check engine ACURA CSX 2006 Service Repair Manual

SymptomDiagnostic procedure Also check for
21-17


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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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21-57
RADIATOR FAN RELAY 4P SOCKET ECM/PCM CONNECTOR A (44P)PUR
JUMPER WIRE
10. Disconnect the jumper wire.
11. Turn the ignition switch to ON (II).
12. Measure the voltage between the radiator fan relay 4P socket terminal No. 3 and body ground.
Go to step 13.
Go to step 37. 13. Turn the ignition switch to LOCK (0).
14. Reinstall the radiator fan relay.
15. Jump the SCS line with the HDS.
NOTE: This step must be done to protect the engine
control module (ECM)/powertrain control module
(PCM) from damage.
16. Disconnect ECM/PCM connector A (44P).
17. Connect the ECM/PCM connector A (44P) terminal No. 4 to body ground with a jumper wire.
18. Turn the ignition switch to ON (II). Check for loose wires or poor connections at
ECM/PCM connector A (44P) terminal No. 4. If the
connections are good, substitute a known-good
ECM/PCM, and recheck. If the symptom/indication
goes away, replace the original ECM/PCM
(see page 11-228).
Repair open in the wire between the radiator
fan relay and the ECM/PCM.
19. Disconnect the jumper wire.
20. Reinstall the radiator fan relay.
21. Disconnect the radiator fan 2P connector.
22. Turn the ignition switch to ON (II), then set the A/C button and fan control dial ON.
(cont’d)
Terminal side of female terminals
Is there battery voltage?
Do t he A/ C cond enser and r ad i at or f ans r un onlow?
08/08/21 14:42:26 61SNR030_210_0058
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21-61
ECM/PCM CONNECTOR A (44P)
GRY
JUMPER WIRE A/C DIODE B 2P SOCKET
A/C DIODE B
1 2
1 2
8. Turn the ignition switch to LOCK (0).
9. Reinstall the A/C condenser fan relay.
10. Jump the SCS line with the HDS. NOTE: This step must be done to protect the engine
control module (ECM)/powertrain control module
(PCM) from damage.
11. Disconnect ECM/PCM connector A (44P).
12. Connect the ECM/PCM connector A (44P) terminal No. 5 to body ground with a jumper wire.
13. Turn the ignition switch to ON (II). Check for loose wires or poor connections at
ECM/PCM connector A (44P) terminal No. 5. If the
connections are good, substitute a known-good
ECM/PCM, and recheck. If the symptom/indication
goes away, replace the original ECM/PCM
(see page 11-228).
Repair open in the wire between the A/C
condenser fan relay and the ECM/PCM. 14. Remove the A/C diode B from the under-hood fuse/
relay box.
15. Turn the ignition switch to ON (II).
16. Measure the voltage between the A/C diode B 2P socket terminal No. 2 and body ground.
Go to step 17.
Replace the under-hood fuse/relay box
(see page 22-65).
17. Using the diode setting ( ) on a DVOM, check for current flow in both directions between the A/C
diode B terminals No. 1 and No. 2.
Replace the under-hood fuse/relay box
(see page 22-65).
Replace the A/C diode B.
Terminal side of female terminals
Does t he A/ C cond enser f an r un on hi gh? Is there battery voltage?
I s t her e cur r ent f l ow i n onl y one d i r ect i on?
08/08/21 14:43:32 61SNR030_210_0062
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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
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21-63
JUMPER WIRE
PUR
A/C COMPRESSOR CLUTCH RELAY 4P SOCKET
A/C COMPRESSOR CLUTCH RELAY 4P SOCKET
BRN ECM/PCM CONNECTOR A (44P)
JUMPER WIRE RED
9. Connect the A/C compressor clutch relay 4P socket
terminals No. 1 and No. 2 with a jumper wire.
Go to step 10.
Go to step 19.
10. Disconnect the jumper wire.
11. Turn the ignition switch to ON (II).
12. Measure the voltage between the A/C compressor clutch relay 4P socket terminal No. 3 and body
ground.
Go to step 13.
Repair open in the wire between the No. 36
(10 A) fuse in the under-dash fuse/relay box and the
A/C compressor clutch relay. 13. Turn the ignition switch to LOCK (0).
14. Reinstall the A/C compressor clutch relay.
15. Jump the SCS line with the HDS.
NOTE: This step must be done to protect the engine
control module (ECM)/powertrain control module
(PCM) from damage.
