engine coolant ACURA CSX 2006 Service Repair Manual

SymptomDiagnostic procedure Also check for
21-17


–
– 



 


 



 


 





Blower fan runs slower
than expected in cold
weather (when in
AUTO mode)
NOTE: It is normal for
the blower fan to run
slowly until the coolant
temperature rises
when in AUTO mode
Probable cause: Engine coolant temperature
(ECT) circuit malfunction
Troubleshooting the ECT sensor circuit:
ECT sensor 2 circuit low voltage (see page
11-170)
ECT sensor 2 circuit high voltage (see page
11-172) HVAC DTCs (see page 21-9)
Powertrain DTCs (see page
11-3)
Blower motor operation
The A/C compressor
clutch cycles rapidly on
and off Probable cause: A/C system is very low on
refrigerant, indicating a possible leak
Do the refrigerant leak check (see page 21-93)
and repair any leaks. Replace the receiver/dryer
(see page 21-89), then recharge the system to
specifications (see page 21-92) HVAC DTCs (see page 21-9)
If there is no leak and the
refrigerant level is normal, do
the A/C compressor clutch
circuit troubleshooting
(see page 21-62), and look for
an intermittent problem
Warm air comes out of
the vents, and the high
pressure liquid line is
very hot Probable causes: The A/C system is overcharged
(too much refrigerant), or the condenser is
malfunctioning
Recover A/C refrigerant (see page 21-90), then
check the condenser for restrictions or poor
airflow. Repair as needed. Recharge the system
to specifications (see page 21-92) Incorrect tension or abnormal
wear on the drive belt. Replace
the belt and/or the belt
tensioner as needed
Proper operation of the
condenser/radiator fans. Repair
as needed
Signs of an overheated engine.
Repair as needed
Warm air comes out of
the vents. The suction
line is cool to warm,
and the discharge line
is warm to hot Probable cause: A/C system is low on refrigerant,
indicating a possible leak
Do the refrigerant leak check (see page 21-93)
and repair any leaks. Recharge the system to
specifications (see page 21-92) HVAC DTCs (see page 21-9)
Add refrigerant oil depending
on the part you replaced
(see page 21-7)
Warm air comes out of
the vents. The suction
line is cool to warm,
the discharge line is
warm to hot, and there
is no frost on the
expansion valve Probable cause: Excessive air and/or moisture in
the system, indicating a possible leak
Do the refrigerant leak check (see page 21-93)
and repair any leaks. Replace the receiver/dryer
(see page 21-89), then recharge the system to
specifications (see page 21-92)
HVAC DTCs (see page 21-9)
Check the amount of refrigerant
oil in the system. Adjust the oil
level as needed
Warm air comes out of
the vents. The liquid
line or the condenser
outlet is abnormally
cool, or there is frost or
condensation on the
receiver/dryer Probable cause: A restriction in the high-pressure
side of the system
Recover A/C refrigerant (see page 21-90), then
check the liquid line, the receiver/dryer, and the
condenser for restrictions. Repair as needed.
Recharge the system to specifications (see page
21-92) HVAC DTCs (see page 21-9)
There is heavy frost or
condensation on the
expansion valve, and
frost on the suction line Probable cause: A restriction in the low-pressure
side of the system
Recover A/C refrigerant (see page 21-90), then
check the suction line and the expansion valve
for restrictions. Repair as needed. Recharge the
system to specifications (see page 21-92) HVAC DTCs (see page 21-9)
(cont’d)
08/08/21 14:40:59 61SNR030_210_0018
ProCarManuals.com
DYNOMITE -2009-


µµ
¦µ § ¦ § ¦§
¦§
A/C Pressure Sensor
A/C System Pressure Sensor Output
Voltage (V out) System Operation
21-21
99
(1)
140
196
(2)
28 3,138
(32)
455 kPa
(kgf/cm )
psi
V
4.575
0.684
0.425
0.2945
OUTPUT
VOLTAGE
(Vout)
Vcc 5 V Vout GND
A/C PRESSURE2
The A/C pressure sensor converts A/C pressure into electrical signals to the ECM/PCM.




Abnormally low pressure: Below 196 kPa
(2.0 kgf/cm , 28 psi)
Below 0.685 V The ECM/PCM disengages the compressor
clutch. The radiator and condenser fans
operate based on engine coolant temperature.
Normal operating pressure: Above 196 kPa (2.0 kgf/cm , 28 psi)
Below 1,470 kPa (15.0 kgf/cm , 213 psi) 0.686 V to 1.944 V The ECM/PCM cycles the compressor clutch
based on cooling demand. The radiator and
condenser fans operate at low speed unless
the engine coolant temperature exceeds 206 °F.
High operating pressure: Above 1,470 kPa (15.0 kgf/cm , 213 psi)
Below 3,138 kPa (32 kgf/cm , 455 psi) 1.945 V to 4.575 V The ECM/PCM cycles the compressor clutch
based on cooling demand. The radiator and
condenser fans operate at high speed.
Abnormally high pressure: More than
3,138 kPa (32 kgf/cm , 455 psi) Above 4.575 V The ECM/PCM disengages the compressor
clutch. The radiator and condenser fans
operate based on engine coolant temperature.
: The A/C system pressure can be monitored in the HDS PGM-FI Data List.
The response of the A/C pressure sensor is shown in the graph.
(cont’d)
222
2
2
2
08/08/21 14:41:00 61SNR030_210_0022
ProCarManuals.com
DYNOMITE -2009-

