Climate Control Acura RDX I рестайлинг

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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 A/C SYSTEM NOISE CHECK ).

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/rdx/i-2009-2012/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/rdx/i-2009-2012/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/rdx/i-2009-2012/remont/charging-system/#charging-system) ). If the drive belt is damaged or shows signs of slippage, replace it 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/rdx/i-2009-2012/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/rdx/i-2009-2012/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/rdx/i-2009-2012/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/rdx/i-2009-2012/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/rdx/i-2009-2012/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 (see «SYMPTOM TROUBLESHOOTING INDEX»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__symptom-troubleshooting-index) ).
11. Check that the A/C compressor clutch armature plate (A) is rotating at the same speed as the rotor pulley and is engaging. If the A/C compressor clutch does not engage, go to the A/C Compressor Clutch Circuit Troubleshooting (see «A/C COMPRESSOR CLUTCH CIRCUIT TROUBLESHOOTING»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__ac-compressor-clutch-circuit-troubleshooting) ).
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 (see «SYMPTOM TROUBLESHOOTING INDEX»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__symptom-troubleshooting-index) ).
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 (see «A/C COMPRESSOR REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__ac-compressor-replacement) ), if necessary.

How to Check for DTCs with the HDS

1. 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).
2. The second method is to run the self-diagnostic function built into the climate control unit.
3. The third method is to use B-CAN system diagnosis test mode A (see «TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A»(/acura/rdx/i-2009-2012/remont/communication-devices/#multiplex-integrated-control-system__troubleshooting-b-can-system-diagnosis-test) ).

Scheme 7

1. Make sure the ignition switch is in LOCK (0).
2. Connect the HDS to the DLC (A) located under the driver's side of the dashboard.
3. Turn the ignition switch to ON (II).
4. Make sure the HDS communicates with the vehicle and the climate control unit. If it does not, go to the DLC circuit troubleshooting (see «DLC CIRCUIT TROUBLESHOOTING»(/acura/rdx/i-2009-2012/remont/testing-diagnostics/#pgm-fi-system__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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) . If no DTCs are indicated, refer to «SYMPTOM TROUBLESHOOTING»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__symptom-troubleshooting-index) . 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 communication with the HVAC 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 ).

1. Make sure the ignition switch is in LOCK (0).
2. Connect the HDS to the DLC.
3. Turn the ignition switch to ON (II).
4. Make sure the HDS communicates with the vehicle and the climate control unit. If it does not, go to the DLC circuit troubleshooting (see «DLC CIRCUIT TROUBLESHOOTING»(/acura/rdx/i-2009-2012/remont/testing-diagnostics/#pgm-fi-system__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/rdx/i-2009-2012/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

Scheme 8

1. Turn the ignition switch to ON (II).
2. Press and hold the OFF button.
3. While holding the OFF button, press the rear window defogger/mirror defogger button five times within 10 seconds. Release the buttons and the self-diagnostic function will begin. NOTE: It may take up to 20 seconds for the self-diagnostic to begin. The blower motor can be run at various speeds regardless of what the panel is displaying. If there is any problem in the system, the driver's temperature indicator will light up the segment (A through P) corresponding to the error. The temperature indicator will then alternate every second between displaying "88" (all segments lit) and the error code segment (A through P). To determine the meaning of the DTC, refer to «CHECKING FOR DTCS»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__checking-for-dtcs) . If there are no problems detected, the segments do not illuminate, and the system appear to be turned off. Canceling the Self-Diagnostic Function
4. Turn the ignition switch to LOCK (0) 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 indicator segments A, C, E and G are on at the same time, there may be an open in the common ground wire. If no DTCs are present, the indicator remains blank.

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The climate control unit has a mode that displays sensor inputs it receives. This mode shows you what the climate control unit is receiving from each of the sensors, one at a time, and it can help you determine if a sensor is faulty.

Checks before using the sensor input display mode

1. Turn the ignition switch to ON (II), and check the recirculation door function; press the recirculation button to switch from FRESH to RECIRC. The air volume and sound should change slightly.
2. Set the temperature control knob to the desired test temperature. When selecting the test temperature, note these items: "Lo" temperature setting will default to MAX COOL, VENT, and RECIRC. "Hi" temperature setting will default to MAX HOT, HEAT, and FRESH. 58 through 86°F settings will use the automatic climate control logic.
3. Turn the ignition switch to LOCK (0).

Run the sensor input display mode

1. Turn the ignition switch to LOCK (0).
2. Press and hold both the AUTO and REC buttons, then start the engine.
3. After the engine starts, release the buttons. The audio-HVAC display panel will flash the sensor number, and then the value for that sensor. Record the value displayed.
4. To advance to the next sensor, press the REAR WINDOW DEFOGGER button. NOTE: The sensor values will be displayed in degrees Celsius (°C) or an alphanumeric code. Use the chart to convert the value to degrees Fahrenheit (°F). If the sensor value displays "Er", this indicates there is an open or short in the circuit or sensor. Check for DTCs using the HDS, or refer to checking DTCs by DTC indication to check for DTCs. If necessary, compare the sensor input display to 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 with a known-good sensor, and recheck. Sensor Item Displayed Value 1 Mode positioning BIT 2 In-car temperature °C 3 Outside air temperature °C 4 Solar radiation sensor value: dark = 00, flashlight = 04, cloudy = 10, sunny = 65 10 kcal/m 2 -h 5 Evaporator temperature °C 6 Driver's air mix opening (low value indicates cooler air distribution, higher value indicates warmer air distribution) % of opening 7 Passenger's air mix opening (low value indicates cooler air distribution, higher value indicates warmer air distribution) % of opening 8 Recirculation opening % of opening 9 Vehicle speed (vehicle must be driven to display speed) 10 km/h A Engine coolant temperature °C b Vent temperature air out (TAO) °C 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 54 128 55 131 56 133 57 135 58 136 59 139 60 140 61 142 62 144 63 145 64 147 65 149 66 151 67 152 68 154 69 158 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 87 188 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 C0 thru C9 -20 thru -29 -4 thru -20 -120 thru -29 D0 thru D9 -30 thru -39 -22 thru -38 -30 thru -39 E0 thru E9 -40 thru -49 -40 thru -56 -40 thru -49 F0 thru F9 -- -- + 100 thru +109 ALPHANUMERIC CONVERSION TABLE (MODE POSITIONING) Display Reading (Alphanumeric) Mode Position 01 OVER VENT 02 VENT 03 VENT-HEAT/VENT 04 HEAT/VENT 05 HEAT/VENT-HEAT 06 HEAT 07 HEAT-HEAT/DEF 08 HEAT/DEF 09 HEAT/DEF-DEF 10 DEF 11 OVER DEF
5. To cancel the sensor input display mode, press the AUTO button or turn the ignition switch to LOCK (0).

DTC Troubleshooting Index

CHECKING DTCS BY 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 (SP-10) 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.

Oil Separator

Oil emission from the A/C compressor to the A/C line is reduced by placing the oil separator in the A/C compressor. This results in a thinner oil film inside of the heat exchanger (A/C condenser and evaporator). Air conditioning efficiency is increased without sacrificing engine performance.

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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 (2.0 kgf/cm 2 , 28 psi) or above 3, 138 kPa (32 kgf/cm 2 , 455 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 (15.0 kgf/cm 2 , 213 psi), the PCM switches the radiator and A/C condenser fans to high speed.

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This system automatically controls the temperature and the vent mode of 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 system.

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CONNECTOR A

CONNECTOR B

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1. Check the battery condition (see «BATTERY TEST»(/acura/rdx/i-2009-2012/remont/body-electrical/#battery) ) and the charging system (see «CHARGING SYSTEM INDICATOR CIRCUIT TROUBLESHOOTING»(/acura/rdx/i-2009-2012/remont/charging-system/#charging-system) ).
2. 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»(/acura/rdx/i-2009-2012/remont/communication-devices/#multiplex-integrated-control-system__troubleshooting-b-can-system-diagnosis-test) ).

1. Check the sensor input display mode, and select "evaporator temperature sensor" according to the table (see «CHECKS BEFORE USING THE SENSOR INPUT DISPLAY MODE»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__checks-before-using-the-sensor-input) ). NOTE: This indication by segment lit on digital segments is assigned for 2 failure causes that it is necessary to decide which one is a true cause. If there is a failure in the sensor or motor, a value corresponded to the sensor or motor in the Sensor Input Display Mode is displayed as "Er", which serves to specify which is a true cause. Is sensor value indicated "Er"? YES -Go to troubleshooting DTC B1231 or DTC indicator G (see «DTC B1231 OR DTC INDICATOR G: AN OPEN IN THE EVAPORATOR TEMPERATURE SENSOR CIRCUIT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__dtc-b1231-or-dtc-indicator-g) ) NO -Go to step 2
2. Turn the ignition switch to LOCK (0), and then back to ON (II).
3. Do the self-diagnostic with the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC indicator G indicated? YES -The climate control unit is faulty, replace the climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ). NO -Intermittent failure, the climate control unit is OK at this time. Check for poor connections at the climate control unit.

Note. If DTC B1205 is detected with HDS, it is not necessary to do step 1.

Scheme 19

1. Check the sensor input display mode, and select "evaporator temperature" according to the table (see «CHECKS BEFORE USING THE SENSOR INPUT DISPLAY MODE»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__checks-before-using-the-sensor-input) ). NOTE: This indication by segment lit on digital segments is assigned for 2 failure causes that it is necessary to decide which one is a true cause. If there is a failure in the sensor or motor, a value corresponded to the sensor or motor in the Sensor Input Display Mode is displayed as "Er", which serves to specify which is a true cause. Is sensor value indicated "Er"? YES -Go to troubleshooting DTC B1232 or DTC indicator H (see «DTC B1232 OR DTC INDICATOR H: A SHORT IN THE EVAPORATOR TEMPERATURE SENSOR CIRCUIT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__dtc-b1232-or-dtc-indicator-h) ) NO -Go to step 2
2. Clear the DTC with the HDS.
3. Turn the ignition switch to LOCK (0), and then back to ON (II).
4. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/rdx/i-2009-2012/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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
5. Check for DTCs. Is DTC B1205 or H indicated? YES -Go to step 6 NO -The system is OK at this time, check for loose wires or poor connections on the gauge control module and climate control unit circuit.
6. Check for DTCs with the HDS. Are DTC B1008, B1011, B1032, B1205, and B1906 also indicated? YES -Go to step 7. NO -The system is OK at this time, check for loose wires or poor connections on the gauge control module and climate control unit circuit.
7. Select UNIT INFORMATION in the BODY ELECTRICAL menu.
8. Select CONNECTED UNIT in the UNIT INFORMATION menu. Is gauge control module detected? YES -Substitute a known-good gauge control module, and recheck. If the symptom/indication goes away, replace the gauge control module (see «GAUGE CONTROL MODULE REPLACEMENT»(/acura/rdx/i-2009-2012/remont/gauges-instrument-panels/#gauges__gauge-control-module-replacement) ). NO -Go to step 9.
9. Disconnect under-dash fuse/relay box connector Q (16P).
10. Disconnect the gauge control module 36P connector.
11. Check for continuity between under-dash fuse/relay box connector Q (16P) terminal No. 6 and gauge control module 36P connector terminal No. 30. Is there continuity? YES -Go to the gauge control module input test (see «GAUGE CONTROL MODULE INPUT TEST»(/acura/rdx/i-2009-2012/remont/gauges-instrument-panels/#gauges__gauge-control-module-input-test) ) NO -Repair an open in the wire between the MICU and the gauge control module.

Note. If DTC B1206 is detected with HDS, it is not necessary to do step 1.

Scheme 20

1. Check the sensor input display mode, and select "driver's air mix control motor" according to the table (see «CHECKS BEFORE USING THE SENSOR INPUT DISPLAY MODE»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__checks-before-using-the-sensor-input) ). NOTE: This indication by segment lit on digital segments is assigned for 2 failure causes that it is necessary to decide which one is a true cause. If there is a failure in the sensor or motor, a value corresponded to the sensor or motor in the Sensor Input Display Mode is displayed as "Er", which serves to specify which is a true cause. Is sensor value indicated "Er"? YES -Go to troubleshooting DTC B1234 or DTC indicator K (see «DTC B1234 OR DTC INDICATOR K: A SHORT IN THE AIR MIX CONTROL MOTOR CIRCUIT (DRIVER'S)»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__dtc-b1234-or-dtc-indicator-k) ) NO -Go to step 2
2. Clear the DTC with the HDS.
3. Turn the ignition switch to LOCK (0), and then back to ON (II).
4. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/rdx/i-2009-2012/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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
5. Check for DTCs. Is DTC B1206 or K indicated? YES -Go to step 6. NO -The system is OK at this time, check for loose wires or poor connections on the gauge control module and climate control unit circuit.
6. Check for DTCs with the HDS. Are DTC B1008, B1011, B1032, B1206, and B1906 also indicated? YES -Go to step 7. NO -The system is OK at this time, check for loose wires or poor connections on the gauge control module and climate control unit circuit.
7. Select UNIT INFORMATION in the BODY ELECTRICAL menu.
8. Select CONNECTED UNIT in the UNIT INFORMATION menu. Is gauge control module detected? YES -Substitute a known-good gauge control module, and recheck. If the symptom/indication goes away, replace the gauge control module (see «GAUGE CONTROL MODULE REPLACEMENT»(/acura/rdx/i-2009-2012/remont/gauges-instrument-panels/#gauges__gauge-control-module-replacement) ). NO -Go to step 9.
9. Disconnect under-dash fuse/relay box connector Q (16P).
10. Disconnect the gauge control module 36P connector.
11. Check for continuity between under-dash fuse/relay box connector Q (16P) terminal No. 6 and gauge control module 36P connector terminal No. 30. Is there continuity? YES -Go to the gauge control module input test (see «GAUGE CONTROL MODULE INPUT TEST»(/acura/rdx/i-2009-2012/remont/gauges-instrument-panels/#gauges__gauge-control-module-input-test) ) NO -Repair an open in the wire between the MICU and the gauge control module.

Note. If DTC B1207 is detected with HDS, it is not necessary to do step 1.

