
11. Check for continuity between climate control unit connector A (32P) terminal No. 25 and climate control unit connector C (20P) terminal No. 2. Is there continuity? YES -Repair a short in the wires between the climate control unit and the driver's air mix control motor. NO -Go to step 12.
12. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between climate control unit connector A (32P) terminal No. 25 and body ground. Is there any voltage? YES -Repair a short to power in the wire between the climate control unit and the driver's air mix control motor. This short may also damage the climate control unit. Repair a short to power before replacing the climate control unit. NO -Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
13. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode, and disconnect climate control unit connector C (20P).
14. Disconnect these items: Driver's air mix control motor Passenger's air mix control motor Humidity/in-car temperature sensor A/C pressure sensor
15. Check for continuity between climate control unit connector C (20P) terminal No. 2 and body ground. Is there continuity? YES -Repair a short to body ground in the wire between the climate control unit and the driver's air mix control motor. NO -Go to step 16.
16. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between climate control unit connector C (20P) terminal No. 2 and body ground. Is there any voltage? YES -Repair a short to power in the wire between the climate control unit and the driver's air mix control motor. This short may have also damaged the climate control unit. Repair a short to power before replacing the climate control unit. NO -Go to step 17.
17. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
18. Reconnect climate control unit connector C (20P).
19. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between climate control unit connector C (20P) terminal No. 2 and body ground. Is there about 5 V? YES -Go to step 20. NO -Check for loose wires or poor connections at climate control unit connector C (20P). If the connection is good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
20. While measuring the voltage between climate control unit connector C (20P) terminal No. 2 and body ground, reconnect these items individually and note the voltage reading each time: Driver's air mix control motor Passenger's air mix control motor Humidity/in-car temperature sensor A/C pressure sensor Does the voltage remain at about 5 V? YES -Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). NO -Replace the component that caused the voltage drop.

Scheme 56

Scheme 57

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode.
3. Do the Self-Diagnostic Function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B1235 or L and AUTO indicated? YES -Go to step 5. NO -Intermittent failure. Check for loose wires or poor connections on the driver's air mix control motor circuit.
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
6. Test the driver's air mix control motor (see «DRIVER'S AIR MIX CONTROL MOTOR TEST»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__drivers-air-mix-control-motor-test) ). Is the driver's air mix control motor OK? YES -Go to step 7. NO -Replace the driver's air mix control motor (see «DRIVER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ), or repair the driver's air mix control linkage or door.
7. Disconnect the driver's air mix control motor 7P connector.
8. Disconnect climate control unit connector A (32P).
9. Check for continuity between the following terminals of climate control unit connector A (32P) and the driver's air mix control motor 7P connector. 32P: 7P: No. 11 No. 1 No. 12 No. 2 Is there continuity? YES -Go to step 10. NO -Repair an open in the wire(s) between the climate control unit and the driver's air mix control motor.
10. Check for continuity between body ground and climate control unit connector A (32P) terminals No. 11 and No. 12 individually. Is there continuity? YES -Repair a short to body ground in the wire(s) between the climate control unit and the driver's air mix control motor. NO -Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

Scheme 58

Scheme 59

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode.
3. Do the Self-Diagnostic Function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B1236 or M and AUTO indicated? YES -Go to step 5. NO -Intermittent failure. Check for loose wires or poor connections on the passenger's air mix control motor circuit.
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
6. Test the passenger's air mix control motor (see «PASSENGER'S AIR MIX CONTROL MOTOR TEST»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__passengers-air-mix-control-motor-test) ). Is the passenger's air mix control motor OK? YES -Go to step 7. NO -Replace the passenger's air mix control motor (see «PASSENGER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
7. Disconnect the passenger's air mix control motor 7P connector.
8. Disconnect climate control unit connectors A (32P) and C (20P).
9. Check for continuity between the following terminals of climate control unit connectors A (32P), C (20P), and the passenger's air mix control motor 7P connector. 32P: 7P: No. 26 No. 3 20P: 7P: No. 1 No. 5 No. 2 No. 7 Is there continuity? YES -Check for loose wires or poor connections at climate control unit connectors A (32P), C (20P), and at the passenger's air mix control motor 7P connector. If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). NO -Repair an open in the wire(s) between the climate control unit and the passenger's air mix control motor.

Scheme 60

Scheme 61

Scheme 62

Scheme 63

Scheme 64

Scheme 65

Scheme 66

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode.
3. Do the Self-Diagnostic Function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B1237 or N and AUTO indicated? YES -Go to step 5. NO -Intermittent failure. Check for loose or poor connection on the passenger's air mix control motor circuit.
5. Check for DTCs. Are these DTCs also present; B1234 or K and AUTO, and/or B2968 or B and WINDSHIELD DEFROST, and/or B2980 or F and WINDSHIELD DEFROST? YES -Go to step 13 . NO -Go to step 6.
6. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
7. Test the passenger's air mix control motor (see «PASSENGER'S AIR MIX CONTROL MOTOR TEST»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__passengers-air-mix-control-motor-test) ). Is the passenger's air mix control motor OK? YES -Go to step 8. NO -Replace the passenger's air mix control motor (see «PASSENGER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
8. Disconnect the passenger's air mix control motor 7P connector.
9. Disconnect climate control unit connectors A (32P) and C (20P).
10. Check for continuity between climate control unit connector A (32P) terminal No. 26 and body ground. Is there continuity? YES -Repair a short to body ground in the wire between the climate control unit and the passenger's air mix control motor. NO -Go to step 11.
11. Check for continuity between climate control unit connector A (32P) terminal No. 26 and climate control unit connector C (20P) terminal No. 2. Is there continuity? YES -Repair a short in the wire between the climate control unit and the passenger's air mix control motor. NO -Go to step 12.
12. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between climate control unit connector A (32P) terminal No. 26 and body ground. Is there any voltage? YES -Repair a short to power in the wire between the climate control unit and the passenger's air mix control motor. This short may also damage the climate control unit. Repair a short to power before replacing the climate control unit. NO -Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
13. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode, and disconnect climate control unit connector C (20P).
14. Disconnect these items: Driver's air mix control motor Passenger's air mix control motor Humidity/in-car temperature sensor A/C pressure sensor
15. Check for continuity between climate control unit connector C (20P) terminal No. 2 and body ground. Is there continuity? YES -Repair a short to body ground in the wire between the climate control unit and the passenger's air mix control motor. NO -Go to step 16.
16. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between climate control unit connector C (20P) terminal No. 2 and body ground. Is there any voltage? YES -Repair a short to power in the wire between the climate control unit and the passenger's air mix control motor. This short may have also damaged the climate control unit. Repair a short to power before replacing the climate control unit. NO -Go to step 17.
17. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
18. Reconnect climate control unit connector C (20P).
19. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between climate control unit connector C (20P) terminal No. 2 and body ground. Is there about 5 V? YES -Go to step 20. NO -Check for loose wires or poor connections at climate control unit connector C(20P). If the connection is good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
20. While measuring the voltage between climate control unit connector C (20P) terminal No. 2 and body ground, reconnect these items individually and note the voltage reading each time: Driver's air mix control motor Passenger's air mix control motor Humidity/in-car temperature sensor A/C pressure sensor Does the voltage remain at about 5 V? YES -Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). NO -Replace the component that caused the voltage drop.

Scheme 67

Scheme 68

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode.
3. Do the Self-Diagnostic Function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B1238 or P and AUTO indicated? YES -Go to step 5. NO -Intermittent failure. Check for loose wires or poor connections on the passenger's air mix control motor circuit.
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
6. Test the passenger's air mix control motor (see «PASSENGER'S AIR MIX CONTROL MOTOR TEST»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__passengers-air-mix-control-motor-test) ). Is the passenger's air mix control motor OK? YES -Go to step 7. NO -Replace the passenger's air mix control motor (see «PASSENGER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ), or repair the passenger's air mix control linkage or door.
7. Disconnect the passenger's air mix control motor 7P connector.
8. Disconnect climate control unit connector A (32P).
9. Check for continuity between the following terminals of climate control unit connector A (32P) and the _ passenger's air mix control motor 7P connector. 32P: 7P: No. 9 No. 1 No. 10 No. 2 Is there continuity? YES -Go to step 10. NO -Repair an open in the wire(s) between the climate control unit and the passenger's air mix control motor.
10. Check for continuity between body ground and climate control unit connector A (32P) terminals No. 9 and No. 10 individually. Is there continuity? YES -Repair a short to body ground in the wire(s) between the climate control unit and the passenger's air mix control motor. NO -Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

Scheme 69

Scheme 70

Scheme 71

Scheme 72

Scheme 73

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode.
3. Do the Self-Diagnostic Function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B1239 or A and MODE indicated? YES -Go to step 5. NO -Intermittent failure. Check for loose wires or poor connections on the driver's mode control motor circuit.
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
6. Test the driver's mode control motor (see «DRIVER'S MODE CONTROL MOTOR TEST»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__drivers-mode-control-motor-test) ). Is the driver's mode control motor OK? YES -Go to step 7. NO -Replace the driver's mode control motor (see «PASSENGER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
7. Disconnect the driver's mode control motor 7P connector.
8. Disconnect climate control unit connectors A (32P) and C (20P).
9. Check for continuity between the following terminals of climate control unit connectors A (32P), C (20P) and the driver's mode control motor 7P connector. 32P: 7P: No. 21 No. 6 No. 22 No. 5 No. 23 No. 4 No. 24 No. 3 20P: 7P: No. 1 No. 7 Is there continuity? YES -Go to step 10. NO -Repair an open in the wire(s) between the climate control unit and the driver's mode control motor.
10. Check for continuity between body ground and climate control unit connector A (32P) terminals No. 21, No. 22, No. 23, and No. 24 individually. Is there continuity? YES -Repair a short to body ground in the wire(s) between the climate control unit and the driver's mode control motor. NO -Go to step 11.
11. Check for continuity between climate control unit connector A (32P) terminals as follows. From terminal To terminals 21 22, 23, 24 22 23, 24 23 24 Is there continuity between any of the terminals? YES -Repair a short in the wires between the climate control unit and the driver's mode control motor. NO -Go to step 12.
12. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between body ground and climate control unit connector A (32P) terminals No. 21, No. 22, No. 23, and No. 24 individually. Is there any voltage? YES -Repair a short to power in the wire(s) between the climate control unit and the driver's mode control motor. This short may also damage the climate control unit. Repair a short to power before replacing the climate control unit. NO -Check for loose wires or poor connections at climate control unit connector A (32P) and at the driver's mode control motor 7P connector. If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

Scheme 74

Scheme 75

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode.
3. Do the Self-Diagnostic Function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B1240 or B and MODE indicated? YES -Go to step 5. NO -Intermittent failure. Check for loose wires or poor connections on the driver's mode control motor circuit.
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
6. Test the driver's mode control motor (see «DRIVER'S MODE CONTROL MOTOR TEST»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__drivers-mode-control-motor-test) ). Is the driver's mode control motor OK? YES -Go to step 7. NO -Replace the driver's mode control motor (see «PASSENGER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ), or repair the driver's mode control linkage or doors.
7. Disconnect the driver's mode control motor 7P connector.
8. Disconnect climate control unit connector A (32P).
9. Check for continuity between the following terminals of climate control unit connector A (32P) and the driver's mode control motor 7P connector. 32P: 7P: No. 7 No. 2 No. 8 No. 1 Is there continuity? YES -Go to step 10. NO -Repair an open in the wire(s) between the climate control unit and the driver's mode control motor.
10. Check for continuity between body ground and climate control unit connector A (32P) terminals No. 7 and No. 8 individually. Is there continuity? YES -Repair a short to body ground in the wire(s) between the climate control unit and the driver's mode control motor. NO -Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

Scheme 76

Scheme 77

Scheme 78

Scheme 79

Scheme 80

Scheme 81

Scheme 82

Scheme 83

Scheme 84

Scheme 85

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode.
3. Do the Self-Diagnostic Function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B1241 or C and MODE indicated? YES -Go to step 5. NO -Intermittent failure. Check for loose wires or poor connections on the blower motor circuit.
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
6. Check the No. 4 (40 A) fuse in the under-hood fuse/relay box, and the No. 16 (7.5 A) fuse in the driver's under-dash fuse/relay box. Are the fuses OK? YES -Go to step 7. NO -Replace the fuse(s), and recheck. If the fuse(s) blow again, check for a short in the No. 4 (40 A) fuse and/or the No. 16(7.5 A) fuse circuit(s).
7. Connect blower motor 2P connector terminal No. 2 to body ground with a Jumper wire.
8. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode. Does the blower motor run? YES -Go to step 9. NO -Go to step 24 .
9. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
10. Disconnect the jumper wire.
11. Disconnect the power transistor 5P connector.
12. Check for continuity between power transistor 5P connector terminal No. 5 and body ground. Is there continuity? YES -Go to step 13. NO -Check for an open in the wire between the power transistor and body ground. If the wire is OK, check for poor ground at G302 (see «CONNECTOR TO FUSE/RELAY BOX INDEX»(/acura/zdx/i-2009-2013/remont/body-electrical/#fuserelay-boxes__connector-to-fuserelay-box-index) ).
13. Connect power transistor 5P connector terminals No, 4 and No. 5 with a jumper wire.
14. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode. Does the blower motor run at high speed? YES -Go to step 15. NO -Repair an open in the GRN wire between the power transistor and the blower motor.
15. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF.
16. Disconnect the jumper wire.
17. Disconnect climate control unit connector A (32P).
18. Check for continuity between body ground and climate control unit connector A (32P) terminals No. 27 and No. 28 individually. Is there continuity? YES -Repair a short to body ground in the wire(s) between the climate control unit and the power transistor. NO -Go to step 19.
19. Check for continuity between the following terminals of the climate control unit connector A (32P) and the power transistor 5P connector. 32P: 5P: No. 27 No. 1 No. 28 No. 3 Is there continuity? YES -Go to step 20. NO -Repair an open in the wire(s) between the climate control unit and the power transistor.
20. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
21. Measure the voltage between body ground and climate control unit connector A (32P) terminals No. 27 and No. 28 individually. Is there voltage? YES -Repair a short to power in the wire(s) between the climate control unit and the power transistor. NO -Go to step 22.
22. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
23. Test the power transistor (see «POWER TRANSISTOR TEST»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). Is the power transistor OK? YES -Check for loose wires or poor connections at climate control unit connector A (32P) and at the power transistor 5P connector. If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). NO -Replace the power transistor. NOTE: If the power transistor is faulty, check the blower motor for damage. If necessary, replace the blower motor.
24. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
25. Disconnect the jumper wire.
26. Disconnect the blower motor 2P connector.
27. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
28. Measure the voltage between blower motor 2P connector terminal No. 1 and body ground. Is there battery voltage? YES -Replace the blower motor (see «BLOWER UNIT COMPONENT REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__blower-unit-component-replacement) ). NO -Go to step 29.
29. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
30. Remove the blower motor relay from the under-hood fuse/relay box, and test it (see «POWER RELAY TEST»(/acura/zdx/i-2009-2013/remont/body-electrical/#relays__power-relay-test) ). Is the relay OK? YES -Go to step 31. NO -Replace the blower motor relay.
31. Check for continuity between blower motor relay 4P socket terminal No. 2 and blower motor 2P connector terminal No. 1. Is there continuity? YES -Go to step 32. NO -Repair an open in the wire between the blower motor relay and blower motor.
32. Measure the voltage between blower motor relay 4P socket terminal No. 1 and body ground. Is there battery voltage? YES -Go to step 33. NO -Replace the under-hood fuse/relay box (see «REMOVAL AND INSTALLATION»(/acura/zdx/i-2009-2013/remont/fuses-circuit-breakers/#under-hood-fuserelay-box__removal-and-installation) ).
33. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
34. Measure the voltage between blower motor relay 4P socket terminal No. 4 and body ground. Is there battery voltage? YES -Check for an open in the wire between blower motor relay 4P socket terminal No. 3 and body ground. If the wire is OK, check for poor body ground at G202 (see «CONNECTOR TO FUSE/RELAY BOX INDEX»(/acura/zdx/i-2009-2013/remont/body-electrical/#fuserelay-boxes__connector-to-fuserelay-box-index) ). NO -Repair an open in the wire between the No. 16 (7.5 A) fuse in the driver's under-dash fuse/relay box and the blower motor relay.

