ACURA CSX 2006 Service Repair Manual


Checking for DTCs
DTC
(Temperature Indicator
Segment and AUTO
Indicator) Detection Item
21-12Climate Control
General Troubleshooting Information (cont’d)
AUTO INDICATOR
NM
TEMPERATURE INDICATOR
EG C
D
H
P
K
L
F
B A
J
The temperature display indicates single or multiple DTCs. If indicator segments A, C, E, G, J, M, and AUTO are on at
the same time, there may be an open in the common ground wire. If no DTCs are present, the indicator remains blank.
A An open in the in-car temperature sensor circuit (see page 21-31)B A short in the in-car temperature sensor circuit (see page 21-32)
C An open in the outside air temperature sensor circuit (see page 21-33)
D A short in the outside air temperature sensor circuit (see page 21-34) E An open in the sunlight sensor circuit (see page 21-35)F A short in the sunlight sensor circuit (see page 21-36)
G An open in the evaporator temperature sensor circuit (see page 21-37) H A short in the evaporator temperature sensor circuit (see page 21-39) J An open in the air mix control motor circuit (see page 21-40)
K A short in the air mix control motor circuit (see page 21-41) L A problem in the air mix control linkage, door, or motor (see page 21-42)
M An open or short in the mode control motor circuit (see page 21-44) N A problem in the mode control linkage, doors, or motor (see page 21-46) P A problem in the blower motor circuit (see page 21-47)
A and AUTO An open in the recirculation control motor circuit (see page 21-52) B and AUTO A problem in the recirculation control linkage, door, or motor (see page 21-51)
C and AUTO Climate control unit internal error (see page 21-28)
D and AUTO Climate control unit lost communication with gauge control module (TACH) (ILLUMI message) (see page 21-28)
E and AUTO A short in the recirculation control motor circuit (see page 21-29) F and AUTO Climate control unit lost communication with gauge control module (TACH) (ECT message) (see page 21-28)
J and AUTO Climate control unit lost communication with gauge control module (TACH) (VSP message) (see page 21-28)
K and AUTO Communication bus line error (see page 22-106) L and AUTO Climate control unit lost communication with gauge control module (TACH) (NE message) (see page 21-28)
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Displaying Sensor Inputs at the Climate Control Unit
Check these items before using the sensor input display mode
To run the sensor input display mode, follow these steps
21-13
The climate control unit has a mode that displays the sensor inputs it receives. This mode shows you what data the
climate control unit is receiving from each of the sensors, one at a time, and it can help you determine if a sensor is
faulty.1. Turn the ignition switch to ON (II), and check the recirculation door function; press the recirculation button to switch from FRESH to RECIRC. The air volume and sound should change slightly.
2. Set the temperature control knob to the desired test temperature. When selecting the test temperature, note these items:
 ‘‘Lo’’ temperature setting will default to MAX COOL, VENT, and RECIRC.
 ‘‘Hi’’ temperature setting will default to MAX HOT, FLOOR, and FRESH.
 19 through 31 °C settings will use the automatic climate control logic.
3. Turn the ignition switch to LOCK (0).
1. Turn the ignition switch to LOCK (0).
2. Press and hold both the AUTO and MODE buttons, then start the engine.
3. After the engine starts, release both buttons. The display panel will flash the sensor number and then the value for that sensor. Record the value displayed.
4. To advance to the next sensor, press the A/C button. Sensor Item Displayed Value1 Mode Positioning BIT
2 In-car Temperature °C
3 Outside Air Temperature °C
4 Solar Radiation Sensor Value: Dark = 00, Flashlight = 04, Cloudy = 10, Sunny = 65 10 kcal/m ·h
5 Evaporator Outlet Air Temperature °C
6 Air Mix Opening (Low value indicates cooler air distribution, higher value indicates warmer air distribution) % of opening
7 Recirculation Opening % of opening
8 Vehicle Speed (Vehicle must be driven to display speed) km/h
9 Engine Coolant Temperature °C
A Vent Temperature Air Out (TAO) °C
NOTE:  The sensor values will be displayed in degrees Celsius (°C) or an alphanumeric code. Use the chart to convert the value to degrees Fahrenheit (°F).
 If the sensor value displays ‘‘Er’’ this indicates there is an open or short in the circuit or sensor. Check for DTCs using the HDS, or use the climate control self-diagnostic function.