Scheme 21

1. Check the sensor input display mode, and select "driver's air mix control motor" according to the table (see «CHECKS BEFORE USING THE SENSOR INPUT DISPLAY MODE»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__checks-before-using-the-sensor-input) ). NOTE: This indication by segment lit on digital segments is assigned for 2 failure causes that it is necessary to decide which one is a true cause. If there is a failure in the sensor or motor, a value corresponded to the sensor or motor in the Sensor Input Display Mode is displayed as "Er", which serves to specify which is a true cause. Is sensor value indicated "Er"? YES -Go to troubleshooting DTC B1233 or DTC indicator J (see «DTC B1233 OR DTC INDICATOR J: AN OPEN IN THE AIR MIX CONTROL MOTOR CIRCUIT (DRIVER'S)»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__dtc-b1233-or-dtc-indicator-j) ) NO -Go to step 2
2. Clear the DTC with the HDS.
3. Turn the ignition switch to LOCK (0), and then back to ON (II).
4. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/rdx/i-2009-2012/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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) )
5. Check for DTCs. Is DTC B1207 or J indicated? YES -Go to step 6. NO -The system is OK at this time, check for loose wires or poor connections on the gauge control module and climate control unit circuit.
6. Check for DTCs with the HDS. Are DTC B1008, B1011, B1032, B1207, and B1906 also indicated? YES -Go to step 7. NO -The system is OK at this time, check for loose wires or poor connections on the gauge control module and climate control unit circuit.
7. Select UNIT INFORMATION in the BODY ELECTRICAL menu.
8. Select CONNECTED UNIT in the UNIT INFORMATION menu. Is gauge control module detected? YES -Substitute a known-good gauge control module, and recheck. If the symptom/indication goes away, replace the gauge control module. NO -Go to step 9.
9. Disconnect under-dash fuse/relay box connector Q (16P).
10. Disconnect the gauge control module 36P connector.
11. Check for continuity between under-dash fuse/relay box connector Q (16P) terminal No. 6 and gauge control module 36P connector terminal No. 30. Is there continuity? YES -Go to the gauge control module input test (see «GAUGE CONTROL MODULE INPUT TEST»(/acura/rdx/i-2009-2012/remont/gauges-instrument-panels/#gauges__gauge-control-module-input-test) ) NO -Repair an open in the wire between the MICU and the gauge control module.

DTC B1225 or DTC indicator A: An Open in the In-Car Temperature Sensor Circuit

Note. If DTC B1225 is detected with HDS, it is not necessary to do step 1.

Scheme 22

Scheme 23

1. Check the sensor input display mode, and select "in-car temperature sensor" according to the table (see «CHECKS BEFORE USING THE SENSOR INPUT DISPLAY MODE»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__checks-before-using-the-sensor-input) ). NOTE: This indication by segment lit on digital segments is assigned for 2 failure causes that it is necessary to decide which one is a true cause. If there is a failure in the sensor or motor, a value corresponded to the sensor or motor in the Sensor Input Display Mode is displayed as "Er", which serves to specify which is a true cause. Is sensor value indicated "Er"? YES -Go to step 2 NO -Go to troubleshooting DTC B1239 or DTC indicator A (see «DTC B1239 OR DTC INDICATOR A: AN OPEN OR SHORT IN THE MODE CONTROL MOTOR CIRCUIT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__dtc-b1239-or-dtc-indicator-a) )
2. Clear the DTC with the HDS.
3. Turn the ignition switch to LOCK (0), and then back to ON (II).
4. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/rdx/i-2009-2012/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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
5. Check for DTCs. Is DTC B1225 or A indicated? YES -Go to step 6. NO -Intermittent failure. Check for loose wires or poor connections on the in-car temperature sensor circuit.
6. Turn the ignition switch to LOCK (0).
7. Remove the in-car temperature sensor (see «IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ), and test it (see «IN-CAR TEMPERATURE SENSOR TEST»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__in-car-temperature-sensor-test) ). Is the in-car temperature sensor OK? YES -With the in-car temperature sensor disconnected, go to step 8. NO -Replace the in-car temperature sensor (see «IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).
8. Disconnect climate control unit connector B (16P).
9. Check for continuity between climate control unit connector B (16P) terminal No. 14 and in-car temperature sensor 2P connector terminal No. 1. Is there continuity? YES -Go to step 10. NO -Repair an open in the wire between the climate control unit and the in-car temperature sensor.
10. Check for continuity between climate control unit connector B (16P) terminal No. 4 and in-car temperature sensor 2P connector terminal No. 2. Is there continuity? YES -Check for loose wires or poor connections at climate control unit connector B (16P) and at the in-car 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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ). NO -Repair an open in the wire between the climate control unit and the in-car temperature sensor.

DTC B1226 or DTC indicator B: A Short in the In-Car Temperature Sensor Circuit

Note. If DTC B1226 is detected with HDS, it is not necessary to do step 1.

Scheme 24

Scheme 25

1. Check the sensor input display mode, and select "in-car temperature sensor" according to the table (see «CHECKS BEFORE USING THE SENSOR INPUT DISPLAY MODE»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__checks-before-using-the-sensor-input) ). NOTE: This indication by segment lit on digital segments is assigned for 2 failure causes that it is necessary to decide which one is a true cause. If there is a failure in the sensor or motor, a value corresponded to the sensor or motor in the Sensor Input Display Mode is displayed as "Er", which serves to specify which is a true cause. Is sensor value Indicated "Er"? YES -Go to step 2 NO -Go to troubleshooting DTC B1240 or DTC indicator B (see «DTC B1240 OR DTC INDICATOR B: A PROBLEM IN THE MODE CONTROL MOTOR CIRCUIT, LINKAGE, DOORS, OR MOTOR»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__dtc-b1240-or-dtc-indicator-b) )
2. Clear the DTC with the HDS.
3. Turn the ignition switch to LOCK (0), and then back to ON (II).
4. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/rdx/i-2009-2012/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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
5. Check for DTCs. Is DTC B1226 or B indicated? YES -Go to step 6. NO -Intermittent failure. Check for loose wires or poor connections on the in-car temperature sensor circuit.
6. Turn the ignition switch to LOCK (0).
7. Remove the in-car temperature sensor (see «IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ), and test it (see «IN-CAR TEMPERATURE SENSOR TEST»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__in-car-temperature-sensor-test) ). Is the in-car temperature sensor OK? YES -With the in-car temperature sensor disconnected, go to step 8. NO -Replace the in-car temperature sensor (see «IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).
8. Disconnect climate control unit connector B (16P).
9. Check for continuity between body ground and climate control unit connector B(16P) terminal No. 14. 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 10.
10. Check for continuity between climate control unit connector B (16P) terminals No. 4 and No. 14. 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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).

Scheme 26

Scheme 27

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II).
3. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/rdx/i-2009-2012/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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B1227 or C 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).
6. Remove the outside air temperature sensor (see «IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ), and test it (see «OUTSIDE AIR TEMPERATURE SENSOR TEST»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__outside-air-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 «IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).
7. Disconnect climate control unit connector A (24P).
8. Check for continuity between climate control unit connector A (24P) terminal No. 14 and outside air 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 outside air temperature sensor.
9. Check for continuity between climate control unit connector A (24P) terminal No. 18 and outside air temperature sensor 2P connector terminal No. 2. Is there continuity? YES -Check for loose wires or poor connections at climate control unit connector A (24P) 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/rdx/i-2009-2012/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 28

Scheme 29

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II).
3. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/rdx/i-2009-2012/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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B1228 or D 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).
6. Remove the outside air temperature sensor (see «IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ), and test it (see «OUTSIDE AIR TEMPERATURE SENSOR TEST»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__outside-air-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 «IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).
7. Disconnect climate control unit connector A (24P).
8. Check for continuity between body ground and climate control unit connector A (24P) terminal No. 14. Is there continuity? YES -Repair a short to body ground in the wires 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 A (24P) terminals No. 14 and No. 18. 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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).

Scheme 30

Scheme 31

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II).
3. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/rdx/i-2009-2012/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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B1229 or E 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).
6. Disconnect the sunlight sensor 5P connector.
7. Disconnect climate control unit connector B (16P).
8. Check for continuity between climate control unit connector B(16P) terminal No. 13 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 B (16P) terminal No. 4 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. Test the sunlight sensor (see «SUNLIGHT SENSOR TEST»(/acura/rdx/i-2009-2012/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 B (16P) 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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ). NO -Replace the sunlight sensor (see «SUNLIGHT SENSOR REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).

DTC B1230 or DTC indicator F: A Short in the Sunlight Sensor Circuit

Note. If DTC B1230 is detected with HDS, it is not necessary to do step 1.

Scheme 32

Scheme 33

1. Check the sensor input display mode, and select "sunlight sensor" according to the table, (see «CHECKS BEFORE USING THE SENSOR INPUT DISPLAY MODE»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__checks-before-using-the-sensor-input) ) NOTE: This indication by segment lit on digital segments is assigned for 2 failure causes that it is necessary to decide which one is a true cause. If there is a failure in the sensor or motor, a value corresponded to the sensor or motor in the Sensor Input Display Mode is displayed as "Er", which serves to specify which is a true cause. Is sensor value indicated "Er"? YES -Go to step 2 NO -Go to troubleshooting DTC B1241 or DTC indicator F (see «DTC B1241 OR DTC INDICATOR F: A PROBLEM IN THE BLOWER MOTOR CIRCUIT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__dtc-b1241-or-dtc-indicator-f) )
2. Clear the DTC with the HDS.
3. Turn the ignition switch to LOCK (0), and then back to ON (II).
4. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/rdx/i-2009-2012/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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
5. Check for DTCs. Is DTC B1230 or F indicated? YES -Go to step 6. NO -Intermittent failure. Check for loose wires or poor connections on the sunlight sensor circuit.
6. Turn the ignition switch to LOCK (0).
7. Disconnect the sunlight sensor 5P connector.
8. Disconnect climate control unit connector B (16P).
9. Check for continuity between body ground and climate control unit connector B(16P) terminal No. 13. 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 10.
10. Check for continuity between climate control unit connector B (16P) terminals No. 4 and No. 13. Is there continuity? YES -Repair a short in the wires between the climate control unit and the sunlight sensor. NO -Go to step 11.
11. Test the sunlight sensor (see «SUNLIGHT SENSOR TEST»(/acura/rdx/i-2009-2012/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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ). NO -Replace the sunlight sensor (see «SUNLIGHT SENSOR REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).

DTC B1231 or DTC indicator G: An Open in the Evaporator Temperature Sensor Circuit

Note. If DTC B1231 is detected with HDS, it is not necessary to do step 1.

Scheme 34

Scheme 35

1. Check the sensor input display mode, and select "evaporator temperature sensor" according to the table (see «CHECKS BEFORE USING THE SENSOR INPUT DISPLAY MODE»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__checks-before-using-the-sensor-input) ). NOTE: This indication by segment lit on digital segments is assigned for 2 failure causes that it is necessary to decide which one is a true cause. If there is a failure in the sensor or motor, a value corresponded to the sensor or motor in the Sensor Input Display Mode is displayed as "Er", which serves to specify which is a true cause. Is Er indicated? YES -Go to step 2 NO -Go to troubleshooting DTC indicator G (see «DTC INDICATOR G: CLIMATE CONTROL UNIT INTERNAL ERROR OR AN OPEN IN THE EVAPORATOR TEMPERATURE SENSOR CIRCUIT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) )
2. Clear the DTC with the HDS.
3. Turn the ignition switch to LOCK (0), and then back to ON (II).
4. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/rdx/i-2009-2012/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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
5. Check for DTCs. Is DTC B1231 or G indicated? YES -Go to step 6. NO -Intermittent failure. Check for loose wires or poor connections on the evaporator temperature sensor circuit.
6. Turn the ignition switch to LOCK (0).
7. Test the evaporator temperature sensor (see «EVAPORATOR TEMPERATURE SENSOR TEST»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__evaporator-temperature-sensor-test) ). Is the evaporator temperature sensor OK? YES -With the evaporator temperature sensor disconnected, go to step 8. NO -Replace the evaporator temperature sensor (see «EVAPORATOR CORE REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).
8. Disconnect climate control unit connector A (24P).
9. Check for continuity between climate control unit connector A (24P) terminal No. 13 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. Check for continuity between climate control unit connector A (24P) terminal No. 18 and evaporator temperature sensor 2P connector terminal No. 1. Is there continuity? YES -Check for loose wires or poor connections at the climate control unit connector A (24P) 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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ). NO -Repair an open in the wire between the climate control unit and the evaporator temperature sensor.

DTC B1232 or DTC indicator H: A Short in the Evaporator Temperature Sensor Circuit

Note. If DTC B1232 is detected with HDS, it is not necessary to do step 1.

Scheme 36

Scheme 37

1. Check the sensor input display mode, and select "evaporator temperature" according to the table (see «CHECKS BEFORE USING THE SENSOR INPUT DISPLAY MODE»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__checks-before-using-the-sensor-input) ). NOTE: This indication by segment lit on digital segments is assigned for 2 failure causes that it is necessary to decide which one is a true cause. If there is a failure in the sensor or motor, a value corresponded to the sensor or motor in the Sensor Input Display Mode is displayed as "Er", which serves to specify which is a true cause. Is sensor value indicated "Er"? YES -Go to step 2 NO -Go to troubleshooting DTC B1205 or DTC indicator H (see «DTC B1205 OR DTC INDICATOR H: CLIMATE CONTROL UNIT LOST COMMUNICATION WITH GAUGE CONTROL MODULE (VSP/NE MESSAGE)»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) )
2. Clear the DTC with the HDS.
3. Turn the ignition switch to LOCK (0), and then back to ON (II).
4. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/rdx/i-2009-2012/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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
5. Check for DTCs. Is DTC B1232 or H indicated? YES -Go to step 6. NO -Intermittent failure. Check for loose wires or poor connections on the evaporator temperature sensor circuit.
6. Turn the ignition switch to LOCK (0).
7. Test the evaporator temperature sensor (see «EVAPORATOR TEMPERATURE SENSOR TEST»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__evaporator-temperature-sensor-test) ). Is the evaporator temperature sensor OK? YES -With the evaporator temperature sensor disconnected, go to step 8. NO -Replace the evaporator temperature sensor (see «EVAPORATOR CORE REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).
8. Disconnect climate control unit connector A (24P).
9. Check for continuity between body ground and climate control unit connector A (24P) terminal No. 13. 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 10.
10. Check for continuity between climate control unit connector A (24P) terminals No. 13 and No. 18. Is there continuity? YES -Repair a short in the wires between the climate control unit and the evaporator 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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).

