2006 ACURA CSX check engine


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K20Z2 engine
11-34611-346 Intake Air System
Air Cleaner Element Inspection/
Replacement
Intake Air Resonator Removal/
Installation
A
B
C
D
E B
C
A
9.8 N·m
(1.0 kgf·m,
7.2 lbf·ft)
1. Open the air cleaner housing cover (A).
2. Remove the air cleaner element (B) from the air
cleaner housing (C).
3. Check the air cleaner element for damage or clogging. If it is damaged or clogged, replace it.
NOTE: Do not use compressed air to clean the air
cleaner element.
4. Clean and remove any debris from inside the air cleaner housing.
5. Install the parts in the reverse order of removal.  If you did not replace the air cleaner element, thisprocedure is complete.
 If the maintenance minder required air cleaner element replacement, reset the maintenance
minder(seepage3-7).
 If you replaced the air cleaner element, reset the ECM/PCM (see page 11-4), and do the ECM/PCM
idle learn procedure (see page 11-310). 1. Remove the front bumper (see page 20-146).
2. Remove the bolts (A), and pipe (B).
3. Remove the intake air resonator (C).
4. Do the battery removal procedure (see page 22-69).
5. Remove the bolt (D), and duct (E).
6. Install the parts in the reverse order of removal.
7. Do the battery installation procedure (see page
22-69).
08/08/21 14:31:09 61SNR030_110_0346
ProCarManuals.com
DYNOMITE -2009-


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K20Z2 engine
11-348Intake Air System
Throttle Body Removal/Installation
A
B
C
D
F E
22 N·m
(2.2 kgf·m, 16 lbf·ft)
Do not insert your fingers into the installed throttle body when you turn the ignition switch to ON (II) or while the
ignition switch is ON (II). If you do, there will be serious injury to your fingers if the throttle valve is activated.
NOTE: If you are replacing or cleaning the throttle body, start at step 1. If you are removing the throttle body, start at
step 4. 1. Connect the HDS to the DLC while the engine is stopped.
2. Select the INSPECTION MENU with the HDS.
3. Do the TP POSITION CHECK in the ETCS TEST.
4. Turn the ignition switch to LOCK (0).
5. Remove the intake air duct (A).
6. Disconnect the throttle body connector (B).
7. Disconnect the water bypass hoses (C), and plug them.
8. Disconnect the vacuum hose (D).
9. Remove the throttle body (E).
10. Install the parts in the reverse order of removal with a new gasket (F), then do these:  Refill the radiator with engine coolant (see page 10-8).
 Do the ECM/PCM idle learn procedure (see page 11-310).
08/08/21 14:31:10 61SNR030_110_0348
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DYNOMITE -2009-


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K20Z3 engine
11-349
22 N·m
(2.2 kgf·m, 16 lbf·ft)A
B
C D
E F
D
G
Do not insert your fingers into the installed throttle body when you turn the ignition switch to ON (II) or while the
ignition switch is ON (II). If you do, there will be serious injury to your fingers if the throttle valve is activated.
NOTE: If you are replacing or cleaning the throttle body, start at step 1. If you are removing the throttle body, start at
step 4. 1. Connect the HDS to the DLC while the engine is stopped.
2. Select the INSPECTION MENU with the HDS.
3. Do the TP POSITION CHECK in the ETCS TEST.
4. Turn the ignition switch to LOCK (0).
5. Remove the intake air duct (A).
6. Disconnect the throttle body connector (B).
7. Disconnect the water bypass hoses (C), and plug them.
8. Disconnect the vacuum hoses (D) and the clamp (E).
9. Remove the throttle body (F).
10. Install the parts in the reverse order of removal with a new gasket (G), then do these:  Refill the radiator with engine coolant (see page 10-8).
 Do the ECM idle learn procedure (see page 11-310).
08/08/21 14:31:11 61SNR030_110_0349
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DYNOMITE -2009-