(#'
)
21-26Climate Control
Circuit Diagram
PNK
RED/BLK
12
1 2
Q6
1 2
GRN/REDRED
IG2 HOT in ON (II)
CAN HI
CAN LO
FAN HI ACC L
FAN LO A14
A4
A5 13
A/C COMPRESSOR
2
RED/WHT
BLU
F26 MICU
1
19
21
A37
A36
BLK
A9 A33 A16 A19 PNK
WHT RED
1
23
RED
LT GRN
5V
BLK
VCC6
ACPD
TW2 GRN12
SG BLK
No. 15
(7.5 A)
(20 A) No. 6 A/C DIODE A
GRY RED
WHT
LT GRN
BRN
42 3 5
1 IG2
BAT
ORNNo. 36 (10 A)
BRN
BLK RED
BLU
2
1
G301 ECM/PCM
BATTERY
No. 1 (BAT) (100 A)
24
2
3
PUR
13
41 No. 9 (40 A)
No. 2 (IG) (50 A)
1
3
42
WHT
BLK
G301
No.20(7.5A)
1
3
2
4
PUR
UNDER-HOOD FUSE/RELAY BOX IGNITION SWITCH
UNDER-DASH
FUSE/RELAY BOX
RADIATOR
FAN RELAY
FAN CONTROL
RELAY
A/C
CONDENSER
FAN RELAY A/C
COMPRESSOR
CLUTCH RELAY
BLOWER
MOTOR
RELAY
RADIATOR
FAN
MOTOR
PGM-FI
SUB
RELAY
A/C
CONDENSER
FAN
MOTOR
ENGINE
COOLANT
TEMPERATURE
(ECT) SENSOR 2A/C PRESSURE
SENSOR
GAUGE
CONTROL
MODULE
(TACH)
A/C
COMPRESSOR
CLUTCH
UNDER-DASH
FUSE/RELAY
BOX
THERMAL
PROTECTOR
A/C
DIODE B
H1 C3 Q16
G12
D1
F11 F14 F12 F2 F7 F20 E8 F1 J2 No. 7 (20 A)
08/08/21 14:41:03 61SNR030_210_0027
ProCarManuals.com
DYNOMITE -2009-

µµµµ

(#'





)
µ
µ
µ
µ µ
µ
µ
µ
YES
NO
YES
NO YES
NO
YES
NO
21-62
Climate Control
A/C Compressor Clutch Circuit Troubleshooting
A/C COMPRESSOR CLUTCH RELAY 4P SOCKET
NOTE:
 It is normal for the A/C compressor to turn off under certain conditions, such as low idle, high engine
coolant temperature, or hard acceleration.
 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 page 11-3).
1. Check the No. 20 (7.5 A) fuse in the under-hood fuse/relay box, and the No. 36 (10 A) fuse in the
under-dash fuse/relay box.
Go to step 2.
Replace the fuses and recheck. If the fuses
blow again, check for a short in the No. 20 (7.5 A)
and No. 36 (10 A) fuses circuit.
2. Connect the HDS to the DLC.
3. Start the engine.
4. Turn on the A/C.
5. Using the HDS, confirm the following values in the PGM-FI Data List at idle.
ECT Sensor 2 80 100 °C (176 212 °F)
TP Sensor About 0.5 V at idle
RPM More than 670
A/C Switch ON
A/C Clutch ON
A/C Pressure
Sensor 196 455 kPa (28 455 psi)
Go to step 6.
Troubleshoot the value that is not within the
specifications. 6. Turn the ignition switch to LOCK (0).
7. Remove the A/C compressor clutch relay from the
under-hood fuse/relay box, and test it (see page
22-70).
Go to step 8.
Replace the A/C compressor clutch relay.
8. Measure the voltage between the A/C compressor clutch relay 4P socket terminal No. 1 and body
ground.
Go to step 9.
Replace the under-hood fuse/relay box
(see page 22-65).
Ar e t he f uses OK ?
Are all the values within specif ications? Is the relay OK ?
Is there battery voltage?
08/08/21 14:43:32 61SNR030_210_0063
ProCarManuals.com
DYNOMITE -2009-




(#'


 )
21-81
Heater Unit/Core Replacement
A
B C
8x1.25mm
12.3 N·m
(1.3 kgf·m, 9.0 lbf·ft)
B A
SRS components are located in this area. Review the
SRS component locations (see page 24-11) and the
precautions and procedures (see page 24-13) before
doing repairs or service.
1. Do the battery terminal disconnection procedure (see page 22-68).
2. Disconnect the A/C line from the evaporator core
(see page 21-78).
3. Remove the air cleaner housing assembly (see page 11-345).
4. When the engine is cool, drain the engine coolant from the radiator (see page 10-8).
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; drain 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
brake lines, etc.
7. Remove the dashboard (see page 20- 108).
8. Disconnect the connector (A) from the blower motor. Remove the wire harness clip (B).
(cont’d)
08/08/21 14:43:43 61SNR030_210_0082
ProCarManuals.com
DYNOMITE -2009-