DTC B1233 or DTC indicator J: An Open in the Air Mix Control Motor Circuit (Driver's)

Note. If DTC B1233 is detected with HDS, it is not necessary to do step 1.

Scheme 38

1. Check the sensor input display mode, and select "driver's air mix control motor" according to the table (see «CHECKS BEFORE USING THE SENSOR INPUT DISPLAY MODE»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__checks-before-using-the-sensor-input) ). NOTE: This indication by segment lit on digital segments is assigned for 2 failure causes that it is necessary to decide which one is a true cause. If there is a failure in the sensor or motor, a value corresponded to the sensor or motor in the Sensor Input Display Mode is displayed as "Er", which serves to specify which is a true cause. Is sensor value indicated "Er"? YES -Go to step 2 NO -Go to troubleshooting DTC B1207 or DTC indicator J (see «DTC B1207 OR DTC INDICATOR J: CLIMATE CONTROL UNIT LOST COMMUNICATION WITH GAUGE CONTROL MODULE (ILLUMI MESSAGE)»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) )
2. Start the engine.
3. Turn on the A/C, then set the driver's climate control switch to max hot.
4. Turn the ignition switch to LOCK (0).
5. Clear the DTC with the HDS.
6. Turn the ignition switch to LOCK (0), and then back to ON (II).
7. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/rdx/i-2009-2012/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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
8. Check for DTCs. Is DTC B1233 or J indicated? YES -Go to step 9. NO -Intermittent failure. Check for loose wires or poor connections on the driver's air mix control motor circuit.
9. Turn the ignition switch to LOCK (0).
10. Disconnect the driver's air mix control motor 7P connector.
11. Disconnect climate control unit connector A (24P).
12. Check for continuity between the following terminals of climate control unit connector A (24P) and the driver's air mix control motor 7P connector. 24P: 7P: No. 5 No. 5 No. 16 No. 3 No. 18 No. 7 Is there continuity? YES -Go to step 13. NO -Repair an open in the wire(s) between the climate control unit and the driver's air mix control motor.
13. Test the driver's air mix control motor (see «DRIVER'S AIR MIX CONTROL MOTOR TEST»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__drivers-air-mix-control-motor-test) ). Is the driver's air mix control motor OK? YES -Check for loose wire or poor connections at climate control unit connector A (24P) 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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ). NO -Replace the driver's air mix control motor (see «DRIVER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).

DTC B1234 or DTC indicator K: A Short in the Air Mix Control Motor Circuit (Driver's)

Note. If DTC B1234 is detected with HDS, it is not necessary to do step 1.

Scheme 39

Scheme 40

1. Check the sensor input display mode, and select "driver's air mix control motor" according to the table (see «CHECKS BEFORE USING THE SENSOR INPUT DISPLAY MODE»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__checks-before-using-the-sensor-input) ). NOTE: This indication by segment lit on digital segments is assigned for 2 failure causes that it is necessary to decide which one is a true cause. If there is a failure in the sensor or motor, a value corresponded to the sensor or motor in the Sensor Input Display Mode is displayed as "Er", which serves to specify which is a true cause. Is sensor value indicated "Er"? YES -Go to step 2 NO -Go to troubleshooting DTC B1206 or DTC indicator K (see «DTC B1206 OR DTC INDICATOR K: CLIMATE CONTROL UNIT LOST COMMUNICATION WITH GAUGE CONTROL MODULE (ECT MESSAGE)»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) )
2. Clear the DTC with the HDS.
3. Turn the ignition switch to LOCK (0), and then back to ON (II).
4. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/rdx/i-2009-2012/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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
5. Check for DTCs. Is DTC B1234 or K indicated? YES -Go to step 6. NO -Intermittent failure. Check for looses wires or poor connections on the driver's air mix control motor circuit.
6. Turn the ignition switch to LOCK (0).
7. Disconnect the driver's air mix control motor 7P connector.
8. Disconnect climate control unit connector A (24P).
9. Check for continuity between body ground and climate control unit connector A (24P) terminals No. 5 and No. 16 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 -Go to step 10.
10. Check for continuity between the terminals of climate control unit connector A (24P) as follows. From terminal To terminals A5 A16, A18 A16 A18 Is there continuity between any of the terminals? YES -Repair a short in the wires. NO -Go to step 11.
11. Turn the ignition switch to ON (II), and measure the voltage between the same terminals and body ground. Is there any voltage? YES -Repair a short to power in the wire(s) between the climate control unit and the driver's air mix control motor. NO -Go to step 12.
12. Test the driver's air mix control motor (see «DRIVER'S AIR MIX CONTROL MOTOR TEST»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__drivers-air-mix-control-motor-test) ). Is the driver's air mix control motor OK? YES -Check for loose wire or poor connections at climate control unit connector A (24P) and at the driver's air mix control motor 7P connector. If the connections are good, check the driver's air mix control motor operation with the original climate control unit. If the motor is not good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away and the driver's air mix control motor runs, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ). NO -Replace the driver's air mix control motor (see «DRIVER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/rdx/i-2009-2012/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).
3. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/rdx/i-2009-2012/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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B1235 or L 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).
6. Test the driver's air mix control motor (see «DRIVER'S AIR MIX CONTROL MOTOR TEST»(/acura/rdx/i-2009-2012/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/rdx/i-2009-2012/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 (24P).
9. Check for continuity between following terminals of climate control unit connector A (24P) and the driver's air mix control motor 7P connector. 24P: 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 driver's air mix control motor.
10. Check for continuity between body ground and climate control unit connector A (24P) 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 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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).

DTC B1236 or DTC indicator M: An Open in the Passenger's Air Mix Control Motor Circuit

Note. If DTC B1236 is detected with HDS, it is not necessary to do step 1.

Scheme 43

1. Check the sensor input display mode, and select "passenger's air mix control motor" according to the table (see «CHECKS BEFORE USING THE SENSOR INPUT DISPLAY MODE»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__checks-before-using-the-sensor-input) ). NOTE: This indication by segment lit on digital segments is assigned for 2 failure causes that it is necessary to decide which one is a true cause. If there is a failure in the sensor or motor, a value corresponded to the sensor or motor in the Sensor Input Display Mode is displayed as "Er", which serves to specify which is a true cause. Is sensor value indicated "Er"? YES -Go to step 2. NO -Go to troubleshooting B1200 or DTC indicator M. (see «DTC B1150: COMMUNICATION CIRCUIT ERROR (BUS-OFF); DTC B1200: COMMUNICATION BUS LINE (BUS-OFF); DTC B1550: COMMUNICATION CIRCUIT ERROR (BUS-OFF); DTC B1750: COMMUNICATION BUS LINE ERROR (BUS-OFF); DTC B1800: COMMUNICATION CIRCUIT ERROR (BUS-OFF); DTC B1900: COMMUNICATION CIRCUIT ERROR (BUS-OFF); DTC U1280: COMMUNICATION BUS LINE ERROR (BUS-OFF)»(/acura/rdx/i-2009-2012/remont/communication-devices/#multiplex-integrated-control-system__dtc-b1150-communication-circuit-error-bus-off) )
2. Start the engine.
3. Turn on the A/C, then set the passenger's climate control switch to max hot.
4. Turn the ignition switch to LOCK (0).
5. Clear the DTC with the HDS.
6. Turn the ignition switch to LOCK (0), and then back to ON (II).
7. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/rdx/i-2009-2012/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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
8. Check for DTCs. Is DTC B1236 or M indicated? YES -Go to step 9. NO -Intermittent failure. Check for loose wires or poor connections on the passenger's air mix control motor circuit.
9. Turn the ignition switch to LOCK (0).
10. Disconnect the passenger's air mix control motor 7P connector.
11. Disconnect climate control unit connector A (24P).
12. Check for continuity between the following terminals of climate control unit connector A (24P) and the passenger's air mix control motor 7P connector. 24P: 7P: No. 5 No. 7 No. 15 No. 3 No. 18 No. 5 Is there continuity? YES -Go to step 13. NO -Repair an open in the wire(s) between the climate control unit and the passenger's air mix control motor.
13. Test the passenger's air mix control motor (see «PASSENGER'S AIR MIX CONTROL MOTOR TEST»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__passengers-air-mix-control-motor-test) ). Is the passenger's air mix control motor OK? YES -Check for loose wire or poor connections at climate control unit connector A (24P) 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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ). NO -Replace the passenger's air mix control motor (see «DRIVER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).

Scheme 44

Scheme 45

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II).
3. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/rdx/i-2009-2012/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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B1237 or N 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).
6. Disconnect the passenger's air mix control motor 7P connector.
7. Disconnect climate control unit connector A (24P).
8. Check for continuity between body ground and climate control unit connector A (24P) terminals No. 5 and No. 15 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 -Go to step 9.
9. Check for continuity between the terminals of climate control unit connector A (24P) as follows. From terminal To terminals A5 A15, A18 A15 A18 Is there continuity between any of the terminals? YES -Repair a short in the wires. NO -Go to step 10.
10. Turn the ignition switch to ON (II), and measure the voltage between the same terminals and body ground. Is there any voltage? YES -Repair a short to power in the wire(s) between the climate control unit and the passenger's air mix control motor. NO -Go to step 11.
11. Test the passenger's air mix control motor (see «PASSENGER'S AIR MIX CONTROL MOTOR TEST»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__passengers-air-mix-control-motor-test) ). Is the passenger's air mix control motor OK? YES -Check for loose wire or poor connections at climate control unit connector A (24P) and at the passenger's air mix control motor 7P connector. If the connections are good, check the passenger's air mix control motor operation with the original climate control unit. If the motor is not good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away and the passenger's air mix control motor runs, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ). NO -Replace the passenger's air mix control motor (see «DRIVER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).

Scheme 46

Scheme 47

1. Clear the DTC with the HDS.
2. Turn the ignition switch to LOCK (0), and then back to ON (II).
3. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/rdx/i-2009-2012/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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
4. Check for DTCs. Is DTC B1238 or P 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).
6. Test the passenger's air mix control motor (see «PASSENGER'S AIR MIX CONTROL MOTOR TEST»(/acura/rdx/i-2009-2012/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 «DRIVER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/rdx/i-2009-2012/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 (24P).
9. Check for continuity between the following terminals of climate control unit connector A (24P) and the passenger's air mix control motor 7P connector. 24P: 7P: No. 11 No. 2 No. 12 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 passenger's air mix control motor.
10. Check for continuity between body ground and climate control unit connector A (24P) 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 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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).

DTC B1239 or DTC indicator A: An Open or Short in the Mode Control Motor Circuit

Note. If DTC B1239 is detected with HDS, it is not necessary to do step 1.

Scheme 48

Scheme 49

Scheme 50

1. Check the sensor input display mode, and select "mode control motor" according to the table (see «CHECKS BEFORE USING THE SENSOR INPUT DISPLAY MODE»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__checks-before-using-the-sensor-input) ). NOTE: This indication by segment lit on digital segments is assigned for 2 failure causes that it is necessary to decide which one is a true cause. If there is a failure in the sensor or motor, a value corresponded to the sensor or motor in the Sensor Input Display Models displayed as "Er", which serves to specify which is a true cause. Is sensor value indicated "Er"? YES -Go to step 2 NO -Go to troubleshooting DTC B1225 or DTC indicator A (see «DTC B1225 OR DTC INDICATOR A: AN OPEN IN THE IN-CAR TEMPERATURE SENSOR CIRCUIT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__dtc-b1225-or-dtc-indicator-a) )
2. Clear the DTC with the HDS.
3. Turn the ignition switch to LOCK (0), and then back to ON (II).
4. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/rdx/i-2009-2012/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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
5. Check for DTCs. Is DTC B1239 or A indicated? YES -Go to step 6. NO -Intermittent failure. Check for loose wires or poor connections on the mode control motor circuit.
6. Turn the ignition switch to LOCK (0).
7. Test the mode control motor (see «MODE CONTROL MOTOR TEST»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__mode-control-motor-test) ). Is the mode control motor OK? YES -Go to step 8. NO -Replace the mode control motor (see «MODE CONTROL MOTOR REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).
8. Disconnect the mode control motor 7P connector.
9. Disconnect climate control unit connector A (24P).
10. Check for continuity between the following terminals of climate control unit connector A (24P) and the mode control motor 7P connector. 24P: 7P: No. 1 No. 6 No. 2 No. 5 No. 3 No. 4 No. 4 No. 3 No. 18 No. 7 Is there continuity? YES -Go to step 11. NO -Repair an open in the wire(s) between the climate control unit and the mode control motor.
11. Check for continuity between body ground and climate control unit connector A (24P) terminals No. 1, 2, 3, and 4 individually. Is there continuity? YES -Repair a short to body ground in the wire(s) between the climate control unit and the mode control motor. NO -Go to step 12.
12. Check for continuity between the terminals of climate control unit connector A (24P) as follows. From terminal To terminals A1 A2, A3, A4, A18 A2 A3, A4, A18 A3 A4, A18 A4 A18 Is there continuity between any of the terminals? YES -Repair a short in the wire(s) between climate control unit and mode control motor. NO -Go to step 13.
13. Turn the ignition switch to ON (II), and measure the voltage between the same terminals and body ground. Is there any voltage? YES -Repair a short to power in the wire(s) between the climate control unit and the mode control motor. NO -Check for loose wire or poor connections at climate control unit connector A (24P) and at the 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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).

DTC B1240 or DTC indicator B: A Problem in the Mode Control Motor Circuit, Linkage, Doors, or Motor

Note. If DTC B1240 is detected with HDS, it is not necessary to do step 1.