Scheme 86

Scheme 87

Scheme 88

Scheme 89

Scheme 90

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode.
3. Do the Self-Diagnostic Function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B1242 or E and MODE indicated? YES -Go to step 5. NO -Intermittent failure. Check for loose wires or poor connections on the passenger's mode control motor circuit.
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
6. Test the passenger's mode control motor (see «PASSENGER'S MODE CONTROL MOTOR TEST»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__passengers-mode-control-motor-test) ). Is the passenger's mode control motor OK? YES -Go to step 7. NO -Replace the passenger's mode control motor (see «PASSENGER'S MODE CONTROL MOTOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
7. Disconnect the passenger's mode control motor 7P connector.
8. Disconnect climate control unit connectors A (32P) and C (20P).
9. Check for continuity between the following terminals of climate control unit connectors A (32P), C (20P) and the passenger's mode control motor 7P connector. 32P: 7P: No. 17 No. 6 No. 18 No. 5 No. 19 No. 4 No. 20 No. 3 20P: 7P: No. 1 No. 7 Is there continuity? YES -Go to step 10. NO -Repair an open in the wire(s) between the climate control unit and the passenger's mode control motor.
10. Check for continuity between body ground and climate control unit connector A (32P) terminals No. 17, No. 18, No. 19, and No. 20 individually. Is there continuity? YES -Repair a short to body ground in the wire(s) between the climate control unit and the passenger's mode control motor. NO -Go to step 11.
11. Check for continuity between climate control unit connector A (32P) terminals as follows. From terminal To terminals 17 18, 19, 20 18 19, 20 19 20 Is there continuity between any of the terminals? YES -Repair a short in the wires between the climate control unit and the passenger's mode control motor. NO -Go to step 12.
12. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between body ground and climate control unit connector A (32P) terminals No. 17, No. 18, No. 19, and No. 20 individually. Is there any voltage? YES -Repair a short to power in the wire(s) between the climate control unit and the passenger's mode control motor. This short may also damage the climate control unit. Repair a short to power before replacing the climate control unit. NO -Check for loose wires or poor connections at climate control unit connector A (32P) and at the passenger's mode control motor 7P connector. If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

Scheme 91

Scheme 92

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode.
3. Do the Self-Diagnostic Function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B1243 or F and MODE indicated? YES -Go to step 5. NO -Intermittent failure. Check for loose wires or poor connections on the passenger's mode control motor circuit.
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
6. Test the passenger's mode control motor (see «PASSENGER'S MODE CONTROL MOTOR TEST»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__passengers-mode-control-motor-test) ). Is the passenger's mode control motor OK? YES -Go to step 7. NO -Replace the passenger's mode control motor (see «PASSENGER'S MODE CONTROL MOTOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ), or repair the passenger's mode control linkage or doors.
7. Disconnect the passenger's mode control motor 7P connector.
8. Disconnect climate control unit connector A (32P).
9. Check for continuity between the following terminals of climate control unit connector A (32P) and the passenger's mode control motor 7P connector. 32P: 7P: No. 5 No. 1 No. 6 No. 2 Is there continuity? YES -Go to step 10. NO -Repair an open in the wire(s) between the climate control unit and the passenger's mode control motor.
10. Check for continuity between body ground and climate control unit connector A (32P) terminals No. 5 and No. 6 individually. Is there continuity? YES -Repair a short to body ground in the wire(s) between the climate control unit and the passenger's mode control motor. NO -Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

Scheme 93

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode.
3. Do the Self-Diagnostic Function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B2967 or A and WINDSHIELD DEFROST indicated? YES -Go to step 5. NO -Intermittent failure, check for loose wires or poor connections on the humidity sensor circuit.
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
6. Remove the humidity/in-car temperature sensor (see «HUMIDITY/IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ), and test it (see «HUMIDITY/IN-CAR TEMPERATURE SENSOR TEST»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). Is the humidity sensor OK? YES -Go to step 7. NO -Replace the humidity/in-car temperature sensor (see «HUMIDITY/IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
7. Disconnect the humidity/in-car temperature sensor 4P connector.
8. Disconnect climate control unit connector C (20P).
9. Check for continuity between the following terminals of climate control unit connector C (20P) and the humidity/in-car temperature sensor 4P connector. 20P: 4P: No. 1 No. 3 No. 2 No. 1 No. 12 No. 2 Is there continuity? YES -Check for loose wires or poor connections at climate control unit connector C (20P) and at the humidity/in-car temperature sensor 4P connector. If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). NO -Repair an open in the wire(s) between the climate control unit and the humidity sensor.

Scheme 94

Scheme 95

Scheme 96

Scheme 97

Scheme 98

Scheme 99

Scheme 100

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode.
3. Do the Self-Diagnostic Function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B2968 or B and WINDSHIELD DEFROST indicated? YES -Go to step 5. NO -Intermittent failure. Check for loose wires or poor connections on the humidity sensor circuit.
5. Check for DTCs. Are these DTCs also present; B1234 or K and AUTO, and/or B1237 or N and AUTO, and/or B2980 or F and WINDSHIELD DEFROST? YES -Go to step 13 . NO -Go to step 6.
6. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
7. Remove the humidity/in-car temperature sensor (see «HUMIDITY/IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ), and test it (see «HUMIDITY/IN-CAR TEMPERATURE SENSOR TEST»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). Is the humidity sensor OK? YES -Go to step 8. NO -Replace the humidity/in-car temperature sensor (see «HUMIDITY/IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
8. Disconnect the humidity/in-car temperature sensor 4P connector.
9. Disconnect climate control unit connector C (20P).
10. Check for continuity between climate control unit connector C (20P) terminal No. 12 and body ground. Is there continuity? YES -Repair a short to body ground in the wire between the climate control unit and the humidity sensor. NO -Go to step 11.
11. Check for continuity between climate control unit connector C (20P) terminals No. 2 and No. 12. Is there continuity? YES -Repair a short in the wires between the climate control unit and the humidity sensor. NO -Go to step 12.
12. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between climate control unit connector C (20P) terminal No. 12 and body ground. Is there any voltage? YES -Repair a short to power in the wire between the climate control unit and the humidity sensor. This short may also damage the climate control unit. Repair a short to power before replacing the climate control unit. NO -Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
13. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode, and disconnect climate control unit connector C (20P).
14. Disconnect these items: Driver's air mix control motor Passenger's air mix control motor Humidity/in-car temperature sensor A/C pressure sensor
15. Check for continuity between climate control unit connector C (20P) terminal No. 2 and body ground. Is there continuity? YES -Repair a short to body ground in the wire between the climate control unit and the humidity sensor. NO -Go to step 16.
16. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between climate control unit connector C (20P) terminal No. 2 and body ground. Is there any voltage? YES -Repair a short to power in the wire between the climate control unit and the humidity sensor. This short may have also damaged the climate control unit. Repair the short to power before replacing the climate control unit. NO -Go to step 17.
17. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
18. Reconnect climate control unit connector C (20P).
19. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode and measure the voltage between climate control unit connector C (20P) terminal No. 2 and body ground. Is there about 5 V? YES -Go to step 20. NO -Check for loose wires or poor connections at climate control unit connector C (20P). If the connection is good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
20. While measuring the voltage between the climate control unit connector C (20P) terminal No. 2 and body ground, reconnect these items individually and note the voltage reading each time: Driver's air mix control motor Passenger's air mix control motor Humidity/in-car temperature sensor A/C pressure sensor Does the voltage remain at about 5 V? YES -Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). NO -Replace the component that caused the voltage drop.

Note. If you are troubleshooting multiple DTCs, be sure to follow the instructions in the B-CAN system diagnosis test mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A ).

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode and then the ON mode.
3. Wait for at least 6 seconds.
4. Do the Self-Diagnostic Function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
5. Check for DTCs. Is DTC B2969 indicated? YES -Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). NO -The system is OK at this time. Check for loose wires or poor connections on the driver's under-dash fuse/relay box and climate control unit circuit.

Scheme 101

Scheme 102

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode.
3. Do the Self-Diagnostic Function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B2979 or E and WINDSHIELD DEFROST indicated? YES -Go to step 5. NO -Intermittent failure. Check for loose wires or poor connections on the A/C pressure sensor circuit.
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
6. Disconnect the A/C pressure sensor 3P connector.
7. Disconnect climate control unit connector C (20P).
8. Check for continuity between the following terminals of climate control unit connector C (20P) and the A/C pressure sensor 3P connector. 20P: 3P: No. 1 No. 3 No. 2 No. 1 No. 11 No. 2 Is there continuity? YES -Go to step 9. NO -Repair an open in the wire(s) between the climate control unit and the A/C pressure sensor.
9. Reconnect climate control unit connector C (20P).
10. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
11. Measure the voltage between climate control unit connector C (20P) terminals No. 1 and No. 2, and between climate control unit connector C (20P) terminals No. 1 and No. 11. Is there about 5 V? YES -Replace the A/C pressure sensor. NO -Check for loose wires or poor connections at climate control unit connector C (20P) and at the A/C pressure sensor 3P connector. If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

Scheme 103

Scheme 104

Scheme 105

Scheme 106

Scheme 107

Scheme 108

Scheme 109

Scheme 110

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode.
3. Do the Self-Diagnostic Function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B2980 or F and WINDSHIELD DEFROST indicated? YES -Go to step 5. NO -Intermittent failure. Check for loose wires or poor connections on the A/C pressure sensor circuit.
5. Check for DTCs. Are these DTCs also present; B1234 or K and AUTO, and/or B1237 or N and AUTO, and/or B2968 or B and WINDSHIELD DEFROST? YES -Go to step 16 . NO -Go to step 6.
6. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
7. Disconnect the A/C pressure sensor 3P connector.
8. Disconnect climate control unit connector C (20P).
9. Check for continuity between climate control unit connector C (20P) terminal No. 11 and body ground. Is there continuity? YES -Repair a short to body ground in the wire between the climate control unit and the A/C pressure sensor. NO -Go to step 10.
10. Check for continuity between climate control unit connector C (20P) terminals No. 2 and No. 11. Is there continuity? YES -Repair a short in the wires between the climate control unit and the A/C pressure sensor. NO -Go to step 11.
11. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between climate control unit connector C (20P) terminal No. 11 and body ground. Is there any voltage? YES -Repair a short to power in the wire between the climate control unit and the A/C pressure sensor. This short may also damage the climate control unit. Repair a short to power before replacing the climate control unit. NO -Go to step 12.
12. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
13. Reconnect climate control unit connector C (20P).
14. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
15. Measure the voltage between climate control unit connector C (20P) terminals No. 1 and No. 2, and between climate control unit connector C (20P) terminals No. 1 and No. 11. Is there about 5 V? YES -Replace the A/C pressure sensor. NO -Check for loose wires or poor connections at climate control unit connector C (20P) and at the A/C pressure sensor 3P connector. If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
16. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode, and disconnect climate control unit connector C (20P).
17. Disconnect these items: Driver's air mix control motor Passenger's air mix control motor Humidity/in-car temperature sensor A/C pressure sensor
18. Check for continuity between climate control unit connector C (20P) terminal No. 2 and body ground. Is there continuity? YES -Repair a short to body ground in the wire between the climate control unit and the A/C pressure sensor. NO -Go to step 19.
19. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between climate control unit connector C (20P) terminal No. 2 and body ground. Is there any voltage? YES -Repair a short to power in the wire. This short may have also damaged the climate control unit. Repair the short to power before replacing the climate control unit. NO -Go to step 20.
20. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
21. Reconnect climate control unit connector C (20P).
22. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between climate control unit connector C (20P) terminal No. 2 and body ground. Is there about 5 V? YES -Go to step 23. NO -Check for loose wires or poor connections at climate control unit connector C (20P). If the connection is good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
23. While measuring the voltage between climate control unit connector C (20P) terminal No. 2 and body ground, reconnect these items individually and note the voltage reading each time: Driver's air mix control motor Passenger's air mix control motor Humidity/in-car temperature sensor A/C pressure sensor Does the voltage remain at about 5 V? YES -Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). NO -Replace the component that caused the voltage drop.

Scheme 111

Scheme 112

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode.
3. Do the Self-Diagnostic Function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check the DTCs. Is DTC B2983 or K and MODE indicated? YES -Go to step 5. NO -Intermittent failure. Check for loose wires or poor connections on the recirculation control motor circuit.
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
6. Test the recirculation control motor (see «RECIRCULATION CONTROL MOTOR TEST»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__recirculation-control-motor-test) ). Is the recirculation control motor OK? YES -Go to step 7. NO -Replace the recirculation control motor (see «RECIRCULATION CONTROL MOTOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ), or repair the recirculation control linkage or door.
7. Disconnect the recirculation control motor 7P connector.
8. Disconnect climate control unit connector C (20P).
9. Check for continuity between the following terminals of climate control unit connector C (20P) and the recirculation control motor 7P connector. 20P: 7P: No. 9 No. 2 No. 10 No. 1 Is there continuity? YES -Go to step 10. NO -Repair an open in the wire(s) between the climate control unit and the recirculation control motor.
10. Check for continuity between body ground and climate control unit connector C (20P) terminals No. 9 and No. 10 individually. Is there continuity? YES -Repair a short to body ground in the wire(s) between the climate control unit and the recirculation control motor. NO -Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

Scheme 113

Scheme 114

1. Check the No. 16 (7.5 A) fuse in the driver's under-dash fuse/relay box. Is the fuse OK? YES -Go to step 2. NO -Replace the fuse, and recheck. If the fuse blows again, check for a short in the No. 16 (7.5 A) fuse circuit.
2. Disconnect climate control unit connector A (32P).
3. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
4. Measure the voltage between climate control unit connector A (32P) terminal No. 15 and body ground. Is there battery voltage? YES -Go to step 5. NO -Repair an open in the wire between the No. 16 (7.5 A) fuse in the driver's under-dash fuse/relay box and the climate control unit.
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
6. Check for continuity between climate control unit connector A (32P) terminal No. 1 and body ground. Is there continuity? YES -Check for loose wires or poor connections at climate control unit connector A (32P). If the connections are good, substitute a known-good climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ), and recheck. NO -Check for an open in the wire between the climate control unit and body ground. If the wire is OK, check for poor body ground at G403 (see «CONNECTOR TO FUSE/RELAY BOX INDEX»(/acura/zdx/i-2009-2013/remont/body-electrical/#fuserelay-boxes__connector-to-fuserelay-box-index) ).