16. Disconnect ECM/PCM connector A (44P).
17. Connect the ECM/PCM connector A (44P) terminal No. 14 to body ground with a jumper wire.
18. Turn the ignition switch to ON (II). Check for loose wires or poor connections at
ECM/PCM connector A (44P). If the connections are
good, check the ECM/PCM grounds. If the grounds
are good, substitute a known-good ECM/PCM, and
recheck. If the symptom/indication goes away,
replace the original ECM/PCM (see page 11-228).
Repair open in the wire between the A/C
compressor clutch relay and the ECM/PCM.
(cont’d)
Terminal side of female terminals
Does the A/ C compressor clutch click?
Is there battery voltage? Does t he A/ C compr essor cl i ck ?
08/08/21 14:43:33 61SNR030_210_0064
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21-6421-64Climate Control
A/C Compressor Clutch Circuit
Troubleshooting (cont’d)
A/C Signal Circuit Troubleshooting
A/C COMPRESSOR CLUTCH RELAY 4P SOCKET
RED/WHT
A/C COMPRESSOR CLUTCH 3P CONNECTOR PUR
REDBRN
CLIMATE CONTROL UNIT 32P CONNECTOR
19. Disconnect the jumper wire.
20. Disconnect the A/C compressor clutch 3P connector.
21. Check for continuity between the A/C compressor
clutch relay 4P socket terminal No. 2 and the A/C
compressor clutch 3P connector terminal No. 2.
Check the A/C compressor clutch clearance,
and the compressor clutch field coil (see page
21-85). Repair as needed.
Repair open in the wire between the A/C
compressor clutch relay and the A/C compressor
clutch. NOTE:
 Do not use this troubleshooting procedure if any of the following items are operative: A/C condenser fan,
radiator fan, A/C compressor. Refer to the symptom
troubleshooting index.
 Before doing symptom troubleshooting, check for powertrain DTCs (see page 11-3).
1. Connect the HDS to the DLC.
2. Start the engine.
3. Turn on the A/C.
4. Check the A/C SWITCH in the PGM-FI Data List with the HDS.
The A/C signal is OK at this time.
Go to step 5.
5. Turn the ignition switch to LOCK (0), and disconnect the climate control unit 32P connector.
6. Measure the evaporator temperature sensor resistance between the climate control unit 32P
connector terminals No. 8 and No. 19.
Go to step 7.
Test the evaporator temperature sensor
(see page 21-70).
Wire side of female terminals
Wire side of female terminals
Is there continuity?Is the A/ C SW IT CH on?
I s r esi st ance l ess t han 24 k ?
08/08/21 14:43:33 61SNR030_210_0065
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DYNOMITE -2009-



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21-6421-64Climate Control
A/C Compressor Clutch Circuit
Troubleshooting (cont’d)
A/C Signal Circuit Troubleshooting
A/C COMPRESSOR CLUTCH RELAY 4P SOCKET
RED/WHT
A/C COMPRESSOR CLUTCH 3P CONNECTOR PUR
REDBRN
CLIMATE CONTROL UNIT 32P CONNECTOR
19. Disconnect the jumper wire.
20. Disconnect the A/C compressor clutch 3P connector.
21. Check for continuity between the A/C compressor
clutch relay 4P socket terminal No. 2 and the A/C
compressor clutch 3P connector terminal No. 2.
Check the A/C compressor clutch clearance,
and the compressor clutch field coil (see page
21-85). Repair as needed.
Repair open in the wire between the A/C
compressor clutch relay and the A/C compressor
clutch. NOTE:
 Do not use this troubleshooting procedure if any of the following items are operative: A/C condenser fan,
radiator fan, A/C compressor. Refer to the symptom
troubleshooting index.
 Before doing symptom troubleshooting, check for powertrain DTCs (see page 11-3).
1. Connect the HDS to the DLC.
2. Start the engine.
3. Turn on the A/C.
4. Check the A/C SWITCH in the PGM-FI Data List with the HDS.
The A/C signal is OK at this time.
Go to step 5.
5. Turn the ignition switch to LOCK (0), and disconnect the climate control unit 32P connector.
6. Measure the evaporator temperature sensor resistance between the climate control unit 32P
connector terminals No. 8 and No. 19.