Scheme 51

Scheme 52

1. Check the sensor input display mode, and select "mode motor" according to the table (see «CHECKS BEFORE USING THE SENSOR INPUT DISPLAY MODE»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__checks-before-using-the-sensor-input) ). NOTE: This indication by segment lit on digital segments is assigned for 2 failure causes that it is necessary to decide which one is a true cause. If there is a failure in the sensor or motor, a value corresponded to the sensor or motor in the Sensor Input Display Mode is displayed as "Er", which serves to specify which is a true cause. Is sensor value indicated "Er"? YES -Go to step 2 NO -Go to troubleshooting DTC B1226 or DTC indicator B (see «DTC B1226 OR DTC INDICATOR B: A SHORT IN THE IN-CAR TEMPERATURE SENSOR CIRCUIT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__dtc-b1226-or-dtc-indicator-b) )
2. Clear the DTC with the HDS.
3. Turn the ignition switch to LOCK (0), and then back to ON (II).
4. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/rdx/i-2009-2012/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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
5. Check for DTCs. Is DTC B1240 or B indicated? YES -Go to step 6. NO -Intermittent failure. Check for loose wires or poor connections on the mode control motor circuit.
6. Turn the ignition switch to LOCK (0).
7. Test the mode control motor (see «MODE CONTROL MOTOR TEST»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__mode-control-motor-test) ). Is the mode control motor OK? YES -Go to step 8. NO -Replace the mode control motor (see «MODE CONTROL MOTOR REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ), or repair the mode control linkage or doors.
8. Disconnect the mode control motor 7P connector.
9. Disconnect climate control unit connector A (24P).
10. Check for continuity between the following terminals of climate control unit connector A (24P) and the mode control motor 7P connector. 24P: 7P: No. 7 No. 2 No. 8 No. 1 Is there continuity? YES -Go to step 11. NO -Repair an open in the wire(s) between the climate control unit and the mode control motor.
11. Check for continuity between body ground and climate control unit connector A (24P) 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 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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).

DTC B1241 or DTC indicator F: A Problem in the Blower Motor Circuit

Note. If DTC B1241 is detected with HDS, it is not necessary to do step 1.

Scheme 53

Scheme 54

Scheme 55

Scheme 56

Scheme 57

Scheme 58

Scheme 59

Scheme 60

Scheme 61

Scheme 62

1. Check the sensor input display mode, and select "sunlight sensor" according to the table (see «CHECKS BEFORE USING THE SENSOR INPUT DISPLAY MODE»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__checks-before-using-the-sensor-input) ). NOTE: This indication by segment lit on digital segments is assigned for 2 failure causes that it is necessary to decide which one is a true cause. If there is a failure in the sensor or motor, a value corresponded to the sensor or motor in the Sensor Input Display Mode is displayed as "Er", which serves to specify which is a true cause. Is sensor value indicated "Er"? YES -Go to troubleshooting DTC B1230 or DTC indicator F (see «DTC B1230 OR DTC INDICATOR F: A SHORT IN THE SUNLIGHT SENSOR CIRCUIT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__dtc-b1230-or-dtc-indicator-f) ) NO -GO to step 2
2. Clear the DTC with the HDS.
3. Turn the ignition switch to LOCK (0), and then back to ON (II).
4. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/rdx/i-2009-2012/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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
5. Check for DTCs. Is DTC B1241 or F indicated? YES -Go to step 6. NO -Intermittent failure. Check for loose wires or poor connections on the blower motor circuit.
6. Turn the ignition switch to LOCK (0).
7. Check the No. 9 (40 A) fuse in the under-hood fuse/relay box, and the No. 36 (10 A) fuse in the under-dash fuse/relay box. Are the fuses OK? YES -Go to step 8. NO -Replace the fuse, and recheck. If the fuse blows again, check for a short in the No. 9 (40 A) and the No. 36 (10 A) fuses circuit.
8. Connect blower motor 2P connector terminal No. 2 to body ground with a jumper wire.
9. Turn the ignition switch to ON (II). Does the blower motor run? YES -Go to step 10. NO -Go to step 26 .
10. Turn the ignition switch to LOCK (0).
11. Disconnect the jumper wire.
12. Disconnect the power transistor 4P connector.
13. Check for continuity between power transistor 4P connector terminal No. 2 and body ground. Is there continuity? YES -Go to step 14. NO -Check for an open in the BLK wire between the power transistor and body ground. If the wire is OK, check for poor ground at G571 (see «CONNECTOR TO FUSE/RELAY BOX INDEX»(/acura/rdx/i-2009-2012/remont/body-electrical/#fuserelay-boxes__connector-to-fuserelay-box-index) ).
14. Connect power transistor 4P connector terminals No. 2 and No. 4 with a jumper wire.
15. Turn the ignition switch to ON (II). Does the blower motor run at high speed? YES -Go to step 16. NO -Repair an open in the GRN wire between the power transistor and the blower motor.
16. Turn the ignition switch to LOCK (0).
17. Disconnect the jumper wire.
18. Disconnect climate control unit connector A (24P).
19. Check for continuity between body ground and climate control unit connector A (24P) terminals No. 22 and No. 23 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 20.
20. Check for continuity between the following terminals of climate control unit connector A (24P) and the power transistor 4P connector. 24P: 4P: No. 22 No. 3 No. 23 No. 1 Is there continuity? YES -Go to step 21. NO -Repair an open in the wire(s) between the climate control unit and the power transistor.
21. Turn the ignition switch to ON (II).
22. Measure the voltage between body ground and climate control unit connector A (24P) terminals No. 22 and No. 23 individually. Is there voltage? YES -Repair a short to power in the wire(s) between the climate control unit and the power transistor. This short may also damage the climate control unit. Repair the short to power before replacing the climate control unit. NO -Go to step 23.
23. Turn the ignition switch to LOCK (0).
24. Reconnect climate control unit connector A (24P).
25. Test the power transistor (see «POWER TRANSISTOR TEST»(/acura/rdx/i-2009-2012/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 (24P) and at the power transistor 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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ). NO -Replace the power transistor (see «POWER TRANSISTOR REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ). NOTE: If the power transistor is faulty, check the blower motor for damage. If necessary, replace the blower motor before installing a new power transistor.
26. Disconnect the jumper wire.
27. Disconnect the blower motor 2P connector.
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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__blower-unit-component-replacement) ). NO -Go to step 29.
29. Turn the ignition switch to LOCK (0).
30. Remove the blower motor relay from the under-hood fuse/relay box, and test it (see «POWER RELAY TEST»(/acura/rdx/i-2009-2012/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 the 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/rdx/i-2009-2012/remont/fuses-circuit-breakers/#under-hood-fuserelay-box__removal-and-installation) ).
33. Turn the ignition switch to ON (II).
34. Measure the voltage between blower motor relay 4P socket terminal No. 3 and body ground. Is there battery voltage? YES -Check for an open in the wire between the blower motor relay 4P socket terminal No. 4 and body ground. If the wire is OK, check for poor ground at G202 (see «CONNECTOR TO FUSE/RELAY BOX INDEX»(/acura/rdx/i-2009-2012/remont/body-electrical/#fuserelay-boxes__connector-to-fuserelay-box-index) ). NO -Repair an open in the wire between the No. 36 (10 A) fuse in the under-dash fuse/relay box and the blower motor relay 4P socket.

Scheme 63

Scheme 64

Scheme 65

Scheme 66

1. Check the No. 36 (10 A) fuse in the 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. 36(10 A) fuse circuit.
2. Disconnect the recirculation control motor 7P connector.
3. Turn the ignition switch to ON (II).
4. Measure the voltage between recirculation control motor 7P connector terminal No. 1 and body ground. Is there battery voltage? YES -Go to step 5. NO -Repair an open in the wire between the No. 36(10 A) fuse in the under-dash fuse/relay box and the recirculation control motor.
5. Turn the ignition switch to LOCK (0).
6. Test the recirculation control motor (see «RECIRCULATION CONTROL MOTOR TEST»(/acura/rdx/i-2009-2012/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 «MODE CONTROL MOTOR REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ), or repair the recirculation control linkage or door.
7. Disconnect climate control unit connector A (24P).
8. Check for continuity between body ground and climate control unit connector A (24P) terminals 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 9.
9. Turn the ignition switch to ON (II), and check the same terminals for voltage to body ground. 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 the short to power before replacing the climate control unit. NO -Go to step 10.
10. Turn the ignition switch to LOCK (0).
11. Check for continuity between the following terminals of climate control unit connector A (24P) and the recirculation control motor 7P connector. 24P: 7P: No. 19 No. 7 No. 20 No. 5 Is there continuity? YES -Check for loose wires or poor connections at climate control unit connector A (24P) 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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) )M NO -Repair an open in the wire(s) the between climate control unit and the recirculation control motor.

Scheme 67

Scheme 68

1. Check the No. 36 (10 A) fuse in the 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. 36 (10 A) fuse circuit.
2. Disconnect climate control unit connector B (16P).
3. Turn the ignition switch to ON (II).
4. Measure the voltage between climate control unit connector B (16P) terminal No. 16 and body ground. Is there battery voltage? YES -Go to step 5. NO -Repair an open in the wire between the No. 36 (10 A) fuse in the under-dash fuse/relay box and the climate control unit.
5. Turn the ignition switch to LOCK (0).
6. Check for continuity between climate control unit connector A (24P) terminal No. 24 and body ground. Is there continuity? YES -Check for loose wires and poor connections at climate control unit connector A (24P). 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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ). NO -Check for an open in the wire between the climate control unit and body ground. If the wire is OK, check for poor ground at G571 (see «CONNECTOR TO FUSE/RELAY BOX INDEX»(/acura/rdx/i-2009-2012/remont/body-electrical/#fuserelay-boxes__connector-to-fuserelay-box-index) ).

Scheme 69

Scheme 70

Scheme 71

Scheme 72

Scheme 73

Scheme 74

Scheme 75

1. Operate the climate control system with the passenger's climate control switch in all modes. Does the climate control system operate? YES -Intermittent failure. NO -Go to step 2.
2. Operate the climate control system with the driver's climate control switch in all modes. Does the climate control system operate? YES -Go to step 3. NO -Go to step 11 .
3. Turn the ignition switch to LOCK (0).
4. Disconnect the passenger's climate control switch 12P connector.
5. Turn the ignition switch to ON (II).
6. Measure the voltage between body ground and passenger's climate control switch 12P connector terminal No. 12. Is there battery voltage? YES -Go to step 7. NO -Repair an open in the wire between the passenger's climate control switch and the No. 36 (10 A) fuse in the under-dash fuse/relay box. If wires are OK, replace the under-hood fuse/relay box (see «REMOVAL AND INSTALLATION»(/acura/rdx/i-2009-2012/remont/fuses-circuit-breakers/#under-hood-fuserelay-box__removal-and-installation) ).
7. Turn the ignition switch to LOCK (0).
8. Disconnect the driver's climate control switch 16P connector.
9. Check for continuity between the passenger's climate control switch 12P connector and the driver's climate control switch 16P connector as shown in illustration. 12P: 16P: No. 3 No. 5 No. 4 No. 2 No. 5 No. 6 No. 8 No. 4 No. 9 No. 3 No. 10 No. 1 Is there continuity? YES -Go to step 10. NO -Repair an open in the wires between the driver's climate control switch and the passenger's climate control switch.
10. Check for continuity between body ground and the passenger's climate control switch 12P connector terminals as shown in illustration. Is there continuity? YES -Repair a short to body ground in the wire(s) between the driver's climate control switch and the passenger's climate control switch. NO -Substitute a known-good passenger's climate control switch, and recheck. If the symptom goes away, replace the original passenger's climate control switch (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).
11. Press and hold the FAN UP switch, then press the OFF switch. Is the REC button LED blinking? YES -Substitute a known-good driver's climate control switch, and recheck the function. If the symptom is still present, replace the climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ). NO -Go to step 12.
12. Check the driver's climate control switch LEDs. Are the REC button and AUTO button LEDs blinking? YES -Driver's climate control switch is faulty, replace the driver's climate control switch (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ). NO -Go to step 13.
13. Check the driver's climate control switch LEDs. Are the REC button and DUAL button LEDs blinking? YES -Substitute a known-good driver's climate control switch, and recheck the function. If the symptom is still present, replace the climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ). NO -Go to step 14.
14. Turn the ignition switch to LOCK (0).
15. Disconnect the driver's climate control switch 16P connector.
16. Turn the ignition switch to ON (II).
17. Measure the voltage between body ground and driver's climate control switch 16P connector terminal No. 9. Is there battery voltage? YES -Go to step 18. NO -Repair an open in the wire between the driver's climate control switch and the No. 36 (10 A) fuse in the under-dash fuse/relay box. If wires are OK, replace the under-hood fuse/relay box (see «REMOVAL AND INSTALLATION»(/acura/rdx/i-2009-2012/remont/fuses-circuit-breakers/#under-hood-fuserelay-box__removal-and-installation) ).
18. Turn the ignition switch to LOCK (0).
19. Check for continuity between body ground and driver's climate control switch 16P connector terminal No. 14. Is there continuity? YES -Go to step 20. NO -Check for an open in the wire between the driver's climate control switch and body ground. If the wire is OK, check for poor ground at G502 (see «CONNECTOR TO FUSE/RELAY BOX INDEX»(/acura/rdx/i-2009-2012/remont/body-electrical/#fuserelay-boxes__connector-to-fuserelay-box-index) ).
20. Disconnect climate control unit connector B (16P).
21. Check for continuity between climate control unit connector B (16P) terminal No. 6 and driver's climate control switch 16P connector terminal No. 13. Is there continuity? YES -Go to step 22. NO -Repair an open in the wire between the driver's climate control switch and the climate control unit.
22. Check for continuity between driver's climate control switch 16P terminals No. 13 and No. 14. Is there continuity? YES -Repair a short to another wire. NO -Substitute a known-good driver's climate control switch, and recheck. If the symptom is still present, replace the climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).

