Climate Control System Acura TL IV

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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, which are not compatible with CFC-12 (R-12) refrigerant or mineral oil Do not use R-12 refrigerant or mineral oil in this system, and do not attempt to use R-12 servicing equipment, damage to the air conditioning system or your servicing equipment will result

Use only service equipment that is U L - listed and is certified to meet the requirements of SAEJ2210 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, don't 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, don't release refrigerant into the atmosphere

A/C Refrigerant Oil Replacement

Recommended PAG oil DENSO ND-OIL 8

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

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

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

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

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

Evaporator 35 mL (1 1/5 fl oz)

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

Leakage repair 25 mL (5/6 fl oz)

A/C Compressor For A/C compressor replacement, subtract the volume of oil drained from the removed A/C compressor from 82 mL (2 7/9 fl oz), and dram the calculated volume of oil from the new A/C compressor 82 mL (2 7/9 fl oz) - Volume of removed A/C compressor = Volume to dram from new A/C compressor

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

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A/C System Inspection

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

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1. Check for collision damage or body shop work
2. Make sure the ignition switch is in LOCK (0), or the vehicle is in the OFF mode Inspect the A/C components, the pressure lines, and the hoses for stains that may indicate a refrigerant or a compressor oil leak
3. Check the A/C condenser for material clogging the fins or for damage to the fins Carefully clean any material from the A/C condenser fins with water and detergent If deeper cleaning is required, clean the fins with Honda Brite cleaner (P/N 08732-0020B) Be sure to dry the A/C condenser (A) completely Refer to the refrigerant leak check (see «REFRIGERANT LEAK CHECK»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__refrigerant-leak-check) ) to confirm leaks if there is visible damage to the A/C condenser
4. Inspect the drive belt (see «DRIVE BELT INSPECTION»(/acura/tl/iv-2008-2011/remont/charging-system/#charging-system) )
5. Make sure no material is blocking the airflow to the A/C condenser
6. Check the dust and pollen filter, and replace it if it is clogged (see «DUST AND POLLEN FILTER REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
7. Check for kinks or sharp bends in the A/C lines and hoses, which can greatly reduce system performance Replace A/C lines and hoses if they are kinked or damaged (see «A/C LINE REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
8. Start the engine, turn the air conditioning system on, and allow it to run for a few minutes and reach stable operation
9. Check that the A/C operates at each position of the blower fan switch (except OFF) If the A/C does not operate, refer to «SYMPTOM TROUBLESHOOTING INDEX»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__symptom-troubleshooting-index) .
10. Check that the A/C compressor clutch (A) is engaged The pressure plate should be rotating at the same speed as the pulley If the pressure plate does not engage, or fails to disengage, refer to to «SYMPTOM TROUBLESHOOTING INDEX»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__symptom-troubleshooting-index) .
11. Check that the A/C condenser fan (B) and the radiator cooling fan (c) operate when the A/C compressor clutch is engaged and blow air into the engine compartment. If either fan fails to operate when the A/C compressor clutch is engaged, refer to to «SYMPTOM TROUBLESHOOTING INDEX»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__symptom-troubleshooting-index) .
12. Check that the engine idle speed is correctly maintained when the A/C is switched on and off, and when the A/C compressor clutch is engaged and disengaged

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1. Make sure the ignition switch is in LOCK (0), or the vehicle ignition is in the OFF mode
2. Connect the HDS to the data link connector (DLC) (A) located under the driver's side of the dashboard
3. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode
4. Make sure the HDS communicates with the vehicle and the climate control unit If it doesn't, troubleshoot the DLC circuit (see «DLC CIRCUIT TROUBLESHOOTING»(/acura/tl/iv-2008-2011/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 If no DTCs are indicated, do all system scan, then refer to to «SYMPTOM TROUBLESHOOTING INDEX»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__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

1. Make sure the ignition switch is in LOCK (0), or the vehicle ignition is in the OFF mode
2. Connect the HDS to the data link connector (DLC)
3. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode
4. Make sure the HDS communicates with the vehicle and the climate control unit If it doesn't, troubleshoot the DLC circuit (see «DLC CIRCUIT TROUBLESHOOTING»(/acura/tl/iv-2008-2011/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

Note. After troubleshooting, clear the DTCs with the HDS For specific operations, refer to the user's manual that came with the HDS

How to Use the Self-diagnostic Function without the HDS

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

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1. Turn the ignition switch to LOCK (0) and then back to ON (II), or press the engine start/stop button to select the OFF mode and then the ON mode
2. Press and hold the FAN ON/OFF button, then within 10 seconds press and release the REAR WINDOW DEFOGGER/MIRROR DEFOGGER button five times Release the FAN ON/OFF button, then the self-diagnostic begins NOTE: The blower motor runs at various speeds regardless of what the panel is displaying If there is a problem with the system, it will flash AUTO, 88 and AUTO, 88 and WINDSHIELD DEFROST, or 88 and MODE, and one or more of the 14 indicator segments (A through N) Refer to «CHECKING FOR DTCS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__checking-for-dtcs) If there is more than one DTC, they are displayed one at a time in sequence followed by a pause (all the display indicator segments illuminate) between the DTCs If there are no problems detected, the segments do not illuminate, and the system appears to be turned off Canceling the Self-diagnostic Function
3. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode to cancel the self-diagnostic function After completing repair work, run the self-diagnostic function again to make sure that there are no other DTCs

Checking for DTCs

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

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

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DTC CHART

Displaying Sensor Inputs at the Climate Control Unit

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

Check these items 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 desired test temperature using the driver's control switch Press the SYNC button off, the LED turns off When selecting the test temperature, note these items "Lo" temperature setting will default to MAX COOL, VENT, and RECIRC "Hi" temperature setting will default to MAX HOT, HEAT, and FRESH through 86°F settings will use the automatic climate control logic
3. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode

To run the sensor input display mode, follow these steps

1. Make sure the ignition switch is in LOCK (0), or the vehicle ignition is in the OFF mode
2. Press and hold both the passenger's AUTO and RECIRCULATION CONTROL buttons, then start the engine
3. After the engine starts, release both buttons The display panel control unit flashes the sensor number, then the value for that sensor Record the value displayed
4. To advance to the next sensor, press the REAR WINDOW DEFOGGER button NOTE: The sensor values are displayed in degrees Celsius (°C) or an alphanumeric code Use the charts to convert degrees Fahrenheit (°F), or convert the alphanumeric code to a numerical value If the sensor value displays "Er" this indicates there is an open or short in the circuit or sensor Check for DTCs using the HDS, or use the climate control unit self-diagnostic function If necessary, compare the sensor input display to a known-good vehicle under the same test conditions If the sensor is out of the normal range, refer to the sensor test or substitute a known-good sensor, and recheck ITEM CHART Sensor Item Displayed Value 1 In-car Temperature °C 2 Outside Air Temperature °C 3 Solar Radiation Sensor Value Dark = 00, Flashlight = 04, Cloudy = 10, Sunny = 65 kcal/m 2 h 4 Radiator Coolant Temperature °C 5 Evaporator Outlet Air Temperature °C 6 Driver's Air Mix Opening (Low value indicates cooler air distribution, higher value indicates warmer air distribution) % of opening Passenger's Air Mix Opening (Low value indicates cooler air distribution, higher value indicates warmer air distribution) (Passenger's side of display) % of opening 7 Vent Temperature Air Out (TAO) °C 8 Vehicle Speed (Vehicle must be driven to display speed) km/h 9 A/C Pressure 10 kPa A Humidity Sensor Value % rh B Fog Margin °C C Solar Radiation azimuth (With navigation) 10° D Solar Radiation angle of elevation (With navigation) 10° Celsius to Fahrenheit Conversion Table CELSIUS TO FAHRENHEIT CONVERSION SPECIFICATION °C °F °C °F °C °F °C °F °C °F 0 32 10 50 20 68 30 86 40 104 1 34 11 52 21 70 31 88 41 106 2 36 12 54 22 72 32 90 42 108 3 37 13 55 23 73 33 91 43 109 4 39 14 57 24 75 34 93 44 111 5 41 15 59 25 77 35 95 45 113 6 43 16 61 26 79 36 97 46 115 7 45 17 63 27 81 37 99 47 117 8 46 18 64 28 82 38 100 48 118 9 48 19 66 29 84 39 102 49 120 CELSIUS TO FAHRENHEIT CONVERSION SPECIFICATION °C °F °C °F °C °F °C °F °C °F 50 122 60 140 70 158 80 176 90 194 51 124 61 142 71 160 81 178 91 196 52 126 62 144 72 162 82 180 92 198 53 127 63 145 73 163 83 181 93 199 54 128 64 147 74 165 84 183 94 201 55 131 65 149 75 167 85 185 95 203 56 133 66 151 76 169 86 187 96 205 57 135 67 152 77 170 87 188 97 207 58 136 68 154 78 172 88 190 98 208 59 139 69 158 79 174 89 192 99 210 Alphanumeric Conversion Table ALPHANUMERIC CONVERSION SPECIFICATION Display Reading (Alphanumeric) °C °F % A1 thru A9 - 1 thru -9 30 thru 16 - 1 thru -9 B0 thru B9 - 10 thru -19 14 thru - 2 -10 thru -19 C0 thru C9 -20 thru -29 -4 thru -20 -20 thru -29 D0 thru D9 -30 thru -39 -22 thru -38 -30 thru -39 E0 thru E9 -40 thru -49 -40 thru -58 -40 thru -49 F0 thru F9 - - +100 thru +109
5. To cancel the sensor input display mode, press the driver's AUTO button or turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode

DTC Troubleshooting Index

Checking the DTCs with the HDS

DTC TROUBLESHOOTING INDEX

Symptom Troubleshooting Index

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 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. Do not mix refrigerants CFC-12 (R-12) and HFC-134a (R-134a) They are not compatible
2. Use only the recommended polyalkyleneglycol (PAG) refrigerant oil (DENSO ND-OIL 8) designed for the R-134a A/C compressor Intermixing the recommended (PAG) refrigerant oil with any other refrigerant oil will result in A/C compressor failure
3. 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 Do not exchange with R-12 parts
4. Use a halogen gas leak detector designed for refrigerant R-134a
5. R-12 and R-134a refrigerant servicing equipment are not interchangeable Use only a recovery/recycling/charging station that is U L - listed and is certified to meet the requirements of SAE J2210 to service the R-134a air conditioning systems
6. Always recover refrigerant R-134a with an approved recovery/recycling/charging station before disconnecting any A/C fitting

A/C Pressure Sensor

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

A/C PRESSURE SENSOR OUTPUT VOLTAGE REFERENCE

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 compressor relay off to protect the A/C compressor When the refrigerant pressure is above 1,390 kPa (14 2 kgf/cm 2 ,202 psi), the PCM switches the radiator and A/C condenser fans to high speed

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Dual Mode Control System

All modes (except defroster) can be controlled independently

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

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

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CONNECTOR A

TERMINALS DESCRIPTION

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CONNECTOR B

TERMINALS DESCRIPTION

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CONNECTOR C

TERMINALS DESCRIPTION

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DTC U0155: Climate Control Unit Lost Communication with Gauge Control Module

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

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1. Clear the DTC with the HDS
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode
3. Do the self-diagnostic function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )
4. Check for DTCs Is DTC U0155 indicated? YES -Go to step 5 NO -The system is OK at this time Check for loose wires or poor connections on the B-CAN lines between the gauge control module and the climate control unit
5. Select UNIT INFORMATION in the BODY ELECTRICAL menu
6. Select CONNECTED UNIT in the UNIT INFORMATION menu Is the gauge control module detected? YES -Substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) NO -Go to step 7
7. Disconnect the gauge control module 32P connector
8. Disconnect climate control unit connector C (20P)
9. Check for continuity between the following terminals of the gauge control module 32P connector and climate control unit connector C (20P) 20P 32P No 7 No 25 No 8 No 26 Is there continuity? YES -Go to the gauge control module input test (see «GAUGE CONTROL MODULE INPUT TEST»(/acura/tl/iv-2008-2011/remont/gauges-instrument-panels/#display-and-gauge-system__gauge-control-module-input-test) ) NO -Repair open in the wire(s) between the climate control unit and the gauge control module

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1. Clear the DTC with the HDS
2. Turn the ignition switch to LOCK (0), and then ON (II) or press the engine start/stop button to select the OFF mode, and then the ON mode
3. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )
4. Check for DTCs Is DTC B1215 or J and MODE indicated? YES -Go to step 5 NO -Intermittent failure Check for loose wires or poor connections on the recirculation control motor circuit
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
6. Test the recirculation control motor (see «RECIRCULATION CONTROL MOTOR TEST»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__recirculation-control-motor-test) ) Is the recirculation control motor OK? YES -Go to step 7 NO -Replace the recirculation control motor (see «RECIRCULATION CONTROL MOTOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
7. Disconnect the recirculation control motor 7P connector
8. Disconnect climate control unit connector C (20P)
9. Check for continuity between the following terminals of climate control unit connector C (20P) and the recirculation control motor 7P connector 20P 7P No 1 No 7 No 18 No 5 No 19 No 4 No 20 No 3 Is there continuity? YES -Go to step 10 NO -Repair open in the wire(s) between the climate control unit and the recirculation control motor
10. Check for continuity between body ground and climate control unit connector C (20P) terminals No 18,19, and 20 individually Is there continuity? YES -Repair short to body ground in the wire(s) between the climate control unit and the recirculation control motor NO -Go to step 11
11. Check for continuity between climate control unit connector C (20P) terminals as follows TERMINALS CONTINUITY REFERENCE CHART From terminal To terminals 18 19, 20 19 20 Is there continuity between any of the terminals? YES -Repair the short in the wire(s) NO -Go to step 12
12. Reconnect climate control unit connector C (20 P)
13. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and check the same terminals for voltage to body ground Is there any voltage? YES -Repair 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 -Check for loose wires or poor connections at climate control unit connector C (20P) and at the recirculation control motor 7P connector If the connections are good, substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit (see «Climate Control Unit Removal/Installation»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )

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1. Clear the DTC with the HDS
2. Make sure the ignition switch is in LOCK (0), or the vehicle ignition is in the OFF mode
3. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )
4. Check for DTCs Is DTC B1225 or A and AUTO indicated? YES -Go to step 5 NO -Intermittent failure Check for loose wires or poor connections on the in-car temperature sensor circuit
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
6. Remove the in-car temperature sensor (see «HUMIDITY/IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ), and test it (see «HUMIDITY/IN-CAR TEMPERATURE SENSOR TEST»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) Is the m-car temperature sensor OK? YES -Go to step 7 NO -Replace the in-car temperature sensor
7. Disconnect climate control unit connectors C (20P)
8. Check for continuity between climate control unit connector C (20P) terminal No 15 and in-car temperature sensor 4P connector terminal No 4 Is there continuity? YES -Go to step 9 NO -Repair open in the wire between the climate control unit and the in-car temperature sensor
9. Check for continuity between climate control unit connector C (20P) terminal No 1 and in-car temperature sensor 4P connector terminal No 3 Is there continuity? YES -Check for loose wires or poor connections at climate control unit connectors C (20P) and at the in-car temperature sensor 4P connector If the connections are good, substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit (see «Climate Control Unit Removal/Installation»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) NO -Repair open in the wire between the climate control unit and the in-car temperature sensor

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1. Clear the DTC with the HDS
2. Make sure the ignition switch is in LOCK (0), or the vehicle ignition is in the OFF mode
3. Do the self-diagnostic function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )
4. Check for DTCs Is DTC B1226 or B and AUTO indicated? YES -Go to step 5 NO -Intermittent failure Check for loose wires or poor connections on the in-car temperature sensor circuit
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
6. Remove the humidity/in-car temperature sensor (see «HUMIDITY/IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ), and test it (see «HUMIDITY/IN-CAR TEMPERATURE SENSOR TEST»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) Is the in-car temperature sensor OK? YES -Go to step 7 NO -Replace the humidity/m-car temperature sensor
7. Disconnect climate control unit connector C (20P)
8. Check for continuity between climate control unit connector C (20P) terminal No 15 and body ground Is there continuity? YES -Repair short to body ground in the wire between the climate control unit and the m-car temperature sensor NO -Go to step 9
9. Check for continuity between climate control unit connector C (20P) terminals No 1 and No 15 Is there continuity? YES -Repair short in the wires between the climate control unit and the m-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/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )