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DTC P0420:
YES
NO YES
NO
YES
NO
11-353
DTC Troubleshooting
Catalyst System Efficiency Below
Threshold
NOTE:
 Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general
troubleshooting information (see page 11-3).
 If some of the DTCs listed below are stored at the same time as DTC P0420, troubleshoot them first,
then recheck for DTC P0420.
P0137, P0138: Sec ondary HO2S (Sensor 2)
P0141: Secondary HO2S (Sensor 2) heater
 Poor quality fuel may cause this DTC.
1. Turn the ignition switch to ON (II).
2. Clear the DTC with the HDS.
3. Start the engine. Hold the engine speed at 3,000 rpm without load (A/T in P or N, M/T in
neutral) until the radiator fan comes on, then let it
idle.
4. Test-drive under these conditions:  Engine coolant temperature (ECT SENSOR 1)above70°C(158°F)
 A/TinD,M/Tin5th
 Vehicle speed between 72 120 km/h (45 75 mph) for 5 minutes or more with cruise
control set
 K20Z2 engine: Maintain the vehicle speed at 88 km/h (55 mph) for 5 minutes or more with
cruise control set
 K20Z3 engine: Maintain the vehicle speed at 88 km/h (55 mph) for 30 seconds or more
5. Monitor the OBD STATUS for DTC P0420 in the DTCs MENU with the HDS.
Go to step 6.
If the screen indicates OUT OF CONDITION,
go to step 4 and recheck. If the screen indicates
PASSED, intermittent failure, the system is OK at
this time. If the screen indicates FAILED, go to step
8.
6. Continue test driving until a result comes on. 7. Monitor the OBD STATUS for DTC P0420 in the
DTCs MENU with the HDS.
Go to step 8.
If the screen indicates PASSED, intermittent
failure, the system is OK at this time. If the screen
indicates EXECUTING, keep driving until a result
comes on. If the screen indicates OUT OF
CONDITION, go to step 4 and recheck.
8. Turn the ignition switch to LOCK (0).
9. Replace the TWC (see page 11-355).
10. Turn the ignition switch to ON (II).
11. Reset the ECM/PCM with the HDS.
12. Do the ECM/PCM idle learn procedure (see page 11-310).
13. Start the engine. Hold the engine speed at 3,000 rpm without load (A/T in P or N, M/T in
neutral) until the radiator fan comes on, then let it
idle.
14. Test-drive for about 10 minutes, varying the vehicle speed.
15. Check the CATA MONITOR CONDITION in the DATA LIST with the HDS.
Go to step 16.
Go to step 13 and recheck.
16. Test-drive under these conditions:  Engine coolant temperature (ECT SENSOR 1)above70°C(158°F)
 A/TinD,M/Tin5th
 K20Z2 engine: Vehicle speed at 88 km/h (55mph) for 5 minutes or more with cruise control set
 K20Z3 engine: Vehicle speed at 88 km/h (55mph) for 30 seconds or more
(cont’d)
Does t he scr een i nd i cat e E X E CU T IN G?Does t he scr een i nd i cat e F AILE D?
Is the condition OK ?
08/08/21 14:31:13 61SNR030_110_0353
ProCarManuals.com
DYNOMITE -2009-

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DTC P0401:
YES
NO
YES
NO YES
NO
YES
NO
11-357
DTC Troubleshooting
EGR Insufficient Flow
NOTE: Before you troubleshoot, record all freeze data
and any on-board snapshot, and review the general
troubleshooting information (see page 11-3).
1. Turn the ignition switch to ON (II).
2. Clear the DTC with the HDS.
3. Start the engine. Hold the engine speed at 3,000 rpm without load (A/T in P or N, M/T in
neutral) until the radiator fan comes on, then let it
idle.
4. Do the EGR TEST in the INSPECTION MENU with the HDS.
Go to step 5.
Go to step 7.
5. Test-drive under these conditions:  Engine coolant temperature (ECT SENSOR 1)above70°C(158°F)
 A/TinD,M/Tin4th
 Drive at a steady speed between 88 120 km/h (55 75 mph) for at least 10 seconds
 During the drive, decelerate (with the throttle fully closed) for 5 seconds
6. Monitor the OBD STATUS for DTC P0401 in the DTCs MENU with the HDS.
RemovetheEGRplate(seepage9-2),and
clean the intake manifold port with throttle plate
and induction cleaner, then go to step 9.
If the screen indicates PASSED, intermittent
failure, the system is OK at this time. Check for
poor connections or loose terminals at the EGR
valve and the ECM/PCM. If the screen indicates
EXECUTING, keep driving until a result comes on. If
the screen indicates OUT OF CONDITION, go to
step 5 and recheck. 7. Turn the ignition switch to LOCK (0).
8. Replace the EGR valve (see page 11-370).
9. Turn the ignition switch to ON (II).
10. Reset the ECM/PCM with the HDS.
11. Do the ECM/PCM idle learn procedure (see page 11-310).
12. Test-drive under these conditions:  Engine coolant temperature (ECT SENSOR 1)above70°C(158°F)
 A/TinD,M/Tin4th
 Drive at a steady speed between 88 120 km/h (55 75 mph) for at least 10 seconds
 During the drive, decelerate (with the throttle fully closed) for 5 seconds
13. Check for Temporary DTCs or DTCs with the HDS.
Check for poor connections or loose
terminals at the EGR valve and the ECM/PCM. If the
connections are OK, go to step 15.
Go to step 14.
14. Monitor the OBD STATUS for DTC P0401 in the DTCs MENU with the HDS.
Troubleshooting is complete. If any other
Temporary DTCs or DTCs were indicated in step 13,
go to the indicated DTC’s troubleshooting.
If the screen indicates FAILED, check for poor
connections or loose terminals at the EGR valve
and the ECM/PCM, then go to step 1. If the screen
indicates EXECUTING, keep driving until a result
comes on. If the screen indicates OUT OF
CONDITION, go to step 12.
(cont’d)
Is the result OK ?
Does t he scr een i nd i cat e F AILE D? Is DT C P0401 ind icated ?
Does t he scr een i nd i cat e PASSE D?
08/08/21 14:31:15 61SNR030_110_0357
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DYNOMITE -2009-