 If necessary, compare the sensor input display to a known-good vehicle under the same test conditions.
 If the sensor is out of the normal range, refer to the sensor test or substitute a known-good sensor, and recheck.
5. To cancel the sensor input display mode, press the AUTO button or turn the ignition switch to LOCK (0). (cont’d)
2
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µµµµ
µµ µ µµ
µµ µµ µµ
µµ µµ µµ
µµ µµ µµ ••• •••´ ´
Celsius to Fahrenheit Conversion Table
Alphanumeric Conversion Table
Alphanumeric Conversion Table (Mode Positioning)
21-14
Climate Control
General Troubleshooting Information (cont’d)
°C °F °C °F °C °F °C °F °C °F
0 3210502068308640104
1 3411522170318841106
2 3612542272329042108
3 3713552373339143109
4 3914572475349344111
5 4115592577359545113
6 4316612679369746115
7 4517632781379947117
8 46186428823810048118
9 48196629843910249120
°C °F °C °F °C °F °C °F °C °F
50 122 60 140 70 158 80 176 90 194
51 124 61 142 71 160 81 178 91 196
52 126 62 144 72 162 82 180 92 198
53 127 63 145 73 163 83 181 93 199
54 128 64 147 74 165 84 183 94 201
55 131 65 149 75 167 85 185 95 203
56 133 66 151 76 169 86 187 96 205
57 135 67 152 77 170 87 188 97 207
58 136 68 154 78 172 88 190 98 208
59 139 69 158 79 174 89 192 99 210
Display Reading (Alphanumeric) °C °F %
A1 thru A9 1 thru 9 30 thru 16 1 thru 9 B0 thru B9 10 thru 19 14 thru 2 10 thru 19
C0 thru C9 20 thru 29 4 thru 20 20 thru 29
D0 thru D9 30 thru 39 22 thru 38 30 thru 39 E0 thru E9 40 thru 49 40 thru 58 40 thru 49F0 thru F9 100 thru 109
Display Reading (Alphanumeric) Mode Position
2OVERVENT
AVENT 8 VENT-HEAT/VENTc HEAT/VENT
d HEAT/VENT-HEAT 9HEAT
b HEAT-HEAT/DEF 3 HEAT/DEF
7 HEAT/DEF-DEF
6DEF
EOVERDEF
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(#'
) Checking the DTCs by HDSDTC Detection Item or Symptom ECU DTC type Page
21-15
DTC Troubleshooting Index
B1200 Communication bus line error Climate control
unit Loss of
communication(see page 22-107)
B1202 Climate control unit internal error Climate control
unit Internal error (see page 21-28)
B1205 Climate control unit lost communication with gauge control module (TACH)
(VSP/NE message) Climate control
unit
Loss of
communication(see page 21-28)
B1206 Climate control unit lost communication with gauge control module (TACH) (ECT
message) Climate control
unit
Loss of
communication(see page 21-28)
B1207 Climate control unit lost communication with gauge control module (TACH)
(ILLUMI message) Climate control
unit
Loss of
communication(see page 21-28)
B1220 A short in the recirculation control motor circuit Climate control
unitSignal error (see page 21-29)
B1225 An open in the in-car temperature sensor circuit Climate control
unitSignal error (see page 21-31)
B1226 A short in the in-car temperature sensor circuit Climate control
unitSignal error (see page 21-32)
B1227 An open in the outside air temperature sensor circuit Climate control
unitSignal error (see page 21-33)
B1228 A short in the outside air temperature sensor circuit Climate control
unitSignal error (see page 21-34)
B1229 An open in the sunlight sensor circuit Climate control unitSignal error (see page 21-35)
B1230 A short in the sunlight sensor circuit Climate control unitSignal error (see page 21-36)
B1231 An open in the evaporator temperature sensor circuit Climate control
unitSignal error (see page 21-37)
B1232 A short in the evaporator temperature sensor circuit Climate control
unitSignal error (see page 21-39)
B1233 An open in the air mix control motor circuit Climate control unitSignal error (see page 21-40)
B1234 A short in the air mix control motor circuit Climate control unitSignal error (see page 21-41)
B1235 A problem in the air mix control linkage, door, or motor Climate control
unitSignal error (see page 21-42)
B1239 An open or short in the mode control motor circuit Climate control
unitSignal error (see page 21-44)
B1240 A problem in the mode control linkage, doors, or motor Climate control
unitSignal error (see page 21-46)
B1241 A problem in the blower motor circuit Climate control unitSignal error (see page 21-47)
B2983 A problem in the recirculation control motor linkage, door, or motor Climate control
unitSignal error (see page 21-51)
B2986 An open in the recirculation control motor circuit Climate control
unitSignal error (see page 21-52)
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Symptom Diagnostic procedure Also check for
21-16
Climate Control
Symptom Troubleshooting Index