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1. Clear the DTC with the HDS
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode
3. Do the self-diagnostic function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )
4. Check for DTCs Is DTC B1227 or C and AUTO indicated? YES -Go to step 5 NO -Intermittent failure Check for loose wires or poor connections on the outside air temperature sensor circuit
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
6. Remove the outside air temperature sensor (see «OUTSIDE AIR TEMPERATURE SENSOR TEST»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__outside-air-temperature-sensor-test) ), and test it (see «OUTSIDE AIR TEMPERATURE SENSOR TEST»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__outside-air-temperature-sensor-test) ) Is the outside air temperature sensor OK? YES -Go to step 7 NO -Replace the outside air temperature sensor
7. Disconnect climate control unit connector C (20P)
8. Check for continuity between climate control unit connector C (20P) terminal No 17 and outside air temperature sensor 2P connector terminal No 2 Is there continuity? YES -Go to step 9 NO -Repair open in the wire between the climate control unit and the outside air temperature sensor
9. Check for continuity between climate control unit connector C (20P) terminal No 1 and outside air temperature sensor 2P connector terminal No 1 Is there continuity? YES -Check for loose wires or poor connections at climate control unit connectors C (20P) and at the outside air temperature sensor 2P connector If the connections are good, substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit NO -Repair open in the wire between the climate control unit and the outside air temperature sensor

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1. Clear the DTC with the HDS
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode
3. Do the self-diagnostic function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )
4. Check for DTCs Is DTC B1228 or D and AUTO indicated? YES -Go to step 5 NO -Intermittent failure Check for loose wires or poor connections on the outside air temperature sensor circuit
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
6. Remove the outside air temperature sensor (see «OUTSIDE AIR TEMPERATURE SENSOR TEST»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__outside-air-temperature-sensor-test) ), and test it (see «OUTSIDE AIR TEMPERATURE SENSOR TEST»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__outside-air-temperature-sensor-test) ) Is the outside air temperature sensor OK? YES -Go to step 7 NO -Replace the outside air temperature sensor
7. Disconnect climate control unit connector C (20P)
8. Check for continuity between climate control unit connector C (20P) terminal No 17 and body ground Is there continuity? YES -Repair short to body ground in the wire between the climate control unit and the outside air temperature sensor NO -Go to step 9
9. Check for continuity between climate control unit connector C (20P) terminals No 1 and No 17 Is there continuity? YES -Repair short in the wire(s) 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/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )

Scheme 41

Scheme 42

1. Clear the DTC with the HDS
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode
3. Do the self-diagnostic function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )
4. Check for DTCs Is DTC B1229 or E and AUTO indicated? YES -Go to step 5 NO -Intermittent failure Check for loose wires or poor connections on the sunlight sensor circuit
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
6. Disconnect the sunlight sensor 2P connector
7. Disconnect climate control unit connector C (20P)
8. Check for continuity between climate control unit connector C (20P) terminal No 14 and sunlight sensor 2P connector terminal No 2 Is there continuity? YES -Go to step 9 NO -Repair open in the wire between the climate control unit and the sunlight sensor
9. Check for continuity between climate control unit connector C (20P) terminal No 1 and sunlight sensor 2P connector terminal No 1 Is there continuity? YES -Go to step 10 NO -Repair open in the wire between the climate control unit and the sunlight sensor
10. Reconnect the sunlight sensor 2P connector
11. Reconnect climate control unit connectors C (20P)
12. Test the sunlight sensor (see «SUNLIGHT SENSOR TEST»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__sunlight-sensor-test) )

Is the sunlight sensor OK?

YES -Check for loose wires or poor connections at climate control unit connector C (20P) and at the sunlight sensor 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 )

NO -Replace the sunlight sensor (see Sunlight Sensor Replacement )

Scheme 43

Scheme 44

1. Clear the DTC with the HDS
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode
3. Do the self-diagnostic function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )
4. Check for DTCs Is DTC B1230 or F and AUTO indicated? YES -Go to step 5. NO -Intermittent failure Check for loose wires or poor connections on the sunlight sensor circuit
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
6. Disconnect the sunlight sensor 2P connector
7. Disconnect climate control unit connectors C (20P)
8. Check for continuity between climate control unit connector C (20P) terminal No 14 and body ground Is there continuity? YES -Repair short to body ground in the wire between the climate control unit and the sunlight sensor NO -Go to step 9
9. Check for continuity between climate control unit connector C (20P) terminals No 1 and No 14 Is there continuity? YES -Repair short in the wires between the climate control unit and the sunlight sensor NO -Go to step 10
10. Reconnect the sunlight sensor 2P connector
11. Reconnect climate control unit connectors C (20P)
12. Test the sunlight sensor (see «SUNLIGHT SENSOR TEST»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__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/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) NO -Replace the sunlight sensor (see «Sunlight Sensor Replacement»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )

Scheme 45

Scheme 46

1. Clear the DTC with the HDS
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode
3. Do the self-diagnostic function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )
4. Check for DTCs Is DTC B1231 or G and AUTO indicated? YES -Go to step 5 NO -Intermittent failure Check for loose wires or poor connections on the evaporator temperature sensor circuit
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
6. Disconnect climate control unit connectors C (20P)
7. Disconnect the evaporator temperature sensor 2P connector.
8. Check for continuity between climate control unit connector C (20P) terminal No 16 and evaporator temperature sensor 2P connector terminal No 1 Is there continuity? YES -Go to step 8 NO -Repair open in the wire between the climate control unit and the evaporator temperature sensor
9. Check for continuity between climate control unit connector C (20P) terminal No 1 and evaporator temperature sensor 2P connector terminal No 2 Is there continuity? YES -Go to step 10 NO -Repair open in the wire between the climate control unit and the evaporator temperature sensor
10. Remove the evaporator temperature sensor (see «EVAPORATOR TEMPERATURE SENSOR TEST»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__evaporator-temperature-sensor-test) ), and test it (see «EVAPORATOR TEMPERATURE SENSOR TEST»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__evaporator-temperature-sensor-test) ) Is the evaporator temperature sensor OK? YES -Check for loose wires or poor connections at climate control unit connector C (20P) and at the evaporator temperature sensor 2P connector If the connections are good, substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit (see «Climate Control Unit Removal/Installation»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) NO -Replace the evaporator temperature sensor (see «Evaporator Temperature Sensor Replacement»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )

Scheme 47

Scheme 48

1. Clear the DTC with the HDS
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode
3. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )
4. Check for DTCs Is DTC B1232 or H and AUTO indicated? YES -Go to step 5 NO -Intermittent failure Check for loose wires or poor connections on the evaporator temperature sensor circuit
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
6. Disconnect climate control unit connector C (20P)
7. Disconnect the evaporator temperature sensor 2P connector.
8. Check for continuity between climate control unit connector C (20P) terminal No 16 and body ground Is there continuity? YES -Repair short to body ground in the wire between the climate control unit and the evaporator temperature sensor NO -Go to step 9
9. Check for continuity between climate control unit connector C (20P) terminals No 1 and No 16 Is there continuity? YES -Repair short in the wires between the climate control unit and the evaporator temperature sensor NO -Go to step 9
10. Remove the evaporator temperature sensor (see «EVAPORATOR TEMPERATURE SENSOR TEST»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__evaporator-temperature-sensor-test) ), and test it (see «EVAPORATOR TEMPERATURE SENSOR TEST»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__evaporator-temperature-sensor-test) )

Is the evaporator temperature sensor OK?

YES -Substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit (see Climate Control Unit Removal/Installation )

NO -Replace the evaporator temperature sensor (see Evaporator Temperature Sensor Replacement )

Scheme 49

Scheme 50

1. Clear the DTC with the HDS
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode
3. Do the self-diagnostic function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )
4. Check for DTCs Is DTC B1233 or J and AUTO indicated? YES -Go to step 5 NO -Intermittent failure Check for loose wires or poor connections on the driver's air mix control motor circuit
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
6. Test the driver's air mix control motor (see «DRIVER'S AIR MIX CONTROL MOTOR TEST»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__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/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
7. Disconnect the driver's air mix control motor 7P connector
8. Disconnect climate control unit connector A (32P) and C (20P)
9. Check for continuity between the following terminals of climate control unit connectors A (32P), C (20P), and the driver's air mix control motor 7P connector 32P 7P No 25 No 3 20P 7P No 1 No 5 No 2 No 7 Is there continuity between any of the terminals? YES -Check for loose wires or poor connections at climate control unit connectors A (32P), C (20P), and at the driver's air mix control motor 7P connector If the connections are good, substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit NO -Repair open in the wire(s) between the climate control unit and the driver's air mix control motor

Scheme 51

Scheme 52

Scheme 53

Scheme 54

Scheme 55

Scheme 56

1. Clear the DTC with the HDS
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode
3. Do the self-diagnostic function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )
4. Check for DTCs Is DTC B1234 or K and AUTO indicated? YES -Go to step 5 NO -Intermittent failure Check for loose or poor connection on the driver's air mix control motor circuit
5. Check for DTCs Are these DTCs also present, B1237 or N and AUTO, and/or B2968 or B and WINDSHIELD DEFROST, and/or B2980 or F and WINDSHIELD DEFROST? YES -Go to step 13 NO -Go to step 6
6. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
7. Test the driver's air mix control motor (see «DRIVER'S AIR MIX CONTROL MOTOR TEST»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__drivers-air-mix-control-motor-test) ) Is the driver's air mix control motor OK? YES -Go to step 8 NO -Replace the driver's air mix control motor (see «DRIVER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
8. Disconnect the driver's air mix control motor 7P connector
9. Disconnect climate control unit connectors A (32P) and C (20P)
10. Check for continuity between body ground and climate control unit connector A (32P) terminal No 25 Is there continuity? YES -Repair short to body ground in the wire between the climate control unit and the driver's air mix control motor NO -Go to step 11
11. Check for continuity between climate control unit connector A (32P) terminal No 25 and climate control unit connector C (20P) terminal No 2 Is there continuity? YES -Repair short in the wires NO -Go to step 12
12. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between climate control unit connector A (32P) terminal No 25 and body ground Is there any voltage? YES -Repair short to power in the wire between the climate control unit and the driver's air mix control motor This short may also damage the climate control unit Repair short to power before replacing the climate control unit NO -Substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit (see «Climate Control Unit Removal/Installation»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
13. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode, and disconnect the climate control unit connector C (20P)
14. Disconnect these items Driver's air mix control motor Passenger's air mix control motor Humidity/in-car temperature sensor A/C pressure sensor
15. Check for continuity between climate control unit connector C (20P) terminal No 2 and body ground Is there continuity? YES -Repair short to body ground in the wire NO -Go to step 16
16. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between the same terminal and body ground Is there any voltage? YES -Repair short to power in the wire This short may have also damaged the climate control unit Repair short to power before replacing the climate control unit NO -Go to step 17
17. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
18. Reconnect climate control unit connector C (20P)
19. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between climate control unit connector C (20P) terminal No 2 and body ground Is there about 5 V? YES -Go to step 20 NO -Check for a loose wire or poor connection at climate control unit connector C (20P) If the connection is good, substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit (see «Climate Control Unit Removal/Installation»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
20. While measuring the voltage as described in step 19, reconnect these items individually and note the voltage reading each time

1. Driver's air mix control motor
2. Passenger's air mix control motor
3. Humidity/in-car temperature sensor
4. A/C pressure sensor

Scheme 57

Does the voltage remain at about 5 V?

YES -Substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit (see Climate Control Unit Removal/Installation )

NO -Replace the component that caused the voltage drop

Scheme 58

Scheme 59

1. Clear the DTC with the HDS
2. Turn the ignition switch to LOCK (0), and then to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode
3. Do the self-diagnostic function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )
4. Check for DTCs Is DTC B1235 or L and AUTO indicated? YES -Go to step 5 NO -Intermittent failure Check for loose wires or poor connections on the driver's air mix control motor circuit
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
6. Test the driver's air mix control motor (see «DRIVER'S AIR MIX CONTROL MOTOR TEST»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__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/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ), or repair the driver's air mix control linkage or door
7. Disconnect the driver's air mix control motor 7P connector
8. Disconnect climate control unit connector A (32P)
9. Check for continuity between the following terminals of climate control unit connector A (32P) and the driver's air mix control motor 7P connector 32P 7P No 11 No 1 No 12 No 2 Is there continuity? YES -Go to step 10 NO -Repair open in the wire(s) between the climate control unit and the driver's air mix control motor
10. Check for continuity between body ground and climate control unit connector A (32P) terminals No 11 and No 12 individually Is there continuity? YES -Repair 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/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )

Scheme 60

Scheme 61

1. Clear the DTC with the HDS
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode
3. Do the self-diagnostic function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )
4. Check for DTCs Is DTC B1236 or M and AUTO indicated? YES -Go to step 5 NO -Intermittent failure Check for loose wires or poor connections on the passenger's air mix control motor circuit
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
6. Test the passenger's air mix control motor (see «Driver's Air Mix Control Motor Test»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__drivers-air-mix-control-motor-test) ) Is the passenger's air mix control motor OK? YES -Go to step 7 NO -Replace the passenger's air mix control motor (see «PASSENGER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
7. Disconnect the passenger's air mix control motor 7P connector
8. Disconnect climate control unit connectors A (32P) and C (20P)
9. Check for continuity between the following terminals of climate control unit connectors A (32P), C (20P), and the passenger's air mix control motor 7P connector 32P 7P No 26 No 3 20P 7P No 1 No 5 No 2 No 7 Is there continuity? YES -Check for loose wires or poor connections at climate control unit connectors A (32P), C (20P), and at the passenger's air mix control motor 7P connector If the connections are good, substitute a known-good climate control unit and recheck If the symptom/indication goes away, replace the original climate control unit NO -Repair open in the wire(s) between the climate control unit and the passenger's air mix control motor

Scheme 62

Scheme 63

Scheme 64

Scheme 65

Scheme 66

Scheme 67

Scheme 68

1. Clear the DTC with the HDS
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode
3. Do the self-diagnostic function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )
4. Check for DTCs Is DTC B1237 or N and AUTO indicated? YES -Go to step 5 NO -Intermittent failure Check for loose or poor connection on the passenger's air mix control motor circuit
5. Check for DTCs Are these DTCs also present, B1234 or K and AUTO, and/or B2968 or B and WINDSHIELD DEFROST, and/or B2980 or F and WINDSHIELD DEFROST? YES -Go to step 13 NO -Go to step 6
6. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
7. Test the passenger's air mix control motor (see «Passenger's Air Mix Control Motor Test»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__passengers-air-mix-control-motor-test) ) Is the passenger's air mix control motor OK? YES -Go to step 8 NO -Replace the passenger's air mix control motor (see «PASSENGER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
8. Disconnect the passenger's air mix control motor 7P connector
9. Disconnect climate control unit connectors A (32P) and C (20P)
10. Check for continuity between body ground and climate control unit connector A (32P) terminal No. 26 Is there continuity? YES -Repair short to body ground in the wire between the climate control unit and the passenger's air mix control motor NO -Go to step 11
11. Check for continuity between climate control unit connector A (32P) terminal No 26 and climate control unit connector C (20P) No 2 terminal Is there continuity? YES -Repair short in the wire NO -Go to step 12
12. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between climate control unit connector A (32P) terminal No 26 and body ground Is there any voltage? YES -Repair short to power in the wire(s) between the climate control unit and the passenger's air mix control motor This short may also damage the climate control unit Repair short to power before replacing the climate control unit NO -Substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit (see «Climate Control Unit Removal/Installation»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
13. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode, and disconnect the climate control unit connector C (20P)
14. Disconnect these items Driver's air mix control motor Passenger's air mix control motor Humidity/in-car temperature sensor A/C pressure sensor
15. Check for continuity between climate control unit connector C (20P) terminal No 2 and body ground Is there continuity? YES -Repair short to body ground in the wire NO -Go to step 16
16. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between the same terminal and body ground Is there any voltage? YES -Repair short to power in the wire This short may have also damaged the climate control unit Repair short to power before replacing the climate control unit NO -Go to step 17
17. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
18. Reconnect climate control unit connector C (20P)
19. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between climate control unit connector C (20P) terminal No 2 and body ground Is there about 5 V? YES -Go to step 20 NO -Check for a loose wire or poor connection at climate control unit connector C (20P) If the connection is good, substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit (see «Climate Control Unit Removal/Installation»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
20. While measuring the voltage as described in step 19, reconnect these items individually and note the voltage reading each time Driver's air mix control motor Passenger's air mix control motor Humidity/m-car temperature sensor A/C pressure sensor Does the voltage remain at about 5 V? YES -Substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit (see «Climate Control Unit Removal/Installation»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) NO -Replace the component that caused the voltage drop