Radiator and A/C Condenser Fan Low Speed Circuit Troubleshooting

Note. Do not use this troubleshooting procedure if the A/C compressor is inoperative. Refer to the symptom troubleshooting index. Before doing symptom troubleshooting, check for PGM-FI DTCs (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 115

Scheme 116

Scheme 117

Scheme 118

Scheme 119

Scheme 120

1. Check the No. 3-2 (SUB FAN MOTOR) (40 A) fuse in the under-hood fuse/relay box, and the No. 16 (7.5 A) fuse in the driver's under-dash fuse/relay box. Are the fuses OK? YES -Go to step 2. NO -Replace the fuse(s), and recheck. If the fuse(s) blow again, check for a short in the No. 3-2 (SUB FAN MOTOR) (40 A) fuse and/or the No. 16 (7.5 A) fuse circuit(s).
2. Remove the A/C condenser fan relay from the under-hood fuse/relay box, and test it (see «POWER RELAY TEST»(/acura/zdx/i-2009-2013/remont/body-electrical/#relays__power-relay-test) ). Is the relay OK? YES -Go to step 3. NO -Replace the A/C condenser fan relay.
3. Reinstall the A/C condenser fan relay.
4. Connect the HDS to the DLC.
5. Start the engine.
6. Turn on the A/C.
7. Check the FAN LOW CTRL in the PGM-FI Data List with the HDS. Is the FAN LOW CTRL on? YES -Go to step 8. NO -Substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/zdx/i-2009-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), and recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM (see «PCM REPLACEMENT»(/acura/zdx/i-2009-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ).
8. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
9. Jump the SCS line with the HDS. NOTE: This step must be done to protect the PCM from damage.
10. Disconnect PCM connector A (49P).
11. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
12. Measure the voltage between PCM connector A terminal No. 4 and body ground. Is there battery voltage? YES -Go to step 13. NO -Repair an open in the wires between the under-hood fuse/relay box and the PCM, or between the No. 16 (7.5 A) fuse in driver's under-dash fuse/relay box and the under-hood fuse/relay box. If wires are OK, replace the under-hood fuse/relay box (see «REMOVAL AND INSTALLATION»(/acura/zdx/i-2009-2013/remont/fuses-circuit-breakers/#under-hood-fuserelay-box__removal-and-installation) ).
13. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
14. Connect the PCM connector A (49P) terminal No. 4 to body ground with a jumper wire.
15. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode. Do the A/C condenser and the radiator fans run on low? YES -Check for loose wires or poor connections at PCM connector A (49P). If the connections are good, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/zdx/i-2009-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), and recheck. If the symptom/indication goes away, replace the original PCM (see «PCM REPLACEMENT»(/acura/zdx/i-2009-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). NO -Go to step 16.
16. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
17. Disconnect the jumper wire.
18. Reconnect PCM connector A (49P).
19. Disconnect the A/C condenser fan motor 2P connector.
20. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, then turn on the A/C.
21. Measure the voltage between A/C condenser fan motor 2P connector terminal No. 2 and body ground. Is there battery voltage? YES -Go to step 22. NO -Repair an open in the wire between the under-hood fuse/relay box and the A/C condenser fan motor. If the wire is OK, replace the under-hood fuse/relay box (see «REMOVAL AND INSTALLATION»(/acura/zdx/i-2009-2013/remont/fuses-circuit-breakers/#under-hood-fuserelay-box__removal-and-installation) ).
22. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
23. Test the A/C condenser fan motor (see «FAN MOTOR TEST»(/acura/zdx/i-2009-2013/remont/cooling-fan/#engine-cooling-system) ). Is the A/C condenser fan motor OK? YES -Go to step 24. NO -Replace the A/C condenser fan motor (see «FAN, FAN MOTOR, AND SHROUD REMOVAL AND INSTALLATION»(/acura/zdx/i-2009-2013/remont/cooling-fan/#engine-cooling-system) ).
24. Remove the relay circuit board (see «REMOVAL AND INSTALLATION»(/acura/zdx/i-2009-2013/remont/fuses-circuit-breakers/#under-hood-fuserelay-box__removal-and-installation) ) from the under-hood fuse/relay box, and test the fan control relay (see «RELAY CIRCUIT BOARD TEST»(/acura/zdx/i-2009-2013/remont/body-electrical/#relays__relay-circuit-board-test) ). Is the relay OK? YES -Go to step 25. NO -Replace the relay circuit board.
25. Disconnect the under-hood fuse/relay box connector C (5P).
26. Check for continuity between under-hood fuse/relay box connector C (5P) terminal No. 5 and A/C condenser fan motor 2P connector terminal No. 1. Is there continuity? YES -Go to step 27. NO -Repair an open in the wire between the under-hood fuse/relay box and the A/C condenser fan motor.
27. Disconnect the radiator fan motor 2P connector.
28. Check for continuity between under-hood fuse/relay box connector C (5P) terminal No. 1 and radiator fan motor 2P connector terminal No. 2. Is there continuity? YES -Go to step 29. NO -Repair an open in wire between the under-hood fuse/relay box and the radiator fan motor.
29. Check for continuity between radiator fan motor 2P connector terminal No. 1 and body ground. Is there continuity? YES -Replace the radiator fan motor (see «FAN, FAN MOTOR, AND SHROUD REMOVAL AND INSTALLATION»(/acura/zdx/i-2009-2013/remont/cooling-fan/#engine-cooling-system) ). NO -Check for an open in the wire between the radiator fan motor and body ground. If the wire is OK, check for poor body ground at G301 (see «CONNECTOR TO FUSE/RELAY BOX INDEX»(/acura/zdx/i-2009-2013/remont/body-electrical/#fuserelay-boxes__connector-to-fuserelay-box-index) ).

A/C Condenser Fan High Speed Circuit Troubleshooting

Note. Do not use this troubleshooting procedure if the A/C compressor is inoperative. Refer to the symptom troubleshooting index. Before doing any symptom troubleshooting, check for PGM-FI DTCs (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 121

Scheme 122

Scheme 123

1. Check the No. 3-2 (SUB FAN MOTOR) (40 A) fuse in the under-hood fuse/relay box, and the No. 16 (7.5 A) fuse in the driver's under-dash fuse/relay box. Are the fuses OK? YES -Go to step 2. NO -Replace the fuse(s), and recheck. If the fuse(s) blow again, check for a short in the No. 3-2 (SUB FAN MOTOR) (40 A) fuse and/or No. 16 (7.5 A) fuse circuit (s).
2. Jump the SCS line with the HDS. NOTE: This step must be done to protect the PCM from damage.
3. Disconnect PCM connector A (49P).
4. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
5. Measure the voltage between PCM connector A terminal No. 5 and body ground. Is there battery voltage? YES -Go to step 6. NO -Repair an open in the wire between the under-hood fuse/relay box and the PCM. If the wire is OK, replace the under-hood fuse/relay box (see «REMOVAL AND INSTALLATION»(/acura/zdx/i-2009-2013/remont/fuses-circuit-breakers/#under-hood-fuserelay-box__removal-and-installation) ).
6. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
7. Connect the PCM connector A (49P) terminals No. 4, No. 5, and No. 40 to body ground with jumper wire.
8. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode. Do the A/C condenser and the radiator fans run on high? YES -Check for loose wires or poor connections at PCM connector A (49P). If the connections are good, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/zdx/i-2009-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), and recheck. If the symptom/indication goes away, replace the original PCM (see «PCM REPLACEMENT»(/acura/zdx/i-2009-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). NO -Go to step 9.
9. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
10. Disconnect under-hood fuse/relay box connector C (5P).
11. Check for continuity between under-hood fuse/relay box connector C (5P) terminal No. 2 and body ground. Is there continuity? YES -Replace the under-hood fuse/relay box (see «REMOVAL AND INSTALLATION»(/acura/zdx/i-2009-2013/remont/fuses-circuit-breakers/#under-hood-fuserelay-box__removal-and-installation) ). NO -Check for an open in the wire between the under-hood fuse/relay box and body ground. If the wire is OK, check for poor ground at G202 (see «CONNECTOR TO FUSE/RELAY BOX INDEX»(/acura/zdx/i-2009-2013/remont/body-electrical/#fuserelay-boxes__connector-to-fuserelay-box-index) ).

A/C Compressor Clutch Circuit Troubleshooting

Note. It is normal for the A/C compressor to turn off under certain conditions, such as low idle, high engine coolant temperature, hard acceleration, or high/low refrigerant pressure. Do not use this troubleshooting procedure if the fans are also inoperative with the A/C on. Refer to the symptom troubleshooting index. Before doing any symptom troubleshooting, check for PGM-FI DTCs (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 124

Scheme 125

Scheme 126

Scheme 127

Scheme 128

1. Check the No. 20 (7.5 A) fuse in the under-hood fuse/relay box, and the No. 16 (7.5 A) fuse in the driver's under-dash fuse/relay box. Are the fuses OK? YES -Go to step 2. NO -Replace the fuse(s), and recheck. If the fuse(s) blow again, check for a short in the No. 20 (7.5 A) fuse and/or the No. 16 (7.5 A) fuse circuit(s).
2. Connect the HDS to the DLC.
3. Start the engine.
4. Turn on the A/C.
5. Check the A/C switch in the PGM-FI Data List with the HDS. Is the A/C switch ON? YES -Go to step 6. NO -Go to A/C Signal Circuit Troubleshooting (see «A/C SIGNAL CIRCUIT TROUBLESHOOTING»(/acura/zdx/i-2009-2013/remont/testing-diagnostics/#idle-control-system) ).
6. Using the HDS, confirm the following values in the PGM-FI Data List at idle. TP SENSOR About 0.5 V ENGINE IDLE 660-760 rpm ECT SENSOR 2 176-212°F (80-100°C) A/C SWITCH ON A/C CLUTCH ON Are all the values within specifications? YES -Go to step 7. NO -Troubleshoot the value that is not within the specifications.
7. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
8. Remove the A/C compressor clutch relay from the under-hood fuse/relay box, and test it (see «POWER RELAY TEST»(/acura/zdx/i-2009-2013/remont/body-electrical/#relays__power-relay-test) ). Is the relay OK? YES -Go to step 9. NO -Replace the A/C compressor clutch relay.
9. Measure the voltage between A/C compressor clutch relay 4P socket terminal No. 1 and body ground. Is there battery voltage? YES -Go to step 10. NO -Replace the under-hood fuse/relay box (see «REMOVAL AND INSTALLATION»(/acura/zdx/i-2009-2013/remont/fuses-circuit-breakers/#under-hood-fuserelay-box__removal-and-installation) ).
10. Connect A/C compressor clutch relay 4P socket terminals No. 1 and No. 2 with a jumper wire. Does the A/C compressor clutch click? YES -Go to step 11. NO -Go to step 20 .
11. Disconnect the jumper wire.
12. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
13. Measure the voltage between A/C compressor clutch relay 4P socket terminal No. 4 and body ground. Is there battery voltage? YES -Go to step 14. NO -Repair an open in the wire between the No. 16 (7.5 A) fuse in the driver's under-dash fuse/relay box and the A/C compressor clutch relay.
14. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
15. Reinstall the A/C compressor clutch relay.
16. Jump the SCS line with the HDS. NOTE: This step must be done to protect the PCM from damage.
17. Disconnect PCM connector A (49P).
18. Connect PCM connector A (49P) terminal No. 13 to body ground with a jumper wire.
19. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode. Does the A/C compressor click? YES -Check for loose wires or poor connections at PCM connector A (49P). If the connections are good, check the PCM grounds. If the grounds are good, substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/zdx/i-2009-2013/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), and recheck. If the symptom/indication goes away, replace the original PCM (see «PCM REPLACEMENT»(/acura/zdx/i-2009-2013/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). NO -Repair an open in the wire between the A/C compressor clutch relay and the PCM.
20. Disconnect the jumper wire.
21. Disconnect the A/C compressor clutch 1P connector.
22. Check for continuity between A/C compressor clutch relay 4P socket terminal No. 2 and A/C compressor clutch 1P connector terminal No. 1. Is there continuity? YES -Check the A/C compressor clutch clearance, and the A/C compressor clutch field coil (see «A/C COMPRESSOR CLUTCH CHECK»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). Repair as needed. NO -Repair an open in the wire between the A/C compressor clutch relay and the A/C compressor clutch.

Scheme 129

Scheme 130

Scheme 131

1. Disconnect audio-navigation and HVAC switch panel connector A (20P).
2. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
3. Measure the voltage between audio-navigation and HVAC switch panel connector A (20P) terminal No. 11 and body ground. Is there battery voltage? YES -Go to step 4. NO -Repair an open in the wire between the No. 16 (7.5 A) fuse in the driver's under-dash fuse/relay box and the audio-navigation and HVAC switch panel.
4. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
5. Disconnect climate control unit connector A (32P) and audio-navigation and HVAC switch panel connector B (32P).
6. Check for continuity between the following terminals of climate control unit connector A (32P) and audio-navigation and HVAC switch panel connector B (32P). 32P: 32P: No. 3 No. 7 No. 4 No. 6 Is there continuity? YES -Go to step 7. NO -Repair an open in the wire between climate control unit connector A (32P) and audio-navigation and HVAC switch panel connector B (32P).
7. Check for continuity between body ground and climate control unit connector A (32P) terminals No. 3 and No. 4 individually. Is there continuity? YES -Repair a short to body ground in the wire between climate control unit connector A (32P) and audio-navigation and HVAC switch panel connector B (32P). NO -Substitute a known-good audio-navigation and HVAC switch panel (see «AUDIO-NAVIGATION AND HVAC SWITCH PANEL REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/entertainment-systems/#audio-system) ), and recheck. If the symptom goes away, replace the original audio-navigation and HVAC switch panel. If the symptom still present, replace the climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

Scheme 132

Scheme 133

Scheme 134

1. Disconnect audio and HVAC switch panel connector A (20P).
2. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
3. Measure the voltage between audio and HVAC switch panel connector A (20P) terminals No. 11 and body ground. Is there any voltage? YES -GO to step 4. NO -Repair an open in the wire between the No. 16 (7.5 A) fuse in the driver's under-dash fuse/relay box and the audio and HVAC switch panel.
4. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
5. Disconnect climate control unit connector A (32P) and audio and HVAC switch panel connector B (32P).
6. Check for continuity between the following terminals of climate control unit connector A (32P) and audio and HVAC switch panel connector B (32P). 32P: 32P: No. 3 No. 7 No. 4 No. 6 Is there continuity? YES -Go to step 7. NO -Repair an open in the wire between climate control unit connector A (32P) and audio and HVAC switch panel connector B (32P).
7. Check for continuity between body ground and climate control unit connector A (32P) terminals No. 3 and No. 4 individually. Is there continuity? YES -Repair a short to body ground in the wire between climate control unit connector A (32P) and audio and HVAC switch panel connector B (32P). NO -Substitute a known-good audio and HVAC switch panel (see «AUDIO AND HVAC SWITCH PANEL REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/entertainment-systems/#audio-system) ), and recheck. If the symptom goes away, replace the original audio and HVAC switch panel. If the symptom still present, replace the climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