 –
– 




 





 





 –
– 





 


The blower and heater
controls and the A/C
system do not work
Probable cause: Climate control unit malfunction
Do the climate control power and ground circuit
troubleshooting (see page 21-53) HVAC DTCs (see page 21-9)
Blown fuse No. 36 (10 A) in the
driver’s under-dash fuse/relay
box
Poor ground at G504 (see page
22-30)
Poor or loose connections at the
terminals
The A/C compressor
clutch and the A/C
condenser/radiator
fans are inoperative,
but the blower and
heater controls work Probable cause: A/C pressure sensor circuit
malfunction
Troubleshoot the pressure sensor circuit:
A/C pressure sensor circuit low voltage
(see page 11-301)
A/C pressure sensor circuit high voltage
(see page 11-303)
NOTE: The A/C pressure sensor can malfunction
without setting a DTC HVAC DTCs (see page 21-9)
Powertrain DTCs (see page
11-3)
A/C signal circuit
troubleshooting (see page
21-64)
Poor or loose connections at the
terminals
The A/C compressor
clutch does not engage,
but the A/C condenser/
radiator fans operate,
and the blower and
heater controls work Probable cause: No power to the A/C compressor
clutch
Do the A/C compressor clutch circuit
troubleshooting (see page 21-62)
HVAC DTCs (see page 21-9)
Blown fuse No. 20 (7.5 A) in the
under-hood fuse/relay box
A/C system pressure is normal
(see page 21-21)
A/C thermal protector has
continuity (see step 4 on page
21-85)
Poor or loose connections at the
terminals
The A/C condenser fan
and/or the radiator fan
do not run with the A/C
on Probable cause: Condenser/radiator fan low
speed circuit malfunction
Do the radiator and A/C condenser fan low speed
circuit troubleshooting (see page 21-56) HVAC DTCs (see page 21-9)
Powertrain DTCs (see page
11-3)
Blown fuse No. 7 (20 A) in the
under-hood fuse/relay box
Poor ground at G301 (see page
22-22)
Poor or loose connections at the
terminals
The condenser/radiator
fans do not run at high
speed, but do run at
low speed Probable cause: Malfunction in the fan(s) high
speed circuit
Do the following troubleshooting as needed:
A/C condenser fan high speed circuit
troubleshooting (see page 21-60)
Radiator fan high speed circuit troubleshooting
(see page 10-26) HVAC DTCs (see page 21-9)
Powertarin DTCs (see page
11-3)
Blown fuse No. 6 (20 A) and/or
No.7 (20 A) in the under-hood
fuse/relay box
Poor ground at G301 (see page
22-22)
Poor or loose connections at the
terminals
Voice commands do
not work Probable cause: Communication problem
between the climate control unit and the
navigation system
Do the navigation communication line circuit
troubleshooting (see page 21-54) HVAC DTCs (see page 21-9)
Navi system link (see page
23-135)
Poor or loose connections at the
terminals
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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
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SymptomDiagnostic procedure Also check for
21-18Climate Control
Symptom Troubleshooting Index (cont’d)





 


 


 –
– 


 

