Acura RL. Manual - part 575

Fig. 86: Resistance And Temperature Graph 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

4. If the resistance is not as specified, replace the outside air temperature sensor (see OUTSIDE AIR 

TEMPERATURE SENSOR REPLACEMENT ).  

OUTSIDE AIR TEMPERATURE SENSOR REPLACEMENT 

1. Lift the tab (A) to release the lock, then remove the outside air temperature sensor (B) from the back 

of the front bumper. Disconnect the 2P connector (C) from the outside air temperature sensor. 

Fig. 87: Identifying Outside Air Temperature Sensor And 2P Connector 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

2. Install the sensor in the reverse order of removal.  

SUNLIGHT SENSOR TEST 

1. Remove the sunlight sensor from the dashboard (see SUNLIGHT SENSOR REPLACEMENT ).  

2. Connect the sunlight sensor 5P connector. 

 

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2005-08 HVAC HVAC - RL

  

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Fig. 88: Connecting Sunlight Sensor 5P Connector 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

3. Turn the ignition switch ON (II). Measure the voltage between the terminals with the (+) probe on the 

No. 4 terminal and the (-) probe on the No. 2 terminal with the 4P connector connected. 

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.  

4. If the voltage is not as specified, replace the sunlight sensor (see SUNLIGHT SENSOR 

REPLACEMENT ).  

SUNLIGHT SENSOR REPLACEMENT 

1. Remove the sunlight sensor (A) from the dashboard, then disconnect the 5P connector (B). Be careful 

not to damage the sensor and the dashboard. 

Fig. 89: Identifying Sunlight Sensor And 5P Connector 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

2. Install the sensor in the reverse order of removal. 

NOTE:

The voltage readings will not change under the light of a flashlight or a 
fluorescent lamp.

 

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2005-08 HVAC HVAC - RL

  

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EVAPORATOR TEMPERATURE SENSOR TEST

1. Remove the evaporator temperature sensor (see EVAPORATOR TEMPERATURE SENSOR 

REPLACEMENT ).  

2. Dip the sensor in ice water, and measure the resistance between its terminals. 

Fig. 90: Measuring Resistance Between Terminals 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

3. Then pour warm water on the sensor, and check for a change in resistance.  

4. Compare the resistance readings with the specifications shown in the graph; the resistance should be 

within the specifications. 

Fig. 91: Resistance And Temperature Graph 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

5. If the resistance is not as specified, replace the evaporator temperature sensor (see EVAPORATOR 

TEMPERATURE SENSOR REPLACEMENT ).  

EVAPORATOR TEMPERATURE SENSOR REPLACEMENT 

1. Remove the driver's dashboard undercover (see DRIVER'S DASHBOARD UNDERCOVER 

REMOVAL/INSTALLATION ).  

2. Disconnect the connectors (A) from the power tilt/ telescopic steering control unit, the adaptive front 

lighting control unit, the electronically controlled power steering control unit, and the daytime running 
lights control unit. Remove the relay (B) and the power tilt/telescopic steering control unit (C), then 
remove the self-tapping screws and the bracket (D). 

 

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2005-08 HVAC HVAC - RL

  

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Fig. 92: Identifying Control Units And Connectors 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

3. Disconnect the connectors (A) from the evaporator temperature sensor and the driver's cool vent 

control motor, then remove the connector clip (B). Remove the self-tapping screw and the evaporator 
temperature sensor (C). 

Fig. 93: Identifying Evaporator Temperature Sensor And Connector 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

4. Install the sensor in the reverse order of removal.  

POWER TRANSISTOR TEST 

1. Remove the passenger's dashboard undercover (see DOCUMENT TRAY 

REMOVAL/INSTALLATION ).  

2. Disconnect the 5P connector from the power transistor.  

3. Measure the resistance between the No. 1 and No. 4 terminals 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.

 

2007 Acura RL 

2005-08 HVAC HVAC - RL

  

me 

 

Friday, June 05, 2009 2:25:43 PM

Page 86 

© 2005 Mitchell Repair Information Company, LLC.