Scheme 135

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Scheme 147

Scheme 148

Scheme 149

Scheme 150

Scheme 151

1. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
2. Disconnect audio-navigation and HVAC switch panel connector A (20P).
3. Check for continuity between audio-navigation and HVAC switch panel connector A (20P) terminal No. 3 and body ground, Is there continuity? YES -Go to step 4. NO -Check for an open in the wire between the audio-navigation and HVAC switch panel and body ground. If the wire is OK, check for poor body ground at G501 (see «CONNECTOR TO FUSE/RELAY BOX INDEX»(/acura/zdx/i-2009-2013/remont/body-electrical/#fuserelay-boxes__connector-to-fuserelay-box-index) ).
4. If the following switches do not work, go to the step indicated below respectively. DRIVER'S SIDE MODE CONTROL button, go to step 5. DRIVER'S SIDE TEMPERATURE CONTROL switch, go to step 5. DRIVER'S SIDE AUTO button, go to step 5. PASSENGER'S SIDE MODE CONTROL button, go to step 16 . PASSENGER'S SIDE TEMPERATURE CONTROL switch, go to step 16 . PASSENGER'S SIDE AUTO button, go to step 16 . ON/OFF button, go to step 27 . FAN CONTROL button, go to step 27 . SYNC button, go to step 27 . WINDSHIELD DEFROST button, go to step 38 . RECIRCULATION button, go to step 38 . AIR CONDITIONING button, go to step 38 . REAR WINDOW DEFOGGER/MIRROR DEFOGGER button, go to step 38 .
5. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
6. Measure the voltage between climate control unit connector B (24P) terminals and body ground as shown in the illustration. Is there about 5 V? YES -Go to step 7. NO -Go to step 11 .
7. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
8. Disconnect audio-navigation and HVAC switch panel connector B (32P).
9. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
10. Measure the voltage between body ground and audio-navigation and HVAC switch panel connector B (32P) terminals No. 10, No. 24, No. 25, and No. 26 individually. Is there about 5 V? YES -Substitute a known-good audio-navigation and HVAC switch panel, and recheck. If the symptom goes away, replace the original audio-navigation and HVAC switch panel (see «AUDIO-NAVIGATION AND HVAC SWITCH PANEL REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/entertainment-systems/#audio-system) ). NO -Repair an open in the wires between the climate control unit and the audio-navigation and HVAC switch panel.
11. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
12. Disconnect climate control unit connector B (24P) and audio-navigation and HVAC switch panel connector B (32P).
13. Check for continuity between body ground and climate control unit connector B (24P) terminals No. 17, No. 18, No. 19 and No. 20 individually. Is there continuity? YES -Repair a short to body ground in the wire(s) between the climate control unit and the audio-navigation and HVAC switch panel. NO -Go to step 14.
14. Reconnect audio-navigation and HVAC switch panel connector B (32P).
15. Check for continuity between body ground and audio-navigation and HVAC switch panel connector B (32P) terminals No. 10, No. 24, No. 25, and No. 26 individually. Do not press the switch or the button. Is there continuity? YES -Substitute a known-good audio-navigation and HVAC switch panel, and recheck. If the symptom goes away, replace the original audio-navigation and HVAC switch panel (see «AUDIO-NAVIGATION AND HVAC SWITCH PANEL REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/entertainment-systems/#audio-system) ). NO -Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
16. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
17. Measure the voltage between body ground and climate control unit connector B (24P) terminals No. 5, No. 6, No. 7 and No. 8 individually. Is there about 5 V? YES -Go to step 18. NO -Go to step 22 .
18. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
19. Disconnect audio-navigation and HVAC switch panel connector B (32P).
20. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
21. Measure the voltage between body ground and audio-navigation and HVAC switch panel connector B (32P) terminals No. 13, No. 14, No. 29 and No. 30 individually. Is there about 5 V? YES -Substitute a known-good audio-navigation and HVAC switch panel, and recheck. If the symptom goes away, replace the original audio-navigation and HVAC switch panel (see «AUDIO-NAVIGATION AND HVAC SWITCH PANEL REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/entertainment-systems/#audio-system) ). NO -Repair an open in the wires between the climate control unit and the audio-navigation and HVAC switch panel.
22. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
23. Disconnect climate control unit connector B (24P) and audio-navigation and HVAC switch panel connector B (32P).
24. Check for continuity between body ground and climate control unit connector B (24P) terminals No. 5, No. 6, No. 7, and No. 8 individually. Is there continuity? YES -Repair a short to body ground in the wire(s) between the climate control unit and the audio-navigation and HVAC switch panel. NO -Go to step 25.
25. Reconnect audio-navigation and HVAC switch panel connector B (32P).
26. Check for continuity between body ground and audio-navigation and HVAC switch panel connector B (32P) terminals No. 13, No. 14, No. 29, and No. 30 individually. Do not press the switch or the button. Is there continuity? YES -Substitute a known-good audio-navigation and HVAC switch panel, and recheck. If the symptom goes away, replace the original audio-navigation and HVAC switch panel (see «AUDIO-NAVIGATION AND HVAC SWITCH PANEL REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/entertainment-systems/#audio-system) ). NO -Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
27. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
28. Measure the voltage between body ground and climate control unit connector B (24P) terminals No. 21, No. 22, No. 23, and No. 24 individually. Is there about 5 V? YES -Go to step 29. NO -Go to step 33 .
29. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
30. Disconnect audio-navigation and HVAC switch panel connector B (32P).
31. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
32. Measure the voltage between body ground and audio-navigation and HVAC switch panel connector B (32P) terminals No. 11, No. 12, No. 27, and No. 28 individually. Is there about 5 V? YES -Substitute a known-good audio-navigation and HVAC switch panel, and recheck. If the symptom goes away, replace the original audio-navigation and HVAC switch panel (see «AUDIO-NAVIGATION AND HVAC SWITCH PANEL REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/entertainment-systems/#audio-system) ). NO -Repair an open in the wires between the climate control unit and the audio-navigation and HVAC switch panel.
33. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
34. Disconnect climate control unit connector B (24P) and audio-navigation and HVAC switch panel connector B (32P).
35. Check for continuity between body ground and climate control unit connector B (24P) terminals No. 21, No. 22, No. 23, and No. 24 individually. Is there continuity? YES -Repair a short to body ground in the wire(s) between the climate control unit and the audio-navigation and HVAC switch panel. NO -Go to step 36.
36. Reconnect audio-navigation and HVAC switch panel connector B (32P).
37. Check for continuity between body ground and audio-navigation and HVAC switch panel connector B (32P) terminal No. 11, No. 12, No. 27, and No. 28 individually. Do not press the switch or the button. Is there continuity? YES -Substitute a known-good audio-navigation and HVAC switch panel, and recheck. If the symptom goes away, replace the original audio-navigation and HVAC switch panel (see «AUDIO-NAVIGATION AND HVAC SWITCH PANEL REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/entertainment-systems/#audio-system) ). NO -Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
38. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
39. Measure the voltage between body ground and climate control unit connector B (24P) terminals No. 9, No. 10, No. 11, and No. 12 individually. Is there about 5 V? YES -Go to step 40. NO -Go to step 44 .
40. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
41. Disconnect audio-navigation and HVAC switch panel connector B (32P).
42. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
43. Measure the voltage between body ground and audio-navigation and HVAC switch panel connector B (32P) terminals No. 15, No. 16, No. 31, and No. 32 individually. Is there about 5 V? YES -Substitute a known-good audio-navigation and HVAC switch panel, and recheck. If the symptom goes away, replace the original audio-navigation and HVAC switch panel (see «AUDIO-NAVIGATION AND HVAC SWITCH PANEL REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/entertainment-systems/#audio-system) ). NO -Repair an open in the wires between the climate control unit and the audio-navigation and HVAC switch panel.
44. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
45. Disconnect climate control unit connector B (24P) and audio-navigation and HVAC switch panel connector B (32P).
46. Check for continuity between body ground and climate control unit connector B (24P) terminals No. 9, No. 10, No. 11, and No. 12 individually. Is there continuity? YES -Repair a short to body ground in the wire(s) between the climate control unit and the audio-navigation and HVAC switch panel. NO -Go to step 47.
47. Reconnect audio-navigation and HVAC switch panel connector B (32P).
48. Check for continuity between body ground and audio-navigation and HVAC switch panel connector B (32P) terminals No. 15, No. 16, No. 31, and No. 32 individually. Do not press the switch or the button. Is there continuity? YES -Substitute a known-good audio-navigation and HVAC switch panel, and recheck. If the symptom goes away, replace the original audio-navigation and HVAC switch panel (see «AUDIO-NAVIGATION AND HVAC SWITCH PANEL REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/entertainment-systems/#audio-system) ). NO -Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

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Scheme 167

Scheme 168

1. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
2. Disconnect audio and HVAC switch panel connector A (20P).
3. Check for continuity between audio and HVAC switch panel connector A (20P) terminal No. 3 and body ground. Is there continuity? YES -Go to step 4. NO -Check for an open in the wire between the audio and HVAC switch panel and body ground. If the wire is OK, check for poor body ground at G501 (see «CONNECTOR TO FUSE/RELAY BOX INDEX»(/acura/zdx/i-2009-2013/remont/body-electrical/#fuserelay-boxes__connector-to-fuserelay-box-index) ).
4. If the following switches do not work, go to the step indicated below respectively. DRIVER'S SIDE MODE CONTROL button, go to step 5. DRIVER'S SIDE TEMPERATURE CONTROL switch, go to step 5. DRIVER'S SIDE AUTO button, go to step 5. PASSENGER'S SIDE MODE CONTROL button, go to step 16 . PASSENGER'S SIDE TEMPERATURE CONTROL switch, go to step 16 . PASSENGER'S SIDE AUTO button, go to step 16 . ON/OFF button, go to step 27 . FAN CONTROL button, go to step 27 . SYNC button, go to step 27 . WINDSHIELD DEFROST button, go to step 38 . RECIRCULATION button, go to step 38 . AIR CONDITIONING button, go to step 38 . REAR WINDOW DEFOGGER/MIRROR DEFOGGER button, go to step 38 .
5. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
6. Measure the voltage between body ground and climate control unit connector B (24P) terminals No. 17, No. 18, No. 19, and No. 20 individually. Is there about 5 V? YES -Go to step 7. NO -Go to step 11 .
7. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
8. Disconnect audio and HVAC switch panel connector B (32P).
9. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
10. Measure the voltage between body ground and audio and HVAC switch panel connector B (32P) terminals No. 10, No. 24, No. 25, and No. 26 individually. Is there about 5 V? YES -Substitute a known-good audio and HVAC switch panel, and recheck. If the symptom goes away, replace the original audio and HVAC switch panel (see «AUDIO AND HVAC SWITCH PANEL REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/entertainment-systems/#audio-system) ). NO -Repair an open in the wires between the climate control unit and the audio and HVAC switch panel.
11. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
12. Disconnect climate control unit connector B (24P) and audio and HVAC switch panel connector B (32P).
13. Check for continuity between body ground and climate control unit connector B (24P) terminals No. 17, No. 18, No. 19 and No. 20 individually. Is there continuity? YES -Repair a short to body ground in the wire(s) between the climate control unit and the audio and HVAC switch panel. NO -Go to step 14.
14. Reconnect audio and HVAC switch panel connector B (32P).
15. Check for continuity between body ground and audio and HVAC switch panel connector B (32P) terminals No. 10, No. 24, No. 25, and No. 26 individually. Do not press the switch or the button. Is there continuity? YES -Substitute a known-good audio and HVAC switch panel, and recheck. If the symptom goes away, replace the original audio and HVAC switch panel (see «AUDIO AND HVAC SWITCH PANEL REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/entertainment-systems/#audio-system) ). NO -Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
16. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
17. Measure the voltage between body ground and climate control unit connector B (24P) terminals No. 5, No. 6, No. 7 and No. 8 individually. Is there about 5 V? YES -Go to step 18. NO -Go to step 22 .
18. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
19. Disconnect audio and HVAC switch panel connector B (32P).
20. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
21. Measure the voltage between body ground and audio and HVAC switch panel connector B (32P) terminals No. 13, No. 14, No. 29 and No. 30 individually. Is there about 5 V? YES -Substitute a known-good audio and HVAC switch panel, and recheck. If the symptom goes away, replace the original audio and HVAC switch panel (see «AUDIO AND HVAC SWITCH PANEL REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/entertainment-systems/#audio-system) ). NO -Repair an open in the wires between the climate control unit and the audio and HVAC switch panel.
22. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
23. Disconnect climate control unit connector B (24P) and audio and HVAC switch panel connector B (32P).
24. Check for continuity between body ground and climate control unit connector B (24P) terminals No. 5, No. 6, No. 7, and No. 8 individually. Is there continuity? YES -Repair a short to body ground in the wire(s) between the climate control unit and the audio and HVAC switch panel. NO -Go to step 25.
25. Reconnect audio and HVAC switch panel connector B (32P).
26. Check for continuity between body ground and audio and HVAC switch panel connector B (32P) terminals No. 13, No. 14, No. 29, and No. 30 individually. Do not press the switch or the button. Is there continuity? YES -Substitute a known-good audio and HVAC switch panel, and recheck. If the symptom goes away, replace the original audio and HVAC switch panel (see «AUDIO AND HVAC SWITCH PANEL REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/entertainment-systems/#audio-system) ). NO -Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
27. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
28. Measure the voltage between body ground and climate control unit connector B (24P) terminals No. 21, No. 22, No. 23, and No. 24 individually. Is there about 5 V? YES -Go to step 29. NO -Go to step 33 .
29. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
30. Disconnect audio and HVAC switch panel connector B (32P).
31. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
32. Measure the voltage between body ground and audio and HVAC switch panel connector B (32P) terminals No. 11, No. 12, No. 27, and No. 28 individually. Is there about 5 V? YES -Substitute a known-good audio and HVAC switch panel, and recheck. If the symptom goes away, replace the original audio and HVAC switch panel (see «AUDIO AND HVAC SWITCH PANEL REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/entertainment-systems/#audio-system) ). NO -Repair an open in the wires between the climate control unit and the audio and HVAC switch panel.
33. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
34. Disconnect climate control unit connector B (24P) and audio and HVAC switch panel connector B (32P).
35. Check for continuity between body ground and climate control unit connector B (24P) terminals No. 21, No. 22, No. 23, and No. 24 individually. Is there continuity? YES -Repair a short to body ground in the wire(s) between the climate control unit and the audio and HVAC switch panel. NO -Go to step 36.
36. Reconnect audio and HVAC switch panel connector B (32P).
37. Check for continuity between body ground and audio and HVAC switch panel connector B (32P) terminals No. 11, No. 12, No. 27, and No. 28 individually. Do not press the switch or the button. Is there continuity? YES -Substitute a known-good audio and HVAC switch panel, and recheck. If the symptom goes away, replace the original audio and HVAC switch panel (see «AUDIO AND HVAC SWITCH PANEL REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/entertainment-systems/#audio-system) ). NO -Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
38. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
39. Measure the voltage between body ground and climate control unit connector B (24P) terminals No. 9, No. 10, No. 11, and No. 12 individually. Is there about 5 V? YES -Go to step 40. NO -Go to step 44 .
40. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
41. Disconnect audio and HVAC switch panel connector B (32P).
42. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
43. Measure the voltage between body ground and audio and HVAC switch panel connector B (32P) terminals No. 15, No. 16, No. 31, and No. 32 individually. Is there about 5 V? YES -Substitute a known-good audio and HVAC switch panel, and recheck. If the symptom goes away, replace the original audio and HVAC switch panel (see «AUDIO AND HVAC SWITCH PANEL REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/entertainment-systems/#audio-system) ). NO -Repair an open in the wires between the climate control unit and the audio and HVAC switch panel.
44. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
45. Disconnect climate control unit connector B (24P) and audio and HVAC switch panel connector B (32P).
46. Check for continuity between body ground and climate control unit connector B (24P) terminals No. 9, No. 10, No. 11, and No. 12 individually. Is there continuity? YES -Repair a short to body ground in the wire(s) between the climate control unit and the audio and HVAC switch panel. NO -Go to step 47.
47. Reconnect audio and HVAC switch panel connector B (32P).
48. Check for continuity between body ground and audio and HVAC switch panel connector B (32P) terminals No. 15, No. 16, No. 31, and No. 32 individually. Do not press the switch or the button. Is there continuity? YES -Substitute a known-good audio and HVAC switch panel, and recheck. If the symptom goes away, replace the original audio and HVAC switch panel (see «AUDIO AND HVAC SWITCH PANEL REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/entertainment-systems/#audio-system) ). NO -Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

Scheme 169

Scheme 170

Scheme 171

Scheme 172

1. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
2. Operate the climate control system in several modes. Is the climate control system OK? YES -Go to step 3. NO -Do the Self-Diagnostic Function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
3. Go into the System Diagnostic Mode (see «SYSTEM LINKS»(/acura/zdx/i-2009-2013/remont/entertainment-systems/#navigation-system) ), and select the Self-Diagnosis Mode to check the System Link. Is the A/C or Mic icon red? YES - If A/C icon is red, go to step 4. If Mic icon is red, go to "Voice control does not work/respond" in the navigation system Symptom Troubleshooting (see «SYMPTOM TROUBLESHOOTING INDEX»(/acura/zdx/i-2009-2013/remont/entertainment-systems/#navigation-system__symptom-troubleshooting-index) ). NO -Go to step 9 .
4. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
5. Disconnect audio-navigation unit connector D (20P).
6. Disconnect climate control unit connector C (20P).
7. Check for continuity between the following terminals of climate control unit connector C (20P) and audio-navigation unit connector D (20P). 20P 20P: No. 4 No. 4 No. 5 No. 5 No. 6 No. 14 Is there continuity? YES -Go to step 8. NO -Repair an open in the wire(s) between the climate control unit and the audio-navigation unit.
8. Check for continuity between body ground and climate control unit connector terminals No. 4, No. 5, and No. 6 individually. Is there continuity? YES -Repair a short to body ground in the wire(s) between the climate control unit and the audio-navigation unit. NO -Reconnect climate control unit connector C (20P), then go to step 10 .
9. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
10. Connect audio-navigation unit connector D (20P) terminals No. 4 and No. 5 with jumper wire, then connect terminals No. 4 and No. 14 with a jumper wire.
11. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
12. Press and hold the AUTO button, then press and hold the ON/OFF button. Is the HEAT/VENT indicator solid with the remaining icons blinking? YES -Substitute a known-good audio-navigation unit (including the HDD), and recheck. If the symptom goes away, replace the original audio-navigation unit (see «AUDIO-NAVIGATION UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/entertainment-systems/#navigation-system__audio-navigation-unit-removalinstallation) ). NO -Substitute a known-good climate control unit, and recheck. If the symptom goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

Humidity Sensor Test

Note. Before testing the sensor, check for climate control DTCs (see HOW TO CHECK FOR DTCS WITH THE HDS ).