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YES
NO
YES
NO
YES
NO
YES
NO
DTC P0404:
11-35811-358EGR System
DTC Troubleshooting (cont’d)
EGR VALVE 6P CONNECTOR
SG2
EGRP
15. Update the ECM/PCM if it does not have the latest
software (see page 11-227), or substitute a known-
good ECM/PCM (see page 11-7).
16. Test-drive under these conditions:  Engine coolant temperature (ECT SENSOR 1)above70°C(158°F)
 A/TinD,M/Tin4th
 Drive at a steady speed between 88 120 km/h (55 75 mph) for at least 10 seconds
 During the drive, decelerate (with the throttle fully closed) for 5 seconds
17. Check for Temporary DTCs or DTCs with the HDS.
Check for poor connections or loose
terminals at the EGR valve and the ECM/PCM. If the
ECM/PCM was updated, substitute a known-good
ECM/PCM (see page 11-7), then go to step 16. If the
ECM/PCM was substituted, go to step 1.
Go to step 18.
18. Monitor the OBD STATUS for DTC P0401 in the DTCs MENU with the HDS.
If the ECM/PCM was updated,
troubleshooting is complete. If the ECM/PCM was
substituted, replace the original ECM/PCM
(see page 11-228). If any other Temporary DTCs or
DTCs were indicated in step 17, go to the indicated
DTC’s troubleshooting.
If the screen indicates FAILED, check for poor
connections or loose terminals at the EGR valve
and the ECM/PCM. If the ECM/PCM was updated,
substitute a known-good ECM/PCM (see page 11-7),
then go to step 16. If the ECM/PCM was substituted,
go to step 1. If the screen indicates EXECUTING,
keep driving until a result comes on. If the screen
indicates OUT OF CONDITION, go to step 16. NOTE: Before you troubleshoot, record all freeze data
and any on-board snapshot, and review the general
troubleshooting information (see page 11-3).
1. Turn the ignition switch to ON (II).
2. Clear the DTC with the HDS.
3. Start the engine. Hold the engine speed at 3,000 rpm without load (A/T in P or N, M/T in
neutral) until the radiator fan comes on, then let it
idle.
4. Do the EGR TEST in the INSPECTION MENU with the HDS.
Intermittent failure, the system is OK at this
time. Clean any carbon build-up on the EGR valve
with throttle plate and induction cleaner.
Go to step 5.
5. Turn the ignition switch to LOCK (0).
6. Disconnect the EGR valve 6P connector.
7. At the EGR valve side, measure the resistance between EGR valve 6P connector terminals No. 1
and No. 2.
Go to step 25.
Go to step 8.EGR Valve Circuit Range/
Performance Problem
Terminal side of male terminals
I s DT Cs P0401 i nd i cat ed ?
Does t he scr een i nd i cat e PASSE D? Is the result OK ?
Is t her e 100 k or mor e?
08/08/21 14:31:16 61SNR030_110_0358
ProCarManuals.com
DYNOMITE -2009-

