Acura RL. Manual - part 568

air temperature sensor.

NO - Go to step 9. 

9. Check for continuity between the climate control unit 40P connector No. 33 and No. 36 terminals. 

Fig. 53: Checking Continuity Between Climate Control Unit 40P Connector 33 And 36 
Terminals 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

Is there continuity?  

YES - Repair short in the wires between the climate control unit and the driver's vent 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 B2977 or Pa VENT sensor open is indicated: An Open in the Passenger's Vent 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 B2977 or PaVENT sensor open indicated?  

YES - Go to step 5. 

NO - Intermittent failure, check for loose wires or poor connections on the passenger's vent air 
temperature sensor circuit. 

5. Turn the ignition switch OFF.  

6. Remove the passenger's vent air temperature sensor (see PASSENGER'S VENT AIR 

TEMPERATURE SENSOR REPLACEMENT ) and test it (see VENT AIR TEMPERATURE 
SENSOR TEST ). 

 

2007 Acura RL 

2005-08 HVAC HVAC - RL

  

me 

 

Friday, June 05, 2009 2:25:43 PM

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© 2005 Mitchell Repair Information Company, LLC. 

Is the passenger's vent air temperature sensor OK?

YES - Go to step 7. 

NO - Replace the passenger's vent air temperature sensor. 

7. Disconnect the climate control unit 40P connector.  

8. Check for continuity between the climate control unit 40P connector No. 37 terminal and the 

passenger's vent air temperature sensor 2P connector No. 1 terminal. 

Fig. 54: Checking Continuity Between Climate Control Unit 40P Connector 37 Terminal And 
Passenger's Vent Air Temperature Sensor 2P Connector No. 1 Terminal 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

Is there continuity?  

YES - Go to step 9. 

NO - Repair open in the wire between the climate control unit and the passenger's vent air 
temperature sensor. 

9. Check for continuity between the climate control unit 40P connector No. 33 terminal and the 

passenger's vent air temperature sensor 2P connector No. 2 terminal. 

Fig. 55: Checking Continuity Between Climate Control Unit 40P Connector 33 Terminal And 
Passenger's Vent Air Temperature Sensor 2P Connector No. 2 Terminal 

 

2007 Acura RL 

2005-08 HVAC HVAC - RL

  

me 

 

Friday, June 05, 2009 2:25:43 PM

Page 56 

© 2005 Mitchell Repair Information Company, LLC. 

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 
passenger's vent 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 passenger's vent air 
temperature sensor. 

DTC B2978 or Pa VENT sensor short is indicated: A Short in the Passenger's Vent 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 B2978 or PaVENT sensor short indicated?  

YES - Go to step 5. 

NO - Intermittent failure. 

5. Turn the ignition switch OFF.  

6. Remove the passenger's vent air temperature sensor (see PASSENGER'S VENT AIR 

TEMPERATURE SENSOR REPLACEMENT ) and test it (see VENT AIR TEMPERATURE 
SENSOR TEST ). 

Is the passenger's vent air temperature sensor OK?  

YES - Go to step 7. 

NO - Replace the passenger's vent 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. 37 

terminal. 

 

2007 Acura RL 

2005-08 HVAC HVAC - RL

  

me 

 

Friday, June 05, 2009 2:25:43 PM

Page 57 

© 2005 Mitchell Repair Information Company, LLC. 

Fig. 56: Checking Continuity Between Body Ground And Climate Control Unit 40P Connector 
37 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 passenger's 
vent air temperature sensor. 

NO - Go to step 9. 

9. Check for continuity between the climate control unit 40P connector No. 33 and No. 37 terminals. 

Fig. 57: Checking Continuity Between Climate Control Unit 40P Connector 33 And 37 
Terminals 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

Is there continuity?  

YES - Repair short in the wires between the climate control unit and the passenger's vent 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 B2979 or PRE sensor open is indicated: An Open in the A/C Pressure Sensor Circuit 

1. Clear the DTC with the HDS.  

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

 

2007 Acura RL 

2005-08 HVAC HVAC - RL

  

me 

 

Friday, June 05, 2009 2:25:43 PM

Page 58 

© 2005 Mitchell Repair Information Company, LLC.