Go to step 7.
Test the evaporator temperature sensor
(see page 21-70).
Wire side of female terminals
Wire side of female terminals
Is there continuity?Is the A/ C SW IT CH on?
I s r esi st ance l ess t han 24 k ?
08/08/21 14:43:33 61SNR030_210_0065
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Possible Leak Area Diagnostic Procedure with theLeak Detector Notes
21-95
4. With the engine OFF, use a halogen leak detector first to detect the leak source. Follow a continuous path in order
to ensure that you will not miss any possible leaks. Test the following areas of the system for leaks:

 





 


Service Ports Check the service ports with
the detector.
If the detector ‘‘sniffs’’ a leak,
use fluorescent dye to
confirm it. When capping the service ports, ensure that the seals
on the port caps are in place, and that the caps are
tight. The caps are used as the final seals in the
system.
Condenser If the detector ‘‘sniffs’’ a leak, use fluorescent dye to confirm it. Check for joints or connections coated with oily
dust.
Check for damaged and corroded areas.
Check all fittings, couplings, brazed/welded areas
and areas around attachment points.
Move the probe slowly (1 inch/second or less), and
keep it within 1/4 inch of the component being
checked. This maximizes the chance of detecting a
leak.
If you detect a leak, blow compressed air over the
area, then recheck for leaks. For large leaks,
clearing the area with compressed air may help
you pinpoint the leak source.
A/C Lines (Low
pressure side) Wiggle the rubber hoses
when checking crimped metal
ends.
If the detector ‘‘sniffs’’ a leak,
use fluorescent dye to
confirm it. Check all fittings, couplings, pressure switches,
brazed/welded areas, and areas around attachment
points on A/C lines and components.
Check for damaged and corroded areas.
Move the probe slowly (1 inch/second or less), and
keep it within 1/4 inch of the component being
checked. This maximizes the chance of detecting a
leak.
5. Close the quick coupler valves, then disconnect the quick couplers from the vehicle service ports.
6. Attach the universal connect set, from the Optimax Jr. Leak Detection Kit, to the service valve fitting. Close the control valve (the black knob on the connect set).
7. Attach the charging station low pressure hose quick coupler to the service valve fitting, and open the quick coupler valve. Evacuate the connect set using the charging station vacuum pump, then close the quick coupler
valve.
8. Detach the universal connect set, and install a Tracer-Stick
dye capsule between the connect set and the service
valve fitting (see the manufacturer’s instructions for more detail).
9. Attach the quick coupler on the universal connect set to the low pressure service port on the vehicle. Open the charging station low pressure hose quick coupler valve, but do not open the control valve.
10. Start the engine, and set the A/C system to MAX A/C. Open the control valve to let refrigerant and the dye enter the A/C system through the low pressure service port. Close the control valve when the Tracer-Stick
dye capsule
is empty.
11. Run the engine and A/C system for 15 minutes to thoroughly circulate the dye. Then shut the engine off, and inspect the following areas of the system for leaks.
(cont’d)
08/08/21 14:44:54 61SNR030_210_0096
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21-97
A/C System Noise Check
 Air conditioning refrigerant or lubricant vaporcan irritate your eyes, nose, or throat.
 Be careful when connecting service equipment.
 Do not breathe refrigerant or vapor.
The A/C system noise check will help you determine the
source of abnormal A/C system noise.
NOTE:  If accidental system discharge occurs, ventilate the work area before resuming service.
 Additional health and safety information may be obtained from the refrigerant and lubricant
manufacturers.
 Identify the conditions when the noise occurs. The weather, the vehicle speed, the vehicle being in gear
or in neutral, the engine temperature, or other
conditions may be factors in determining the noise
source.
 Do an A/C system inspection (see page 21-6), and correct any problems found prior to diagnosing
abnormal noises.
 Abnormal A/C noises can be misleading. For example,
a sound similar to a failed bearing may be caused by
loose fasteners, loose mounting brackets, or faulty
compressor clutch assembly.