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YES
NO
YES
NO
YES
NO
11-360EGR System
DTC Troubleshooting (cont’d)
14. Remove the EGR valve (see page 11-370).
15. Remove the EGR plate (see page 9-2), and clean the
intake manifold EGR port with throttle plate and
induction cleaner. Also, clean the passage inside
the EGR valve with throttle plate and induction
cleaner.
16. Install the EGR valve (see page 11-370).
17. Reconnect the EGR valve 6P connector.
18. Reconnect ECM/PCM connector B (44P).
19. Turn the ignition switch to ON (II).
20. Reset the ECM/PCM with the HDS.
21. Do the ECM/PCM idle learn procedure (see page 11-310).
22. Start the engine. Hold the engine speed at 3,000 rpm without load (A/T in P or N, M/T in
neutral) until the radiator fan comes on, then let it
idle.
23. Do the EGR TEST in the INSPECTION MENU with the HDS.
Go to step 32.
Go to step 24. 24. Turn the ignition switch to LOCK (0).
25. Replace the EGR valve (see page 11-370).
26. Reconnect all connectors.
27. Turn the ignition switch to ON (II).
28. Reset the ECM/PCM with the HDS.
29. Do the ECM/PCM idle learn procedure (see page
11-310).
30. Start the engine. Hold the engine speed at 3,000 rpm without load (A/T in P or N, M/T in
neutral) until the radiator fan comes on, then let it
idle.
31. Do the EGR TEST in the INSPECTION MENU with the HDS.
32. Check for Temporary DTCs or DTCs with the HDS.
Check for poor connections or loose
terminals at the EGR valve and the ECM/PCM, then
go to step 1. If the connections and terminals are
OK,gotostep34.
Go to step 33.
33. Monitor the OBD STATUS for DTC P0404 in the DTCs MENU with the HDS.
Troubleshooting is complete. If any other
Temporary DTCs or DTCs were indicated in step 32,
go to the indicated DTC’s troubleshooting.
If the screen indicates FAILED, check for poor
connections or loose terminals at the EGR valve
and the ECM/PCM, then go to step 1. If the screen
indicates EXECUTING, keep idling until a result
comes on. If the screen indicates OUT OF
CONDITION, go to step 30.
Is the result OK ? Is DT C P0404 ind icated ?
Does t he scr een i nd i cat e PASSE D?
08/08/21 14:31:17 61SNR030_110_0360
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DYNOMITE -2009-


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YES
NO
YES
NO
YES
NO
YES
NO
DTC P0406:
11-36111-361
EGR VALVE 6P CONNECTOR
VCC2 (YEL/BLU)
SG2 (GRN/BLK)
34. Update the ECM/PCM if it does not have the latest
software (see page 11-227), or substitute a known-
good ECM/PCM (see page 11-7).
35. Start the engine. Hold the engine speed at 3000 rpm wit hout load (A/T in P or N, M/T in
neutral) until the radiator fan comes on, then let it
idle.
36. Do the EGR TEST in the INSPECTION MENU with the HDS.
37. Check for Temporary DTCs or DTCs with the HDS.
Check for poor connections or loose
terminals at the EGR valve and the ECM/PCM. If the
ECM/PCM was updated, substitute a known-good
ECM/PCM (see page 11-7), then go to step 35. If the
ECM/PCM was substituted, go to step 1.
Go to step 38.
38. Monitor the OBD STATUS for DTC P0404 in the DTCs MENU with the HDS.
If the ECM/PCM was updated,
troubleshooting is complete. If the ECM/PCM was
substituted, replace the original ECM/PCM
(see page 11-228). If any other Temporary DTCs or
DTCs were indicated in step 37, go to the indicated
DTC’s troubleshooting.
If the screen indicates FAILED, check for poor
connections or loose terminals at the EGR valve
and the ECM/PCM. If the ECM/PCM was updated,
substitute a known-good ECM/PCM (see page 11-7),
then go to step 35. If the ECM/PCM was substituted,
go to step 1. If the screen indicates EXECUTING,
keep idling until a result comes on. If the screen
indicates OUT OF CONDITION, go to step 35. NOTE: Before you troubleshoot, record all freeze data
and any on-board snapshot, and review the general
troubleshooting information (see page 11-3).
1. Turn the ignition switch to ON (II).
2. Check EGR VLS in the DATA LIST with the HDS.
Go to step 3.
Intermittent failure, the system is OK at this
time. Check for poor connections or loose terminals
at the EGR valve and the ECM/PCM.
3. Turn the ignition switch to LOCK (0).
4. Disconnect EGR valve 6P connector.
5. Turn the ignition switch to ON (II).
6. Measure the voltage between EGR valve 6P connector terminals No. 2 and No. 3.
Go to step 11.
Go to step 7.
(cont’d)EGR Valve Position Sensor
Circuit High Voltage
Wire side of female terminals
I s DT Cs P0404 i nd i cat ed ?
Does t he scr een i nd i cat e PASSE D? I s 4.88 V or mor e i nd i cat ed ?
Is t her e about 5 V ?
08/08/21 14:32:24 61SNR030_110_0361
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DYNOMITE -2009-