Scheme 173

Scheme 174

1. Remove the humidity/in-car temperature sensor (see «HUMIDITY/IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
2. Connect the humidity/in-car temperature sensor 4P connector.
3. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode. Measure the voltage between the terminals with the (+) probe on terminal No. 2 and the (-) probe on terminal No. 3 with the connector connected.
4. If the voltage is not as specified, replace the humidity/in-car temperature sensor (see «HUMIDITY/IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

In-Car Temperature Sensor Test

Note. Before testing the sensor, check for climate control DTCs (see HOW TO CHECK FOR DTCS WITH THE HDS ).

Scheme 175

Scheme 176

1. Remove the humidity/in-car temperature sensor (see «HUMIDITY/IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
2. Test the humidity/in-car temperature sensor while holding it in front of the dashboard center vent. Measure the resistance with the system set to Max Cool. Measure the resistance with the system set to Max Hot.
3. Compare the resistance reading between terminals No. 3 and No. 4 of the humidity/in-car temperature sensor with the specifications shown in the graph; the resistance should be within the specifications.
4. If the resistance is not as specified, replace the humidity/in-car temperature sensor (see «HUMIDITY/IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
5. Clear any DTCs set when you disconnected the humidity/in-car temperature sensor.

Outside Air Temperature Sensor Test

Note. Before testing the sensor, check for climate control DTCs (see HOW TO CHECK FOR DTCS WITH THE HDS ).

Scheme 177

Scheme 178

1. Remove the outside air temperature sensor (see «OUTSIDE AIR TEMPERATURE SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
2. Dip the sensor in ice water, and measure the resistance. Then pour warm water on the sensor, and check for a change in resistance.
3. Compare the resistance reading between terminals No. 1 and No. 2 of the outside air temperature sensor with the specifications shown in the graph; the resistance should be within the specifications.
4. If the resistance is not as specified, replace the outside air temperature sensor (see «OUTSIDE AIR TEMPERATURE SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

Sunlight Sensor Test

Note. Before testing the sensor, check for climate control DTCs (see HOW TO CHECK FOR DTCS WITH THE HDS ).

Scheme 179

1. Remove the sunlight sensor (A) (see «SUNLIGHT SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
2. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode. Measure the voltage between terminals with the (+) probe on terminal No. 4 and the (-) probe on terminal No. 2 with the connector connected. NOTE: The voltage readings do not change under the light of a flashlight or a fluorescent lamp. Voltage should be: 3.56 V with no sunlight or the sensor covered up Less than 3.56 V with the sunlight on sensor (depending on sunlight intensity)
3. If the voltage is not as specified, replace the sunlight sensor (see «SUNLIGHT SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

Evaporator Temperature Sensor Test

Note. Before testing the sensor, check for climate control DTCs (see HOW TO CHECK FOR DTCS WITH THE HDS ).

Scheme 180

Scheme 181

1. Remove the evaporator temperature sensor (see «EVAPORATOR TEMPERATURE SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
2. Dip the sensor in ice water, and measure the resistance between terminals No. 1 and No. 2.
3. Pour warm water on the sensor, and measure the resistance.
4. Compare the resistance readings with the specifications shown in the graph; the resistance should be within the specifications.
5. If the resistance is not as specified, replace the evaporator temperature sensor (see «EVAPORATOR TEMPERATURE SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

Scheme 182

Scheme 183

1. Remove the passenger's dashboard undercover (see «GLOVE BOX DAMPER REPLACEMENT»(/acura/zdx/i-2009-2013/remont/gauges-instrument-panels/#dashboard__glove-box-damper-replacement) ).
2. Disconnect the 5P connector from the power transistor.
3. Measure the resistance between terminals No. 1 and No. 4 of the power transistor. It should be about 1.5 kohms. If the resistance is within the specifications, go to step 4. If the resistance is not within the specifications, replace the power transistor. NOTE: Also check the blower motor. Power transistor failure can be caused by a defective blower motor.
4. Reconnect the 5P connector to the power transistor.
5. Disconnect climate control unit connector A (32P).
6. Connect climate control unit connector A (32P) terminals No. 15 and No. 28 with a jumper wire.
7. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and check that the blower motor runs. If the blower motor does not run, replace the power transistor. NOTE: A faulty blower motor can cause the power transistor to fail. If the power transistor is replaced, also check the blower motor for binding, and replace it if necessary. If the blower motor runs, the power transistor is OK.

Driver's Air Mix Control Motor Test

Special Tools Required

Backprobe Set 07SAZ-001000A

Note. Before testing the motor, check for climate control DTCs (see HOW TO CHECK FOR DTCS WITH THE HDS ).

Scheme 184

1. Disconnect the 7P connector from the driver's air mix control motor. NOTE: Incorrectly applying power and ground to the driver's air mix control motor will damage it. Follow the instructions carefully.
2. Connect battery power to terminal No. 1 of the driver's air mix control motor, and ground terminal No. 2; the driver's air mix control motor should run, and stop at Max Cool. If it does not, reverse the connections; the driver's air mix control motor should run, and stop at Max Hot. When the driver's air mix control motor stops running, disconnect battery power immediately.
3. If the driver's air mix control motor did not run in step 2 , remove it, then check the driver's air mix control linkage and door for smooth movement. If the linkage and door move smoothly, replace the driver's air mix control motor (see «DRIVER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). If the linkage or door sticks or binds, repair them as needed. If the driver's air mix control motor runs smoothly, go to step 4.
4. Measure the resistance between terminals No. 5 and No. 7 of the driver's air mix control motor. It should be between 4.2 and 7.8 kohms.
5. Reconnect the air mix control motor 7P connector, then turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
6. Using the backprobe set (07SAZ-001000A), measure the voltage between terminals No. 3 and No. 5. Max Cool: About 1.0 V Max Hot: About 4.0 V
7. If either the resistance or the voltage readings are not as specified, replace the driver's air mix control motor (see «DRIVER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

Passenger's Air Mix Control Motor Test

Special Tools Required

Backprobe Set 07SAZ-001000A

Note. Before testing the motor, check for climate control DTCs (see HOW TO CHECK FOR DTCS WITH THE HDS ).

Scheme 185

1. Disconnect the 7P connector from the driver's air mix control motor. NOTE: Incorrectly applying power and ground to the passenger's air mix control motor will damage it. Follow the instructions carefully.
2. Connect battery power to terminal No. 1 of the passenger's air mix control motor, and ground terminal No. 2; the passenger's air mix control motor should run, and stop at Max Cool. If it does not, reverse the connections; the passenger's air mix control motor should run, and stop at Max Hot. When the passenger's air mix control motor stops running, disconnect battery power immediately.
3. If the passenger's air mix control motor did not run in step 2 , remove it, then check the passenger's air mix control linkage and door for smooth movement. If the linkage and door move smoothly, replace the passenger's air mix control motor (see «PASSENGER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). If the linkage or door sticks or binds, repair them as needed. If the passenger's air mix control motor runs smoothly, go to step 4.
4. Measure the resistance between terminals No. 5 and No. 7 of the passenger's air mix control motor. It should be between 4.2 and 7.8 kohms.
5. Reconnect the air mix control motor 7P connector, then turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
6. Using the backprobe set (07SAZ-001000A), measure the voltage between terminals No. 3 and No. 5. Max Cool: About 1.0 V Max Hot: About 4.0 V
7. If either the resistance or the voltage readings are not as specified, replace the passenger's air mix control motor (see «PASSENGER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

Driver's Mode Control Motor Test

Note. Before testing the motor, check for climate control DTCs (see HOW TO CHECK FOR DTCS WITH THE HDS ).

Scheme 186

1. Disconnect the 7P connector from the driver's mode control motor. NOTE: Incorrectly applying power and ground to the driver's mode control motor will damage it. Follow the instructions carefully.
2. Connect battery power to terminal No. 1 of the driver's mode control motor, and ground terminal No. 2; the driver's mode control motor should run, and stop at Vent. If it does not, reverse the connections; the driver's mode control motor should run, and stop at Defrost. When the driver's mode control motor stops running, disconnect battery power immediately.
3. If the driver's mode control motor did not run in step 2 , remove it, then check the mode control linkage and door for smooth movement. If the linkage and door move smoothly, replace the driver's mode control motor (see «PASSENGER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). If the linkage or door sticks or binds, repair them as needed. If the driver's mode control motor runs smoothly, go to step 4.
4. Use a digital multimeter with an output of 1 mA or less at the 20 kohms range. Operate the driver's mode control motor as in step 2 , and check for continuity between terminals No. 3, No. 4, No. 5, and No. 6 and terminal No. 7 individually. There should be continuity for a moment at each terminal as the motor moves through its travel.
5. If there is no continuity for a moment at each terminal, replace the driver's mode control motor (see «PASSENGER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

Passenger's Mode Control Motor Test

Note. Before testing the motor, check for climate control DTCs (see HOW TO CHECK FOR DTCS WITH THE HDS ).

Scheme 187

1. Disconnect the 7P connector from the passenger's mode control motor. NOTE: Incorrectly applying 'power and ground to the mode control motor will damage it. Follow the instructions carefully.
2. Connect battery power to terminal No. 1 of the passenger's mode control motor, and ground terminal No. 2; the passenger's mode control motor should run, and stop at Heat. If it does not, reverse the connections; the passenger's mode control motor should run, and stop at Vent. When the passenger's mode control motor stops running, disconnect battery power immediately.
3. If the passenger's mode control motor did not run in step 2 , remove it, then check the mode control linkage and door for smooth movement. If the linkage and door move smoothly, replace the passenger's mode control motor (see «PASSENGER'S MODE CONTROL MOTOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). If the linkage or door sticks or binds, repair them as needed. If the passenger's mode control motor runs smoothly, go to step 4.
4. Use a digital multimeter with an output of 1 mA or less at the 20 kohms range. Operate the passenger's mode control motor as in step 2 , and check for continuity between terminals No. 3, No. 4, No. 5, and No. 6 and terminal No. 7 individually. There should be continuity for a moment at each terminal as the motor moves through its travel.
5. If there is no continuity for a moment at each terminal, replace the passenger's mode control motor (see «PASSENGER'S MODE CONTROL MOTOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

Recirculation Control Motor Test

Note. Before testing the motor, check for climate control DTCs (see HOW TO CHECK FOR DTCS WITH THE HDS ).

Scheme 188

1. Disconnect the 7P connector from the recirculation control motor. NOTE: Incorrectly applying power and ground to the recirculation control motor will damage it. Follow the instructions carefully.
2. Connect battery power to terminal No. 1 of the recirculation control motor, and ground terminal No. 2; the recirculation control motor should run smoothly, and stop at Recirculate. If it does not, reverse the connections; the recirculation control motor should run smoothly, and stop at Fresh. When the recirculation control motor stops running, disconnect battery power immediately.
3. If the recirculation control motor did not run in step 2 , remove it, then check the recirculation control linkage and door for smooth movement. If the. linkage and door move smoothly, replace the recirculation control motor (see «RECIRCULATION CONTROL MOTOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). If the linkage or door stick or bind, repair them as needed. If the recirculation control motor runs smoothly, go to step 4.
4. Use a digital multimeter with an output of 1 mA or less at the 20 kohms range. Operate the recirculation control motor running as in step 2 , and check for continuity between terminals No. 3, No. 4, and No. 5 and terminal No. 7 individually. There should be continuity for a moment at each terminal as the motor through its travel.
5. If there is no continuity for a moment at each terminal, replace the recirculation control motor (see «RECIRCULATION CONTROL MOTOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).

Scheme 189

Scheme 190

Scheme 191

1. Check the pressure plate for discoloration, peeling, or other damage. If there is damage, replace the clutch set (see «A/C COMPRESSOR CLUTCH OVERHAUL»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__ac-compressor-clutch-overhaul) ).
2. Check the pulley bearing play and drag by rotating the pulley by hand. Also check for grease leakage from the bearing. Replace the clutch set with a new one if it is noisy, has excessive play/drag, or has bearing grease contamination on the clutch faces (see «A/C COMPRESSOR CLUTCH OVERHAUL»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__ac-compressor-clutch-overhaul) ). NOTE: The pulley and the pressure plate were mated at the factory by a burnishing operation. Always replace the pulley and the pressure plate as a set. Replacing only one part of the clutch set will cause clutch slippage.
3. Measure the clearance between the rotor pulley (A) and the pressure plate (B) all the way around. If the clearance is not within specified limits, remove the pressure plate (see «A/C COMPRESSOR CLUTCH OVERHAUL»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__ac-compressor-clutch-overhaul) ) and add or remove shims as needed to increase or decrease clearance. Clearance: 0.35-0.60 mm (0.014-0.023 in) NOTE: The shims are available in three thicknesses: 0.1 mm, 0.3 mm, and 0.5 mm.
4. Remove the pressure plate (see «A/C COMPRESSOR CLUTCH OVERHAUL»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__ac-compressor-clutch-overhaul) ), and inspect the pressure plate and pulley friction surface for wear. If there is excessive wear, roughness, or scoring, replace the clutch set.
5. Inspect the friction surfaces and the A/C compressor shaft hub for excess oil. If excess oil is present, and it is not from the engine or power steering system, then the A/C compressor shaft seal is leaking. In that case, replace the A/C compressor (see «A/C COMPRESSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__ac-compressor-replacement) ).
6. Check the resistance of the field coil. If resistance is not within specifications, replace the field coil (see «A/C COMPRESSOR CLUTCH OVERHAUL»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__ac-compressor-clutch-overhaul) ). Field Coil Resistance: 3.9-4.3 ohms at 68°F (20°C)

Refrigerant Leak Check

Special Tools Required

1. Leak Detector YGK-H-10PM*
2. Leak Detector HLD-100*
3. Leak Detector TIFZX-1*
4. OPTIMAX Jr. A/C Leak Detection Kit TRP124893*

*: These tools are available through the Acura Tool and Equipment Program; call 888-424-6857

Note. If accidental system discharge occurs, ventilate the work area before resuming service. Additional health and safety information may be obtained from the refrigerant and lubricant manufacturers. Check the system for leaks using an R-134a refrigerant leak detector with an accuracy of 14 g (0.49 oz) per year or better.

Leak Detector Usage Tips (Refer to the Operator's Manual for complete operating instructions)

1. Position the vehicle in a wind-free work area. This will aid in detecting small leaks.
2. When using the leak detector for the first time, allow it to warm up for 2 minutes with the probe in a clean atmosphere. This lets the temperature sensor in the detector stabilize.
3. The calibration check should be done in the "Search 2" mode. Once that is done, the other check modes do not need calibrating.
4. When leak checking through the HVAC module drain hose, avoid drawing water into the probe. Water can damage the internal pump and sensor.
5. Avoid creasing the flexible probe extension. Creases can restrict airflow and give false readings.
6. Because the detector recalibrates itself for ambient gases, it may be necessary to move the detector away from the leak to clear the sensor. Once the sensor has cleared, recheck the suspected leak.
7. When removing the clear probe tip, be careful not to lose the flow ball.
8. R-134a is heavier than air; always check below and to the sides of all potential leak sources.
9. Halogen leak detectors are sensitive to chemicals: windshield washing solutions, solvents/cleaners, and some vehicle adhesives. Keep these chemicals out of the area when doing leak detection.