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 powertrain DTCs (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 76

Scheme 77

Scheme 78

Scheme 79

Scheme 80

Scheme 81

Scheme 82

Scheme 83

Scheme 84

Scheme 85

Scheme 86

1. Check the No. 7 (30 A) fuse in the under-hood fuse/relay box, and the No. 36 (10 A) fuse in the under-dash fuse/relay box. Are the fuses OK? YES -Go to step 2. NO -Replace the fuse, and recheck. If the fuse blows again, check for a short in the No. 7 (30 A) and the No. 36 (10 A) fuses circuit.
2. Remove the A/C condenser fan relay from the under-hood fuse/relay box, and test it (see «POWER RELAY TEST»(/acura/rdx/i-2009-2012/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. Connect the HDS to the DLC (see «HOW TO CHECK FOR DTCS WITH THE HDS»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__how-to-check-for-dtcs-with) ).
4. Turn the ignition switch to ON (II).
5. Turn on the A/C.
6. Check the FAN LOW CTRL in the PGM-FI Data List with the HDS. Is the FAN LOW CTRL on? YES -Go to step 7. NO -Substitute a known-good PCM (see «SUBSTITUTING THE PCM»(/acura/rdx/i-2009-2012/remont/testing-diagnostics/#fuel-and-emissions-systems__substituting-the-pcm) ), and retest. If the symptom/indication goes away with a known-good PCM, replace the original PCM (see «PCM REPLACEMENT»(/acura/rdx/i-2009-2012/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ).
7. Measure the voltage between A/C condenser fan relay 4P socket terminal No. 1 and body ground. Is there battery voltage? YES -Go to step 8. NO -Replace the under-hood fuse/relay box (see «REMOVAL AND INSTALLATION»(/acura/rdx/i-2009-2012/remont/fuses-circuit-breakers/#under-hood-fuserelay-box__removal-and-installation) ).
8. Connect A/C condenser fan relay 4P socket terminals No. 1 and No. 2 with a jumper wire. Does the A/C condenser and radiator fans run on low? YES -Go to step 9. NO -Go to step 17 .
9. Disconnect the jumper wire.
10. Measure the voltage between A/C condenser fan relay 4P socket terminal No. 3 and body ground. Is there battery voltage? YES -Go to step 11. NO -Go to step 35 .
11. Turn the ignition switch to LOCK (0).
12. Reinstall the A/C condenser fan relay.
13. Jump the SCS line with the HDS. NOTE: This step must be done to protect the powertrain control module (PCM) from damage.
14. Disconnect PCM connector A (44P).
15. Connect PCM connector A (44P) terminal No. 4 to body ground with a jumper wire.
16. Turn the ignition switch to ON (II). Do the A/C condenser and radiator fans run on low? YES -Check for loose wires or poor connections at PCM connector A (44P) terminal No. 4. If the connections are good, substitute a known-good PCM, and recheck. If the symptom/indication goes away, replace the original PCM (see «PCM REPLACEMENT»(/acura/rdx/i-2009-2012/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ). NO -Repair an open in the wire between the A/C condenser fan relay and the PCM.
17. Disconnect the jumper wire.
18. Reinstall the A/C condenser fan relay.
19. Disconnect the A/C condenser fan 2P connector.
20. Set the A/C button and fan control button ON.
21. Measure the voltage between A/C condenser fan 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 A/C condenser fan relay and the A/C condenser fan.
22. Set the A/C button and fan control dial OFF, then turn the ignition switch to LOCK (0).
23. Reconnect the A/C condenser fan 2P connector.
24. Connect A/C condenser fan 2P connector terminal No. 1 to body ground with a jumper wire.
25. Turn the ignition switch to ON (II), then set the A/C button and fan control button ON. Does the A/C condenser fan run at high speed? YES -Go to step 26. NO -Replace the A/C condenser fan motor (see «FAN, FAN MOTOR, AND SHROUD REMOVAL AND INSTALLATION»(/acura/rdx/i-2009-2012/remont/cooling-fan/#engine-cooling-system) ).
26. Set the A/C button and fan control dial to OFF, then turn the ignition switch to LOCK (0).
27. Disconnect the jumper wire.
28. Remove the fan control relay from the under-hood relay box, and test it (see «POWER RELAY TEST»(/acura/rdx/i-2009-2012/remont/body-electrical/#relays__power-relay-test) ). Is the relay OK? YES -Go to step 29. NO -Replace the fan control relay.
29. Turn the ignition switch to ON (II), then set the A/C button and fan control button ON.
30. Measure the voltage between fan control relay 5P socket terminal No. 1 and body ground. Is there battery voltage? YES -Go to step 31. NO -Repair an open in the wire between the A/C condenser fan and the fan control relay.
31. Set the A/C button and fan control button OFF, then turn the ignition switch to LOCK (0).
32. Disconnect the radiator fan 2P connector.
33. Check for continuity between fan control relay 5P socket terminal No. 4 and radiator fan 2P connector terminal No. 2. Is there continuity? YES -Go to step 34. NO -Repair an open in the wire between the fan control relay and the radiator fan.
34. Check for continuity between radiator fan 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/rdx/i-2009-2012/remont/cooling-fan/#engine-cooling-system) ). NO -Check for an open in the wire between radiator fan and body ground. If the wire is OK, check for poor ground at G201 (see «CONNECTOR TO FUSE/RELAY BOX INDEX»(/acura/rdx/i-2009-2012/remont/body-electrical/#fuserelay-boxes__connector-to-fuserelay-box-index) ).
35. Turn the ignition switch to LOCK (0).
36. Remove A/C diode A from the under-hood fuse/relay box.
37. Using the diode setting (N) on a DVOM, check for current flow in both directions between A/C diode A terminals No. 1 and No. 2. Is there current flow in only one direction? YES -Go to step 38. NO -Replace A/C diode AM
38. Turn the ignition switch to ON (II).
39. Measure the voltage between A/C diode A 2P socket terminal No. 2 and body ground. Is there battery voltage? YES -Replace the under-hood fuse/relay box (see «REMOVAL AND INSTALLATION»(/acura/rdx/i-2009-2012/remont/fuses-circuit-breakers/#under-hood-fuserelay-box__removal-and-installation) ). NO -Repair an open in the wire between the No. 36 (10 A) fuse in the under-dash fuse/relay box and A/C diode AM

A/C Condenser Fan High Speed Circuit Troubleshooting

Note. Do not use this troubleshooting procedure if the radiator fan and/or the A/C compressor is inoperative. Refer to the SYMPTOM TROUBLESHOOTING INDEX . Before doing symptom troubleshooting, check for powertrain DTCs (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 87

Scheme 88

Scheme 89

Scheme 90

Scheme 91

1. Check the No. 36 (10 A) fuse in the 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. 36 (10 A) fuse circuit.
2. Remove the fan control relay from the under-hood relay box, and test it (see «POWER RELAY TEST»(/acura/rdx/i-2009-2012/remont/body-electrical/#relays__power-relay-test) ). Is the relay OK? YES -Go to step 3. NO -Replace the fan control relay.
3. Turn the ignition switch to ON (II).
4. Measure the voltage between fan control relay 5P socket terminal No. 5 and body ground. Is there battery voltage? YES -Go to step 5. NO -Go to step 12 .
5. Turn the ignition switch to LOCK (0).
6. Check for continuity between fan control relay 5P socket terminal No. 2 and body ground. Is there continuity? YES -Go to step 7. NO -Check for an open in the wire between the fan control relay and body ground. If the wire is OK, check for poor ground at G202 (see «CONNECTOR TO FUSE/RELAY BOX INDEX»(/acura/rdx/i-2009-2012/remont/body-electrical/#fuserelay-boxes__connector-to-fuserelay-box-index) ).
7. Jump the SCS line with the HDS. NOTE: This step must be done to protect the powertrain control module (PCM) from damage.
8. Disconnect PCM connector A (44P).
9. Check for continuity between fan control relay 5P socket terminal No. 3 and PCM connector A (44P) terminal No. 5. Is there continuity? YES -Go to step 10. NO -Repair an open in the wire between the fan control relay and the PCM.
10. Reconnect PCM connector A (44P).
11. Check the DTCs by selecting the DTC MENU (DTCs) from the HDS (see «GENERAL TROUBLESHOOTING INFORMATION»(/acura/rdx/i-2009-2012/remont/testing-diagnostics/#fuel-and-emissions-systems) ). Is DTC P0532, P0533, P2184, and/or P2185 indicated? YES - DTC P0532 indicated: Go to A/C pressure sensor circuit low voltage troubleshooting (see «DTC P0532: A/C PRESSURE SENSOR CIRCUIT LOW VOLTAGE»(/acura/rdx/i-2009-2012/remont/testing-diagnostics/#idle-control-system__dtc-p0532-ac-pressure-sensor-circuit) ). DTC P0533 indicated: Go to A/C pressure sensor circuit high voltage troubleshooting (see «DTC P0533: A/C PRESSURE SENSOR CIRCUIT HIGH VOLTAGE»(/acura/rdx/i-2009-2012/remont/testing-diagnostics/#idle-control-system__dtc-p0533-ac-pressure-sensor-circuit) ). DTC P2184 indicated: Go to ECT 2 sensor circuit low voltage troubleshooting (see «DTC P2184: ECT SENSOR 2 CIRCUIT LOW VOLTAGE»(/acura/rdx/i-2009-2012/remont/testing-diagnostics/#pgm-fi-system__dtc-p2184-ect-sensor-2-circuit) ). DTC P2185 indicated: Go to ECT 2 sensor circuit high voltage troubleshooting (see «DTC P2185: ECT SENSOR 2 CIRCUIT HIGH VOLTAGE»(/acura/rdx/i-2009-2012/remont/testing-diagnostics/#pgm-fi-system__dtc-p2185-ect-sensor-2-circuit) ). NO -Check for loose wires or poor connections at PCM connector A (44P). If the connections are good, substitute a known-good PCM, and recheck. If the symptom/indication goes away, replace the original PCM (see «PCM REPLACEMENT»(/acura/rdx/i-2009-2012/remont/testing-diagnostics/#pgm-fi-system__pcm-replacement) ).
12. Turn the ignition switch to LOCK (0).
13. Remove A/C diode A from the under-hood fuse/relay box.
14. Using the diode setting on a DVOM, check for current flow in both directions between A/C diode A terminals No. 1 and No. 2. Is there current flow in only one direction? YES -Go to step 15. NO -Replace A/C diode A.
15. Turn the ignition switch to ON (II).
16. Measure the voltage between A/C diode A 2P socket terminal No. 2 and body ground. Is there battery voltage? YES -Replace the under-hood fuse/relay box (see «REMOVAL AND INSTALLATION»(/acura/rdx/i-2009-2012/remont/fuses-circuit-breakers/#under-hood-fuserelay-box__removal-and-installation) ). NO -Repair an open in the wire between the No. 36 (10 A) fuse in the under-dash fuse/relay box and A/C diode A.

A/C Compressor Clutch Circuit Troubleshooting

Note. The PCM can turn the A/C compressor OFF under certain conditions, such as low idle, high engine coolant temperature, or hard acceleration. 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 powertrain DTCs (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 92

Scheme 93

Scheme 94

Scheme 95

Scheme 96

1. Check the No. 20 (7.5 A) fuse in the under-hood fuse/relay box, and the No. 36 (10 A) fuse in the under-dash fuse/relay box. Are the fuses OK? YES -Go to step 2. NO -Replace the fuse, and recheck. If the fuse blows again, check for a short in the No. 20 (7.5 A) and the No. 36 (10 A) fuses circuit.
2. Connect the HDS to the DLC.
3. Check for these PGM-FI DTCs: P0117, P0118, P0506, P0507, P0532, and P0533. Are any of these DTCs indicated? YES -Go to the appropriate troubleshooting information. NO -Go to step 4.
4. Start the engine.
5. Turn on the A/C.
6. Check the A/C CLUTCH in the PGM-FI Data List with the HDS. Is the A/C CLUTCH on? YES -Go to step 8 . NO -Go to step 7.
7. Using the HDS, confirm the following values in the PGM-FI Data List at idle. TP SENSOR A About 0.5 V RPM 670-770 ECT SENSOR 2 176-212°F (80-100 °C) A/C SWITCH ON A/C CLUTCH ON A/C PRESSURE SENSOR 196-3, 138 kPa (2-32 kgf/cm 2 ) [28-455 psi] Are all the values within specifications? YES -Go to step 8. NO -Troubleshoot the value that is not with in the specifications.
8. Turn the ignition switch to LOCK (0).
9. Remove the A/C compressor clutch relay from the under-hood fuse/relay box, and test it (see «POWER RELAY TEST»(/acura/rdx/i-2009-2012/remont/body-electrical/#relays__power-relay-test) ). Is the relay OK? YES -With the A/C compressor clutch relay disconnected, go to step 10. NO -Replace the A/C compressor clutch relay.
10. 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 11. NO -Replace the under-hood fuse/relay box (see «REMOVAL AND INSTALLATION»(/acura/rdx/i-2009-2012/remont/fuses-circuit-breakers/#under-hood-fuserelay-box__removal-and-installation) ).
11. 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 12. NO -Go to step 21 .
12. Disconnect the jumper wire.
13. Turn the ignition switch to ON (II).
14. Measure the voltage between A/C compressor clutch relay 4P socket terminal No. 3 and body ground. Is there battery voltage? YES -Go to step 15. NO -Repair an open in the wire between the No. 36 (10 A) fuse in the under-dash fuse/relay box and the A/C compressor clutch relay.
15. Turn the ignition switch to LOCK (0).
16. Reinstall the A/C compressor clutch relay.
17. Jump the SCS line with the HDS. NOTE: This step must be done to protect the powertrain control module (PCM) from damage.
18. Disconnect PCM connector A (44P).
19. Connect PCM connector A (44P) terminal No. 14 to body ground with a jumper wire.
20. Turn the ignition switch to ON (II). Does the A/C compressor clutch click? YES -Check for loose wires or poor connections at PCM connector A (44P). If the connections are good, check the PCM grounds. If the grounds are good, substitute a known-good PCM, and recheck. If the symptom/indication goes away, replace the original PCM (see «PCM REPLACEMENT»(/acura/rdx/i-2009-2012/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.
21. Disconnect the jumper wire.
22. Disconnect the A/C compressor clutch 3P connector.
23. Check for continuity between A/C compressor clutch relay 4P socket terminal No. 2 and A/C compressor clutch 3P connector terminal No. 3. Is there continuity? YES -Check the A/C compressor clutch clearance and the A/C compressor clutch field coil. Repair as needed (see «A/C COMPRESSOR CLUTCH CHECK»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ). NO -Repair an open in the wire between the A/C compressor clutch relay and the A/C compressor clutch.