Scheme 69

Scheme 70

1. Clear the DTC with the HDS
2. Turn the ignition switch to LOCK (0), and then back to ON (II) or press the engine start/stop button to select the OFF mode, and then the ON mode
3. Do the self-diagnostic function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )
4. Check for DTCs Is DTC B1238 or P and AUTO indicated? YES -Go to step 5 NO -Intermittent failure Check for loose wires or poor connections on the passenger's air mix control motor circuit
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
6. Test the passenger's air mix control motor (see «Passenger's Air Mix Control Motor Test»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__passengers-air-mix-control-motor-test) ) Is the passenger's air mix control motor OK? YES -Go to step 7 NO -Replace the passenger's air mix control motor (see «PASSENGER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ), or repair the passenger's air mix control linkage or door
7. Disconnect the passenger's air mix control motor 7P connector
8. Disconnect climate control unit connector A (32P)
9. Check for continuity between the following terminals of climate control unit connector A (32P) and the passenger's air mix control motor 7P connector 32P 7P No 9 No 1 No 10 No 2 Is there continuity? YES -Go to step 10 NO -Repair open in the wire(s) between the climate control unit and the passenger's air mix control motor
10. Check for continuity between body ground and climate control unit connector A (32P) terminals No 9 and No 10 individually Is there continuity? YES -Repair 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/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )

Scheme 71

Scheme 72

Scheme 73

Scheme 74

Scheme 75

1. Clear the DTC with the HDS
2. Turn the ignition switch to LOCK (0), and then back to ON (II) or press the engine start/stop button to select the OFF mode, and then the ON mode
3. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )
4. Check for DTCs Is DTC B1239 or A and MODE indicated? YES -Go to step 5 NO -Intermittent failure Check for loose wires or poor connections on the driver's mode control motor circuit
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
6. Test the driver's mode control motor (see «DRIVER'S MODE CONTROL MOTOR TEST»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__drivers-mode-control-motor-test) ) Is the driver's mode control motor OK? YES -Go to step 7 NO -Replace the driver's mode control motor (see «DRIVER'S MODE CONTROL MOTOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
7. Disconnect the driver's mode control motor 7P connector
8. Disconnect climate control unit connectors A (32P) and C (20P)
9. Check for continuity between the following terminals of climate control unit connector A (32P), C (20P) and the driver's mode control motor 7P connector 32P 7P No 21 No 6 No 22 No 5 No 23 No 4 No 24 No 3 20P 7P No 1 No 7 Is there continuity? YES -Go to step 10 NO -Repair open in the wire(s) between the climate control unit and the driver's mode control motor
10. Check for continuity between body ground and climate control unit connector A (32P) terminals No 21,22, 23, and 24 individually Is there continuity? YES -Repair short to body ground in the wire(s) between the climate control unit and the driver's mode control motor NO -Go to step 11
11. Check for continuity between climate control unit connector A (32P) terminals as follows TERMINALS CONTINUITY REFERENCE CHART From terminal To terminals 21 22,23,24 22 23,24 23 24 Is there continuity between any of the terminals? YES -Repair the short in the wires NO -Go to step 12
12. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between the same terminal and body ground Is there any voltage? YES -Repair short to power in the wire(s) between the climate control unit and the driver's mode control motor This short may also damage the climate control unit Repair the short to power before replacing the climate control unit NO -Check for loose wires or poor connections at climate control unit connector A (32P) and at the driver's mode control motor 7P connector If the connections are good, substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit (see «Climate Control Unit Removal/Installation»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )

Scheme 76

1. Clear the DTC with the HDS
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode
3. Do the self-diagnostic function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )
4. Check for DTCs Is DTC B1240 or B and MODE indicated? YES -Go to step 5 NO -Intermittent failure Check for loose wires or poor connections on the driver's mode control motor circuit
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
6. Test the driver's mode control motor (see «DRIVER'S MODE CONTROL MOTOR TEST»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__drivers-mode-control-motor-test) ) Is the driver's mode control motor OK? YES -Go to step 7 NO -Replace the driver's mode control motor (see «DRIVER'S MODE CONTROL MOTOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ), or repair the driver's mode control linkage or doors
7. Disconnect the driver's mode control motor 7P connector
8. Disconnect climate control unit connector A (32P)
9. Check for continuity between the following terminals of climate control unit connector A (32P) and the driver's mode control motor 7P connector 32P 7P No 7 No 2 No 8 No 1 Is there continuity? YES -Go to step 10 NO -Repair open in the wire(s) between the climate control unit and the driver's mode control motor
10. Check for continuity between body ground and climate control unit connector A (32P) terminals No 7 and No 8 individually

Scheme 77

Is there continuity?

YES -Repair short to body ground in the wire(s) between the climate control unit and the driver's mode control motor

NO -Substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit (see Climate Control Unit Removal/Installation )

Scheme 78

Scheme 79

Scheme 80

Scheme 81

Scheme 82

Scheme 83

Scheme 84

Scheme 85

Scheme 86

Scheme 87

1. Clear the DTC with the HDS
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode
3. Do the self-diagnostic function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )
4. Check for DTCs Is DTC B1241 or C and MODE indicated? YES -Go to step 5 NO -Intermittent failure Check for loose wires or poor connections on the blower motor circuit
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
6. Check the No 8 (40 A) fuse in the under-hood fuse/relay box, and the No 16 (7 5 A) fuse in the driver's under-dash fuse/relay box Are the fuses OK? YES -Go to step 7 NO -Replace the fuse(s), and recheck If the fuse(s) blow again, check for a short in the No 8 (40 A) fuse and the No 16 (7 5 A) fuse circuits
7. Connect the blower motor 2P connector terminal No 2 to body ground with a jumper wire
8. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode Does the blower motor run? YES -Go to step 9 NO -Go to step 25
9. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
10. Disconnect the jumper wire
11. Disconnect the power transistor 5P connector
12. Check for continuity between the power transistor 5P connector terminal No 5 and body ground Is there continuity? YES -Go to step 13 NO -Check for an open in the wire between the power transistor and body ground If the wire is OK, check for poor ground at G302 (see «LEFT ENGINE COMPARTMENT WIRE HARNESS (ENGINE COMPARTMENT BRANCH)»(/acura/tl/iv-2008-2011/remont/body-electrical/#connectors-and-harnesses__left-engine-compartment-wire-harness-engine) ).
13. Connect power transistor 5P connector terminals No 4 and No 5 with a jumper wire
14. Turn the ignition switch to ON (II), or press the engine start/stop button to select the OFF mode Does the blower motor run at high speed? YES -Go to step 15 NO -Repair open in the GRN wire between the power transistor and the blower motor
15. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF
16. Disconnect the jumper wire
17. Disconnect climate control unit connector A (32P)
18. Check for continuity between body ground and climate control unit connector A (32P) terminals No 27 and No 28 individually Is there continuity? YES -Repair short to body ground in the wire(s) between the climate control unit and the power transistor NO -Go to step 19
19. Check for continuity between the following terminals of the climate control unit connector A (32P) and the power transistor 5P connector 32P 5P No 27 No 1 No 28 No 3 Is there continuity? YES -Go to step 20 NO -Repair open in the wire(s) between the climate control unit and the power transistor
20. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode
21. Measure the voltage between body ground and climate control unit connector A (32P) terminals No 27 and No 28 individually Is there voltage? YES -Repair short to power in the wire(s) NO -Go to step 22
22. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
23. Reconnect climate control unit connector A (32P)
24. Test the power transistor (see «POWER TRANSISTOR TEST»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) Is the power transistor OK? YES -Check for loose wires or poor connections at the climate control unit connector A (32P) and at the power transistor 5P connector If the connections are good, substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit (see «Climate Control Unit Removal/Installation»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) NO -Replace the power transistor
25. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
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 Removal/Installation»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) NO -Go to step 29
29. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
30. Remove the blower motor relay from the under-hood fuse/relay box, and test it (see «POWER RELAY TEST»(/acura/tl/iv-2008-2011/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 open in the wire between the blower motor relay and blower motor
32. Measure the voltage between blower motor relay 4P socket terminal No 1 and body ground Is there battery voltage? YES -Go to step 33 NO -Replace the under-hood fuse/relay box (see «REMOVAL AND INSTALLATION»(/acura/tl/iv-2008-2011/remont/body-electrical/#under-hood-fuserelay-box__removal-and-installation) )
33. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode
34. Measure the voltage between blower motor relay 4P socket terminal No 3 and body ground Is there battery voltage? YES -Check for an open in the wire between blower motor relay 4P socket terminal No 3 and body ground If the wire is OK, check for poor body ground at G302 (see «LEFT ENGINE COMPARTMENT WIRE HARNESS (ENGINE COMPARTMENT BRANCH)»(/acura/tl/iv-2008-2011/remont/body-electrical/#connectors-and-harnesses__left-engine-compartment-wire-harness-engine) ) NO -Repair open in the wire between the No 16 (7 5 A) fuse in the driver's under-dash fuse/relay box and the blower motor relay 4P socket

Scheme 88

Scheme 89

Scheme 90

Scheme 91

Scheme 92

1. Clear the DTC with the HDS
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode
3. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )
4. Check for DTCs Is DTC B1242 or E and MODE indicated? YES -Go to step 5 NO -Intermittent failure Check for loose wires or poor connections on the passenger's mode control motor circuit
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
6. Test the passenger's mode control motor (see «Passenger's Mode Control Motor Test»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__passengers-mode-control-motor-test) ) Is the passenger's mode control motor OK? YES -Go to step 7 NO -Replace the passenger's mode control motor (see «PASSENGER'S MODE CONTROL MOTOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
7. Disconnect the passenger's mode control motor 7P connector
8. Disconnect climate control unit connectors A (32P) and C (20P)
9. Check for continuity between the following terminals of climate control unit connector A (32P), C (20P) and the passenger's mode control motor 7P connector 32P 7P No 17 No 6 No 18 No 5 No 19 No 4 No 20 No 3 20P 7P No 1 No 7 Is there continuity? YES -Go to step 10 NO -Repair open in the wire(s) between the climate control unit and the passenger's mode control motor
10. Check for continuity between body ground and climate control unit connector A (32P) terminals No 17,18,19, and 20 individually Is there continuity? YES -Repair short to body ground in the wire(s) between the climate control unit and the passenger's mode control motor NO -Go to step 11
11. Check for continuity between climate control unit connector A (32P) terminals as follows TERMINALS CONTINUITY REFERENCE CHART From terminal To terminals 17 18,19,20 18 19,20 19 20 Is there continuity between any of the terminals? YES -Repair the short in the wires NO -Go to step 12
12. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between the same terminals and body ground Is there any voltage? YES -Repair short to power in the wire(s) between the climate control unit and the passenger's mode control motor This short may also damage the climate control unit Repair the short to power before replacing the climate control unit NO -Check for loose wires or poor connections at climate control unit connector A (32P) and at the passenger's mode control motor 7P connector If the connections are good, substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit (see «Climate Control Unit Removal/Installation»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )

Scheme 93

Scheme 94

1. Clear the DTC with the HDS
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode and then the ON mode
3. Do the self-diagnostic function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )
4. Check for DTCs Is DTC B1243 or F and MODE indicated? YES -Go to step 5 NO -Intermittent failure Check for loose wires or poor connections on the passenger's mode control motor circuit
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
6. Test the passenger's mode control motor (see «Passenger's Mode Control Motor Test»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__passengers-mode-control-motor-test) ) Is the passenger's mode control motor OK? YES -Go to step 7 NO -Replace the passenger's mode control motor (see «PASSENGER'S MODE CONTROL MOTOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ), or repair the Passenger's mode control linkage or doors
7. Disconnect the passenger's mode control motor 7P connector
8. Disconnect climate control unit connector A (32P)
9. Check for continuity between the following terminals of climate control unit connector A (32P) and the passenger's mode control motor 7P connector 32P 7P No 5 No 2 No 6 No 1 Is there continuity? YES -Go to step 10 NO -Repair open in the wire(s) between the climate control unit and the passenger's mode control motor
10. Check for continuity between body ground and climate control unit connector A (32P) terminals No 5 and No 6 individually Is there continuity? YES -Repair short to body ground in the wire(s) between the climate control unit and the passenger's mode control motor NO -Substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit (see «Climate Control Unit Removal/Installation»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )

Scheme 95

1. Clear the DTC with the HDS
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode and then the ON mode
3. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )
4. Check for DTCs Is DTC B2967 or A and WINDSHIELD DEFROST indicated? YES -Go to step 5 NO -Intermittent failure, check for loose wires or poor connections on the humidity sensor circuit
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
6. Remove the humidity/in-car temperature sensor (see «HUMIDITY/IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ), and test it (see «HUMIDITY/IN-CAR TEMPERATURE SENSOR TEST»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) Is the humidity sensor OK? YES -Go to step 7 NO -Replace the humidity/in-car temperature sensor
7. Disconnect the humidity/in-car temperature sensor 4P connector
8. Disconnect climate control unit connector C (20P)
9. Check for continuity between the following terminals of climate control unit connector C (20P) and the humidity/in-car temperature sensor 4P connector 20P 4P No 1 No 3 No 2 No 1 No 12 No 2 Is there continuity? YES -Check for loose wires or poor connections at climate control unit connector C (20P) and at the humidity/in-car temperature sensor 4P connector If the connections are good, substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit (see «Climate Control Unit Removal/Installation»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) NO -Repair open in the wire(s) between the climate control unit and the humidity sensor