Fluorescent Dye Usage Tips

1. Use only Tracer-Stick single dose fluorescent dye capsules from Tracerline®. Other dyes contain solvents that may contaminate the refrigerant oil, leading to component failure.
2. Adding excessive amounts of dye can damage the A/C compressor.
3. PAG oil is water soluble, so condensation on the evaporator core or the refrigerant lines may wash the PAG oil and fluorescent dye away from the actual leak. Condensation may also carry dye through the evaporator module drain.
4. After checking and repairing leaks, thoroughly clean any residual dye from the areas where leaks were found. Use GLO-AWAY dye cleaner, from Tracerline®, and hot water to remove the dye (follow the instructions on the bottle). Residual dye stains can cause misdiagnosis of any future A/C system leaks.
5. If any refrigerant dye contacts an exterior paint surface, remove it by doing this: Carefully wash the affected surfaces to remove any dirt, and to prevent paint scratching. Mix water and isopropyl alcohol in a 50/50 mixture. Soak a soft 100 % cotton towel with the water/alcohol mixture, and place the cloth on the affected areas to remove the dye. After removing the dye with the water/alcohol-soaked cloth, carefully wash the affected areas, and check that there is no remaining dye.

Scheme 192

1. Connect an R-134a refrigerant recovery/recycling/charging station (A) to the high-pressure service port (B) and the low-pressure service port (C), as shown in the illustration, following the equipment manufacturer's instructions.
2. Recover refrigerant from the A/C system (see «REFRIGERANT RECOVERY»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__refrigerant-recovery) ), and evacuate the system (see «SYSTEM EVACUATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__system-evacuation) ). If the system achieves a vacuum of approximately -93.3 kPa (-700 mmHg, -27.55 inHg) in 15 minutes, and holds the vacuum for 15 minutes, then the system does not have a leak at this time. If the system cannot achieve or hold a vacuum, continue the refrigerant leak check.
3. Open the high pressure valve to charge the system to the specified capacity. Select the appropriate units of measure for your refrigerant charging station. Refrigerant Capacity: 480 to 530 g 16.9 to 18.7 oz 0.48 to 0.53 kg 1.06 to 1.12 lbs
4. With the engine OFF, use a halogen leak detector first to detect the leak source. Follow a continuous path in order to ensure that you will not miss any possible leaks. Test the following areas of the system for leaks: Possible Leak Area Diagnostic Procedure with the Leak Detector Notes Service ports Check the service ports with caps installed If the detector "sniffs" a leak, use fluorescent dye to confirm it When capping the service ports, ensure that the seals on the port caps are in place, and that the caps are tight. The caps are used as the final seals in the system A/C condenser If the detector "sniffs" a leak, use fluorescent dye to confirm it Check for joints or connections coated with oily dust Check for damaged and corroded areas Check all fittings, couplings, brazed/welded areas and areas around attachment points Move the probe slowly (1 in/second or less), and keep it within 1/4 in of the component being checked. This maximizes the chance of detecting a leak If you detect a leak, blow compressed air over the area, then recheck for leaks. For large leaks, cleaning the area with compressed air may help you pinpoint the leak source Evaporator Check at the evaporator drain hose Check at the passenger's side vent and turn the blower on at low speed A/C lines Wiggle the rubber hoses when checking crimped metal ends If the detector "sniffs" a leak, use fluorescent dye to confirm it Check all fittings, couplings, pressure switches, brazed/welded areas, and areas around attachment points on A/C lines and components Check for damaged and corroded areas Move the probe slowly {1 in/second or less), and keep it within 1/4 in of the component being checked. This maximizes the chance of detecting a leak
5. Close the quick coupler valves, then disconnect the quick couplers from the vehicle service ports.
6. Attach the universal connect set, from the Optimax Jr. Leak Detection Kit, to the service valve fitting. Close the control valve (the black knob on the connect set).
7. Attach the charging station low pressure hose quick coupler to the service valve fitting, and open the quick coupler valve. Evacuate the connect set using the charging station vacuum pump, then close the quick coupler valve.
8. Detach the universal connect set, and install a Tracer-Stick® dye capsule between the connect set and the service valve fitting (see the manufacturer's instructions for more detail).
9. Attach the quick coupler on the universal connect set to the low pressure service port on the vehicle. Open the charging station low pressure hose quick coupler valve, but do not open the control valve.
10. Start the engine, and set the A/C system to maximum cooling. Open the control valve to let refrigerant and the dye enter the A/C system through the low pressure service port. Close the control valve when the Tracer-Stick® dye capsule is empty.
11. Run the engine and A/C system for 15 minutes to thoroughly circulate the dye. Then shut the engine off, and inspect the following areas of the system for leaks. NOTE: Check for leaks in a dark work area, and use the UV light and the special glasses from the leak check kit. Other UV lights may not work well with the Tracer-Stick® dye. Small leaks may take up to 1 week of vehicle operation (with normal A/C use) to become visible. Possible Leak Area Diagnostic Procedure with Fluorescent Dye Service ports If a leak is found, replace the cap/o-ring seal or A/C line as needed A/C lines Use a permanent marker pen to circle the leak area If a leak is found, remove and replace the A/C line (see «A/C LINE REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ) A/C condenser If a leak is found, remove the A/C condenser (see «A/C CONDENSER REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ) Determine whether leak is in the A/C condenser or the receiver/dryer Use a permanent marker pen to circle the leak area Replace either the receiver/dryer (see «RECEIVER/DRYER DESICCANT REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__receiverdryer-desiccant-replacement) ), or the A/C condenser (see «A/C CONDENSER REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ), depending upon which is leaking A/C compressor Check for leaks at all of the A/C compressor joints, the clutch center, the A/C compressor front housing bolts, and the scroll bolts on the back of the A/C compressor If a leak is found, use a permanent marker pen to circle the leak area If the A/C compressor relief valve appears to be leaking, determine whether the leak is coming from the relief valve, or the joint between the A/C compressor casing and the valve. If the leak is from the relief valve, check the A/C system pressures, and refer to the «PRESSURE TEST»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__pressure-test) table in the A/C system test (see «A/C SYSTEM TEST»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__ac-system-test) ). If the leak is from the casing/valve joint, replace the A/C compressor relief valve (see «A/C COMPRESSOR RELIEF VALVE REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__ac-compressor-relief-valve-replacement) ) If the leak is coming from the suction hose and/or discharge hose fittings on the A/C compressor, clean the A/C fittings and replace the suction/discharge fitting O-rings For all other A/C compressor leaks, remove and replace the A/C compressor (see «A/C COMPRESSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__ac-compressor-replacement) ) Evaporator Start checking for evaporator leaks by illuminating the evaporator drain tube area If a leak is found, remove the evaporator core (see «EVAPORATOR CORE REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ) Determine whether leak is from evaporator or expansion valve Use a permanent marker pen to circle leak area Replace the expansion valve (see «EXPANSION VALVE REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ), or the evaporator core (see «EVAPORATOR CORE REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ), depending upon which is leaking

A/C System Noise Check

The A/C system noise check will help you determine the source of abnormal A/C system noise.

Note. If accidental system discharge occurs, ventilate the work area before resuming service. Additional health and safety information may be obtained from the refrigerant and lubricant manufacturers. Identify the conditions when the noise occurs. The weather, the vehicle speed, the vehicle being in gear or in neutral, the engine temperature, or other conditions may be factors in determining the noise source. Do the A/C system inspection (see A/C SYSTEM INSPECTION ), and correct any problems found prior to diagnosing abnormal noises. Abnormal A/C noises can be misleading. For example, a sound similar to a failed bearing may be caused by loose fasteners, loose mounting brackets, or a faulty A/C compressor clutch assembly.

1. Inspect the air inlet grille in the cowl cover for debris. If debris is present, remove it.
2. Sit inside the vehicle, close the doors and windows, and turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, but do not start the engine. Cycle the HVAC system through all blower speeds and all air distribution modes to determine where and when the noise occurs.
3. Operate the blower at each speed with the engine and A/C off, and check for unusual noises and excessive vibration. If noise and/or vibration are present, do the following checks: If the noise or vibration occurs only in a specific mode or setting, then check these items: Operation of the mode control motor(s), door(s), and linkage Operation of the air mix control motor(s), door(s), and linkage Operation of the recirculation control motor, door, and linkage If there is a squeaking or chirping noise, but no unusual vibration, replace the blower motor (see «BLOWER UNIT COMPONENT REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__blower-unit-component-replacement) ). Remove the blower unit (see «BLOWER UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ), and check for foreign material (leaves or twigs, for example) on the blower motor and fan. If foreign material is present, remove it, and recheck for noise. If you do not find any foreign material, remove the blower motor (see «BLOWER UNIT COMPONENT REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__blower-unit-component-replacement) ), and check these items: Check if the fan blades are cracked or broken Make sure the fan retainer is tight Inspect the fan alignment on the blower motor shaft Replace the blower motor if any problems are present.
4. Set up the vehicle for the running A/C checks: Select a quiet area for testing Apply the parking brake Shift the vehicle to P or N Start the engine Set the temperature control switches to Max Cool Set the mode control buttons to Vent Set the fan control button to minimum (but not OFF) Turn the air conditioning button ON Switch the A/C compressor on and off several times to clearly identify the sound during A/C compressor operation. Listen to the noise while the A/C compressor clutch is engaged and disengaged. Probe the A/C system with a stethoscope to pinpoint the noise. NOTE: If the noise does not change when the A/C compressor clutch engages or disengages, the noise may be caused by an engine-related component. Probe the engine area with a stethoscope to pinpoint the noise.
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode, and check the drive belt for excessive wear, oil contamination, improper routing, or a faulty belt tensioner (see «DRIVE BELT INSPECTION»(/acura/zdx/i-2009-2013/remont/charging-system/#charging-system) ). Correct any problems found. Start the engine, run the A/C system, and check if the noise is coming from the drive belt, the belt tensioner or any of the pulleys. Repair or replace any faulty components.
6. Listen for noises coming from the A/C lines, the A/C hoses, the A/C condenser, the evaporator, the receiver/dryer, or the expansion valve, and check these items: Noises caused by A/C components touching other components or the body. Reroute or insulate the A/C component(s) as needed, and recheck for noise. Loose, damaged or excessively worn A/C components or mounting hardware. Repair or replace the faulty component(s) or hardware, and recheck for noise. A moaning noise from the A/C suction line. If there is a moaning noise, check the system refrigerant charge (see «SYSTEM CHARGING»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__system-charging) ). If the refrigerant charge is OK, replace the receiver/dryer. A whistling or hissing noise from the expansion valve. Evacuate the system for 3 hours (see «SYSTEM EVACUATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__system-evacuation) ), then recheck. If the noise is still present, replace the expansion valve (see «EXPANSION VALVE REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
7. Check the operation of the A/C compressor clutch: Make sure A/C compressor clutch engages without slipping. If the clutch does not engage, troubleshoot the A/C compressor clutch circuit (see «A/C COMPRESSOR CLUTCH CIRCUIT TROUBLESHOOTING»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__ac-compressor-clutch-circuit-troubleshooting) ). If the A/C compressor clutch slips, replace the A/C compressor clutch assembly (see «A/C COMPRESSOR CLUTCH OVERHAUL»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__ac-compressor-clutch-overhaul) ). And if there is a leak from the shaft seal when the A/C compressor clutch slips, replace the A/C compressor also (see «A/C COMPRESSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__ac-compressor-replacement) ). Make sure the A/C compressor clutch disengages. If the clutch does not disengage, do the A/C compressor clutch circuit troubleshooting (see «A/C COMPRESSOR CLUTCH CIRCUIT TROUBLESHOOTING»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__ac-compressor-clutch-circuit-troubleshooting) ). If the clutch circuit is OK, do the A/C compressor clutch check (see «A/C COMPRESSOR CLUTCH CHECK»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ), and see if the clutch is mechanically jammed. If there are no electrical or mechanical problems with the A/C compressor clutch, replace the A/C compressor (see «A/C COMPRESSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__ac-compressor-replacement) ). Make sure the A/C compressor clutch cycles normally. If the A/C compressor clutch is cycling rapidly, the A/C system is probably low on refrigerant due to a leak. Do the refrigerant leak check (see «REFRIGERANT LEAK CHECK»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__refrigerant-leak-check) ). If the refrigerant charge is OK, and there are no leaks, troubleshoot the A/C compressor clutch circuit (see «A/C COMPRESSOR CLUTCH CIRCUIT TROUBLESHOOTING»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__ac-compressor-clutch-circuit-troubleshooting) ).
8. Listen with a stethoscope for noises coming from the A/C compressor, and check these items: The noise changes when the A/C compressor clutch disengages. If the noise does not change when the A/C compressor disengages, the noise may be caused by an engine-related component. Probe the engine area with a stethoscope to pinpoint the noise. The A/C system operating pressures are normal. If the system pressures are abnormal, troubleshoot the problem using the pressure test table in the A/C system test (see «A/C SYSTEM TEST»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__ac-system-test) ). Correct the pressure-related problem(s), and recheck for noise. The A/C compressor hose connections, mounting brackets, and fasteners are in good condition. If any of these components are loose, damaged, or excessively worn, repair or replace the faulty component(s), and recheck for noise. If these components are in good condition, and the noise is still present, replace the A/C compressor (see «A/C COMPRESSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__ac-compressor-replacement) ).

A/C System Test

Special Tools Required

1. Big Digit Hygro-Thermometer PYR445703, commercially available
2. Throttle Pedal Depressor Tool B240B, commercially available

Performance Test

The performance test will help determine if the A/C system is operating within specifications.

Note. If accidental system discharge occurs, ventilate the work area before resuming service. Additional health and safety information may be obtained from the refrigerant and lubricant manufacturers.

Scheme 193

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1. Do the A/C system inspection (see «A/C SYSTEM INSPECTION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__ac-system-inspection) ), and correct any problems found.
2. Connect an R-134a refrigerant recovery/recycling/charging station to the high-pressure service port and the low-pressure service port, following the equipment manufacturer's instructions.
3. Determine the relative humidity and air temperature.
4. Remove the glove box (see «GLOVE BOX REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/gauges-instrument-panels/#dashboard__glove-box-removalinstallation) ).
5. Insert a thermometer (A) in the center vent.
6. Place a thermometer (B) near the blower unit's recirculation inlet duct.
7. Test conditions: Move the vehicle out of direct sunlight and let it cool down to the surrounding (ambient) temperature. If necessary, wash the vehicle to cool it down more quickly. The blower intake temperature must be at least 68°F (20°C). Open the hood. Open the front doors. Start the engine. Set the temperature control switches to Max Cool, the mode control buttons to Vent, and the RECIRCULATION button to Recirculate. Turn the air conditioning button ON and the fan control button to Max. Run the engine speed at 1, 500 rpm. No driver or passengers in the vehicle.
8. Inspect the A/C components for the following conditions: A/C compressor clutch not engaged. Abnormal frost areas. Unusual noises. If you observe any of these conditions, refer to the «SYMPTOM TROUBLESHOOTING INDEX»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__symptom-troubleshooting-index) .
9. After running the air conditioning for 10 minutes under the above test conditions, read the delivery temperature from the thermometer in the center vent, the intake temperature near the blower unit, and the discharge (high) and suction (low) pressures on the A/C gauges.
10. To complete the vent (delivery)/intake temperature chart: Mark the vent (delivery) temperature on the vertical line. Mark the intake temperature on the bottom line. Draw a vertical line from the intake temperature mark. Draw a horizontal line from the vent (delivery) temperature mark until it intersects the vertical line. NOTE: The vent temperature and the intake temperature should intersect in the shaded area. Any measurements outside the area may indicate the need for further inspection.
11. To complete the high side (discharge) pressure/intake temperature chart: Mark the high side (discharge) pressure on the vertical line. Mark the intake temperature on the bottom line. Draw a vertical line from the intake temperature mark. Draw a horizontal line from the high side (discharge) pressure mark until it intersects the vertical line. NOTE: The high side pressure and the intake temperature should intersect in the shaded area. Any measurements outside the area may indicate the need for further inspection.
12. To complete the low side (suction) pressure/intake temperature chart: Mark the low side (suction) pressure along the vertical line. Mark the intake temperature along the bottom line. Draw, a vertical line from the intake temperature mark. Draw a horizontal line from the low side (suction) pressure mark until it intersects the vertical line. NOTE: The low side pressure and the intake temperature should intersect in the shaded area. Any measurements outside the area may indicate the need for further inspection.