Scheme 97

Scheme 98

Scheme 99

1. Turn the ignition switch to LOCK (0).
2. Disconnect climate control unit connector B (16P)and audio unit connector C (28P).
3. Check for continuity between climate control unit connector B (16P) terminal No. 11 and audio unit connector C (28P) terminal No. 15. Is there continuity? YES -Go to step 4. NO -Repair an open in the wire between climate control unit connector B (16P) and audio unit connector C (28P).
4. Check for continuity between body ground and climate control unit connector B (16P) terminal No. 11. Is there continuity? YES -Repair a short to body ground in the wire between climate control unit connector B (16P) and audio unit connector C (28P). NO -Go to step 5.
5. Reconnect climate control unit connector B (16P).
6. Disconnect the in-car temperature sensor 2P connector (see «IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).
7. Connect climate control unit connector B (16P) terminals No. 11 and No. 14 with a jumper wire.
8. Turn the ignition switch to ON (II).
9. Press and hold the DEF button and OFF button. Is the DEF button LED blinking? YES -Audio unit is faulty, replace the audio unit (see «AUDIO UNIT REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/entertainment-systems/#audio-system) ). NO -Climate control unit is faulty, replace the climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).

Scheme 100

Scheme 101

Scheme 102

Scheme 103

1. Operate the climate control system in several modes; Is the climate control system OK? YES -Go to step 2. NO -Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/rdx/i-2009-2012/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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).
2. Do the Navi system link (see «SYSTEM LINKS»(/acura/rdx/i-2009-2012/remont/entertainment-systems/#navigation-system) ). Is the Air-Con or TALK/BACK icon red? YES - If Air-con icon is red, go to step 3. If TALK/BACK icon is red, go to "voice control does not work/respond" in the navigation system symptom troubleshooting (see «VOICE CONTROL DOES NOT WORK/RESPOND»(/acura/rdx/i-2009-2012/remont/entertainment-systems/#navigation-system) ). NO -Go to step 9 .
3. Turn the ignition switch to LOCK (0).
4. Disconnect navigation unit connector B (32P).
5. Disconnect climate control unit connector B (1%P).
6. Check for continuity between the following terminals of climate control unit connector B (16P) and navigation unit connector B (32P). 16P: 32P: No. 1 No. 20 No. 9 No. 21 No. 10 No. 4 Is there continuity? YES -Go to step 7. NO -Repair an open in the wire(s) between the climate control unit and the navigation unit.
7. Check for continuity between body ground and climate control unit connector B (16P) terminals No. 1, 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 navigation unit. NO -Go to step 8.
8. Reconnect climate control unit connector 6 (16P).
9. Disconnect navigation unit connector B (32P).
10. Connect the navigation unit connector B (32P) terminals No. 4, 20, and No. 21 with a jumper wire.
11. Turn the ignition switch to ON (II).
12. Press and hold the AUTO button, then press and hold the OFF button. Is the HEAT/VENT indicator solid with the remaining icons blinking? YES -Do the Unit Check with the navigation system (see «UNIT CHECK (QUICK CHECK)»(/acura/rdx/i-2009-2012/remont/entertainment-systems/#navigation-system__unit-check-quick-check) ). 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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).

A/C Signal Circuit Troubleshooting

Note. If the blower does run, or if there is a blower motor DTC, the compressor and the cooling fans will not operate (No signal). Do not use this troubleshooting procedure if any of the following items are operative: A/C condenser fan, radiator fan, A/C compressor. Refer to the SYMPTOM TROUBLESHOOTING INDEX . Before doing any symptom troubleshooting, check for powertrain DTCs (see GENERAL TROUBLESHOOTING INFORMATION ).

Scheme 104

Scheme 105

Scheme 106

1. Connect the HDS to the DLC and check for blower motor DTCs. Are there any DTCs? YES -Do the appropriate DTC troubleshooting. NO -Go to step 2.
2. Start the engine.
3. Turn on the A/C.
4. Check the blower motor operates at all speeds. Does the blower motor operate at all speeds? YES -Go to step 5. NO -Repair the problem in the blower motor circuit (see «DTC B1241 OR DTC INDICATOR F: A PROBLEM IN THE BLOWER MOTOR CIRCUIT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__dtc-b1241-or-dtc-indicator-f) ).
5. Check the A/C SWITCH in the PGM-FI Data List with the HDS. Is the A/C SWITCH ON? YES -The A/C signal is OK at this time. NO -Go to step 6.
6. Check the evaporator temperature sensor input to the climate control unit (see «DISPLAYING SENSOR INPUTS AT THE CLIMATE CONTROL UNIT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ). If the evaporator temperature sensor #5 reading above 0°C(32°F)? YES -Go to step 10 . NO -Go to step 7.
7. Turn the ignition switch to LOCK (0).
8. Disconnect climate control unit connector A (24P).
9. Measure the evaporator temperature sensor resistance between climate control unit connector A (24P) terminals No. 13 and No. 18. Is the resistance less than 24 kohms? YES -Go to step 11 . NO -Test the evaporator temperature sensor (see «EVAPORATOR TEMPERATURE SENSOR TEST»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__evaporator-temperature-sensor-test) ).
10. Turn the ignition switch to LOCK (0), then disconnect climate control unit connector A (24P).
11. Turn the ignition switch to ON (II).
12. Measure the voltage between climate control unit connector A (24P) terminal No. 17 and body ground. Is there battery voltage? YES -Go to step 13. NO -Repair an open in the wire between the climate control unit and the MICU.
13. Turn the ignition switch to LOCK (0).
14. Reconnect climate control unit connector A (24P).
15. Set the A/C button and the fan control switch to ON, then turn the ignition switch to ON (II).
16. Measure the voltage between climate control unit connector A (24P) terminal No. 17 and body ground. Is there 0.5 V or less? YES -Replace the under-dash fuse/relay box (see «REMOVAL AND INSTALLATION»(/acura/rdx/i-2009-2012/remont/fuses-circuit-breakers/#under-dash-fuserelay-box__removal-and-installation) ). NO -Check for loose wires or poor connections at climate control unit connector A (24P). 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/rdx/i-2009-2012/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 107

1. Remove the in-car temperature sensor (see «IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).
2. Test the 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. land No. 2 of the in-car temperature sensor with the specifications shown in the graph; the resistance should be within the specifications for whatever the ambient temperature is.
4. If the resistance is not as specified, replace the in-car temperature sensor (see «IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).

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 108

1. Remove the outside air temperature sensor (see «IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/rdx/i-2009-2012/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 «IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/rdx/i-2009-2012/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 109

1. Pull out the sunlight sensor from the dashboard.
2. Turn the ignition switch to ON (II). Measure the voltage between the terminals with the (+) probe on terminal No. 4 and the (-) probe on terminal No. 2 with the connector connected. NOTE: The voltage readings will not change under the light of a flashlight or a fluorescent lamp. Voltage should be: 3.6-3.7 V or more with the sensor out of direct sunlight. 3.3-3.5 V or less with the sensor in direct sunlight.
3. If the voltage is not as specified, replace the sunlight sensor (see «SUNLIGHT SENSOR REPLACEMENT»(/acura/rdx/i-2009-2012/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 110

Scheme 111

1. Remove the evaporator temperature sensor (see «EVAPORATOR CORE REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).
2. Dip the sensor in ice water, and measure the resistance between its terminals.
3. Pour warm water on the sensor, and check for a change in 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 CORE REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).

Scheme 112

Scheme 113

1. Disconnect the 4P connector from the power transistor.
2. Measure the resistance between terminals No. 3 and No. 4 of the power transistor. It should be about 1.5 kohms. If the resistance is within the specifications, go to step 3. If the resistance is not within the specifications, replace the power transistor (see «POWER TRANSISTOR REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ). NOTE: Also check the blower motor. Power transistor failure can be caused by a defective blower motor.
3. Carefully release the lock tab on terminal No. 1 (YEL) (A) in the 4P connector, then remove the terminal and insulate it from body ground.
4. Reconnect the 4P connector to the power transistor.
5. Make sure the YEL wire is completely isolated, then supply 12 V to the No. 1 cavity with a jumper wire.
6. Turn the ignition switch to ON (II), and check that the blower motor runs. If the blower motor does not run, replace the power transistor (see «POWER TRANSISTOR REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ). 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 before installing the new power transistor. If the blower motor does not turn freely, replace it. If the blower motor runs, the power transistor is OK.

Driver's Air Mix Control Motor Test

Special Tools Required

Backprobe Set 07SAZ-001000A (2)

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

Scheme 114

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 smoothly, and stop at Max Hot. If it does not, reverse the connections; the driver's air mix control motor should run smoothly, and stop at Max Cool. 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/rdx/i-2009-2012/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. It should be between 4.2 and 7.8 kohms.
5. Reconnect the driver's air mix control motor 7P connector, then turn the ignition switch to ON (II).
6. Using the backprobe set (07SAZ-001000A), measure the voltage between terminals No. 3 and No. 7. Max Cool: About 0.5 V Max Hot: About 4.5 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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).

Passenger's Air Mix Control Motor Test

Special Tools Required

Backprobe Set 07SAZ-001000A (2)

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

Scheme 115

1. Disconnect the 7P connector from the passenger'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 smoothly, and stop at Max Cool. If it does not, reverse the connections; the passenger's air mix control motor should run smoothly, 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 «DRIVER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/rdx/i-2009-2012/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. It should be between 4.2 and 7.8 kohms.
5. Reconnect the passenger's air mix control motor 7P connector, then turn the ignition switch to ON (II).
6. Using the backprobe set (07SAZ-001000A), measure the voltage between terminals No. 3 and No. 5. Max Cool: About 1.5 V Max Hot: About 4.5 V
7. If either the resistance or the voltage readings are not as specified, replace the passenger's air mix control motor (see «DRIVER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).

Mode Control Motor Test

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

Scheme 116

1. Disconnect the 7P connector from the 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 mode control motor, and ground terminal No. 2; the mode control motor should run smoothly, and stop at Vent. If it does not, reverse the connections; the mode control motor should run smoothly, and stop at Defrost. When the mode control motor stops running, disconnect battery power immediately.
3. If the mode control motor did not run in step 2 , remove it, then check the mode control linkage and doors for smooth movement. If the linkage and doors move smoothly, replace the mode control motor (see «MODE CONTROL MOTOR REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ). If the linkage or doors stick or bind, repair them as needed. If the 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 mode control motor running as in step 2 , and check for continuity between terminals No. 3, 4, 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 mode control motor (see «MODE CONTROL MOTOR REPLACEMENT»(/acura/rdx/i-2009-2012/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 117

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 terminals No. 5 or No. 7; the recirculation control motor should run smoothly. To avoid damaging the recirculation control motor, do not reverse power and ground. Disconnect the No. 5 or No. 7 terminals from ground; the recirculation control motor should stop at Fresh (when the No. 7 terminal is disconnected) or Recirculate (when the No. 5 terminal is disconnected). Do not cycle the recirculation control motor for a long time.
3. If the recirculation control motor did not run in step 2 , remove it, then check the recirculation control linkage and doors for smooth movement.

1. If the linkage and doors move smoothly, replace the recirculation control motor (see «MODE CONTROL MOTOR REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).
2. If the linkage or doors stick or bind, repair them as needed.

Scheme 118

Scheme 119

Scheme 120

Scheme 121

1. Check the armature plate for discoloration, peeling, or other damage. If there is damage, replace the clutch set (see «A/C COMPRESSOR CLUTCH OVERHAUL»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__ac-compressor-clutch-overhaul) ).
2. Check the rotor pulley bearing play and drag by rotating the rotor 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 (see «A/C COMPRESSOR CLUTCH OVERHAUL»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__ac-compressor-clutch-overhaul) ). NOTE: The rotor pulley and the armature plate were mated at the factory by a burnishing operation. Always replace the rotor 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 armature plate (B) all the way around. If the clearance is not within specified limits, remove the armature plate (see «A/C COMPRESSOR CLUTCH OVERHAUL»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__ac-compressor-clutch-overhaul) ) and add or remove shims as needed to increase or decrease clearance. Clearance: 0.35-0.65 mm (0.0138-0.0256 in) NOTE: The shims are available in four thicknesses: 0.1 mm, 0.2 mm, 0.4 mm, and 0.5 mm.
4. Remove the armature plate (see «A/C COMPRESSOR CLUTCH OVERHAUL»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__ac-compressor-clutch-overhaul) ), and inspect the armature plate and the rotor 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. Replace the A/C compressor (see «A/C COMPRESSOR REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__ac-compressor-replacement) ).
6. Check for continuity between the A/C compressor clutch connector terminals No. 1 and No. 2. If there is no continuity, replace the thermal protector (see «A/C COMPRESSOR THERMAL PROTECTOR REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ). NOTE: The thermal protector will have no continuity above about 252 to 262°F (122 to 128 °C). When the temperature drops below about 241 to 219°F (116 to 104 °C), the thermal protector will have continuity.
7. Disconnect the field coil connector (A). Check resistance of the field coil. If resistance is not within specifications, replace the field coil (see «A/C COMPRESSOR CLUTCH OVERHAUL»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__ac-compressor-clutch-overhaul) ). Field Coil Resistance: 3.35-3.65 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 Honda Tool and Equipment Program 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 (0.5 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 air flow 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 HVAC 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 122

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 illustration, following the equipment manufacturer's instructions.
2. Recover refrigerant from the A/C system (see «REFRIGERANT RECOVERY»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__refrigerant-recovery) ), and evacuate the system (see «SYSTEM EVACUATION»(/acura/rdx/i-2009-2012/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: 450 to 500 g 0.45 to 0.50 kg 1.0 to 1.1 lbs 15.8 to 17.6 oz
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 the detector with the cap installed and tight. 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 (low pressure side) 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/rdx/i-2009-2012/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/rdx/i-2009-2012/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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__receiverdryer-desiccant-replacement) ), or the A/C condenser (see «A/C CONDENSER REPLACEMENT»(/acura/rdx/i-2009-2012/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 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, diagnose and repair the cause of excessive A/C system pressure, then replace the A/C compressor relief valve (see «A/C COMPRESSOR RELIEF VALVE REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__ac-compressor-relief-valve-replacement) ). If the leak is from the casing/valve joint, replace the A/C compressor relief valve (see «A/C COMPRESSOR RELIEF VALVE REPLACEMENT»(/acura/rdx/i-2009-2012/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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__ac-compressor-replacement) ). Evaporator Start checking for evaporator leaks by illuminating the evaporator drain tube area. Let the vehicle sit for 30 minutes with the engine off, and the doors and windows closed. Then place the detector probe in the center vent, and turn the fan on to low speed. If a leak is found, remove the evaporator core (see «EVAPORATOR CORE REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ). Determine whether leak is from the evaporator or the expansion valve. Uses a permanent marker pen to circle the leak area. Replace the expansion valve (see «EXPANSION VALVE REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ), or the evaporator core (see «EVAPORATOR CORE REPLACEMENT»(/acura/rdx/i-2009-2012/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 HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS ), 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), 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, door, and linkage Operation of the air mix control motor(s), door(s), and linkage Operation of the recirculation motors, doors, and linkage If there is a squeaking or chirping noise, but no unusual vibration, replace the blower motor (see «BLOWER UNIT COMPONENT REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__blower-unit-component-replacement) ). Remove the blower unit (see «BLOWER UNIT REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/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/rdx/i-2009-2012/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 to N Start the engine Set the temperature control button to Max Cool Set the mode control button to Vent Set the fan ON/OFF button to minimum (but not OFF) Turn the A/C 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), and check the drive belt for excessive wear, oil contamination, improper routing, or a faulty belt tensioner (see «DRIVE BELT INSPECTION»(/acura/rdx/i-2009-2012/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 ). If the refrigerant charge is OK, replace the receiver/dryer.
7. Check the operation of the A/C compressor clutch: Make sure the 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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__ac-compressor-clutch-circuit-troubleshooting) ). If the A/C compressor clutch slips, replace the complete clutch assembly (see «A/C COMPRESSOR CLUTCH OVERHAUL»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__ac-compressor-clutch-overhaul) ). Make sure the A/C compressor clutch disengages. If the clutch does not disengage, do the A/C compressor clutch check (see «A/C COMPRESSOR CLUTCH CHECK»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ), If the A/C compressor clutch is OK, replace the A/C compressor (see «A/C COMPRESSOR REPLACEMENT»(/acura/rdx/i-2009-2012/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/rdx/i-2009-2012/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.
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/rdx/i-2009-2012/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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__ac-compressor-replacement) ).

