Acura RL. Manual - part 587

Fig. 168: Ambient Temperature Vs. Vent (Delivery) Temperature Graph 
Courtesy of AMERICAN HONDA MOTOR CO., INC.

 

2007 Acura RL 

2005-08 HVAC HVAC - RL

  

me 

 

Friday, June 05, 2009 2:25:44 PM

Page 131  © 2005 Mitchell Repair Information Company, LLC. 

Fig. 169: Ambient Temperature Vs. High side (Discharge) Pressure Graph 
Courtesy of AMERICAN HONDA MOTOR CO., INC.

 

2007 Acura RL 

2005-08 HVAC HVAC - RL

  

me 

 

Friday, June 05, 2009 2:25:44 PM

Page 132  © 2005 Mitchell Repair Information Company, LLC. 

Fig. 170: Ambient Temperature Vs. Low side (Suction) Pressure Graph 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

Pressure Test 

SYMPTOMS REFERENCE 

Test results

Related symptoms

Probable cause

Remedy

Discharge 
(high) pressure 
abnormally 
high

After stopping A/C 
compressor, pressure drops 
about 196 kPa (2.0 kgf/cm

2

, 

28 psi) quickly, and then 
falls gradually.

Air in system

Recover, evacuate (see 
REFRIGERANT 
RECOVERY ), and recharge 
with specified amount (see 
SYSTEM CHARGING ).

Reduced or no airflow 
through A/C condenser.



Clogged A/C 
condenser or 
radiator fins  



A/C condenser 
or radiator fan 
not working 
properly  



Clean.  



Check voltage and fan 
rpm.  



Check fan direction.  

Line to A/C condenser is 
excessively hot.

Restricted flow of 
refrigerant in system

Restricted lines.

 

2007 Acura RL 

2005-08 HVAC HVAC - RL

  

me 

 

Friday, June 05, 2009 2:25:44 PM

Page 133  © 2005 Mitchell Repair Information Company, LLC. 

Discharge 
pressure 
abnormally low

High and low-pressures are 
balanced soon after stopping 
A/C compressor. Low side is 
higher than normal.



Faulty A/C 
compressor 
discharge valve  



Faulty A/C 
compressor seal 

Replace the A/C compressor.

Outlet of expansion valve is 
not frosted, low-pressure 
gauge indicates vacuum.



Faulty 
expansion valve 



Moisture in 
system  



Replace.  



Recover, evacuate, and 
recharge with specified 
amount.  

Suction (low) 
pressure 
abnormally low

Expansion valve is not 
frosted, and low-pressure 
line is not cold. Low-
pressure gauge indicates 
vacuum.



Frozen 
expansion valve 
(Moisture in 
system)  



Faulty 
expansion valve 



Recover, evacuate, and 
recharge With specified 
amount,  



Replace the expansion 
valve.  

Discharge temperature is 
low, and the airflow from 
vents is restricted.

Frozen evaporator

Run the fan with A/C 
compressor off, then check 
evaporator temperature sensor.

Expansion valve is frosted.

Clogged expansion 
valve

Clean or replace.

Suction 
pressure 
abnormally 
high

Low-pressure hose and 
service port are cooler than 
the temperature around 
evaporator.

Expansion valve open 
too long

Repair or replace.

Suction pressure is lowered 
when A/C condenser is 
cooled by water.

Excessive refrigerant 
in system

Recover, evacuate, and recharge 
with specified amount.

High and low-pressures are 
equalized as soon as the A/C 
compressor is stopped, and 
both gauges fluctuate while 
running.



Faulty gasket  



Faulty high-
pressure valve  



Foreign particle 
stuck in high-
pressure valve  

Replace the A/C compressor.

Suction and 
discharge 
pressures 
abnormally 
high

Reduced airflow through 
A/C condenser.



Clogged A/C 
condenser or 
radiator fins  



A/C condenser 
or radiator fan 
not working 
properly  



Clean.  



Check voltage and fan 
rpm.  



Check fan direction.  

Suction and 
discharge 
pressures 
abnormally low

Low-pressure hose and 
metal fittings are cooler than 
evaporator.

Clogged or kinked 
low-pressure hose 
parts

Repair or replace.

Temperature around 
expansion valve is too low 
compared with that around 

Clogged high-pressure 
line

Repair or replace.

 

2007 Acura RL 

2005-08 HVAC HVAC - RL

  

me 

 

Friday, June 05, 2009 2:25:44 PM

Page 134  © 2005 Mitchell Repair Information Company, LLC.