Pressure Test

Scheme 197

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Scheme 200

1. Recover the refrigerant with a recovery/recycling/charging station (see «REFRIGERANT RECOVERY»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__refrigerant-recovery) ).
2. Do the battery terminal disconnection procedure (see «BATTERY TERMINAL DISCONNECTION AND RECONNECTION»(/acura/zdx/i-2009-2013/remont/body-electrical/#battery) ).
3. Remove the front bumper (see «FRONT BUMPER REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/exterior-body-panels/#bumpers__front-bumper-removalinstallation) ).
4. Remove the bolt, then disconnect the receiver line (A) from the A/C condenser. Remove the O-ring (B).
5. Remove the bolt, then disconnect the discharge hose (A) from the A/C condenser. Remove the O-ring (B).
6. Remove the bolts and the radiator upper brackets (A).
7. Remove the bolts, then remove the A/C condenser upper mount brackets (A). Remove the A/C condenser (B) by lifting it up. Be careful not to damage the radiator or the A/C condenser fins when removing the A/C condenser.
8. Install the A/C condenser in the reverse order of removal, and note these items: If you're installing a new A/C condenser, add refrigerant oil (DENSO ND-OIL 8) (see «A/C REFRIGERANT OIL REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__ac-refrigerant-oil-replacement) ). Replace the O-rings with new ones at each fitting, and apply a thin coat of refrigerant oil before installing them. Be sure to use the correct O-rings for HFC-134a (R-134a) to avoid leakage. Immediately after using the oil, reinstall the cap on the container, and seal it to avoid moisture absorption. Do not spill the refrigerant oil on the vehicle; it may damage the paint; if the refrigerant oil contacts the paint, wash it off immediately. Be careful not to damage the radiator or the A/C condenser fins when installing the A/C condenser. Charge the system (see «SYSTEM CHARGING»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__system-charging) ).
9. Do the battery terminal reconnection procedure (see «BATTERY TERMINAL DISCONNECTION AND RECONNECTION»(/acura/zdx/i-2009-2013/remont/body-electrical/#battery) ).

Receiver/Dryer Desiccant Replacement

Note. Install the receiver/dryer as quickly as possible to prevent the system from absorbing moisture from the air.

Scheme 201

1. Remove the A/C condenser (see «A/C CONDENSER REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
2. Remove the cap (A) from the bottom of the A/C condenser. Remove the O-ring (B) and the desiccant (C).
3. Install the receiver/dryer in the reverse order of removal, and note these items: If you are installing a new desiccant, add refrigerant oil (DENSO ND-OIL 8) (see «REFRIGERANT RECOVERY»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__refrigerant-recovery) ). Replace the O-rings with new ones, and apply a thin coat of refrigerant oil (DENSO ND-OIL 8) before installing them. Be sure to use the correct O-rings for HFC-134a (R-134a) to avoid leakage. Install the cap to the specified torque. It is made of plastic and can be easily stripped.

A/C Compressor Replacement

Note. Do not install the A/C compressor into a system unless you are completely sure that the system is free of contamination. Installing the A/C compressor into a contaminated system can result in premature A/C compressor failure.

Scheme 202

Scheme 203

1. If the A/C compressor is marginally operable, run the engine at idle speed, and let the air conditioning work for a few minutes, then shut the engine off.
2. Recover the refrigerant with a recovery/recycling/charging station (see «REFRIGERANT RECOVERY»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__refrigerant-recovery) ).
3. Remove the A/C condenser fan shroud assembly (see «FAN, FAN MOTOR, AND SHROUD REMOVAL AND INSTALLATION»(/acura/zdx/i-2009-2013/remont/cooling-fan/#engine-cooling-system) ). NOTE: To avoid damage to the radiator, cover it with cardboard after removing the fan shroud.
4. Remove the alternator (see «ALTERNATOR REMOVAL AND INSTALLATION»(/acura/zdx/i-2009-2013/remont/charging-system/#charging-system) ).
5. Disconnect the A/C compressor clutch connector (A). Remove the bolts and the nut, then disconnect the suction hose (B) and the discharge hose (C) from the A/C compressor. Remove the O-rings (D). Plug or cap the lines immediately after disconnecting them to avoid moisture and dust contamination.
6. Remove the mounting bolts and the A/C compressor (A). Be careful not to damage the radiator fins when removing the A/C compressor.
7. Install the A/C compressor in the reverse order of removal, and note these items: Before installing a new A/C compressor, adjust the A/C compressor oil level (see «A/C REFRIGERANT OIL REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__ac-refrigerant-oil-replacement) ). Inspect the A/C lines for any signs of contamination. Replace the O-rings with new ones at each fitting, and apply a thin coat of refrigerant oil before installing them. Be sure to use the correct O-rings for HFC-134a (R-134a) to avoid leakage. Use only refrigerant oil (DENSO ND-OIL 8) for HFC-134a DENSO A/C compressors only. To avoid contamination, do not return the oil to the container once dispensed, and never mix it with other refrigerant oils. Immediately after using the oil, reinstall the cap on the container, and seal it to avoid moisture absorption. Do not spill the refrigerant oil on the vehicle; it may damage the paint. If the refrigerant oil contacts the paint, wash it off immediately. Be careful not to damage the radiator fins when installing the A/C compressor and the A/C condenser fan shroud. Charge the system (see «SYSTEM CHARGING»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__system-charging) ).

A/C Compressor Clutch Overhaul

Special Tools Required

A/C Compressor Kit 07AAF-000A150

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Scheme 207

1. Remove the center bolt (A) while holding the pressure plate with the A/C clutch holder (B).
2. Remove the pressure plate (A) and the shim(s) (B), taking care not to lose the shim(s). If the clutch needs adjustment, increase or decrease the number and thickness of shims as necessary, then reinstall the pressure plate, and recheck its clearance (see «A/C COMPRESSOR CLUTCH CHECK»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). NOTE: The shims are available in three thicknesses: 0.1 mm, 0.3 mm, and 0.5 mm. Do not pry on the pressure plate with screwdrivers or similar tools. Prying damages the pressure plate and the pulley. When replacing the clutch set, place a trial stack of shims, 1 mm total thickness, on the A/C compressor shaft. Install the pressure plate, and check its clearance (see «A/C COMPRESSOR CLUTCH CHECK»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ). If the clearance is not within specification, add or subtract shims as needed.
3. If you are replacing the field coil, remove the snap ring (A) with snap ring pliers, then remove the pulley (B). Be careful not to damage the pulley or the A/C compressor. NOTE: Do not use a hammer to remove the snap rings. Using a hammer damages the A/C compressor. Do not hammer or pry on the pulley to remove it. Using a hammer damages the A/C compressor. If the pulley is difficult to remove, use a commercially available pulley removing tool. Make sure the jaws of the pulling tool engage the back face of the pulley, not the pulley grooves.
4. Remove the screw from the field coil ground terminal (A), then remove the wire harness (B) and the bracket (C). Disconnect the field coil connector (D). Remove the snap ring (E) with snap ring pliers, then remove the field coil (F). Be careful not to damage the field coil or the A/C compressor.
5. Reassemble the clutch in the reverse order of disassembly, and note these items: When replacing the field coil, check that the new coil has the correct resistance (see step 6 ). Install the field coil with the wire side facing down, and align the boss on the field coil with the hole in the A/C compressor. If the clutch surface is oil soaked, check the compressor front seal for leakage. Installing a new clutch assembly on a leaking compressor will damage the new clutch assembly friction surfaces. Clean the pulley and A/C compressor friction surfaces with contact cleaner or other non-petroleum solvent. Install new snap rings, note the installation direction, and make sure they are fully seated in the grooves. Make sure that the pulley turns smoothly after it's reassembled. Route and clamp the wires properly to prevent damage by the pulley.
6. Cycle the A/C clutch approximately 20 times by running the engine at 1, 500-2, 000 rpm and setting the climate control temperature to Lo with the air conditioning button ON. This procedure seats the clutch friction surfaces, and increases clutch torque capacity.

A/C Compressor Relief Valve Replacement

Note. If the A/C compressor relief valve released refrigerant to the atmosphere, determine and correct the cause of the excessive system pressure, then replace the relief valve.

Scheme 208

1. Recover the refrigerant with a recovery/recycling/charging station (see «REFRIGERANT RECOVERY»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__refrigerant-recovery) ).
2. Remove the relief valve (A) and the O-ring (B). Plug the opening to keep moisture and foreign material from entering the system, and the A/C compressor oil from running out.
3. Clean the mating surfaces.
4. Replace the O-ring with a new one, and apply a thin coat of refrigerant oil before installing it.
5. Remove the plug you installed in step 2 , then install and tighten the relief valve.
6. Charge the system (see «SYSTEM CHARGING»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__system-charging) ).

A/C Refrigerant Oil Replacement

Special Tools Required

Oil Injector Tool Robinair ROB16256*, commercially available

*Available through the Acura Tool and Equipment Program; call 888-424-6857

Recommended PAG oil: DENSO ND-OIL 8

P/N 38897-PR7-A01AH: 120 mL (4 fl.oz)

It is important to have the correct amount of refrigerant oil in the A/C system to ensure proper lubrication of the A/C compressor. Too little oil damages the A/C compressor; too much oil reduces the cooling capacity of the system, and can produce high vent temperatures.

1. To avoid contamination, do not return the oil to the container once dispensed, and never mix it with other refrigerant oils.
2. Immediately after using the oil, reinstall the cap on the container, and seal it to avoid moisture absorption.
3. Do not spill the refrigerant oil on the vehicle; it may damage the paint; if it gets on the paint, wash it off immediately.

Add the recommended refrigerant oil in the amount listed if you replace any of the following parts

A/C condenser (including Dryer Desiccant)...................35 mL (1 1/5 fl.oz)

Evaporator.................35 mL(1 1/5 fl.oz)

Line or hose...............10 mL (1/3 fl.oz)

Dryer desiccant...........10 mL (1/3 fl.oz)

Leakage repair...........25 mL (5/6 fl.oz)

A/C compressor.........For A/C compressor replacement, subtract the volume of oil drained from the removed A/C compressor from 102 mL (3 4/9 fl.oz), and drain the calculated volume of oil from the new A/C compressor: 102 mL (3 4/9 fl.oz) - Volume of removed A/C compressor = Volume to drain from new A/C compressor.

Note. Even if no oil is drained from the removed A/C compressor, do not drain more than 50 mL (1 2/3 fl.oz) from the new A/C compressor.

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Scheme 213

1. Open the glove box. Remove the glove box separator (A) by carefully pulling it straight back.
2. Remove the dust and pollen filter assembly (A) from the blower unit.
3. Remove the filter (A) from the housing (B), and replace the filter.
4. Install the filter in the reverse order of removal. Make sure that there is no air leaking out of the blower unit.

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Scheme 219

1. Remove these items: Passenger's dashboard undercover (see «GLOVE BOX DAMPER REPLACEMENT»(/acura/zdx/i-2009-2013/remont/gauges-instrument-panels/#dashboard__glove-box-damper-replacement) ) Passenger's dashboard trim (see «PASSENGER'S DASHBOARD TRIM PANEL REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/gauges-instrument-panels/#dashboard) ) Glove box (see «GLOVE BOX REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/gauges-instrument-panels/#dashboard__glove-box-removalinstallation) ) Passenger's kick panel (see «TRIM REMOVAL/INSTALLATION - DOOR AREAS»(/acura/zdx/i-2009-2013/remont/exteriorinterior-trim/#interior-trim__trim-removalinstallation-door-areas) )
2. Detach the harness clips (A). Remove the bolts, and the glove box frame (B).
3. Cut the plastic cross brace (A) in the glove box opening with diagonal cutters in the area shown in the illustration. Retain the plastic cross brace to be reinstalled later.
4. Detach the harness clip (A), then remove the self-tapping screws, and the passenger's heater duct (B).
5. Disconnect the blower motor connector (A) and the climate control unit connectors (B), and detach the harness clips (C).
6. Remove the self-tapping screws, and disconnect the recirculation control motor connector (A).
7. Disconnect the right engine compartment harness connector (C205) (A) and detach the harness clips (B). Remove the mounting nuts, and the blower unit (C).
8. Install the unit in the reverse order of removal. Make sure that there are no air leaks.

Blower Unit Component Replacement

Note these items when overhauling the blower unit

Scheme 220

1. The recirculation control motor (A), the blower motor (B), and the dust and pollen filter (C) can be replaced without removing the blower unit.
2. Before reassembly, make sure that the recirculation control linkage and door move smoothly without binding.
3. After reassembly, make sure the recirculation control motor runs smoothly (see «RECIRCULATION CONTROL MOTOR TEST»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__recirculation-control-motor-test) ).

Scheme 221

1. Remove the evaporator core (see «EVAPORATOR CORE REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
2. Remove the insulator (A) and bolts, then remove the expansion valve (B) and O-rings (C).
3. Install the expansion valve in the reverse order of removal, and note these items: Replace the O-rings with new ones at each fitting, and apply a thin coat of refrigerant oil before installing them. Be sure to use the correct O-rings for HFC-134a (R-134a) to avoid leakage. Immediately after using the oil, reinstall the cap on the container, and seal it to avoid moisture absorption. Do not spill the refrigerant oil on the vehicle; it may damage the paint; if the refrigerant oil contacts the paint, wash it off immediately. Charge the system (see «SYSTEM CHARGING»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__system-charging) ). Make sure that there is no air leakage. Make sure that there is no refrigerant leakage.

Scheme 222

Scheme 223

Scheme 224

Scheme 225

1. Recover the refrigerant with a recovery/recycling/ charging station (see «REFRIGERANT RECOVERY»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__refrigerant-recovery) ).
2. Remove the bolt from the A/C line clamp (A).
3. Remove the bolt, then disconnect the A/C line (A) from the evaporator core. Replace the O-rings (B).
4. Remove the blower unit (see «BLOWER UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
5. Disconnect the power transistor connector (A). Detach the harness clips (B). Remove the self-tapping screws, the joint duct (C), and the seal (D).
6. Carefully pull out the evaporator core (A) without bending the lines, then remove the plate (B). NOTE: Be careful not to damage the wire harness.
7. Install the core in the reverse order of removal, and note these items: If you're installing a new evaporator core, add refrigerant oil (DENSO ND-OIL 8) (see «A/C REFRIGERANT OIL REPLACEMENT»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__ac-refrigerant-oil-replacement) ). Replace the O-rings with new ones at each fitting, and apply a thin coat of refrigerant oil before installing them. Be sure to use the correct O-rings for HFC-134a (R-134a) to avoid leakage. Immediately after using the oil, reinstall the cap on the container, and seal it to avoid moisture absorption. Do not spill the refrigerant oil on the vehicle; it may damage the paint; if the refrigerant oil contacts the paint, wash it off immediately. Charge the system (see «SYSTEM CHARGING»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__system-charging) ). Make sure that there is no air leakage. Make sure that there is no refrigerant leakage.

Heater Unit/Core Replacement

SRS components are located in this area. Review the SRS component locations (see COMPONENT LOCATION INDEX ) and the precautions and procedures (see PRECAUTIONS AND PROCEDURES ) before doing repairs or service.