1. Inspect the air inlet grille in the cowl cover for debris. If debris is present, remove it.
2. Sit inside the vehicle, close the doors and windows, and turn the ignition switch to ON (II), but do not
start the engine. Cycle the HVAC system through all
blower speeds and all air distribution modes to
determine where and when the noise occurs. 3. Operate the blower at each speed with the engine
and A/C off, and check for unusual noises and
excessive vibration. If noise and/or vibration are
present, do the following checks:
–1 If the noise or vibration occurs only in a specific mode or setting, then check these
items: Operation of the mode control motor, door, and linkage
 Operation of the air mix control motor(s), door(s), and linkage
 Operation of the recirculation motor, door, and linkage
–2 If there is a squeaking or chirping noise, but no unusual vibration, replace the blower motor
(see page 21-77).
–3 Remove the blower unit (see page 21-76), and check for foreign material (leaves or twigs, for
example) on the blower motor and fan. If
foreign material is present, remove it, and
recheck for noise. If you don’t find any foreign
material, remove the blower motor (see page
21-77), and check these items: Check if the fan blades are cracked or broken
 Make sure the fan retainer is tight
 Inspect the fan alignment on the blower motor shaft
Replace the blower motor if any problems are
present.
4. Set up the vehicle for the running A/C che cks:
 Select a quiet area for testing
 Apply the parking brake
 Shift the vehicle in PARK or in Neutral
 Start the engine
 Set the temperature control dial to Max Cool
 Set the mode control switch to Vent
 Set the fan control dial to minimum (but not OFF)
 Turn the A/C switch ON
Switch the compressor on and off several times to
clearly identify the sound during A/C compressor
operation. Listen to the noise while the A/C
compressor clutch is engaged and disengaged.
Probe the A/C system with a stethoscope to
pinpoint the noise.
NOTE: If the noise does not change when the A/C
compressor clutch engages or disengages, the
noise may be caused by an engine-related
component. Probe the engine area with a
stethoscope to pinpoint the noise. (cont’d)
08/08/21 14:44:54 61SNR030_210_0098
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21-98Climate Control
A/C System Noise Check (cont’d)
5. Turn the ignition switch to LOCK (0), and check the
drive belt for excessive wear, oil contamination,
improper routing, or a faulty belt tensioner
(see page 4-30). Correct any problems found. Start
the engine, run the A/C system, and check if the
noise is coming from the drive belt, the belt
tensioner or any of the pulleys. Repair or replace
any faulty components.
6. Listen for noises coming from the A/C lines, the A/C hoses, the condenser, the evaporator, the receiver/
drier, or the expansion valve, and check these
items:
 Noises caused by A/C components touching other components or the body. Reroute or
insulate the A/C component(s) as needed, and
recheck for noise.
 Loose, damaged or excessively worn A/C components or mounting hardware. Repair or
replace the faulty component(s) or hardware, and
recheck for noise.
 A moaning noise coming from the A/C suction line. If there is a moaning noise, check the
system refrigerant charge (see page 21-92). If the
refrigerant charge is OK, replace the receiver/
dryer.
7. Check the operation of the A/C compressor clutch:  Make sure compressor clutch engages withoutslipping. If the clutch does not engage,
troubleshoot the A/C compressor clutch circuit
(see page 21-62). If the compressor clutch slips,
replace the complete clutch assembly (see page
21-86).
 Make sure the compressor clutch disengages. If the clutch does not disengage, do the A/C
compressor clutch check (see page 21-85). If the
compressor clutch is OK, replace the A/C
compressor (see page 21-83).
 Make sure the compressor clutch cycles normally. If the compressor clutch is cycling rapidly, the
A/C system is probably low on refrigerant due to
a leak. Do the refrigerant leak check (see page
21-93). If the refrigerant charge is OK, and there
are no leaks, troubleshoot the A/C compressor
clutch circuit. 8. Listen with a stethoscope for noises coming from
the A/C compressor, and check these items:
 The noise changes when the compressor clutch disengages. If the noise does not change when
the A/C compressor disengages, the noise may
be caused by an engine-related component.
Probe the engine area with a stethoscope to
pinpoint the noise.
 The A/C system operating pressures are normal. If the system pressures are abnormal,
troubleshoot the problem using the pressure test
table in the A/C system check (see page 21-99).
Correct the pressure-related problem(s), and
recheck for noise.
 The compressor hose connections, mounting brackets, and fasteners are in good condition. If
any of these components are loose, damaged, or
excessively worn, repair or replace the faulty
component(s), and recheck for noise. If these
components are in good condition, and the noise
is still present, replace the A/C compressor
(see page 21-83).
08/08/21 14:44:54 61SNR030_210_0099
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