Scheme 96

Scheme 97

Scheme 98

Scheme 99

Scheme 100

Scheme 101

Scheme 102

1. Clear the DTC with the HDS
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode and then the ON mode
3. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )
4. Check for DTCs Is DTC B2968 or B and WINDSHIELD DEFROST indicated? YES -Go to step 5 NO -Intermittent failure Check for loose wires or poor connections on the humidity sensor circuit
5. Check for DTCs Are these DTCs also present, B1234 or K and AUTO, and/or B1237 or N and AUTO, and/or B2980 or F and WINDSHIELD DEFROST? YES -Go to step 13 NO -Go to step 6
6. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
7. Remove the humidity/in-car temperature sensor (see «HUMIDITY/IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ), and test it (see «HUMIDITY/IN-CAR TEMPERATURE SENSOR TEST»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) Is the humidity sensor OK? YES -Go to step 8 NO -Replace the humidity/in-car temperature sensor
8. Disconnect the humidity/in-car temperature sensor 4P connector
9. Disconnect climate control unit connector C (20P)
10. Check for continuity between body ground and climate control unit connector C (20P) terminal No 12 Is there continuity? YES -Repair short to body ground in the wire between the climate control unit and the humidity sensor NO -Go to step 11
11. Check for continuity between climate control unit connector C (20P) terminals No 2 and No 12 Is there continuity? YES -Repair short in the wires NO -Go to step 12
12. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between climate control unit connector C (20P) terminal No 12 and body ground Is there any voltage? YES -Repair short to power in the wire between the climate control unit and the humidity sensor This short may also damage the climate control unit Repair the short to power before replacing the climate control unit NO -Substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit (see «Climate Control Unit Removal/Installation»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
13. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode, and disconnect climate control unit connector C (20P)
14. Disconnect these items Driver's air mix control motor Passenger's air mix control motor Humidity/in-car temperature sensor A/C pressure sensor
15. Check for continuity between climate control unit connector C (20P) terminal No 2 and body ground Is there continuity? YES -Repair short to body ground in the wire NO -Go to step 16
16. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between the same terminal and body ground Is there any voltage? YES -Repair short to power in the wire This short may have also damaged the climate control unit Repair the short to power before replacing the climate control unit NO -Go to step 17
17. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
18. Reconnect the climate control unit connector C (20P)
19. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode and measure the voltage between climate control unit connector C (20P) terminal No 2 and body ground Is there about 5V? YES -Go to step 20 NO -Check for a loose wire or poor connection at climate control unit connector C (20P) If the connection is good, substitute a known-good climate control unit and recheck If the symptom/indication goes away, replace the original climate control unit (see «Climate Control Unit Removal/Installation»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
20. While measuring the voltage as described in step 19, reconnect these items individually and note the voltage reading each time Driver's air mix control motor Passenger's air mix control motor Humidity/in-car temperature sensor A/C pressure sensor Does the voltage remain at about 5 V? YES -Substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit (see «Climate Control Unit Removal/Installation»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) NO -Replace the component that caused the voltage drop

DTC B2969: Climate Control Unit Lost Communication with Driver's MICU (WIPSW message)

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

1. Clear the DTC with the HDS
2. Turn the ignition switch to LOCK (0), and then back to ON (II), or press the engine start/stop button to select the OFF mode and then the ON mode
3. Wait for at least 6 seconds
4. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )
5. Check the DTCs Is DTC B2969 indicated? YES -Go to step 6 NO -Intermittent failure Check for loose wires or poor connections on the climate control unit connector C (20P)
6. Check for DTCs with the HDS (Do all system scan) Are any of the following DTCs indicated, B1958, B1063, or B1156 indicated? YES -Do the driver's MICU input test (see «MICU INPUT TEST»(/acura/tl/iv-2008-2011/remont/communication-devices/#multiplex-integrated-control-system__micu-input-test) ) NO -Do the climate control unit power and ground troubleshooting (see «CLIMATE CONTROL POWER AND GROUND CIRCUIT TROUBLESHOOTING»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )

Scheme 103

Scheme 104

1. Clear the DTC with the HDS
2. Turn the ignition switch to LOCK (0) and then back to ON (II), or press the engine start/stop button to select the OFF mode and then the ON mode
3. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )
4. Check for DTCs Is DTC B2979 or E and WINDSHIELD DEFROST indicated? YES -Go to step 5 NO -Intermittent failure Check for loose wires or poor connections on the A/C pressure sensor circuit
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
6. Disconnect the A/C pressure sensor 3P connector
7. Disconnect climate control unit connector C (20P)
8. Check for continuity between the following terminals of climate control unit connector C (20P) and the A/C pressure sensor 3P connector 20P 3P No 1 No 3 No 2 No 1 No 11 No 2 Is there continuity? YES -Go to step 9 NO -Repair open in the wire(s) between the climate control unit and the A/C pressure sensor
9. Reconnect climate control unit connector C (20P)
10. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode
11. Measure the voltage between climate control unit connector C (20P) terminals No 1 and No 2, and between climate control unit connector C (20P) terminals No 1 and No 11 Is there about 5 V? YES -Replace the A/C pressure sensor NO -Check for loose wires or poor connections at climate control unit connector C (20P) and at the A/C pressure sensor 3P connector If the connections are good, substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit (see «Climate Control Unit Removal/Installation»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )

Scheme 105

Scheme 106

Scheme 107

Scheme 108

Scheme 109

Scheme 110

Scheme 111

Scheme 112

1. Clear the DTC with the HDS
2. Turn the ignition switch to LOCK (0) and then back to ON (II), or press the engine start/stop button to select the OFF mode and then the ON mode
3. Do the self-diagnostic with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )
4. Check for DTCs Is DTC B2980 or F and WINDSHIELD DEFROST indicated? YES -Go to step 5 NO -Intermittent failure Check for loose wires or poor connections on the A/C pressure sensor circuit
5. Check for DTCs Are these DTCs also present, B1234 or K and AUTO, and/or B1237 or N and AUTO, and/or B2968 or B and WINDSHIELD DEFROST? YES -Go to step 16 NO -Go to step 6
6. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
7. Disconnect the A/C pressure sensor 3P connector
8. Disconnect climate control unit connector C (20P)
9. Check for continuity between body ground and climate control unit connector C (20P) terminal No 11 Is there continuity? YES -Repair short to body ground in the wire between the climate control unit and the A/C pressure sensor NO -Go to step 10
10. Check for continuity between climate control unit connector C (20P) terminals No 2 and No 11 Is there continuity? YES -Repair short in the wires NO -Go to step 11
11. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between body ground and climate control unit connector C (20P) terminal No 11 Is there any voltage? YES -Repair short to power in the wire between the climate control unit and the A/C pressure sensor This short may also damage the climate control unit Repair the short to power before replacing the climate control unit NO -Go to step 12
12. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
13. Reconnect climate control unit connector C (20P)
14. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode
15. Measure the voltage between climate control unit connector C (20P) terminals No 1 and No 2, and between climate control unit connector C (20P) terminals No 1 and No 11 Is there about 5 V? YES -Replace the A/C pressure sensor NO -Check for loose wires or poor connections at climate control unit connector C (20P) and at the A/C pressure sensor 3P connector If the connections are good, substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit
16. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode, and disconnect climate control unit connector C (20P)
17. Disconnect these items Driver's air mix control motor Passenger's air mix control motor Humidity/in-car temperature sensor A/C pressure sensor
18. Check for continuity between climate control unit connector C (20P) terminal No 2 and body ground Is there continuity? YES -Repair short to body ground in the wire NO -Go to step 19
19. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between the same terminal and body ground Is there any voltage? YES -Repair short to power in the wire This short may have also damaged the climate control unit Repair the short to power before replacing the climate control unit NO -Go to step 20
20. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
21. Reconnect climate control unit connector C (20P)
22. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between climate control unit connector C (20P) terminal No 2 and body ground Is there about 5 V? YES -Go to step 23 NO -Check for a loose wire or poor connection at climate control unit connector C (20P) If the connection is good, substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit (see «Climate Control Unit Removal/Installation»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
23. While measuring the voltage as described in step 22, reconnect these items individually and note the voltage reading each time Driver's air mix control motor Passenger's air mix control motor Humidity/in-car temperature sensor A/C pressure sensor Does the voltage remain at about 5 V? YES -Substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit (see «Climate Control Unit Removal/Installation»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) NO -Replace the component that caused the voltage drop

Scheme 113

Scheme 114

1. Clear the DTC with the HDS
2. Turn the ignition switch to LOCK (0) and then back to ON (II), or press the engine start/stop button to select the OFF mode and then the ON mode
3. Do the self-diagnostic function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )
4. Check the DTCs Is DTC B2983 or K and MODE indicated? YES -Go to step 5 NO -Intermittent failure Check for loose wires or poor connections on the recirculation control motor circuit
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
6. Test the recirculation control motor (see «RECIRCULATION CONTROL MOTOR TEST»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__recirculation-control-motor-test) ) Is the recirculation control motor OK? YES -Go to step 7 NO -Replace the recirculation control motor (see «RECIRCULATION CONTROL MOTOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ), or repair the recirculation control linkage or door
7. Disconnect the recirculation control motor 7P connector
8. Disconnect climate control unit connector C (20P)
9. Check for continuity between the following terminals of climate control unit connector C (20P) and the recirculation control motor 7P connector 20P 7P No 9 No 2 No 10 No 1 Is there continuity? YES -Go to step 10 NO -Repair open in the wire(s) between the climate control unit and the recirculation control motor
10. Check for continuity between body ground and climate control unit connector C (20P) terminals No 9 and No 10 individually Is there continuity? YES -Repair short to body ground in the wire(s) between the climate control unit and the recirculation control motor NO -Substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit (see «Climate Control Unit Removal/Installation»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )

Scheme 115

Scheme 116

1. Check the No 16 (7 5 A) fuse in the driver's under-dash fuse/relay box Is the fuse OK? YES -Go to step 2 NO -Replace the fuse, and recheck If the fuse blows again, check for a short in the No 16(7.5 A) fuse circuit
2. Disconnect climate control unit connector A (32P)
3. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode
4. Measure the voltage between the climate control unit connector A (32P) terminal No 15 and body ground Is there battery voltage? YES -Go to step 5 NO -Repair open in the wire between the No 16 (7.5 A) fuse in the driver's under-dash fuse/relay box and the climate control unit
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
6. Check for continuity between the climate control unit connector A (32P) terminal No 1 and body ground Is there continuity? YES -Check for loose wires or poor connections at climate control unit connector A (32P) If the connections are good, substitute a known-good climate control unit, and recheck NO -Check for an open in the wire between the climate control unit and body ground If the wire is OK, check for poor body ground at G403 (see «DASHBOARD WIRE HARNESS (VIEW OF MIDDLE TO PASSENGER'S SIDE)»(/acura/tl/iv-2008-2011/remont/body-electrical/#connectors-and-harnesses__dashboard-wire-harness-view-of-middle) )

Scheme 117

Scheme 118

Scheme 119

Scheme 120

1. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode
2. Operate the climate control system in several modes Is the climate control system OK? YES -Go to step 3 NO -Do the self-diagnostic function with the HDS (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) ) or the climate control unit (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )
3. Go into the «SYSTEM DIAGNOSTIC MODE»(/acura/tl/iv-2008-2011/remont/navigation-system/#navigation-system) , and select the Self-Diagnosis Mode to check the System Link (see «SYSTEM LINKS»(/acura/tl/iv-2008-2011/remont/navigation-system/#navigation-system) ). Is the A/C or Mic icon red? YES - If A/C icon is red, go to step 4 If Mic icon is red, go to "voice control does not work/respond" in the navigation system symptom troubleshooting (see «VOICE CONTROL DOES NOT WORK/RESPOND»(/acura/tl/iv-2008-2011/remont/navigation-system/#navigation-system) ). NO -Go to step 10
4. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
5. Disconnect audio-navigation unit connector D (20P)
6. Disconnect climate control unit connector C (20P)
7. Check for continuity between the following terminals of climate control unit connector C (20P) and audio-navigation unit connector D (20P) 20P 20P No 4 No 4 No 5 No 5 No 6 No 14 Is there continuity? YES -Go to step 8 NO -Repair open in the wire(s) between the climate control unit and the audio-navigation unit
8. Check for continuity between body ground and climate control unit connector terminals No 4,5, and 6 individually Is there continuity? YES -Repair short to body ground in the wire(s) between the climate control unit and the audio-navigation unit NO -Go to step 9
9. Reconnect climate control unit connector C (20P)
10. Connect the audio-navigation unit connector D (20P) terminals No 4,5, and 14 with jumper wires
11. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode
12. Press and hold the AUTO button, then press and hold the 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/tl/iv-2008-2011/remont/navigation-system/#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/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )

Scheme 121

Scheme 122

Scheme 123

1. Disconnect climate control unit connector A (32P) and the audio-navigation switch panel 24P connector
2. Check for continuity between the following terminals of climate control unit connector A (32P) and the audio-navigation switch panel 24P connector 32P 24P No 3 No 7 No 4 No 19 Is there continuity? YES -Go to step 3 NO -Repair open in the wire between climate control unit connector A (32P) and the audio-navigation switch panel 24P connector
3. Check for continuity between body ground and climate control unit connector A (32P) terminals No 3 and No 4 individually Is there continuity? YES -Repair short to body ground in the wire between climate control unit connector A (32P) and the audio-navigation switch panel 24P connector NO -Go to step 4
4. Reconnect climate control unit connector A (32P)
5. Connect the audio-navigation switch panel 24P connector terminals No 7 and No 19 with a jumper wire
6. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode
7. Press and hold the front DEF button and OFF button

Is the front DEF button LED blinking?

YES -The audio-navigation switch panel is faulty, replace the audio-navigation switch panel (see AUDIO-NAVIGATION SWITCH PANEL REMOVAL/INSTALLATION )

NO -The climate control unit is faulty, replace the climate control unit (see CLIMATE CONTROL UNIT REMOVAL/INSTALLATION )

Scheme 124

Scheme 125

Scheme 126

1. Disconnect climate control unit connector A (32P) and the audio-HVAC display unit 12P connector
2. Check for continuity between the following terminals of climate control unit connector A (32P) and the audio-HVAC display unit 12P connector Without navigation 32P 12P No 3 No 7 No 4 No 8 Is there continuity? YES -Go to step 3 NO -Repair open in the wire between climate control unit connector A (32P) and the audio-HVAC display unit 12P connector
3. Check for continuity between body ground and climate control unit connector A (32P) terminals No 3 and No 4 individually Is there continuity? YES -Repair short to body ground in the wire between climate control unit connector A (32P) and the audio-HVAC display unit 12P connector NO -Go to step 4
4. Reconnect climate control unit connector A (32P)
5. Connect the audio-HVAC display unit 12P connector No 7 and No 8 terminals with a jumper wire
6. Turn the ignition switch to ON (II)
7. Press and hold the front DEF button and OFF button Is the front DEF button LED blinking? YES -The audio-HVAC display unit is faulty, replace the audio-HVAC display unit (see «AUDIO-HVAC DISPLAY UNIT REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/entertainment-systems/#audio-system) ) NO -The climate control unit is faulty, replace the climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )

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 performing symptom troubleshooting, check for powertrain DTCs (see GENERAL TROUBLESHOOTING INFORMATION )