Scheme 226

Scheme 227

Scheme 228

Scheme 229

Scheme 230

Scheme 231

Scheme 232

Scheme 233

1. Do the battery terminal disconnection procedure (see «BATTERY TERMINAL DISCONNECTION AND RECONNECTION»(/acura/zdx/i-2009-2013/remont/body-electrical/#battery) ).
2. Recover the refrigerant with a recovery/recycling/ charging station (see «REFRIGERANT RECOVERY»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__refrigerant-recovery) ).
3. Disconnect the A/C line from the evaporator core (see step 3 ).
4. When the engine is cool, drain the engine coolant from the radiator (see «COOLANT CHECK»(/acura/zdx/i-2009-2013/remont/cooling-fan/#engine-cooling-system) ).
5. From under the hood, slide the hose clamps (A) back. Disconnect the inlet heater hose (B) and the outlet heater hose (C) from the heater unit. Note the layout of the hoses. Engine coolant will run out when the hoses are disconnected; drain it into a clean drip pan. Be sure not to let coolant spill on the electrical parts or the painted surfaces. If any coolant spills, rinse it off immediately.
6. Remove the mounting nut from the heater unit. Take care not to damage or bend the fuel lines or the brake lines.
7. Remove the dashboard (see «DASHBOARD/STEERING HANGER BEAM REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/gauges-instrument-panels/#dashboard) ).
8. Disconnect the right engine compartment wire harness connector (C201) (A). Remove the duct (B) and the drain hose (C). Then remove the mounting nuts and the blower-heater unit (D).
9. Disconnect the connector (A) from the blower motor. Detach the harness clips (B).
10. Disconnect these connectors (A): The passenger's mode control motor, the power transistor, and the passenger's air mix control motor. Detach the harness clips (B).
11. Disconnect these connectors (A): The recirculation control motor, and the climate control unit. Detach the harness clip (B).
12. Disconnect these connectors (A): the driver's air mix control motor, the driver's mode control motor, and evaporator temperature sensor. Detach the harness clips (B) and remove the wire harness (C).
13. Remove the self-tapping screws, the passenger's heater duct (A), the joint duct (B), the seal (C), and the heater core cover (D).
14. Remove the self-tapping screw, the heater pipe bracket (E), and the grommet (F), and carefully pull out the heater core (G).
15. Install the heater core in the reverse order of removal.
16. Install the heater unit in the reverse order of removal, and note these items: Do not interchange the inlet and outlet heater hoses, and install the hose clamps securely. Refill the cooling system with engine coolant (see «COOLANT CHECK»(/acura/zdx/i-2009-2013/remont/cooling-fan/#engine-cooling-system) ). Make sure that there is no coolant leakage. Charge the system (see «SYSTEM CHARGING»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__system-charging) ). Make sure that there is no air leakage. Make sure that there is no refrigerant leakage.
17. Do the battery terminal reconnection procedure (see «BATTERY TERMINAL DISCONNECTION AND RECONNECTION»(/acura/zdx/i-2009-2013/remont/body-electrical/#battery) ).

Scheme 234

Scheme 235

1. Remove the driver's dashboard undercover (see «DRIVER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/gauges-instrument-panels/#dashboard) ).
2. Remove the self-tapping screws, the aspirator hose (A), and the driver's heater duct (B).
3. Disconnect the 7P connector (A) from the driver's air mix control motor (B). Remove the self-tapping screws and the driver's air mix control motor from the heater unit.
4. Make sure the air mix door and linkage move smoothly. Then install the motor in the reverse order of removal. Make sure the pin on the motor is properly engaged with the linkage. After installation, make sure the motor runs smoothly.

Scheme 236

Scheme 237

1. Remove the passenger's dashboard undercover (see «GLOVE BOX DAMPER REPLACEMENT»(/acura/zdx/i-2009-2013/remont/gauges-instrument-panels/#dashboard__glove-box-damper-replacement) ).
2. Remove the glove box (see «GLOVE BOX REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/gauges-instrument-panels/#dashboard__glove-box-removalinstallation) ).
3. Detach the harness clip (A), then remove the self-tapping screws and the passenger's heater duct
4. Disconnect the 5P connector (A) from the power transistor, and the 7P connector (B) from the passenger's air mix control motor (C). Remove the self-tapping screws and the passenger's air mix control motor from the heater unit.
5. Make sure the air mix door and linkage move smoothly. Then install the motor in the reverse order of removal. Make sure the pin on the motor is properly engaged with the linkage. After installation, make sure the motor runs smoothly.

Scheme 238

1. Remove the driver's dashboard undercover (see «DRIVER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/gauges-instrument-panels/#dashboard) ).
2. Disconnect the 7P connector (A) from the driver's mode control motor (B). Remove the self-tapping screws and the driver's mode control motor from the heater unit.
3. Install the motor in the reverse order of removal. Make sure the pin on the motor is properly engaged with the linkage. After installation, make sure the motor runs smoothly.

Removal

Note. Set the passenger's side climate control to the VENT position before removing the motor.

Scheme 239

Scheme 240

Scheme 241

1. Remove the passenger's dashboard undercover (see «GLOVE BOX DAMPER REPLACEMENT»(/acura/zdx/i-2009-2013/remont/gauges-instrument-panels/#dashboard__glove-box-damper-replacement) ).
2. Remove the glove box (see «GLOVE BOX REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/gauges-instrument-panels/#dashboard__glove-box-removalinstallation) ).
3. Remove the glove box frame (see step 2 ).
4. Detach the harness clip (A), then remove the self-tapping screws and the passenger's heater duct (B).
5. Disconnect the 7P connector (A) from the passenger's mode control motor (B). Release the wire from its harness clip (C), then remove the self-tapping screws and the passenger's mode control motor from the heater unit.

Scheme 242

Scheme 243

Scheme 244

Scheme 245

1. Release the lock (A), then remove the motor lever (B) from the mode control motor (C). NOTE: Before installing the mode control motor, plug in the 7P connector, and set the passenger's side climate control mode to VENT. Check that the motor output shaft is lined up as indicated (D).
2. Align the position of the damper lever pins (A), then install the motor lever (B).
3. Make sure the damper lever pins in the motor lever are visible through the holes.
4. Install the mode control motor (A) while holding the motor lever (B).
5. After installation, make sure the motor runs smoothly.

Scheme 246

1. Remove the passenger's dashboard undercover (see «GLOVE BOX DAMPER REPLACEMENT»(/acura/zdx/i-2009-2013/remont/gauges-instrument-panels/#dashboard__glove-box-damper-replacement) ).
2. Remove the glove box (see «GLOVE BOX REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/gauges-instrument-panels/#dashboard__glove-box-removalinstallation) ).
3. Remove the climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control) ).
4. Disconnect the 7P connector (A) from the recirculation control motor (B). Remove the self-tapping screws and the recirculation control motor from the blower unit.

Scheme 247

Scheme 248

1. Make sure the damper lever pins in the motor lever are visible through the holes.
2. While holding the recirculation control motor (A), install the self-tapping screws and connect the 7P connector (B).
3. Reinstall the climate control unit.
4. After installation, make sure the motor runs smoothly.

Scheme 249

Scheme 250

1. Remove the driver's dashboard trim (see «DRIVER'S OUTER DASHBOARD TRIM REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/gauges-instrument-panels/#dashboard) ).
2. Disconnect the connector (A) from the humidity/in-car temperature sensor (B).
3. Unhook the lock tabs (C) of the humidity/in-car temperature sensor, and pull it
4. Disconnect the aspirator hose (A), and remove the humidity/in-car temperature sensor.
5. Install the sensor in the reverse order of removal.

Scheme 251

1. From behind the bumper, disconnect the 2P connector (A). Detach the clip and remove the outside air temperature sensor (B).
2. Install the sensor in the reverse order of removal.

Scheme 252

1. Pull out the sunlight sensor (A) from the speaker lid, then disconnect the connector (B). Be careful not to damage the sensor or the dashboard.
2. Install the sensor in the reverse order of removal.

Scheme 253

1. Remove the driver's dashboard undercover (see «DRIVER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION»(/acura/zdx/i-2009-2013/remont/gauges-instrument-panels/#dashboard) ).
2. Disconnect the 7P connector (A) from the driver's mode control motor (B) and detach the harness clips (C). Disconnect the 2P connector (D) from the evaporator temperature sensor (E) by pressing the lock tab toward the evaporator housing, and remove the connector clip (F). Remove the self-tapping screw and the evaporator temperature sensor.
3. Install the sensor in the reverse order of removal.

Scheme 254

1. Remove the passenger's dashboard undercover (see «GLOVE BOX DAMPER REPLACEMENT»(/acura/zdx/i-2009-2013/remont/gauges-instrument-panels/#dashboard__glove-box-damper-replacement) ).
2. Disconnect the connectors (A). Remove the bolts (B) and the climate control unit (C).
3. Install the climate control unit in the reverse order of removal. After installation, operate the various functions to make sure they work properly.
4. Run the self-diagnostic function to confirm that there are no problems in the system (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).

Refrigerant Recovery

Note. If accidental system discharge occurs, ventilate the work area before resuming service. Additional health and safety information may be obtained from the refrigerant and lubricant manufacturers.

Scheme 255

1. Connect an R-134a refrigerant recovery/recycling/charging station (A) to the high-pressure service port (B) and the low-pressure service port (C), as shown in the illustration, following the equipment manufacturer's instructions.
2. Measure the amount of refrigerant oil removed from the A/C system after the recovery process is completed. Be sure to put the same amount of new refrigerant oil back into the A/C system before charging.

System Evacuation

Special Tools Required

Compact Electronic Vacuum Gauge Robinair ROB14777*, commercially available

*Available through the Acura Tool and Equipment Program; call 888-424-6857

Note. If accidental system discharge occurs, ventilate the work area before resuming service. Additional health and safety information may be obtained from the refrigerant and lubricant manufacturers. Do not allow moisture to contaminate the A/C system oil. Moisture in the oil is difficult to remove, and it can damage the A/C compressor. Using a compact electronic vacuum gauge may decrease the required evacuation time because you can measure actual moisture level with this tool.

A more efficient way to measure moisture removal is with a special tool called a compact electronic vacuum gauge, measuring vacuum levels in microns.

Connect the tool according to the manufacturers instructions and allow the vacuum pump to run until the gauge reads 500 microns.

Shut off and isolate the vacuum pump, then observe the gauge reading

1. If the vacuum level remains stable at 500 microns for at least three minutes, all moisture in the system has been removed.
2. A slow increase in the micron reading means there is still moisture boiling out of the system. Restart the vacuum pump and continue evacuating.
3. A quick increase of micron levels indicates a leak is present in the system or your service equipment. Determine the cause and correct the leak before continuing.

Scheme 256

1. When an A/C System has been opened to the atmosphere, such as during installation or repair, it must be evacuated using an R-134a refrigerant recovery/recycling/charging station. If the system has been open for several days, replace the receiver/dryer, drain the refrigerant oil, and add fresh oil (see «A/C SERVICE TIPS AND PRECAUTIONS»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__ac-service-tips-and-precautions) ). then evacuate the system for several hours before charging it.
2. Connect an R-134a refrigerant recovery/recycling/charging station (A) to the high-pressure service port (B) and the low-pressure service port (C), as shown in the illustration, following the equipment manufacturer's instructions.
3. Evacuate the system. The vacuum pump should run for a minimum of 30 minutes to eliminate all moisture from the system. When the suction gauge reads -93.3 kPa (-700 mmHg, -27.55 inHg) for at least 30 minutes, close all valves, and turn off the vacuum pump.
4. If the suction gauge does not reach approximately -93.3 kPa (-700 mmHg, -27.55 inHg) in 15 minutes, there is probably a large leak in the system. Partially charge the system, and check for leaks (see «REFRIGERANT LEAK CHECK»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__refrigerant-leak-check) ).

System Charging

Note. If accidental system discharge occurs, ventilate the work area before resuming service. Additional health and safety information may be obtained from the refrigerant and lubricant manufacturers.

Scheme 257

1. Connect an R-134a refrigerant recovery/recycling/charging station (A) to the high-pressure service port (B) and the low-pressure service port (C), as shown in the illustration, following the equipment manufacturer's instructions.
2. Recover the refrigerant in the A/C system (see «REFRIGERANT RECOVERY»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__refrigerant-recovery) ).
3. Evacuate the system (see «SYSTEM EVACUATION»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__system-evacuation) ). If the system cannot reach a vacuum of -93.3 kPa (-700 mmHg, -27.55 inHg) in 15 minutes, or cannot hold a vacuum for at least 15 minutes, there is probably a large leak. Do the refrigerant leak check (see «REFRIGERANT LEAK CHECK»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__refrigerant-leak-check) ), and repair any leaks before charging the system.
4. Add the same amount of new refrigerant oil to the system that was removed during recovery. Use only DENSO ND-OIL 8 refrigerant oil.
5. Charge the system with the specified amount of R-134a refrigerant. Do not overcharge the system; the A/C compressor will be damaged. Select the appropriate units of measure for your refrigerant charging station. Refrigerant Capacity: 480 to 530 g 16.9 to 18.7 oz 0.48 to 0.53 kg 1.06 to 1.12 lbs
6. Check for refrigerant leaks (see «REFRIGERANT LEAK CHECK»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__refrigerant-leak-check) ).
7. Check the system performance (see «PERFORMANCE TEST»(/acura/zdx/i-2009-2013/remont/automatic-hvac-system/#climate-control__performance-test) ).

See also:
• DRIVE BELT INSPECTION
• DRIVE BELT REPLACEMENT
• TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A
• DLC CIRCUIT TROUBLESHOOTING
• DTC U1280: COMMUNICATION BUS LINE ERROR (BUS-OFF)
• CONNECTOR TO FUSE/RELAY BOX INDEX
• A/C SIGNAL CIRCUIT TROUBLESHOOTING
• RADIATOR FAN HIGH SPEED CIRCUIT TROUBLESHOOTING
• HOW TO CHECK ERROR HISTORY (NAVIGATION DTCS)
• DTC P2183: ECT SENSOR 2 CIRCUIT RANGE/PERFORMANCE PROBLEM
• COOLANT CHECK
• GAUGE CONTROL MODULE INPUT TEST
• POWER RELAY TEST
• REMOVAL AND INSTALLATION
• GENERAL TROUBLESHOOTING INFORMATION
• SUBSTITUTING THE PCM
• PCM REPLACEMENT
• RELAY CIRCUIT BOARD TEST
• AUDIO-NAVIGATION AND HVAC SWITCH PANEL REMOVAL/INSTALLATION
• SYSTEM LINKS
• SYMPTOM TROUBLESHOOTING INDEX
• AUDIO-NAVIGATION UNIT REMOVAL/INSTALLATION
• GLOVE BOX DAMPER REPLACEMENT
• GLOVE BOX REMOVAL/INSTALLATION
• BATTERY TERMINAL DISCONNECTION AND RECONNECTION
• FRONT BUMPER REMOVAL/INSTALLATION
• PASSENGER'S DASHBOARD TRIM PANEL REMOVAL/INSTALLATION
• TRIM REMOVAL/INSTALLATION - DOOR AREAS
• COMPONENT LOCATION INDEX
• A/C SYSTEM NOISE CHECK
• A/C LINE REPLACEMENT
• REFRIGERANT LEAK CHECK
• HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS
• CHECKING FOR DTCS
• A/C COMPRESSOR CLUTCH CIRCUIT TROUBLESHOOTING
• HOW TO CHECK FOR DTCS WITH THE HDS
• RUN THE SENSOR INPUT DISPLAY MODE
• EVAPORATOR TEMPERATURE SENSOR TEST
• SYSTEM DESCRIPTION
• RADIATOR AND A/C CONDENSER FAN LOW SPEED CIRCUIT TROUBLESHOOTING
• A/C CONDENSER FAN HIGH SPEED CIRCUIT TROUBLESHOOTING
• A/C COMPRESSOR RELIEF VALVE REPLACEMENT
• REFRIGERANT RECOVERY
• RECIRCULATION CONTROL MOTOR TEST
• DRIVER'S AIR MIX CONTROL MOTOR TEST
• PASSENGER'S AIR MIX CONTROL MOTOR TEST
• IN-CAR TEMPERATURE SENSOR TEST
• SUNLIGHT SENSOR TEST
• DRIVER'S MODE CONTROL MOTOR TEST
• BLOWER UNIT COMPONENT REPLACEMENT
• PASSENGER'S MODE CONTROL MOTOR TEST
• A/C COMPRESSOR CLUTCH OVERHAUL
• A/C COMPRESSOR REPLACEMENT
• SYSTEM EVACUATION
• RECEIVER/DRYER DESICCANT REPLACEMENT
• PRESSURE TEST
• A/C SYSTEM TEST
• A/C SYSTEM INSPECTION
• SYSTEM CHARGING
• SYMPTOM TROUBLESHOOTING INDEX
• A/C REFRIGERANT OIL REPLACEMENT
• A/C SERVICE TIPS AND PRECAUTIONS
• PERFORMANCE TEST