(#'



 )
21-8321-83
A/C Compressor Replacement
A C
B
6x1.0mm
9.8 N·m
(1.0 kgf·m,
7.2 lbf·ft)
A
B
13. Remove the self-tapping screws, the heater core cover (A), the grommet (B). and carefully pull out
the heater core (C).
14. Install the heater core and the evaporator 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 page 10-8).
 Make sure that there is no coolant leakage.
 Make sure that there is no air leakage.
 Refer to evaporator core replacement (see page 21-78).
16. Do the battery terminal reconnection procedure (see page 22-68). NOTE: Do not install an 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.
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 page 21-90).
3. Remove the drive belt (see page 4-31).
4. Remove the front bulkhead and the condenser fan shroud (see page 10-19).
5. Remove the splash shield (see page 20-172).
6. Remove the bolt and the nut, then disconnect the suction hose (A) and discharge hose (B) from the
A/C compressor. Plug or cap the lines immediately
after disconnecting them to avoid moisture and
dust contamination.
(cont’d)
08/08/21 14:43:45 61SNR030_210_0084
ProCarManuals.com
DYNOMITE -2009-


(#'



 )
21-8321-83
A/C Compressor Replacement
A C
B
6x1.0mm
9.8 N·m
(1.0 kgf·m,
7.2 lbf·ft)
A
B
13. Remove the self-tapping screws, the heater core cover (A), the grommet (B). and carefully pull out
the heater core (C).
14. Install the heater core and the evaporator 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 page 10-8).
 Make sure that there is no coolant leakage.
 Make sure that there is no air leakage.
 Refer to evaporator core replacement (see page 21-78).
16. Do the battery terminal reconnection procedure (see page 22-68). NOTE: Do not install an 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.
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 page 21-90).
3. Remove the drive belt (see page 4-31).
4. Remove the front bulkhead and the condenser fan shroud (see page 10-19).
5. Remove the splash shield (see page 20-172).
6. Remove the bolt and the nut, then disconnect the suction hose (A) and discharge hose (B) from the
A/C compressor. Plug or cap the lines immediately
after disconnecting them to avoid moisture and
dust contamination.
(cont’d)
08/08/21 14:43:45 61SNR030_210_0084
ProCarManuals.com
DYNOMITE -2009-

µµµ
(#'

)
Description
Outside Air Temperature Indicator Logic Update to the outside air temperature
indicator while driving
Troubleshooting
22-279
Outside Air Temperature Indicator Calibration
The outside temperature sensor is located behind the
center of the front bumper. The gauge control module
(tach) uses measurements from this sensor to display
the outside air temperature.
Because of the location of the sensor, it may be affected
by heat reflection from the road, engine and radiator
heat or hot exhaust from surrounding traffic.
These conditions can heat soak the outside air
temperature sensor and cause inaccurate readings.
Logic has been written into the gauge control module
(tach) to help prevent abnormal or fluctuating outside
air temperature indicator readings.
Initial outside air temperature indication after the
ignition switch is turned to ON (II).
 If the engine coolant temperature is 60 °C (140 °F) or higher when the ignition switch is turned to ON (II),
the outside air temperature indicated the last time the
key was turned off will be displayed regardless of the
current temperature measured by the outside air
temperature sensor.
 If the engine coolant temperature is 59 °C (139 °F) or lower when the ignition switch is turned to ON (II), the
current temperature measured by the outside air
temperature sensor will be indicated. If the temperature measured by the outside air
temperature sensor is greater than the temperature on
the outside air temperature indicator, the outside air
temperature indicator will increase by 1 °C (1.8 °F) per
minute after the vehicle speed is greater than 30 km/h
(19 mph) for more than 1 minute and 30 seconds. It will
continue to increase until the current outside air
temperature is indicated. So, the first change to the
outside air temperature indicator is 1 minute and
30 seconds after the vehicle speed is greater than
30 km/h (19 mph). If the vehicle speed drops below
30 km/h (19 mph), the indicator will not update again
until the vehicle speed is increased to 30 km/h (19 mph)
or more for more than 1 minute and 30 seconds again.
If the outside air temperature is less than the indicated
temperature, the temperature will decrease 1 °C every
2 seconds (1 °F
every 1.1 seconds) until the current
outside air temperature is indicated regardless of
vehicle speed.
If the indicator displays ‘‘ ’’ for more than 2
seconds after selecting the outside air temperature
display mode, check the outside air temperature sensor
(see page 21-68), or gauge control module self-
diagnosis (see page 22-241).
(cont’d)
08/08/21 14:36:00 61SNR030_220_0281
ProCarManuals.com
DYNOMITE -2009-