Scheme 127

Scheme 128

Scheme 129

Scheme 130

Scheme 131

Scheme 132

1. Check the No 3-3 (SUB FAN MTR) (30 A without SH-AWD) or No 3-2 (SUB FAN MTR) (40 A with SH-AWD) fuse in the under-hood fuse/relay, and the No 16 (7 5 A) fuse in the driver's under-dash fuse/relay box Are your fuses OK? YES -Go to step 2 NO -Replace the fuse(s), and recheck If the fuse(s) blow again, check for a short in the No 3-3 (SUB FAN MTR) (30 A without SH-AWD) or No 3-2 (SUB FAN MTR) (40A with SH-AWD) fuse or the No 16 (7 5 A) fuse circuits
2. Remove the A/C condenser fan relay from the relay block, and test it (see «POWER RELAY TEST»(/acura/tl/iv-2008-2011/remont/body-electrical/#relays__power-relay-test) ) Is the relay OK? YES -Go to step 3 NO -Replace the A/C condenser fan relay
3. Reinstall the A/C condenser fan relay
4. Connect the HDS to the DLC
5. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode
6. Turn on the A/C
7. Check the FAN LOW CTRL in the PGM-FI Data List with the HDS Is the FAN LOW CTRL on? YES -Go to step 8 NO -Substitute a known-good PCM (see «SUBSTITUTING THE ECM/PCM»(/acura/tl/iv-2008-2011/remont/auxiliary-emission-control-systems/#fuel-and-emissions-systems__substituting-the-ecmpcm) ), and retest If the symptom/indication goes away with a known-good PCM, replace the original PCM (see «ECM/PCM REPLACEMENT»(/acura/tl/iv-2008-2011/remont/testing-diagnostics/#pgm-fi-system__ecmpcm-replacement) )
8. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
9. Jump the SCS line with the HDS NOTE: This step must be done to protect the engine control module/powertrain control module (ECM/PCM) from damage
10. Disconnect PCM connector A (49P)
11. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode
12. Measure the voltage between PCM connector A terminal No 4 and body ground Is there battery voltage? YES -Go to step 13 NO -Repair open in the wires between the under-hood fuse/relay box and the PCM, or between the No 16 (7 5 A) fuse in driver's under-dash fuse/relay box and the under-hood fuse/relay box If wires are OK, replace the under-hood fuse/relay box (see «REMOVAL AND INSTALLATION»(/acura/tl/iv-2008-2011/remont/body-electrical/#under-hood-fuserelay-box__removal-and-installation) )
13. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
14. Connect the PCM connector A (49P) terminal No 4 to body ground with a jumper wire
15. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode Do the A/C condenser and radiator fans run on low? YES -Check for loose wires or poor connections at PCM connector A (49P) 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 «ECM/PCM REPLACEMENT»(/acura/tl/iv-2008-2011/remont/testing-diagnostics/#pgm-fi-system__ecmpcm-replacement) ) NO -Go to step 16
16. Turn the ignition switch to LOCK(0), or press the engine start/stop button to select the OFF mode
17. Disconnect the jumper wire
18. Reconnect PCM connector A (49P)
19. Disconnect the A/C condenser fan 2P connector
20. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, then set the A/C button and fan control button ON
21. Measure the voltage between the A/C condenser fan 2P connector terminal No 2 and body ground Is there battery voltage? YES -Go to step 22 NO -Repair open in the wire between the under-hood fuse/relay box and the A/C condenser fan. If the wire is OK, replace the under-hood fuse/relay box (see «REMOVAL AND INSTALLATION»(/acura/tl/iv-2008-2011/remont/body-electrical/#under-hood-fuserelay-box__removal-and-installation) )
22. Set the A/C button and fan control button OFF, then turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
23. Test the A/C condenser fan motor. Is the A/C condenser fan motor OK? YES -Go to step 24 NO -Replace the A/C condenser fan motor (see «FAN, FAN MOTOR, AND SHROUD REMOVAL AND INSTALLATION»(/acura/tl/iv-2008-2011/remont/cooling-system-mechanical/#cooling-system) )
24. Remove the relay circuit board (see «REMOVAL AND INSTALLATION»(/acura/tl/iv-2008-2011/remont/body-electrical/#under-hood-fuserelay-box__removal-and-installation) under-hood fuse/relay box), and and test the fan control relay (see «POWER RELAY TEST»(/acura/tl/iv-2008-2011/remont/body-electrical/#relays__power-relay-test) ). Is the relay OK? YES -Go to step 25 NO -Replace the relay circuit board
25. Disconnect under-hood fuse/relay box connector C (5P).
26. Disconnect the A/C condenser fan motor 2P connector.
27. Check for continuity between under-hood fuse/relay box connector C (5P) terminal No. 5 and A/C condenser fan motor 2P connector terminal No. 1. Is there continuity? YES -Go to step 28 NO -Repair an open in the wire between the under-hood fuse/relay box and the A/C condenser fan motor
28. Disconnect the radiator fan motor 2P connector.
29. Check for continuity between under-hood fuse/relay box connector C (5P) terminal No. 1 and radiator fan motor 2P connector terminal No. 2. Is there continuity? YES -Go to step 30 NO -Repair an open in wire between the under-hood fuse/relay box and the radiator fan motor.
30. Check for continuity between radiator fan motor 2P connector terminal No. 1 and body ground. Is there continuity? YES -Replace the radiator fan motor (see «FAN, FAN MOTOR, AND SHROUD REMOVAL AND INSTALLATION»(/acura/tl/iv-2008-2011/remont/cooling-system-mechanical/#cooling-system) ). NO -Check for an open in the wire between the radiator fan motor and body ground. If the wire is OK, check for poor body ground at G302 (see «LEFT ENGINE COMPARTMENT WIRE HARNESS (ENGINE COMPARTMENT BRANCH)»(/acura/tl/iv-2008-2011/remont/body-electrical/#connectors-and-harnesses__left-engine-compartment-wire-harness-engine) ).

A/C Condenser Fan High Speed Circuit Troubleshooting

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

Scheme 133

Scheme 134

Scheme 135

1. Check the No 3-3 (SUB FAN MTR) (30 A without SH-AWD) or No 3-2 (SUB FAN MTR) (40 A with SH-AWD) fuse in the under-hood fuse/relay, and the No 16 (7 5 A) fuse in the driver's under-dash fuse/relay box Are the fuses OK? YES -Go to step 2 NO -Replace the fuse(s), and recheck If fuse(s) blow again, check for a short in the No 3-3 (SUB FAN MTR) (30 A without SH-AWD) or No 3-2 (SUB FAN MTR) (40 A with SH-AWD) fuse, or No 16 (7 5 A) fuse circuits.
2. Jump the SCS line with the HDS NOTE: This step must be done to protect the powertrain control module (PCM) from damage
3. Disconnect PCM connector A (49P)
4. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode
5. Measure the voltage between PCM connector A terminal No 5 and body ground Is there battery voltage? YES -Go to step 6 NO -Repair open in the wire between the under-hood fuse/relay box and the PCM If the wire is OK, replace the under-hood fuse/relay box (see «REMOVAL AND INSTALLATION»(/acura/tl/iv-2008-2011/remont/body-electrical/#under-hood-fuserelay-box__removal-and-installation) )
6. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
7. Connect the ECM/PCM connector A (49P) terminals No. 4, No. 5, and No. 40 to body ground with jumper wires.
8. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode Does the A/C condenser fan run on high? YES -Check for loose wires or poor connections at ECM/PCM connector A (49P) terminals No. 4, No. 5., and No. 40. If the connections are good, substitute a known-good PCM, and recheck If the symptom/indication goes away, replace the original PCM (see «ECM/PCM REPLACEMENT»(/acura/tl/iv-2008-2011/remont/testing-diagnostics/#pgm-fi-system__ecmpcm-replacement) ) NO -Go to step 9
9. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
10. Disconnect under-hood fuse/relay box connector C (5P)
11. Check for continuity between under-hood fuse/relay box connector C (5P) terminal No. 2 and body ground Is there continuity? YES -Replace the under-hood fuse/relay box (see «REMOVAL AND INSTALLATION»(/acura/tl/iv-2008-2011/remont/body-electrical/#under-hood-fuserelay-box__removal-and-installation) ) NO -Check for an open in the wire between the under-hood fuse/relay box and body ground. If the wire is OK, check for poor ground at G302 (see «LEFT ENGINE COMPARTMENT WIRE HARNESS (DASHBOARD BRANCH)»(/acura/tl/iv-2008-2011/remont/body-electrical/#connectors-and-harnesses__left-engine-compartment-wire-harness-dashboard) )

A/C Compressor Clutch Circuit Troubleshooting

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

Scheme 136

Scheme 137

Scheme 138

Scheme 139

1. Check the No 20 (7.5 A) fuse in the under-hood fuse/relay box, and the No 16 (7.5 A) fuse in the driver's under-dash fuse/relay box Are the fuses OK? YES -Go to step 2 NO -Replace the fuse(s) and recheck If the fuse(s) blow again, check for a short in the No 20 (7.5 A) fuse and the No 16 (7.5 A) fuse circuits
2. Connect the HDS to the DLC
3. Start the engine
4. Turn on the A/C
5. Check the A/C switch in the PGM-FI data list with the HDS Is the A/C switch ON? YES -Go to step 6 NO -go to A/C signal circuit troubleshooting (see «A/C SIGNAL CIRCUIT TROUBLESHOOTING»(/acura/tl/iv-2008-2011/remont/testing-diagnostics/#idle-control-system) )
6. Using the HDS, confirm the following values in the PGM-FI Data List at idle DATA LIST TP SENSOR About 0.5V RPM 700-800 ECT SENSOR 2 176-212 °F (80-100 °C) A/C SWITCH ON A/C CLUTCH ON Are all the values within specifications? YES -Go to step 7 NO -Troubleshoot the value that is not within the specifications
7. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
8. Remove the A/C compressor clutch relay from the under-hood fuse/relay box, and test it (see «POWER RELAY TEST»(/acura/tl/iv-2008-2011/remont/body-electrical/#relays__power-relay-test) ) Is the relay OK? YES -Go to step 9 NO -Replace the A/C compressor clutch relay
9. Measure the voltage between A/C compressor clutch relay 4P socket terminal No 1 and body ground Is there battery voltage? YES -Go to step 10 NO -Replace the under-hood fuse/relay box (see «REMOVAL AND INSTALLATION»(/acura/tl/iv-2008-2011/remont/body-electrical/#under-hood-fuserelay-box__removal-and-installation) )
10. Connect A/C compressor clutch relay 4P socket terminals No 1 and No 2 with a jumper wire Does the A/C compressor clutch click? YES -Go to step 11 NO -Go to step 20
11. Disconnect the jumper wire
12. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode
13. Measure the voltage between A/C compressor clutch relay 4P socket terminal No 3 and body ground Is there battery voltage? YES -Go to step 14 NO -Repair open in the wire between the No 16 (7 5 A) fuse in the driver's under-dash fuse/relay box and the A/C compressor clutch relay
14. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
15. Reinstall the A/C compressor clutch relay
16. Jump the SCS line with the HDS NOTE: This step must be done to protect the powertrain control module (PCM) from damage
17. Disconnect PCM connector A (49P)
18. Connect PCM connector A (49P) terminal No 13 to body ground with a jumper wire
19. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode Does the A/C compressor click? YES -Check for loose wires or poor connections at PCM connector A (49P) If the connections are good, check the PCM grounds If the grounds are good, substitute a known-good PCM, and recheck If the symptom/indication goes away, replace the original PCM (see «ECM/PCM REPLACEMENT»(/acura/tl/iv-2008-2011/remont/testing-diagnostics/#pgm-fi-system__ecmpcm-replacement) ) NO -Repair open in the wire between the A/C compressor clutch relay and the PCM
20. Disconnect the jumper wire
21. Disconnect the A/C compressor clutch 1P connector
22. Check for continuity between A/C compressor clutch relay 4P socket terminal No 2 and A/C compressor clutch 1P connector terminal No 1

Scheme 140

Is there continuity?

YES -Check the A/C compressor clutch clearance, and the compressor clutch field coil (see A/C COMPRESSOR CLUTCH CHECK ) Repair as needed

NO -Repair open in the wire between the A/C compressor clutch relay and the A/C compressor clutch

Humidity Sensor Test

Note. Before testing the sensor, check for HVAC DTCs (see GENERAL TROUBLESHOOTING INFORMATION )

Scheme 141

1. Remove the humidity/in-car temperature sensor (see «HUMIDITY/IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
2. Connect the humidity/in-car temperature sensor 4P connector
3. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode Measure the voltage between the terminals with the (+) probe on terminal No 2 and the (-) probe on the No 3 terminal with the connector connected
4. If the voltage is not as specified, replace the humidity/m-car temperature sensor (see «HUMIDITY/IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )

In-car Temperature Sensor Test

Note. Before testing the sensor, check for HVAC DTCs (see GENERAL TROUBLESHOOTING INFORMATION )

Scheme 142

1. Remove the humidity/in-car temperature sensor (see «HUMIDITY/IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
2. Test the humidity/in-car temperature sensor while holding it in front of the dashboard center vent Measure the resistance with the system set to Max Cool Measure the resistance with the system set to Max Hot
3. Compare the resistance reading between terminals No 4 and No 3 of the humidity/in-car temperature sensor with the specifications shown in the graph, the resistance should be within the specifications
4. If the resistance is not as specified, replace the humidity/in-car temperature sensor (see «HUMIDITY/IN-CAR TEMPERATURE SENSOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
5. Clear any DTCs set when you disconnected the humidity/in-car temperature sensor

Scheme 143

Scheme 144

Scheme 145

1. Remove these items Driver's dashboard undercover (see «DRIVER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/exteriorinterior-trim/#dashboard) ) Remote slot (with keyless access) (see «ENGINE START/STOP SWITCH TEST/REPLACEMENT»(/acura/tl/iv-2008-2011/remont/door-locks-anti-theft-systems/#keyless-access-system) )
2. Disconnect the air hose from the heater unit (see step 2 on «DRIVER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) Keep grip on air hose while doing following procedures to assist in removal of sensor
3. Disconnect the connector (A) from the Humidity/in-car temperature sensor (B) View from top
4. Unhook the left lock tab (A) of the humidity/in-car temperature sensor by pushing your thumb (B) between the sensor and tab(C)
5. Pull sensor toward steering column to unlock right lock tab Maintain the pressure with thumb to keep left tab unlocked while unhooking right lock tab then pull out the sensor
6. Install the sensor in the reverse order of removal

Outside Air Temperature Sensor Test

Note. before testing the sensor, check for HVAC DTCs (see GENERAL TROUBLESHOOTING INFORMATION )

Scheme 146

1. Remove the outside air temperature sensor (see «Outside Air Temperature Sensor Replacement»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
2. Dip the sensor in ice water, and measure the resistance Then pour warm water on the sensor, and check for a change in resistance
3. Compare the resistance reading between terminals No 1 and No 2 of the outside air temperature sensor with the specifications shown in the graph, the resistance should be within the specifications
4. If the resistance is not as specified, replace the outside air temperature sensor (see «Outside Air Temperature Sensor Replacement»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )

Scheme 147

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

Sunlight Sensor Test

Note. Before testing the sensor, check for HVAC DTCs (see GENERAL TROUBLESHOOTING INFORMATION )

Scheme 148

1. Remove the sunlight sensor (A) (see «Sunlight Sensor Replacement»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
2. Turn the ignition switch to ON (II) Measure the voltage between terminals with the (+) probe on terminal No 2 and the (-) probe on terminal No 1 with the connector connected NOTE: The voltage readings do not change under the light of a flashlight or a fluorescent lamp Voltage should be 3.6-3.7 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/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )

Scheme 149

1. Remove the center speaker lid (see «FRONT CENTER SPEAKER»(/acura/tl/iv-2008-2011/remont/entertainment-systems/#audio-system) )
2. Push out the sunlight sensor (A) from the speaker lid, then disconnect the connector (B) Be careful not to damage the sensor or the dashboard
3. Install the sensor in the reverse order of removal

Evaporator Temperature Sensor Test

Note. Before testing the sensor, check for HVAC DTCs (see GENERAL TROUBLESHOOTING INFORMATION )

Scheme 150

Scheme 151

1. Remove the evaporator temperature sensor (see «Evaporator Temperature Sensor Replacement»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
2. Dip the sensor in ice water, and measure the resistance between its terminals No. 1 and 2.
3. Pour warm water on the sensor, and measure the resistance
4. Compare the resistance readings with the specifications shown in the graph, the resistance should be within the specifications
5. If the resistance is not as specified, replace the evaporator temperature sensor (see «Evaporator Temperature Sensor Replacement»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )

Scheme 152

1. Remove the driver's dashboard undercover (see «DRIVER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/exteriorinterior-trim/#dashboard) )
2. Disconnect the 2P connector (A) from the evaporator temperature sensor (B) by pressing the lock tab toward the evaporator housing, then slide the male coupler down, and remove the connector clip (C) Remove the self-tapping screw and the evaporator temperature sensor
3. Install the sensor in the reverse order of removal