Warm air comes out of
the vents, and there is
frost on the expansion
valve
Probable cause: The expansion valve is stuck
closed
Replace the expansion valve (see page 21-80)
HVAC DTCs (see page 21-9)
Check the old expansion valve
for contamination. If
contaminants are found,
replace the A/C system
component that caused the
contamination
The temperature of the
liquid line is the same
on both sides of the
expansion valve, and
the evaporator coil or
suction line has heavy
condensation Probable cause: The expansion valve is stuck
open
Replace the expansion valve (see page 21-80)
HVAC DTCs (see page 21-9)
Check the old expansion valve
for contamination. If
contaminants are found,
replace the A/C system
component that caused the
contamination
Warm air comes out of
the vents, but
operation is normal
otherwise Probable cause: Compressor failure
Do the A/C system test (see page 21-99), and
correct any problems. If necessary, replace the
compressor (see page 21-83) HVAC DTCs (see page 21-9)
Add refrigerant oil depending
on the part you replaced
(see page 21-7)
Driver’s and
passenger’s side vent
temperatures vary by
more than 11 °C (20 °F) Probable causes: The recirculation control door
or the air mix door is malfunctioning
Do the following troubleshooting:
Recirculation control motor test (see page
21-74)
Air mix control motor test (see page 21-72) HVAC DTCs (see page 21-9)
Poor or loose connections at the
terminals
Insufficient heating 1. 2.
3.
4.
5.
6.
7.Check the coolant level (see page 10-7)
Check the radiator cap (see page 10-4)
Check the coolant temperature during normal
operation
Check the heater core inlet hose temperature:
If it is COLD, check for restrictions in the hose,
a damaged or leaking thermostat, or a
damaged or leaking water pump
If it is HOT, check for restrictions in the
heater core. Back flush or replace the heater
core
Do the air mix control motor test (see page
21-72)
Check the blower motor unit for obstructions
Check for air leaks around the ducts and vents HVAC DTCs (see page 21-9)
Damaged cylinder head gasket
08/08/21 14:40:59 61SNR030_210_0019
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21-19
System Description
EXPANSION VALVE
(Meters the required amount of
refrigerant into the evaporator) RECEIVER/DRYER
DESICCANT
(Traps debris, and
removes moisture)A/C COMPRESSOR
(Suction and compression)
A/C CONDENSER
(Radiation of heat)
A/C PRESSURE SENSOR
(Triple function)
BLOWER FAN
EVAPORATOR
(Absorption of heat)
EVAPORATOR TEMPERATURE SENSOR
RELIEF VALVE
(Relieves pressure at the A/C compressor
when the pressure is too high)
HIGH PRESSURE VAPORHIGH PRESSURE LIQUID
LOW PRESSURE LIQUID
LOW PRESSURE VAPOR
The air conditioning (A/C) system removes heat from the passenger compartment by transferring heat from the
ambient air to the evaporator. The A/C system refrigerant expands in the evaporator, and the evaporator becomes
very cold and absorbs the heat from the ambient air. The blower fan pushes air across the evaporator where the heat
is absorbed, and then it blows the cool air into the passenger compartment.
This vehicle uses HFC-134a (R-134a) refrigerant, which does not contain chlorofluorocar bons. Pay attention to the
following service items:
 Do not mix refrigerants CFC-12 (R-12) and HFC-134a (R-134a). They are not compatible.
 Use only the recommended polyalkyleneglycol (PAG) refrigerant oil (SP-10) designed for the R-134a A/C compressor. Intermixing the recommended (PAG) refrigerant oil with any other refrigerant oil will result in A/C
compressor failure.
 All A/C system parts (A/C compressor, discharge line, suction line, evaporator, A/C condenser, receiver/dryer, expansion valve, O-rings for joints) are designed for refrigerant R-134a. Do not exchange with R-12 parts.
 Use a halogen gas leak detector designed for refrigerant R-134a.
 R-12 and R-134a refrigerant servicing equipment are not interchangeable. Use only a recovery/recycling/charging station that is U.L.-listed and is certified to meet the requirements of SAE J2210 to service the R-134a air
conditioning systems.
 Always recover refrigerant R-134a with an approved recovery/recycling/charging station before disc onnecting any
A/C fitting.
(cont’d)
When the refrigerant is below
196 kPa (2.0 kgf/cm , 28 psi)
or above 3,138 kPa (32 kgf/cm ,
455 psi), the ECM/PCM turns the
compressor relay off to protect
the A/C compressor.
When the refrigerant is above
1,470 kPa (15.0 kgf/cm , 213 psi),
the A/C pressure sensor
switches the radiator and
A/C condenser fans to high speed.22
2
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Oil Separator
21-20Climate Control
System Description (cont’d)
OUTLET SIDE
(To A/C condenser)
OIL SEPARATOR
FROM INSIDE
A/C COMPRESSOR
INLET SIDE
(To inside
A/C compressor)
EVAPORATOR
A/C COMPRESSOR A/C CONDENSER
EXPANSION VALVE
HIGH REFRIGERANT OIL FLOWLOW REFRIGERANT OIL FLOW
OIL SEPARATOR
Oil emission from the A/C compressor to the A/C line is reduced by placing the oil separator in the A/C compressor.
This results in a thinner oil film inside of the heat exchangers (A/C condenser and evaporator). Air conditioning
efficiency is increased without sacrificing engine performance.
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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
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