A/C System Test

Special Tools Required

1. Throttle Pedal Depressor Tool B240B, commercially available
2. Big Digit Hygro-Thermometer PYR445703, 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 123

Scheme 124

Scheme 125

Scheme 126

1. Do the A/C system inspection (see «A/C SYSTEM INSPECTION»(/acura/rdx/i-2009-2012/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. Open the glove box. Remove the glove box stop on each side, then let the glove box hang down (see «PASSENGER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/gauges-instrument-panels/#dashboard) ).
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 60 ° F(16°C). Open the hood. Open the front doors. Set the temperature control button to Max Cool, the mode control button to Vent, and the recirculation control button to Recirculate. Turn the A/C button ON and the fan control button to Max. Hold the engine speed at 1, 500 RPM. No driver or passengers in 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/rdx/i-2009-2012/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)/ambient air (intake) temperature chart: Mark the vent (delivery) temperature on the vertical line. Mark the ambient air (intake) temperature on the bottom line. Draw a vertical line from the ambient air (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 ambient air temperature lines 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/ambient air (intake) temperature chart: Mark the high side (discharge) pressure on the vertical line. Mark the ambient air (intake) temperature on the bottom line. Draw a vertical line from the ambient air (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 ambient air temperature lines 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/ambient air (intake) temperature chart: Mark the low side (suction) pressure along the vertical line. Mark the ambient air (intake) temperature along the bottom line. Draw a vertical line from the ambient air (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 ambient air temperature lines should intersect in the shaded area. Any measurements outside the area may indicate the need for further inspection. PRESSURE TEST Test results Related symptoms Probable cause Driver and passenger's side A/C vent temperatures may vary by approx. 20°F (11 °C) or more. Suction pressure may be low. Low refrigerant charge. Expansion valve not opening sufficiently Air mix door DTCs present. One air mix door stuck or inoperative. Discharge pressure abnormally high. Discharge pressure reduced when A/C condenser cooled with water spray. Significant refrigerant overcharge. Restricted/weak airflow through A/C condenser. With doors open, fresh air selected and radiator and A/C condenser fan run on high speed, temperature drop across A/C condenser inlet to outlet is less than about 41°F(5°C). Dirty A/C condenser or damaged fins. Debris between A/C condenser and radiator. One or more cooling fans malfunctioning. Discharge pressure abnormally low. Suction and discharge pressures equalize rapidly after stopping compressor. Suction pressure higher than normal. Faulty A/C compressor discharge valve or seal. Suction pressure abnormally low. Weak or insufficient airflow across evaporator. Restricted blower intake or pollen filter. Suction pressure varies from near normal to a vacuum, as moisture freezes in expansion valve orifice. Moisture in the system. Faulty expansion valve. Reduced airflow from vents. Vent temperature is very low. Condensation freezing on evaporator. Faulty evaporator temp sensor (check DTC). Faulty expansion valve or compressor relay. Suction pressure abnormally high. Lack of slight suction pressure variation at 1, 500 RPM when "Recirculated" airflow is switched to "Fresh Air". Discharge pressure near normal. Expansion valve stuck open or open too long. Suction and discharge pressures abnormally high. Sheet of paper does not stick to front of A/C condenser surface with cooling fans on. With doors open, fresh air selected and radiator and A/C condenser fan run on high speed, temperature drop across A/C condenser inlet to outlet is less than about 41°F (5 °C). One (or both) cooling fan motor inoperative or wires reversed. Compressor clutch remains engaged during off cycle. Pressure relief valve may open. Insufficient compressor clutch clearance. Compressor relay or circuit problem. Excessive air in system. Suction and discharge pressures abnormally low. Suction line from expansion valve to compressor is not cold. Excessively low refrigerant charge. Lack of slight suction pressure variation at 1, 500 RPM when "Recirculated" airflow is switched to "Fresh Air". Expansion valve clogged with debris/desiccant, stuck closed, or not opening sufficiently. More than 50 - 60°F(10 - 16°C) temperature drop across A/C condenser inlet to outlet pipes. Blocked or restricted A/C condenser internal passages or lines/components restricting refrigerant flow. Significant temperature difference along high or low side A/C lines or components. NOTE: Some restrictions may not show up until 3, 000 RPM. Restriction in A/C suction or discharge lines or components (check temperatures to isolate). Suction pressure high and discharge pressure low. Excessive A/C compressor noise. Pressures equalize quickly and noise after compressor turns off. A/C compressor internal damage (Check for A/C system debris contamination). Suction and discharge pressures normal (or near normal). Vent temperature too high. Slightly low refrigerant charge. Excessive refrigerant oil in system. Heater valve (if equipped) misadjusted. Air mix door sticking, misadjusted or Static pressures high with A/C system equalized. (After engine is off 4 - 12 hours). Air/non-condensable gasses in system. Contaminated or incorrect refrigerant.

Scheme 127

Scheme 128

Scheme 129

Scheme 130

1. Recover the refrigerant with a recovery/recycling/charging station (see «REFRIGERANT RECOVERY»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__refrigerant-recovery) ).
2. Remove the front bumper (see «FRONT BUMPER REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/exterior-body-panels/#bumpers__front-bumper-removalinstallation) ).
3. Do the battery terminal disconnection procedure (see «USING THE GR8 BATTERY DIAGNOSTIC STATION»(/acura/rdx/i-2009-2012/remont/body-electrical/#battery) )
4. Remove the bolts, then disconnect the discharge hose (A) from the A/C condenser.
5. Remove the bolt, then disconnect the receiver line (A) from the A/C condenser.
6. Remove the bolts, then pull the bracket (A) down slightly.
7. Remove the bolts and brackets (A), then remove the A/C condenser (B). Be careful not to damage the radiator and 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 (SP-10) (see «A/C COMPRESSOR RELIEF VALVE REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__ac-compressor-relief-valve-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 and the A/C condenser fins when installing the A/C condenser. Charge the system (see «SYSTEM CHARGING»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__system-charging) ).
9. Do the battery terminal reconnection procedure (see «USING THE GR8 BATTERY DIAGNOSTIC STATION»(/acura/rdx/i-2009-2012/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 131

1. Remove the A/C condenser (see «A/C CONDENSER REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).
2. Remove the bolts from the A/C condenser, then remove the receiver/dryer (A), the bracket (B), and the O-rings (C).
3. Install the receiver/dryer in the reverse order of removal. Replace the O-rings with new ones, and apply a thin coat of refrigerant oil (SP-10) before installing them. Be sure to use the correct O-rings for HFC-134a (R-134a)to avoid leakage.

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 132

Scheme 133

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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__refrigerant-recovery) ).
3. Do the battery terminal disconnection procedure (see «USING THE GR8 BATTERY DIAGNOSTIC STATION»(/acura/rdx/i-2009-2012/remont/body-electrical/#battery) ).
4. Remove the alternator (see «ALTERNATOR REMOVAL AND INSTALLATION»(/acura/rdx/i-2009-2012/remont/charging-system/#charging-system) ).
5. Remove the bolt and the nut, then disconnect the suction hose (A), discharge hose (B) and connector (C) from the A/C compressor. After the hoses are disconnected, remove the O-rings (D) and 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 compressor in the reverse order of removal, and note these items: Inspect the A/C lines for any signs of contamination. If you're installing a new A/C compressor, you must calculate the amount of refrigerant oil to be removed from it (see «A/C REFRIGERANT OIL REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__ac-refrigerant-oil-replacement) ). A new A/C compressor comes with a full charge of oil. 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 refrigerant oil (SP-10) for HFC-134a SANDEN spiral type A/C compressor 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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__system-charging) ).
8. Do the battery terminal reconnection procedure (see «USING THE GR8 BATTERY DIAGNOSTIC STATION»(/acura/rdx/i-2009-2012/remont/body-electrical/#battery) ).

A/C Compressor Clutch Overhaul

Special Tools Required

A/C Compressor Kit 07AAF-000A150

Scheme 134

Scheme 135

Scheme 136

Scheme 137

1. Remove the center nut (A) while holding the armature plate (B) with the A/C clutch holder (C).
2. Remove the armature 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 armature plate, and recheck its clearance (see «A/C COMPRESSOR CLUTCH CHECK»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ). NOTE: The shims are available in three thicknesses: 0.1 mm, 0.2 mm, 0.4 mm, and 0.5 mm. Do not pry on the armature plate with screwdrivers or similar tools. Prying damages the armature plate and the rotor pulley. When replacing the clutch set, place a trial stack of shims, 1 mm total thickness, on the A/C compressor shaft. Install the armature plate, and check its clearance (see «A/C COMPRESSOR CLUTCH CHECK»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ). If the clearance is not with 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 rotor pulley (B). Be careful not to damage the rotor pulley and A/C compressor. NOTE: Do not hammer or pry on the rotor pulley to remove it. Using a hammer damages the A/C compressor. If the rotor pulley is difficult to remove, use a commercially available rotor pulley removing tool. Make sure the jaws of the pulling tool engage the back face of the rotor pulley, not the rotor pulley grooves.
4. Remove the bolt (A), then disconnect the field coil connector (B). Remove the snap ring (C) with snap ring pliers, then remove the field coil (D). Be careful not to damage the field coil and 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 7 ) 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. Clean the rotor 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 groove. Make sure that the rotor pulley turns smoothly after it's reassembled. Route and clamp the wires properly to prevent damage by the rotor 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 A/C button ON. This procedure seats the clutch friction surfaces, and increases clutch torque capacity.

Scheme 138

Scheme 139

1. Remove the bolt and the stay (A), and remove the bolt and the holder (B). Disconnect the field coil connector (C), then detach the harness clip and remove the thermal protector (D).
2. Replace the thermal protector (A) with a new one, and apply silicone sealant (B) to the bottom of the thermal protector.
3. Install the thermal protector in the reverse order of removal.

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 140

1. Recover the refrigerant with a recovery/recycling/charging station (see «REFRIGERANT RECOVERY»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__refrigerant-recovery) ).
2. Remove the relief valve (A), and the O-ring (B). Plug the opening to keep foreign matter 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 at the relief valve, 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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__system-charging) ).

A/C Refrigerant Oil Replacement

Special Tools Required

Oil Injector Tool Robinair ROB16256, commercially available

*This tool is available through the Honda Tool and Equipment Program; call 888-424-6857

Recommended PAG oil: SP-10

P/N 38897-P13-A01 AH: 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..........40 mL (1 1/3 fl-oz)

Evaporator................40 mL (1 1/3 fl-oz)

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

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

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

A/C compressor........Since the oil separator is equipped inside the A/C compressor for this vehicle, oil drainage is unnecessary at the time of A/C compressor replacement.

Scheme 141

Scheme 142

Scheme 143

1. Open the glove box. Remove the damper from the glove box, then let the glove box hang down (see «PASSENGER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/gauges-instrument-panels/#dashboard) ).
2. Remove the dust and pollen filter assembly 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.

Scheme 144

Scheme 145

Scheme 146

Scheme 147

Scheme 148

1. Remove the glove box (see «PASSENGER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/gauges-instrument-panels/#dashboard) ).
2. Remove the climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).
3. Remove the harness clip (A), the self-tapping screws, and the passenger's heater duct (B).
4. Remove the harness clip (A) and the bolts. Cut the plastic cross brace (B) in the glove box opening with diagonal cutters in the area shown. Retain these parts to be reinstalled later.
5. Disconnect the connector (A) from the recirculation control motor.
6. Disconnect the connector (A) from the blower motor, then remove the wire harness clip (B) and the ground terminal bolt (C).
7. Remove the self-tapping screws, the bolts, the mounting nut, and the blower unit (A).
8. Install the unit in the reverse order of removal. Make sure that there is no air leakage.

Blower Unit Component Replacement

Note these items when overhauling the blower unit

Scheme 149

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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__recirculation-control-motor-test) ).

Scheme 150

1. Remove the evaporator core (see «EVAPORATOR CORE REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).
2. Remove the bolts (A), the O-rings (B), and the expansion valve (C).
3. Install the 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. Make sure that there is no air leakage. Charge the system (see «SYSTEM CHARGING»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__system-charging) ).