Scheme 153

Scheme 154

1. Remove the passenger's dashboard undercover (see «PASSENGER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/exteriorinterior-trim/#dashboard) )
2. Disconnect the 5P connector from the power transistor
3. Measure the resistance between terminals No 1 and No 4 of the power transistor It should be about 1.5 kohms If the resistance is within the specifications, go to step 4 If the resistance is not within the specifications, replace the power transistor NOTE: Also check the blower motor Power transistor failure can be caused by a defective blower motor
4. Reconnect the 5P connector to the power transistor
5. Disconnect climate control unit connector A (32P)
6. Connect climate control unit connector A (32P) terminals No 15 and No 28 with a jumper wire
7. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and check that the blower motor runs If the blower motor does not run, replace the power transistor NOTE: A faulty blower motor can cause the power transistor to fail If the power transistor is replaced, also check the blower motor for binding, and replace it if necessary If the blower motor runs, the power transistor is OK

Driver's Air Mix Control Motor Test

Special Tools Required

Backprobe Set 07SAZ-001000A (2)

Note. Before testing the motor, check for HVAC DTCs (see GENERAL TROUBLESHOOTING INFORMATION )

Scheme 155

1. Disconnect the 7P connector from the driver's air mix control motor NOTE: Incorrectly applying power and ground to the air mix control motor will damage it Follow the instructions carefully
2. Connect battery power to terminal No 1 of the driver's air mix control motor, and ground terminal No 2, the driver's air mix control motor should run, and stop at Max Cool If it doesn't, reverse the connections, the driver's air mix control motor should run, and stop at Max Hot When the driver's air mix control motor stops running, disconnect battery power immediately
3. If the driver's air mix control motor did not run in step 2, remove it, then check the driver's air mix control linkage and door for smooth movement If the linkage and door move smoothly, replace the driver's air mix control motor (see «DRIVER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) If the linkage or door sticks or binds, repair them as needed If the air mix control motor runs smoothly, go to step 4
4. Measure the resistance between terminals No 5 and No 7 of the driver's air mix control motor It should be between 4,2 and 7.8 kohms
5. Reconnect the air mix control motor 7P connector, then turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode
6. Using the backprobe set, measure the voltage between terminals No 3 and No 7 Max Cool About 1.0 V Max Hot About 4.0 V
7. If either the resistance or the voltage readings are not as specified, replace the driver's air mix control motor (see «DRIVER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )

Scheme 156

Scheme 157

1. Remove the driver's dashboard undercover (see «DRIVER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/exteriorinterior-trim/#dashboard) )
2. Remove the self-tapping screws, the air hose (A), and the driver's heater duct (B)
3. Disconnect the 7P connector (A) from the driver's air mix control motor (B) Remove the self-tapping screws and the driver's air mix control motor from the heater unit
4. 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

Passenger's Air Mix Control Motor Test

Special Tools Required

Backprobe Set 07SAZ-001000A (2)

Note. Before testing the motor, check for HVAC DTCs (see GENERAL TROUBLESHOOTING INFORMATION )

Scheme 158

1. Disconnect the 7P connector from the driver's air mix control motor NOTE: Incorrectly applying power and ground to the passenger's air mix control motor will damage it Follow the instructions carefully
2. Connect battery power to terminal No 1 of the passenger's air mix control motor, and ground terminal No 2, the passenger's air mix control motor should run, and stop at Max Cool If it doesn't, reverse the connections, the passenger's air mix control motor should run, and stop at Max Hot When the passenger's air mix control motor stops running, disconnect battery power immediately
3. If the passenger's air mix control motor did not run in step 2, remove it, then check the passenger's air mix control linkage and door for smooth movement If the linkage and door move smoothly, replace the passenger's air mix control motor (see «PASSENGER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) If the linkage or door sticks or binds, repair them as needed If the passenger's air mix control motor runs smoothly, go to step 4
4. Measure the resistance between terminals No 5 and No 7 of the passenger's air mix control motor It should be between 4.2 and 7.8 kohms
5. Reconnect the air mix control motor 7P connector, then turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode
6. Using the backprobe set, measure the voltage between terminals No 3 and No 5 Max Cool About 1.0 V Max Hot About 4.0 V
7. If either the resistance or the voltage readings are not as specified, replace the passenger's air mix control motor (see «PASSENGER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )

Scheme 159

Scheme 160

1. Remove the passenger's dashboard undercover (see «PASSENGER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/exteriorinterior-trim/#dashboard) )
2. Remove the glove box (see «GLOVE BOX REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/exteriorinterior-trim/#dashboard__glove-box-removalinstallation) )
3. Release the wire from its harness clip (A), then remove the self-tapping screws and the passenger's heater duct (B)
4. Disconnect the 5P connector (A) from the power transistor, and the 7P connector (B) from the passenger's air mix control motor (C) Remove the self-tapping screws and the passenger's air mix control motor from the heater unit
5. 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

Driver's Mode Control Motor Test

Note. Before testing the motor, check for HVAC DTCs (see GENERAL TROUBLESHOOTING INFORMATION )

Scheme 161

1. Disconnect the 7P connector from the driver's mode control motor NOTE: Incorrectly applying power and ground to the driver's mode control motor will damage it Follow the instructions carefully
2. Connect battery power to terminal No 1 of the driver's mode control motor, and ground terminal No 2, the driver's mode control motor should run, and stop at Vent If it doesn't, reverse the connections, the driver's mode control motor should run, and stop at Defrost When the driver's mode control motor stops running, disconnect battery power immediately
3. If the driver's mode control motor did not run in step 2, remove it, then check the mode control linkage and door for smooth movement If the linkage and door move smoothly, replace the driver's mode control motor (see «DRIVER'S MODE CONTROL MOTOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) If the linkage or door sticks or binds, repair them as needed If the driver's mode control motor runs smoothly, go to step 4
4. Use a digital multimeter with an output of 1 mA or less at the 20 kohms range Operate the driver's mode control motor as in step 2, and check for continuity between terminals No 3, 4, 5, and 6 and terminal No 7 individually There should be continuity for a moment at each terminal as the motor moves through its travel
5. If there is no continuity for a moment at each terminal, replace the driver's mode control motor (see «DRIVER'S MODE CONTROL MOTOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )

Scheme 162

1. Remove the driver's dashboard undercover (see «DRIVER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/exteriorinterior-trim/#dashboard) )
2. Disconnect the 7P connector (A) from the driver's mode control motor (B) Remove the self-tapping screws and the driver's mode control motor from the heater unit
3. Install the motor in the reverse order of removal Make sure the pin on the motor is properly engaged with the linkage After installation, make sure the motor runs smoothly

Passenger's Mode Control Motor Test

Note. Before testing the motor, check for HVAC DTCs (see GENERAL TROUBLESHOOTING INFORMATION )

Scheme 163

1. Disconnect the 7P connector from the passenger's mode control motor NOTE: Incorrectly applying power and ground to the mode control motor will damage it Follow the instructions carefully
2. Connect battery power to terminal No 1 of the passenger's mode control motor, and ground terminal No 2, the passenger's mode control motor should run, and stop at Vent If it doesn't, reverse the connections, the passenger's mode control motor should run, and stop at Defrost When the passenger's mode control motor stops running, disconnect battery power immediately
3. If the passenger's mode control motor did not run in step 2, remove it, then check the mode control linkage and door for smooth movement If the linkage and door move smoothly, replace the passenger's mode control motor (see «PASSENGER'S MODE CONTROL MOTOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) If the linkage or door sticks or binds, repair them as needed If the passenger's mode control motor runs smoothly, go to step 4
4. Use a digital multimeter with an output of 1 mA or less at the 20 kohms range Operate the passenger's mode control motor as in step 2, and check for continuity between terminals No 3, 4, 5, and 6 and terminal No 7 individually There should be continuity for a moment at each terminal as the motor moves through its travel
5. If there is no continuity for a moment at each terminal, replace the passenger's mode control motor (see «PASSENGER'S MODE CONTROL MOTOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )

Removal

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

Scheme 164

Scheme 165

1. Remove the passenger's dashboard undercover (see «PASSENGER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/exteriorinterior-trim/#dashboard) )
2. Remove the glove box (see «GLOVE BOX REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/exteriorinterior-trim/#dashboard__glove-box-removalinstallation) )
3. Remove the glove box frame (see step 4 on «BLOWER UNIT REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
4. Release the wire from its harness clip (A), then remove the self-tapping screws and the passenger's heater duct (B)
5. Disconnect the 7P connector (A) from the passenger's mode control motor (B) Release the wire from its harness clip (C), then remove the self-tapping screws and the passenger's mode control motor from the heater unit

Scheme 166

Scheme 167

Scheme 168

Scheme 169

Scheme 170

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

Recirculation Control Motor Test

Note. Before testing the motor, check for HVAC DTCs (see GENERAL TROUBLESHOOTING INFORMATION )

Scheme 171

1. Disconnect the 7P connector from the recirculation control motor NOTE: Incorrectly applying power and ground to the recirculation control motor will damage it Follow the instructions carefully
2. Connect battery power to terminal No 1 of the recirculation control motor, and ground terminal No 2, the recirculation control motor should run smoothly, and stop at Recirculate If it doesn't, reverse the connections, the recirculation control motor should run smoothly, and stop at Fresh When the recirculation control motor stops running, disconnect battery power immediately.
3. If the recirculation control motor did not run in step 2, remove it, then check the recirculation control linkage and door for smooth movement. If the linkage and door move smoothly, replace the recirculation control motor (see «RECIRCULATION CONTROL MOTOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ). If the linkage or door stick or bind, repair them as needed If the recirculation control motor runs smoothly, go to step 4
4. Use a digital multimeter with an output of 1 mA or less at the 20 kohms range Operate the recirculation control motor running as in step 2, and check for continuity between terminals No 3,4, and 5 and terminal No 7 individually There should be continuity for a moment at each terminal as the motor through its travel
5. If there is no continuity for a moment at each terminal, replace the recirculation control motor (see «RECIRCULATION CONTROL MOTOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )

1. Remove the passenger's dashboard undercover (see «PASSENGER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/exteriorinterior-trim/#dashboard) )
2. Remove the glove box (see «GLOVE BOX REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/exteriorinterior-trim/#dashboard__glove-box-removalinstallation) )
3. Remove the climate control unit (see «CLIMATE CONTROL UNIT REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
4. Disconnect the 7P connector (A) from the recirculation control motor (B) Remove the self-tapping screws and the recirculation control motor from the blower unit

Scheme 172

Scheme 173

Scheme 174

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

Scheme 175

1. Remove the passenger's dashboard undercover (see «PASSENGER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/exteriorinterior-trim/#dashboard) )
2. Disconnect the connectors (A) Remove the bolts (B) and the climate control unit (C)
3. Install the climate control unit in the reverse order of removal After installation, operate the various functions to make sure they work properly
4. Run the self-diagnostic function to confirm that there are no problems in the system (see «HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__how-to-use-the-self-diagnostic-function) )

Scheme 176

1. Remove the audio-navigation unit (with navigation) (see «AUDIO-NAVIGATION UNIT REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/navigation-system/#navigation-system__audio-navigation-unit-removalinstallation) ), or the audio unit (without navigation) (see «AUDIO UNIT REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/entertainment-systems/#audio-system) )
2. Remove the self-tapping screws and the climate control switches (A)
3. Install the control switches in the reverse order of removal After installation, operate the various functions to make sure they work properly

Scheme 177

Scheme 178

Scheme 179

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

Scheme 180

Scheme 181

Scheme 182

Scheme 183

Scheme 184

Scheme 185

1. Remove the passenger's dashboard undercover (see «PASSENGER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/exteriorinterior-trim/#dashboard) )
2. Remove the passenger's dashboard trim (see «PASSENGER'S DASHBOARD TRIM REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/exteriorinterior-trim/#dashboard) )
3. Remove the glove box (see «GLOVE BOX REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/exteriorinterior-trim/#dashboard__glove-box-removalinstallation) )
4. Remove the harness clips (A), the bolts, and the glove box frame (B)
5. Cut the plastic cross brace (A) in the glove box opening with diagonal cutters in the area shown, and discard it
6. Release the wire from its harness clip (A), then remove the self-tapping screws, and the passenger's heater duct (B)
7. Disconnect the connector (A) from the blower motor, and detach the wire harness clips (B)
8. Remove the self-tapping screws and disconnect the climate control unit connector (A), and recirculation control motor connector (B)
9. Disconnect the right engine compartment harness connector (C205) (A) and harness clips (B) Remove the mounting nuts, and the blower unit (C)
10. Install the unit in the reverse order of removal Make sure that there are no air leaks

Blower Unit Component Replacement

Note these items when overhauling the blower unit

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/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__recirculation-control-motor-test) )

Scheme 186

Scheme 187

Scheme 188

Scheme 189

Scheme 190

1. Recover the refrigerant with a recovery/recycling/charging station (see «RECEIVER/DRYER DESICCANT REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__receiverdryer-desiccant-replacement) )
2. Remove the bolt from the A/C line clamp (A)
3. Remove the bolt, then disconnect the A/C line (A) from the evaporator core Replace the O-rings (B)
4. Remove the blower unit (see «BLOWER UNIT REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
5. Disconnect the power transistor connector (A) Detach the harness clip (B) Remove the self-tapping screws, the joint duct (C), and the seal (D)
6. Carefully pull out the evaporator core (A) without bending the lines, then remove the plate (B) NOTE: Be careful not to damage the wire harness
7. Install the core in the reverse order of removal, and note these items If you're installing a new evaporator core, add refrigerant oil (DENSO ND-OIL 8) (see «A/C SERVICE TIPS AND PRECAUTIONS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__ac-service-tips-and-precautions) ) 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/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__system-charging) )

Scheme 191

1. Remove the evaporator core (see «EVAPORATOR CORE REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
2. Remove the insulator (A) and bolts, then remove the expansion valve (B) and O-rings (C)
3. Install the expansion valve in the reverse order of removal, and note these items

1. 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
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 the refrigerant oil contacts the paint, wash it off immediately
4. Make sure that there are no air leaks
5. Charge the system (see «SYSTEM CHARGING»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__system-charging) )

Heater Unit/Core Replacement

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

Scheme 192

Scheme 193

Scheme 194

Scheme 195

Scheme 196

Scheme 197

Scheme 198

Scheme 199

1. Do the battery terminal disconnection procedure (see «BATTERY TERMINAL DISCONNECTION AND RECONNECTION»(/acura/tl/iv-2008-2011/remont/body-electrical/#battery) )
2. Recover the refrigerant with a recovery/recycling/charging station (see «RECEIVER/DRYER DESICCANT REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__receiverdryer-desiccant-replacement) )
3. Disconnect the A/C line from the evaporator core (see «EVAPORATOR CORE REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
4. When the engine is cool, drain the engine coolant from the radiator (see «COOLANT REPLACEMENT»(/acura/tl/iv-2008-2011/remont/cooling-system-mechanical/#cooling-system) )
5. From under the hood, slide the hose clamps (A) back Disconnect the inlet heater hose (B) and the outlet heater hose (C) from the heater unit Note the orientation of the hoses Engine coolant will run out when the hoses are disconnected, dram it into a clean drip pan Be sure not to let coolant spill on the electrical parts or the painted surfaces If any coolant spills, rinse it off immediately
6. Remove the mounting nut from the heater unit Take care not to damage or bend the fuel lines or the brake lines
7. Remove the dashboard (see «DASHBOARD REPLACEMENT»(/acura/tl/iv-2008-2011/remont/exteriorinterior-trim/#dashboard) )
8. Disconnect the left engine compartment wire harness connectors (C301 and 302) (A) Remove the ducts (B), and the drain hose (C) Then remove the mounting nuts, and the blower-heater unit (D)
9. Disconnect the connector (A) from the blower motor Remove the wire harness clips (B)
10. Disconnect these connectors (A) The passenger's mode control motor, the power transistor, and the passenger's air mix control motor Detach the harness clips (B)
11. Disconnect these connectors (A) The recirculation control motor, and the climate control unit Detach the harness clip (B)
12. Disconnect these connectors (A) the driver's air mix control motor, the driver's mode control motor, and evaporator temperature sensor Detach the harness clips (B) and the wire harness (C)
13. Remove the self-tapping screws and the passenger's heater duct (A) Remove the self-tapping screws and the joint duct (B) Remove the self-tapping screw and the heater core cover (C) Remove the self-tapping screw, the heater pipe bracket (D), and the grommet (E), and carefully pull out the heater core (F)
14. Install the heater core in the reverse order of removal
15. 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 REPLACEMENT»(/acura/tl/iv-2008-2011/remont/cooling-system-mechanical/#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/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__system-charging) )
16. Do the battery terminal reconnection procedure (see «BATTERY TERMINAL DISCONNECTION AND RECONNECTION»(/acura/tl/iv-2008-2011/remont/body-electrical/#battery) )

