Acura RL. Manual - part 563

YES - Repair short in the wires between the climate control unit and the in-car temperature sensor.

NO - Substitute a known-good climate control unit, and recheck. If the symptom/indication goes 
away, replace the original climate control unit. 

DTC B1227 or TAM sensor open is indicated: An Open in the Outside Air Temperature Sensor Circuit 

1. Clear the DTC with the HDS.  

2. Turn the ignition switch OFF and then ON (II).  

3. Do the self-diagnostic with the HDS (see HOW TO USE THE SELF-DIAGNOSTIC FUNCTION 

WITH THE HDS ) or climate control unit (see HOW TO USE THE SELF-DIAGNOSTIC 
FUNCTION WITHOUT HDS ).  

4. Check for DTCs. 

Is DTC B1227 or TAM sensor open 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 OFF.  

6. Remove the outside air temperature sensor (see OUTSIDE AIR TEMPERATURE SENSOR 

REPLACEMENT ) and test it (see 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 the climate control unit 40P connector.  

8. Check for continuity between the climate control unit 40P connector No. 16 terminal and the outside 

air temperature sensor 2P connector No. 2 terminal. 

Fig. 28: Checking Continuity Between Climate Control Unit 40P Connector 16 Terminal And 
Outside Air Temperature Sensor 2P 2 Terminal 
Courtesy of AMERICAN HONDA MOTOR CO., INC.

 

2007 Acura RL 

2005-08 HVAC HVAC - RL

  

me 

 

Friday, June 05, 2009 2:25:42 PM

Page 35 

© 2005 Mitchell Repair Information Company, LLC. 

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 the climate control unit 40P connector No. 33 terminal and the outside 

air temperature sensor 2P connector No. 1 terminal. 

Fig. 29: Checking Continuity Between Climate Control Unit 40P Connector 33 Terminal And 
Outside Air Temperature Sensor 2P Terminal 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

Is there continuity?  

YES - Check for loose wires or poor connections at the climate control unit 40P connector 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. 

DTC B1228 or TAM sensor short is indicated: A Short in the Outside Air Temperature Sensor Circuit 

1. Clear the DTC with the HDS.  

2. Turn the ignition switch OFF and then ON (II).  

3. Do the self-diagnostic with the HDS (see HOW TO USE THE SELF-DIAGNOSTIC FUNCTION 

WITH THE HDS ) or climate control unit (see HOW TO USE THE SELF-DIAGNOSTIC 
FUNCTION WITHOUT HDS ).  

4. Check for DTCs. 

Is DTC B1228 or TAM sensor short indicated?  

YES - Go to step 5. 

NO - Intermittent failure. 

5. Turn the ignition switch OFF.  

 

2007 Acura RL 

2005-08 HVAC HVAC - RL

  

me 

 

Friday, June 05, 2009 2:25:42 PM

Page 36 

© 2005 Mitchell Repair Information Company, LLC. 

6. Remove the outside air temperature sensor (see OUTSIDE AIR TEMPERATURE SENSOR 

REPLACEMENT ) and test it (see 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 the climate control unit 40P connector.  

8. Check for continuity between body ground and the climate control unit 40P connector No. 16 

terminal. 

Fig. 30: Checking Continuity Between Body Ground And Climate Control Unit 40P Connector 
16 Terminal 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

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 the climate control unit 40P connector No. 16 and No. 33 terminals. 

Fig. 31: Checking Continuity Between Climate Control Unit 40P Connector 16 And 33 
Terminals 
Courtesy of AMERICAN HONDA MOTOR CO., INC.

 

2007 Acura RL 

2005-08 HVAC HVAC - RL

  

me 

 

Friday, June 05, 2009 2:25:42 PM

Page 37 

© 2005 Mitchell Repair Information Company, LLC. 

Is there continuity?  

YES - Repair short in the wires between the climate control unit and the outside air temperature 
sensor. 

NO - Substitute a known-good climate control unit, and recheck. If the symptom/indication goes 
away, replace the original climate control unit. 

DTC B1229 or TS sensor open is indicated: An Open in the Sunlight Sensor Circuit 

1. Clear the DTC with the HDS.  

2. Turn the ignition switch OFF and then ON (II).  

3. Do the self-diagnostic with the HDS (see HOW TO USE THE SELF-DIAGNOSTIC FUNCTION 

WITH THE HDS ) or climate control unit (see HOW TO USE THE SELF-DIAGNOSTIC 
FUNCTION WITHOUT HDS ).  

4. Check for DTCs. 

Is DTC B1229 or TS sensor open 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 OFF.  

6. Disconnect the sunlight sensor 5P connector.  

7. Disconnect the climate control unit 40P connector.  

8. Check for continuity between the climate control unit 40P connector No. 18 terminal and the sunlight 

sensor 5P connector No. 4 terminal. 

Fig. 32: Checking Continuity Between Climate Control Unit 40P Connector 18 Terminal And 
Sunlight Sensor 5P Terminal 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

Is there continuity?  

YES - Go to step 9. 

 

2007 Acura RL 

2005-08 HVAC HVAC - RL

  

me 

 

Friday, June 05, 2009 2:25:43 PM

Page 38 

© 2005 Mitchell Repair Information Company, LLC.