Scheme 151

Scheme 152

Scheme 153

Scheme 154

Scheme 155

Scheme 156

Scheme 157

1. Recover the refrigerant with a recovery/recycling/charging station (see «REFRIGERANT RECOVERY»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__refrigerant-recovery) ).
2. Remove the bolt (A).
3. Remove the nut, then disconnect the A/C lines (A), and remove the O-rings (B) from the evaporator core.
4. Remove the stud bolt (A).
5. Remove the blower unit (see «BLOWER UNIT REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).
6. Disconnect the connectors (A) from the evaporator temperature sensor and the power transistor, then remove the connector clip (B). Remove the self-tapping screws, the expansion valve cover (C), and the seal (D).
7. Carefully pull out the evaporator core (A) without bending the lines, then remove the plate (B).
8. Remove the clip (A) and the evaporator temperature sensor (B). NOTE: The evaporator temperature sensor is installed in the fin at the 7th fin from the left side by the factory preset.
9. When the evaporator temperature sensor is reinstalled, set the evaporator temperature sensor in the eight fin from the left side (one fin over from the previous position).
10. Install the core in the reverse order of removal and note these items: If you're installing a new evaporator core, add the appropriate amount of refrigerant oil (SP-10) (see «A/C COMPRESSOR RELIEF VALVE REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__ac-compressor-relief-valve-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. Make sure that there is no air leakage. Charge the system (see «SYSTEM CHARGING»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__system-charging) ).

Scheme 158

Scheme 159

Scheme 160

1. From under the hood, open the cable clamp (A), then disconnect the heater valve cable (B) from the heater valve arm (C).
2. From under the dash, disconnect the heater valve cable housing from the cable clamp (A), and disconnect the heater valve cable (B) from the air mix control linkage (C).
3. Set the temperature control button to Max Cool (Lo) with the ignition switch to ON (II).
4. Attach the heater valve cable to the air mix control linkage as shown in step 2 . Hold the end of the heater valve cable housing against the stop, then snap the heater valve cable housing into the cable clamp. NOTE: Make sure the ring-end of the cable is pushed all the way to the base of the pin on air mix control linkage.
5. From under the hood, turn the heater valve arm (A) to the fully closed position as shown in illustration, and hold it. Attach the heater valve cable (B) to the heater valve arm, and gently pull on the heater valve cable housing to take up any slack, then install the heater valve cable housing into the cable clamp (C).

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 161

Scheme 162

Scheme 163

Scheme 164

Scheme 165

Scheme 166

Scheme 167

Scheme 168

Scheme 169

1. Do the battery terminal disconnection procedure (see «USING THE GR8 BATTERY DIAGNOSTIC STATION»(/acura/rdx/i-2009-2012/remont/body-electrical/#battery) ).
2. Disconnect the A/C line from the evaporator core (see «EVAPORATOR CORE REPLACEMENT»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).
3. Remove the air cleaner housing assembly (see «AIR CLEANER REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/mechanical/#intake-air-system) ).
4. From under the hood, open the cable clamp (A), then disconnect: the heater valve cable (B) from the heater valve arm \\C). Turn the heater valve arm to the fully opened position as shown in illustration.
5. When the engine is cool, drain the engine coolant from the radiator (see «COOLANT CHECK»(/acura/rdx/i-2009-2012/remont/cooling-fan/#engine-cooling-system) ).
6. 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.
7. Remove the mounting nut from the heater unit. Take care not to damage or bend the fuel lines or the brake lines.
8. Remove the dashboard (see «DASHBOARD REPLACEMENT»(/acura/rdx/i-2009-2012/remont/gauges-instrument-panels/#dashboard) ).
9. Disconnect the connector (A) from the blower motor. Remove the wire harness clip (B) and the ground terminal bolt (C)
10. Disconnect the connector (A) from the recirculation control motor.
11. Disconnect these connectors (A) from the climate control unit, the mode control motor, the passenger's air mix control motor, the evaporator temperature sensor, and the power transistor. Remove the wire harness clip (B).
12. Disconnect these connectors (A) from the driver's air mix control motor and the A/C wire harness. Remove the connector clip (B), the wire harness clips (C), and the wire harness (D).
13. Remove the mounting bolts, the mounting nuts, and the blower-heater unit (A).
14. Remove the self-tapping screws, the heater core cover (A), the grommet (B), and carefully pull out the heater core (C).
15. Install the heater core and the evaporator 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/rdx/i-2009-2012/remont/cooling-fan/#engine-cooling-system) ). Make sure that there is no coolant leakage. Make sure that there is no air leakage. Charge the system, (see «SYSTEM CHARGING»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__system-charging) )
17. Do the battery terminal reconnection procedure (see «USING THE GR8 BATTERY DIAGNOSTIC STATION»(/acura/rdx/i-2009-2012/remont/body-electrical/#battery) ).
18. After installation, operate the various functions to see whether it works properly.
19. Run the self-diagnostic function to confirm that there are no problems in the system (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).

Scheme 170

1. Remove the accelerator pedal module (see «APP SENSOR SIGNAL INSPECTION»(/acura/rdx/i-2009-2012/remont/engine-control-systems/#electronic-throttle-control-system__app-sensor-signal-inspection) ).
2. 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.
3. With the motor removed, make sure the door linkage moves smoothly and does not bind.
4. 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 171

1. Remove the glove box (see «PASSENGER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/gauges-instrument-panels/#dashboard) ).
2. Remove the climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).
3. Disconnect the connector (A) from the passenger's air mix control motor (B), then remove the self-tapping screws and the passenger's air mix control motor from the heater unit.
4. With the motor removed, make sure the door linkage moves smoothly and does not bind.
5. 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 172

Scheme 173

1. Remove the glove box (see «PASSENGER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/gauges-instrument-panels/#dashboard) ).
2. Remove the climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).
3. Remove the harness clip (A), the self-tapping screws, and the passenger's heater duct (B).
4. Disconnect the 7P connector (A) from the mode control motor (B). Remove the self-tapping screws and the mode control motor from the heater unit.
5. 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 174

Scheme 175

1. Remove the glove box (see «PASSENGER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/gauges-instrument-panels/#dashboard) ).
2. Remove the climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).
3. Remove the harness clip (A), the self-tapping screws, and the passenger's heater duct (B).
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.
5. 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 176

1. Remove the driver's dashboard undercover (see «CENTER PANEL REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/gauges-instrument-panels/#dashboard__center-panel-removalinstallation) ).
2. Remove the in-car temperature sensor (A) from the instrument panel (B).
3. Install the sensor in the reverse order of removal. Be sure to connect the air hose securely.

Scheme 177

1. Lift the tab (A) to release the lock, then remove the outside air temperature sensor (B) from the front bumper beam. Disconnect the 2P connector (C) from the outside air temperature sensor.
2. Install the sensor in the reverse order of removal.

Scheme 178

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

Scheme 179

1. Remove the passenger's dashboard undercover (see «PASSENGER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/gauges-instrument-panels/#dashboard) ).
2. Remove the glove box (see «PASSENGER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/gauges-instrument-panels/#dashboard) ).
3. Disconnect the 4P connector (A) from the power transistor (B), then remove the screws.
4. Pull out the power transistor from the expansion valve cover.
5. Install the power transistor in the reverse order of removal.

Scheme 180

1. Remove the passenger's dashboard undercover (see «PASSENGER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/gauges-instrument-panels/#dashboard) ).
2. Disconnect the connectors (A) from the climate control unit.
3. Remove the self-tapping screws and the climate control unit (B).
4. Install the control unit in the reverse order of removal. After installation, operate the various functions to see whether it works properly.
5. Run the self-diagnostic function to confirm that there are no problems in the system (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).

Scheme 181

1. Remove the center panel (see «CENTER PANEL REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/gauges-instrument-panels/#dashboard__center-panel-removalinstallation) ).
2. Remove the self-tapping screws and the climate control switches (A).
3. Install the switches in the reverse order of removal. After installation, operate the various functions to see whether it works 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/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__how-to-use-the-self-diagnostic-function) ).

Scheme 182

Scheme 183

1. Remove the climate control switch (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control) ).
2. Remove the screws and the cover (A) from the driver's climate control switch (B).
3. Remove the bulb(s) with a flat-tip screwdriver.
4. Install the bulb(s) in the reverse order of removal. After installation, operate the various functions to see whether it works properly.

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 184

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 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

*This tool is available through the Honda 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 thermistor 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 thermistor 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 for at least 3 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 185

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, 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 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 step 4 ).

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 186

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 illustration, following the equipment manufacturer's instructions.
2. Recover the refrigerant in the A/C system (see «REFRIGERANT RECOVERY»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__refrigerant-recovery) ).
3. Evacuate the system (see «SYSTEM EVACUATION»(/acura/rdx/i-2009-2012/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/rdx/i-2009-2012/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 SP-10 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: 450 to 500 g 0.45 to 0.50 kg 1.0 to 1.1 lbs 15.8 to 17.6 oz
6. Check for refrigerant leaks (see «REFRIGERANT LEAK CHECK»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__refrigerant-leak-check) ).
7. Check the system performance (see «A/C SYSTEM TEST»(/acura/rdx/i-2009-2012/remont/automatic-hvac-system/#climate-control__ac-system-test) ).

See also:
• DRIVE BELT INSPECTION
• TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A
• DLC CIRCUIT TROUBLESHOOTING
• DTC B1150: COMMUNICATION CIRCUIT ERROR (BUS-OFF); DTC B1200: COMMUNICATION BUS LINE (BUS-OFF); DTC B1550: COMMUNICATION CIRCUIT ERROR (BUS-OFF); DTC B1750: COMMUNICATION BUS LINE ERROR (BUS-OFF); DTC B1800: COMMUNICATION CIRCUIT ERROR (BUS-OFF); DTC B1900: COMMUNICATION CIRCUIT ERROR (BUS-OFF); DTC U1280: COMMUNICATION BUS LINE ERROR (BUS-OFF)
• CONNECTOR TO FUSE/RELAY BOX INDEX
• SYSTEM DIAGNOSTIC MODE
• GENERAL TROUBLESHOOTING INFORMATION
• RADIATOR FAN HIGH SPEED CIRCUIT TROUBLESHOOTING
• DTC P2183: ECT SENSOR 2 CIRCUIT RANGE/PERFORMANCE PROBLEM
• COOLANT CHECK
• BATTERY TEST
• GAUGE CONTROL MODULE REPLACEMENT
• GAUGE CONTROL MODULE INPUT TEST
• POWER RELAY TEST
• REMOVAL AND INSTALLATION
• SUBSTITUTING THE PCM
• PCM REPLACEMENT
• DTC P0532: A/C PRESSURE SENSOR CIRCUIT LOW VOLTAGE
• DTC P0533: A/C PRESSURE SENSOR CIRCUIT HIGH VOLTAGE
• DTC P2184: ECT SENSOR 2 CIRCUIT LOW VOLTAGE
• DTC P2185: ECT SENSOR 2 CIRCUIT HIGH VOLTAGE
• AUDIO UNIT REMOVAL/INSTALLATION
• UNIT CHECK (QUICK CHECK)
• REMOVAL AND INSTALLATION
• PASSENGER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION
• FRONT BUMPER REMOVAL/INSTALLATION
• COMPONENT LOCATION INDEX
• AIR CLEANER REMOVAL/INSTALLATION
• APP SENSOR SIGNAL INSPECTION
• CENTER PANEL REMOVAL/INSTALLATION
• 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
• SYMPTOM TROUBLESHOOTING INDEX
• A/C COMPRESSOR CLUTCH CIRCUIT TROUBLESHOOTING
• A/C COMPRESSOR REPLACEMENT
• DTC B1225 OR DTC INDICATOR A: AN OPEN IN THE IN-CAR TEMPERATURE SENSOR CIRCUIT
• DTC B1239 OR DTC INDICATOR A: AN OPEN OR SHORT IN THE MODE CONTROL MOTOR CIRCUIT
• DTC B1226 OR DTC INDICATOR B: A SHORT IN THE IN-CAR TEMPERATURE SENSOR CIRCUIT
• DTC B1240 OR DTC INDICATOR B: A PROBLEM IN THE MODE CONTROL MOTOR CIRCUIT, LINKAGE, DOORS, OR MOTOR
• DTC B1230 OR DTC INDICATOR F: A SHORT IN THE SUNLIGHT SENSOR CIRCUIT
• DTC B1241 OR DTC INDICATOR F: A PROBLEM IN THE BLOWER MOTOR CIRCUIT
• DTC B1231 OR DTC INDICATOR G: AN OPEN IN THE EVAPORATOR TEMPERATURE SENSOR CIRCUIT
• DTC B1232 OR DTC INDICATOR H: A SHORT IN THE EVAPORATOR TEMPERATURE SENSOR CIRCUIT
• DTC B1233 OR DTC INDICATOR J: AN OPEN IN THE AIR MIX CONTROL MOTOR CIRCUIT (DRIVER'S)
• DTC B1234 OR DTC INDICATOR K: A SHORT IN THE AIR MIX CONTROL MOTOR CIRCUIT (DRIVER'S)
• DTC B1236 OR DTC INDICATOR M: AN OPEN IN THE PASSENGER'S AIR MIX CONTROL MOTOR CIRCUIT
• HOW TO CHECK FOR DTCS WITH THE HDS
• A/C SIGNAL CIRCUIT TROUBLESHOOTING
• A/C SYSTEM TEST
• RADIATOR AND A/C CONDENSER FAN LOW SPEED CIRCUIT TROUBLESHOOTING
• A/C CONDENSER FAN HIGH SPEED CIRCUIT TROUBLESHOOTING
• RECEIVER/DRYER DESICCANT REPLACEMENT
• SYSTEM CHARGING
• A/C COMPRESSOR RELIEF VALVE REPLACEMENT
• REFRIGERANT RECOVERY
• A/C REFRIGERANT OIL REPLACEMENT
• DRIVER'S AIR MIX CONTROL MOTOR TEST
• PASSENGER'S AIR MIX CONTROL MOTOR TEST
• CHECKS BEFORE USING THE SENSOR INPUT DISPLAY MODE
• IN-CAR TEMPERATURE SENSOR TEST
• OUTSIDE AIR TEMPERATURE SENSOR TEST
• SUNLIGHT SENSOR TEST
• EVAPORATOR TEMPERATURE SENSOR TEST
• MODE CONTROL MOTOR TEST
• BLOWER UNIT COMPONENT REPLACEMENT
• RECIRCULATION CONTROL MOTOR TEST
• A/C COMPRESSOR CLUTCH OVERHAUL
• SYSTEM EVACUATION
• A/C SYSTEM INSPECTION