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 200

Scheme 201

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 «RECEIVER/DRYER DESICCANT REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__receiverdryer-desiccant-replacement) )
3. Remove the drive belt (see «DRIVE BELT REPLACEMENT»(/acura/tl/iv-2008-2011/remont/charging-system/#charging-system__drive-belt-replacement) )
4. Remove the condenser fan shroud (see «FAN, FAN MOTOR, AND SHROUD REMOVAL AND INSTALLATION»(/acura/tl/iv-2008-2011/remont/cooling-system-mechanical/#cooling-system) )
5. Disconnect the A/C compressor clutch connector (A). Remove the bolts and the nut, then disconnect the suction hose (B) and the discharge hose (C) from the A/C compressor. Remove the O-rings (D) Plug or cap the lines immediately after disconnecting them to avoid moisture and dust contamination.
6. Raise the vehicle on a lift, then remove the front splash shield (see «FRONT SPLASH SHIELD REPLACEMENT»(/acura/tl/iv-2008-2011/remont/exterior-body-panels/#fenderwell__front-splash-shield-replacement) )
7. Remove the mounting bolts and the A/C compressor (A) Be careful not to damage the radiator fins when removing the compressor
8. Install the A/C compressor in the reverse order of removal, and note these items Inspect the A/C lines for any signs of contamination Replace the O-rings with new ones at each fitting, and apply a thin coat of refrigerant oil before installing them Be sure to use the correct O-rings for HFC-134a (R-134a) to avoid leakage Use only refrigerant oil (DENSO ND-OIL 8) for HFC-134a DENSO A/C compressors only To avoid contamination, do not return the oil to the container once dispensed, and never mix it with other refrigerant oils Immediately after using the oil, reinstall the cap on the container, and seal it to avoid moisture absorption Do not spill the refrigerant oil on the vehicle, it may damage the paint If the refrigerant oil contacts the paint, wash it off immediately Be careful not to damage the radiator fins when installing the compressor and the A/C condenser fan shroud Charge the system (see «SYSTEM CHARGING»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__system-charging) )

Scheme 202

Scheme 203

Scheme 204

1. Check the pressure plate for discoloration, peeling, or other damage If there is damage, replace the clutch set (see «A/C COMPRESSOR CLUTCH OVERHAUL»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__ac-compressor-clutch-overhaul) )
2. Check the pulley bearing play and drag by rotating the pulley by hand Also check for grease leakage from the bearing Replace the clutch set with a new one if it is noisy, has excessive play/drag, or has bearing grease contamination on the clutch faces (see «A/C COMPRESSOR CLUTCH OVERHAUL»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__ac-compressor-clutch-overhaul) ) NOTE: The pulley and the pressure plate were mated at the factory by a burnishing operation Always replace the pulley and the pressure plate as a set Replacing only one part of the clutch set will cause clutch slippage
3. Measure the clearance between the rotor pulley (A) and the pressure plate (B) all the way around If the clearance is not within specified limits, remove the pressure plate (see «A/C COMPRESSOR CLUTCH OVERHAUL»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__ac-compressor-clutch-overhaul) ) and add or remove shims as needed to increase or decrease clearance Clearance 0.35-0.60 mm (0.014-0.024 in) NOTE: The shims are available in three thicknesses 0 1 mm, 0 3 mm, and 0 5 mm
4. Remove the pressure plate (see «A/C COMPRESSOR CLUTCH OVERHAUL»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__ac-compressor-clutch-overhaul) ), and inspect the pressure plate and pulley friction surface for wear If there is excessive wear, roughness, or scoring, replace the clutch set
5. Inspect the friction surfaces and the A/C compressor shaft hub for excess oil If excess oil is present, and it is not from the engine or power steering system, then the A/C compressor shaft seal is leaking In that case, replace the A/C compressor (see «A/C COMPRESSOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__ac-compressor-replacement) )
6. Check the resistance of the field coil If resistance is not within specifications, replace the field coil (see «A/C COMPRESSOR CLUTCH OVERHAUL»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__ac-compressor-clutch-overhaul) ) Field Coil Resistance 3.9-4.3 ohms at 68 °F (20 °C)

A/C Compressor Clutch Overhaul

Special Tools Required

A/C clutch holder Robinair 10290, Kent-Moore J37872, Honda Tool and Equipment ACT499A, or commercially available

Scheme 205

Scheme 206

Scheme 207

Scheme 208

1. Remove the center bolt (A) while holding the pressure plate with a commercially available A/C clutch holder (B)
2. Remove the pressure plate (A) and the shim(s) (B), taking care not to lose the shim(s) If the clutch needs adjustment, increase or decrease the number and thickness of shims as necessary, then reinstall the pressure plate, and recheck its clearance (see «A/C COMPRESSOR CLUTCH CHECK»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) NOTE: The shims are available in three thicknesses 0.1 mm, 0.3 mm, and 0.5 mm Do not pry on the pressure plate with screwdrivers or similar tools Prying damages the pressure plate and the pulley When replacing the clutch set, place a trial stack of shims, 1 mm total thickness, on the A/C compressor shaft Install the pressure plate, and check its clearance (see «A/C COMPRESSOR CLUTCH CHECK»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) 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 pulley (B) Be careful not to damage the pulley or the A/C compressor NOTE: Do not use a hammer to remove the snap rings Using a hammer damages the A/C compressor Do not hammer or pry on the pulley to remove it If the pulley is difficult to remove, use a commercially available pulley removing tool Make sure the jaws of the pulling tool engage the back face of the pulley, not the pulley grooves
4. Remove the screw from the field coil ground terminal (A), then remove the wire harness (B) and the bracket (C) Disconnect the field coil connector (D) Remove the snap ring (E) with snap ring pliers, then remove the field coil (F) Be careful not to damage the field coil or the A/C compressor
5. Reassemble the clutch in the reverse order of disassembly, and note these items When replacing the field coil, check that the new coil has the correct resistance (see step 6 on «A/C COMPRESSOR CLUTCH CHECK»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) 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 pulley and A/C compressor sliding surfaces with contact cleaner or other non-petroleum solvent Install new snap rings, note the installation direction, and make sure they are fully seated in the grooves Make sure that the pulley turns smoothly after it's reassembled Route and clamp the wires properly to prevent damage by the pulley
6. Cycle the A/C clutch approximately 20 times by running the engine at 1,500-2,000 rpm and setting the climate control temperature to Lo with the A/C button ON This procedure seats the clutch friction surfaces, and increases clutch torque capacity

A/C Compressor Relief Valve Replacement

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

Scheme 209

1. Recover the refrigerant with a recovery/recycling/charging station (see «RECEIVER/DRYER DESICCANT REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__receiverdryer-desiccant-replacement) )
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, 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/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__system-charging) )

Scheme 210

Scheme 211

Scheme 212

Scheme 213

Scheme 214

1. Recover the refrigerant with a recovery/recycling/charging station (see «RECEIVER/DRYER DESICCANT REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__receiverdryer-desiccant-replacement) )
2. Remove the front bumper (see «FRONT BUMPER REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/exterior-body-panels/#bumper-system__front-bumper-removalinstallation) )
3. Remove the intake duct (see «THROTTLE BODY REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/testing-diagnostics/#intake-air-system__throttle-body-removalinstallation) )
4. Do the battery terminal disconnection procedure (see «BATTERY TERMINAL DISCONNECTION AND RECONNECTION»(/acura/tl/iv-2008-2011/remont/body-electrical/#battery) )
5. Remove the bolt, then disconnect the receiver line (A) from the A/C condenser Remove the O-ring (B)
6. Remove the bolt, then disconnect the discharge hose (A) from the A/C condenser Remove the O-ring (B)
7. Remove the bolts and the radiator upper mount brackets (A) Remove the clips and the front bulkhead brace cover (B)
8. Remove the bolts and the A/C condenser upper mount brackets (A)
9. Remove the A/C condenser (A) by lifting it up Be careful not to damage the radiator or the condenser fins when removing the condenser
10. Install the A/C condenser in the reverse order of removal, and note these items If you're installing a new A/C condenser, add refrigerant oil (DENSO ND-OIL 8) (see «A/C SERVICE TIPS AND PRECAUTIONS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__ac-service-tips-and-precautions) ) Replace the O-rings with new ones at each fitting, and apply a thin coat of refrigerant oil before installing them Be sure to use the correct O-rings for HFC-134a (R-134a) to avoid leakage Immediately after using the oil, reinstall the cap on the container, and seal it to avoid moisture absorption Do not spill the refrigerant oil on the vehicle, it may damage the paint, if the refrigerant oil contacts the paint, wash it off immediately Be careful not to damage the radiator or the A/C condenser fins when installing the A/C condenser Charge the system (see «SYSTEM CHARGING»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__system-charging) )
11. Do the battery terminal reconnection procedure (see «BATTERY TERMINAL DISCONNECTION AND RECONNECTION»(/acura/tl/iv-2008-2011/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 215

1. Remove the A/C condenser (see «A/C Condenser Replacement»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
2. Remove the cap (A) from the bottom of the A/C condenser Remove the O-ring (B) and the desiccant (C)
3. Install the receiver/dryer in the reverse order of removal, and note these items Replace the O-rings with new ones, and apply a thin coat of refrigerant oil (DENSO ND-OIL 8) before installing them Be sure to use the correct O-rings for HFC-134a (R-134a) to avoid leakage Install the cap to the specified torque It is made of plastic and can be easily stripped

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 216

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, 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

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

Scheme 217

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, dram the refrigerant oil, and add fresh oil (see «A/C SERVICE TIPS AND PRECAUTIONS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__ac-service-tips-and-precautions) ) then evacuate the system for several hours before charging it
2. Connect an R-134a refrigerant recovery/recycling/charging station (A) to the high-pressure service port (B) and the low-pressure service port (C), as shown, following the equipment manufacturer's instructions Recover the refrigerant, if any, from the A/C system (see «RECEIVER/DRYER DESICCANT REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__receiverdryer-desiccant-replacement) )
3. Evacuate the system The vacuum pump should run for a minimum of 45 minutes to eliminate all moisture from the system When the suction gauge reads -93 3 kPa (700 mmHg, 27 6 in Hg) for at least 45 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 6 in Hg) in 15 minutes, there is probably a leak in the system Partially charge the system, and check for leaks (see «REFRIGERANT LEAK CHECK»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__refrigerant-leak-check) )

System Charging

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

Scheme 218

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, following the equipment manufacturer's instructions
2. Recover the refrigerant in the A/C system (see «RECEIVER/DRYER DESICCANT REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__receiverdryer-desiccant-replacement) )
3. Evacuate the system (see «SYSTEM EVACUATION»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__system-evacuation) ) If the system cannot reach a vacuum of -93 3 kPa (700 mmHg, 27 6 in Hg) in 15 minutes, or cannot hold a vacuum for at least 15 minutes, there is probably a leak Do the refrigerant leak check (see «REFRIGERANT LEAK CHECK»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__refrigerant-leak-check) ), and repair any leaks before charging the system
4. Add the same amount of new refrigerant oil to the system that was removed during recovery Use only DENSO ND-OIL 8 refrigerant oil
5. Charge the system with the specified amount of R-134a refrigerant Do not overcharge the system, the A/C compressor will be damaged Select the appropriate units of measure for your refrigerant charging station Refrigerant Capacity 500 to 550 g (17.6 to 19.4 oz) 0.50 to 0.55 kg 1.1 to 1.2 lbs
6. Check for refrigerant leaks (see «REFRIGERANT LEAK CHECK»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__refrigerant-leak-check) )
7. Check the system performance (see «A/C SYSTEM TEST»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )

Refrigerant Leak Check

Special Tools Required

1. Leak detector YGK-H-10PM
2. Leak detector HLD-100
3. Leak detector TIFZX-1, or commercially available
4. OPTIMAX Jr A/C Leak Ditection Kit (TRP124893)

These tools are 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 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 compressor
3. PAG oil is water soluble, so condensation on the evaporator core or the refrigerant lines may wash the PAG oil and fluorescent dye away from the actual leak Condensation may also carry dye through the evaporator module drain
4. After checking and repairing leaks, thoroughly clean any residual dye from the areas where leaks were found Use GLO-AWAY dye cleaner, from Tracerline®, and hot water to remove the dye (follow the instructions on the bottle) Residual dye stains can cause misdiagnosis of any future A/C system leaks
5. If any refrigerant dye contacts an exterior paint surface, remove it by doing this

1. Carefully wash the affected surfaces to remove any dirt, and to prevent paint scratching
2. Mix water and isopropyl alcohol in a 50/50 mixture
3. Soak a soft cotton towel with the water/alcohol mixture, and place the cloth on the affected areas to remove the dye
4. After removing the dye with the water/alcohol-soaked cloth, carefully wash the affected areas, and check that there is no remaining dye

Scheme 219

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, following the equipment manufacturer's instructions
2. Recover refrigerant from the A/C system (see «RECEIVER/DRYER DESICCANT REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__receiverdryer-desiccant-replacement) ), and evacuate the system (see «SYSTEM EVACUATION»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__system-evacuation) ) If the system achieves a vacuum of approximately 93.3 kPa (700 mmHg, 27.6 in Hg) 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 500 to 550 g (17.6 to 19.4 oz) 0.50 to 0.55 kg 1.1 to 1.2 lbs
4. With the engine OFF, use a halogen leak detector first to detect the leak source Follow a continuous path in order to ensure that you will not miss any possible leaks Test the following areas of the system for leaks DIAGNOSTIC PROCEDURE CHART Possible Leak Area Diagnostic Procedure with the Leak Detector Notes Service Ports Check the service ports with the detector 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 inch/second or less), and keep it within 1/4 inch 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 blower on low speed A/C Lines Wiggle the rubber hoses when checking crimped metal ends If the detector "sniffs" a leak, use fluorescent dye to confirm it Check all fittings, couplings, pressure switches, brazed/welded areas, and areas around attachment points on A/C lines and components Check for damaged and corroded areas Move the probe slowly (1 inch/second or less), and keep it within 1/4 inch 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

DIAGNOSTIC PROCEDURE CHART

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 an A/C system inspection (see A/C SYSTEM INSPECTION ), and correct any problems found prior to diagnosing abnormal noises Abnormal A/C noises can be misleading For example, a sound similar to a failed bearing may be caused by loose fasteners, loose mounting brackets, or a faulty 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 -2 If there is a squeaking or chirping noise, but no unusual vibration, replace the blower motor (see «BLOWER UNIT COMPONENT REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__blower-unit-component-replacement) ) -3 Remove the blower unit (see «BLOWER UNIT REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ), 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 don't find any foreign material, remove the blower motor (see «BLOWER UNIT COMPONENT REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__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 in PARK or in Neutral 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 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/tl/iv-2008-2011/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 condenser, the evaporator, the receiver-drier, or the expansion valve, and check these items Noises caused by A/C components touching other components or the body Reroute or insulate the A/C component(s) as needed, and recheck for noise Loose, damaged or excessively worn A/C components or mounting hardware Repair or replace the faulty component(s) or hardware, and recheck for noise A moaning noise from the A/C suction line If there is a moaning noise, check the system refrigerant charge (see «SYSTEM CHARGING»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__system-charging) ) If the refrigerant charge is OK, replace the receiver/dryer A whistling or hissing noise from the expansion valve Evacuate the system for 3 hours (see «SYSTEM EVACUATION»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__system-evacuation) ), then recheck If the noise is still present, replace the expansion valve (see «EXPANSION VALVE REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) )
7. Check the operation of the A/C compressor clutch Make sure 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/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__ac-compressor-clutch-circuit-troubleshooting) ) If the compressor clutch slips, replace the complete clutch assembly (see «A/C COMPRESSOR CLUTCH OVERHAUL»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__ac-compressor-clutch-overhaul) ) Make sure the A/C compressor clutch disengages If the clutch does not disengage, do the A/C compressor clutch circuit troubleshooting (see «A/C COMPRESSOR CLUTCH CIRCUIT TROUBLESHOOTING»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__ac-compressor-clutch-circuit-troubleshooting) ) If the clutch circuit is OK, do the A/C compressor clutch check (see «A/C COMPRESSOR CLUTCH CHECK»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ), and see if the clutch is mechanically jammed If there are no electrical or mechanical problems with the compressor clutch, replace the A/C compressor (see «A/C COMPRESSOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__ac-compressor-replacement) ) Make sure the A/C compressor clutch cycles normally If the 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/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__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 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/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) 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/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__ac-compressor-replacement) )

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 220

Scheme 221

Scheme 222

Scheme 223

1. Do the A/C system inspection (see «A/C SYSTEM INSPECTION»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__ac-system-inspection) ), and correct any problems found
2. Connect an R-134a refrigerant recovery/recycling/charging station to the high-pressure service port and the low-pressure service port, following the equipment manufacturer's instructions
3. Determine the relative humidity and air temperature
4. Remove the glove box (see «GLOVE BOX REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/exteriorinterior-trim/#dashboard__glove-box-removalinstallation) )
5. Insert a thermometer (A) in the center vent
6. Place a thermometer (B) near the blower unit's recirculation inlet duct
7. Test conditions Move the vehicle out of direct sunlight and let it cool down to the surrounding (ambient) temperature If necessary, wash the vehicle to cool it down more quickly The ambient 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 ON/OFF button to Max Hold the engine speed at 1,500 rpm No driver or passengers in the vehicle
8. Inspect the A/C components for the following conditions A/C compressor clutch not engaged Abnormal frost areas Unusual noises If you observe any of these conditions, refer to the «SYMPTOM TROUBLESHOOTING INDEX»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__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 ambient air temperature should intersect in the shaded area Any measurements outside the area may indicate the need for further inspection
11. To complete the high side (discharge) pressure/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 ambient air temperature should intersect in the shaded area Any measurements outside the area may indicate the need for further inspection
12. To complete the low side (suction) pressure/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 ambient air temperature should intersect in the shaded area Any measurements outside the area may indicate the need for further inspection SYMPTOMS REFERENCE Test results Related symptoms Probable cause Remedy Suction and discharge pressures are normal Warm air from the vents The A/C system contains too much refrigerant oil The air mix door is not operating properly Evacuate the system (see «SYSTEM EVACUATION»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__system-evacuation) ) Adjust the oil level (see «A/C SERVICE TIPS AND PRECAUTIONS»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__ac-service-tips-and-precautions) ), then recharge the system (see «SYSTEM CHARGING»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__system-charging) ) Check air mix door operation, driver's (see «DRIVER'S AIR MIX CONTROL MOTOR TEST»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__drivers-air-mix-control-motor-test) ), passenger's (see «DRIVER'S AIR MIX CONTROL MOTOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ), and repair as needed Suction and discharge pressures are roughly equal and steady The suction and discharge pressures equalize when the engine is revved The A/C compressor clutch or the drive belt is slipping, or the compressor shaft seal is leaking If the drive belt is slipping, replace the drive belt (see «DRIVE BELT REPLACEMENT»(/acura/tl/iv-2008-2011/remont/charging-system/#charging-system__drive-belt-replacement) ) Also inspect the drive belt auto-tensioner (see «DRIVE BELT AUTO-TENSIONER REPLACEMENT»(/acura/tl/iv-2008-2011/remont/charging-system/#charging-system) ) If the A/C compressor clutch is slipping, replace it (see «A/C COMPRESSOR CLUTCH OVERHAUL»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__ac-compressor-clutch-overhaul) ) Check the A/C compressor shaft seal If it's leaking, replace the A/C compressor (see «A/C COMPRESSOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__ac-compressor-replacement) ) Suction and discharge pressures are roughly equal but fluctuate Suction and discharge pressures fluctuate during operation, and equalize when the compressor clutch disengages The compressor discharge valve or the compressor gasket is faulty Replace the A/C compressor (see «A/C COMPRESSOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__ac-compressor-replacement) ) Suction and discharge pressures are roughly equal and abnormally low The suction and discharge pressures do not change during continued operation The A/C system is undercharged Do the refrigerant leak check (see «REFRIGERANT LEAK CHECK»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__refrigerant-leak-check) ) Repair any leaks, then recharge the system (see «SYSTEM CHARGING»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__system-charging) ) Suction and discharge pressures are abnormally high, but normalize when the condenser is cooled The suction pressure decreases when cool water is sprayed on the A/C condenser The A/C system is overcharged Evacuate the A/C system (see «SYSTEM EVACUATION»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__system-evacuation) ), and recharge it to specifications (see «SYSTEM CHARGING»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__system-charging) ) Suction and discharge pressures are abnormally high, and refrigerant line temperatures are abnormal The vapor line to the condenser is too hot The liquid line from the expansion valve is not cold There is an abrupt temperature change in the system The A/C system refrigerant flow is restricted Replace the restricted line or component The suction pressure is low, the discharge pressure is high, and the refrigerant temperature changes abnormally somewhere in the system The high pressure liquid line going into the expansion valve is cold There is an abrupt temperature drop in an A/C line or hose The A/C system refrigerant flow is restricted Replace the restricted line or component Discharge pressure is so high that the compressor relief valve has opened Suction pressure is normal or below normal The temperature drop between the condenser inlet and outlet is less than 30 °F (16 °C) or more than 60 °F (32 °C) The A/C condenser or receiver/dryer is restricted Replace the restricted component, the condenser (see «A/C COMPRESSOR RELIEF VALVE REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__ac-compressor-relief-valve-replacement) ) or the receiver/dryer (see «RECEIVER/DRYER DESICCANT REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__receiverdryer-desiccant-replacement) ) Discharge pressure is so high that the compressor relief valve has opened Suction pressure is also above normal No evidence of restricted refrigerant flow The A/C compressor clutch stays engaged with the A/C switch off The A/C compressor clutch circuit is always on (energized), or the compressor clutch is mechanically lammed Do the A/C compressor clutch circuit troubleshooting (see «A/C COMPRESSOR CLUTCH CIRCUIT TROUBLESHOOTING»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__ac-compressor-clutch-circuit-troubleshooting) ), and repair the problem with the circuit If the A/C compressor clutch circuit is OK, do the A/C compressor clutch check (see «A/C COMPRESSOR CLUTCH CHECK»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ), and repair as needed Suction and discharge pressures are abnormally high, but drop rapidly when the compressor disengages Discharge pressure quickly drops about 196 kPa (28 psi) when the clutch disengages Expansion valve inlet and outlet temperatures are different There is excess air in the A/C system Evacuate the A/C system (see «SYSTEM EVACUATION»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__system-evacuation) ), and recharge it (see «SYSTEM CHARGING»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__system-charging) ) Suction and discharge pressures are abnormally high, and there is little or no airflow through the A/C condenser Suction and discharge pressures normalize when water is sprayed on the A/C condenser The condenser and/or radiator fins are clogged The condenser fins are damaged The condenser and/or radiator fans are not working properly Clean debris from the condenser and/or radiator fins Comb the condenser fins to repair any damage Troubleshoot the A/C condenser fan and/or the radiator fan circuit(s) The suction pressure is high and the discharge pressure is low Both pressures are steady The liquid line temperature is similar on both sides of expansion valve System pressures do not vary at a steady engine speed The expansion valve is stuck open Replace the expansion valve (see «EXPANSION VALVE REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) The suction pressure is high, the discharge pressure is low, and there are particle contaminants in the refrigerant lines Metal flakes or Desiccant particles are in the discharge hose or expansion valve The A/C compressor is malfunctioning Replace the A/C compressor (see «A/C COMPRESSOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__ac-compressor-replacement) ) If the system is contaminated with desiccant, replace the receiver/dryer (see «RECEIVER/DRYER DESICCANT REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__receiverdryer-desiccant-replacement) ) The suction pressure is high, the discharge pressure is low, and the pressures quickly change when the A/C disengages The discharge and suction pressures equalize soon after the A/C compressor stops The A/C compressor seal is faulty Replace the A/C compressor (see «A/C COMPRESSOR REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__ac-compressor-replacement) ) Suction and discharge pressures are both low and none of the refrigerant lines are cold There is no frost on the expansion valve, and the low-pressure liquid line is not cold The A/C system has a leak (very low refrigerant charge) Do the refrigerant leak check (see «REFRIGERANT LEAK CHECK»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__refrigerant-leak-check) ), repair any leaks, and recharge the A/C system (see «SYSTEM CHARGING»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__system-charging) ) Suction and discharge pressures are both low, and the expansion valve or the suction line is abnormally cold Expansion valve inlet temperature is much lower than receiver/dryer outlet temperature The low pressure (suction) hose/line is cooler than the evaporator The discharge hose/line is clogged or kinked, which is restricting refrigerant flow The suction hose/line is clogged or kinked, which is restricting refrigerant flow Repair or replace the faulty A/C line or hose (see «A/C LINE REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) Initially, the suction and discharge pressure are normal, but both become abnormally low during operation During extended operation, the air flow from the vents decreases The evaporator is freezing up Run the fan with A/C compressor off to warm the evaporator, then test the evaporator temperature sensor (see «EVAPORATOR TEMPERATURE SENSOR TEST»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__evaporator-temperature-sensor-test) ) If necessary, replace the evaporator temperature sensor Suction and discharge pressures are both low and there are abnormal temperature changes at the expansion valve During operation, the suction pressure decreases, and heavy frost occurs on the low pressure liquid line The low pressure liquid line is cold at the expansion valve, but warm after the valve There is frost on the expansion valve The expansion valve is stuck closed Replace the expansion valve (see «EXPANSION VALVE REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ), and the receiver/dryer (see «RECEIVER/DRYER DESICCANT REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__receiverdryer-desiccant-replacement) ) Check the old expansion valve for contamination If contaminants are found, replace the component that caused the contamination The discharge pressure is low, the suction pressure is extremely low, and the expansion valve outlet is abnormally warm There is no frost on the expansion valve outlet, and the liquid line temperature changes significantly across the expansion valve There is excessive moisture in the A/C system Evacuate the A/C system (see «SYSTEM EVACUATION»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__system-evacuation) ), and replace the receiver/dryer (see «RECEIVER/DRYER DESICCANT REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__receiverdryer-desiccant-replacement) ) Recharge the A/C system (see «SYSTEM CHARGING»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__system-charging) ) The discharge pressure is low, the suction pressure is extremely low, and the suction line is abnormally cold There is frost on the line from the evaporator to the compressor The evaporator is internally contaminated or plugged Replace the evaporator core (see «EVAPORATOR CORE REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) The discharge pressure is low, the suction pressure is extremely low, and the refrigerant temperature doesn't change going through the expansion valve The low pressure liquid line is not cold The liquid line temperatures are similar on both sides of expansion valve The expansion valve is faulty Replace the expansion valve (see «EXPANSION VALVE REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) The discharge pressure is low, the suction pressure is extremely low, and the expansion valve is abnormally cold There is frost on the expansion valve Excessive moisture in the system is freezing the expansion valve Replace the receiver/dryer (see «RECEIVER/DRYER DESICCANT REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__receiverdryer-desiccant-replacement) ) Evacuate the A/C system (see «SYSTEM EVACUATION»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__system-evacuation) ), and recharge the A/C system (see «SYSTEM CHARGING»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__system-charging) ) The discharge pressure is low, the suction pressure is extremely low, and the high pressure liquid line is abnormally cold There is frost on the line from the receiver/dryer to the expansion valve The receiver/dryer is clogged Replace the receiver/dryer (see «RECEIVER/DRYER DESICCANT REPLACEMENT»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__receiverdryer-desiccant-replacement) ) Evacuate the A/C system (see «SYSTEM EVACUATION»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__system-evacuation) ), and recharge the A/C system (see «SYSTEM CHARGING»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system__system-charging) )

See also:
• DRIVE BELT INSPECTION
• DLC CIRCUIT TROUBLESHOOTING
• DTC U0199: DRIVER'S MICU LOST COMMUNICATION WITH DOOR MULTIPLEX CONTROL UNIT
• DASHBOARD WIRE HARNESS (VIEW OF MIDDLE TO PASSENGER'S SIDE)
• GENERAL TROUBLESHOOTING INFORMATION
• A/C SIGNAL CIRCUIT TROUBLESHOOTING
• LEFT ENGINE COMPARTMENT WIRE HARNESS (ENGINE COMPARTMENT BRANCH)
• RADIATOR FAN HIGH SPEED CIRCUIT TROUBLESHOOTING
• HOW TO CHECK ERROR HISTORY
• DTC P2183: ECT SENSOR 2 CIRCUIT RANGE/PERFORMANCE PROBLEM
• COOLANT CHECK
• TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE D
• GAUGE CONTROL MODULE INPUT TEST
• POWER RELAY TEST
• REMOVAL AND INSTALLATION
• MICU INPUT TEST
• SYSTEM DIAGNOSTIC MODE
• UNIT CHECK (QUICK CHECK)
• AUDIO-NAVIGATION SWITCH PANEL REMOVAL/INSTALLATION
• SUBSTITUTING THE ECM/PCM
• ECM/PCM REPLACEMENT
• LEFT ENGINE COMPARTMENT WIRE HARNESS (DASHBOARD BRANCH)
• DRIVER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION
• ENGINE START/STOP SWITCH TEST/REPLACEMENT
• GLOVE BOX REMOVAL/INSTALLATION
• AUDIO-NAVIGATION UNIT REMOVAL/INSTALLATION
• COMPONENT LOCATIONS
• BATTERY TERMINAL DISCONNECTION AND RECONNECTION
• DRIVE BELT REPLACEMENT
• FRONT SPLASH SHIELD REPLACEMENT
• FRONT BUMPER REMOVAL/INSTALLATION
• THROTTLE BODY REMOVAL/INSTALLATION
• REFRIGERANT LEAK CHECK
• DUST AND POLLEN FILTER REPLACEMENT
• SYMPTOM TROUBLESHOOTING INDEX
• CHECKING FOR DTCS
• DTC B2969: CLIMATE CONTROL UNIT LOST COMMUNICATION WITH DRIVER'S MICU (WIPSW MESSAGE)
• A/C COMPRESSOR CLUTCH CIRCUIT TROUBLESHOOTING
• A/C PRESSURE SENSOR
• 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
• DRIVER'S AIR MIX CONTROL MOTOR TEST
• TO RUN THE SENSOR INPUT DISPLAY MODE, FOLLOW THESE STEPS
• HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS
• RECIRCULATION CONTROL MOTOR TEST
• OUTSIDE AIR TEMPERATURE SENSOR TEST
• SUNLIGHT SENSOR TEST
• EVAPORATOR TEMPERATURE SENSOR TEST
• Passenger's Air Mix Control Motor Test
• DRIVER'S MODE CONTROL MOTOR TEST
• Passenger's Mode Control Motor Test
• A/C SERVICE TIPS AND PRECAUTIONS
• A/C COMPRESSOR CLUTCH OVERHAUL
• A/C COMPRESSOR REPLACEMENT
• SYSTEM EVACUATION
• A/C SYSTEM INSPECTION
• BLOWER UNIT COMPONENT REPLACEMENT