2006 ACURA CSX fuel




11-336Fuel Supply System
Fuel Tank Unit Removal and Installation (cont’d)
A
B
07AAA-SNAA100 A
120 N·m
(12.2 kgf·m, 88.2 lbf·ft) A
A
4. Install a locknut plate (A) and a new locknut (B).
5. Using the special tool, tighten the new locknut (A) to the specified torque.
NOTE: After tightening, make sure the marks are still aligned.
 After installation, check the base gasket, visually or by hand, to make sure it is not pinched. 6. Connect the fuel tank unit 4P connector, then
connect the quick-connect fitting.
7. Reconnect the negative cable to the battery, and turn the ignition switch to ON (II) (but do not
operate the starter motor). The fuel pump will run
for about 2 seconds, and fuel pressure will rise.
Repeat this two or three times, then check that
there is no leakage in the fuel supply system.
8. Install the access panel (A) to the floor.
9. Install the rear floor upper cross-member (A).
10. Install the rear seat cushion (see page 20-131).
11. Install the fuel fill cap.
08/08/21 14:30:59 61SNR030_110_0336
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11-33711-337
Fuel Pressure Regulator
Replacement Fuel Filter Replacement
A
B
C
D A
D B
C D
B
1. Remove the fuel tank unit (see page 11-334).
2. Remove the bracket (A).
3. Remove the ground ring (B).
4. Remove the fuel pressure regulator (C).
5. Install the parts in the reverse order of removal with new O-rings (D) and a new bracket (A). When
installing the fuel tank unit, align the marks on the
unit and the fuel tank (see page 11-335).
NOTE: Coat the O-rings with clean engine oil; do
not use any other oil.
Do not pinch the O-rings during installation. The fuel filter should be replaced when
ever the fuel
pressure drops below the specified value (see page
11-325), after making sure that the fuel pump and the
fuel pressure regulator are OK.
1. Remove the fuel tank unit (see page 11-334).
2. Remove the fuel filter set (A).
3. Check these items before installing the fuel tank unit:
 When connecting the wire harness, make sure the connection is secure and the connectors (B)
are firmly locked into place.
 When installing the fuel gauge sending unit (C), make sure the connection is secure and the
connector is firmly locked into place. Be careful
not to bend or twist it excessively.
4. Install the parts in the reverse order of removal with new O-rings (D). When installing the fuel tank
unit, align the marks on the unit and the fuel tank
(see page 11-335).
08/08/21 14:31:00 61SNR030_110_0337
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11-338Fuel Supply System
Fuel Pump/Fuel Gauge Sending Unit Replacement
A
B
C
1. Remove the fuel tank unit (see page 11-334).
2. Remove the fuel level sensor (fuel sending unit) (A)from the fuel tank unit (B).
3. Check these items before installing the fuel tank unit:
 When connecting the wire harness, make sure the connection is secure and the connector (C) is
firmly locked into place.
 When installing the fuel gauge sending unit, be careful not to bend or twist it excessively.
4. Install the parts in the reverse order of removal. When installing the fuel tank unit, align the marks
on the unit and the fuel tank (see page 11-335).
08/08/21 14:31:00 61SNR030_110_0338
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11-339
Fuel Tank Replacement
C
D
E
H
22 N·m
(2.2 kgf·m,
16 lbf·ft)
38 N·m
(3.9 kgf·m, 28 lbf·ft)
I A
B
F G
1. Drain the fuel tank (see page 11-325), then disconnect fuel tank unit 4P connector (A) and the quick-connect fittings
(B).
2. Raise the vehicle on a lift.
3. Remove the cover (C), and the EVAP canister guard pipe (D).
4. Disconnect the fuel fill tube (E). Slide back the clamps, then twist the hoses as you pull to avoid damaging them.
5. Disconnect the quick-connect fitting (F) and the fuel tank vapor recirculation tube (G).
6. Place a jack or other support under the fuel tank (H).
7. Remove the strap bolts and the strap (I).
8. Remove the fuel tank.
9. Install the parts in the reverse order of removal.
08/08/21 14:31:01 61SNR030_110_0339
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11-340 Fuel Supply System
Fuel Gauge Sending Unit Test
A
A
B
FUEL TANK UNIT 4P CONNECTOR
ORN
LT GRN
NOTE: For the fuel gauge system circuit diagram, refer
to the Gauges Circuit Diagram (see page 22-244). 1. Check the No. 10 METER (7.5 A) fuse in the under- dash fuse/relay box before testing.
2. Check for body electrical system DTCs.  If no DTCs are found, go to step 3.
 If DTC B1175 or B1176 is indicated, go to theindicated DTC’s troubleshooting.
3. Turn the ignition switch to LOCK (0).
4. Remove the rear seat cushion (see page 20-131).
5. Remove the rear floor upper cross-member (A). 6. Remove the access panel (A) from the floor.
7. Disconnect the fuel tank unit 4P connector (B).
8. Measure the voltage between fuel tank unit 4P
connector terminals No. 1 and No. 3 with the
ignition switch ON (II). There should be battery
voltage.
 If the voltage is OK, go to step 9.
 If the voltage is not as specified, check for: – a short in the ORN wire to ground.
– anopenintheORNorLTGRNwire.
9. Turn the ignition switch to LOCK (0).
10. Remove the fuel tank unit from the fuel tank (see page 11-334).
Wire side of female terminals
08/08/21 14:31:01 61SNR030_110_0340
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11-34111-341
Low Fuel Indicator Test
F
1/2
E LOW
11. Measure the resistance between fuel tank unit 4P
connector terminals No. 1 and No. 3 with the float
at E (EMPTY), LOW (LOW FUEL INDICATOR), 1/2
(HALF FULL), and F (FULL) positions.
If you do not get the following readings, replace the
fuel gauge sending unit (see page 11-338).
F
139.8 mm (5.5 in.) 1/2
72.1 mm (2.8 in.) LOW
19.5 mm (0.77 in.) E
8.9 mm
(0.35 in.)
() 19 to
21 205.8 to
215.8 537.5 to
707 772 to
788
12. Reconnect the fuel tank unit 4P connector.
13. Remove the No. 23 BACK UP (10 A) fuse from the under-hood fuse/relay box for at least 10 seconds,
then reinstall it.
14. Turn the ignition switch to ON (II).
15. Check that the pointer of the fuel gauge indicates F with the float at F.
 If the pointer of the fuel gauge does not indicate F, replace the gauge assembly.
 If the gauge is OK, the test is complete.
NOTE:  The pointer of the fuel gauge returns to the bottom of the gauge dial when the ignition switch
is turned to ACC or to LOCK (0), regardless of the
fuel level.
 Remove the No. 23 BACK UP (10 A) fuse from the under-hood fuse/relay box for at least 10 seconds
after completing troubleshooting, otherwise it
may take up to 20 minutes for the fuel gauge to
indicate the correct fuel level. 1. Do the gauge self-diagnostic function (see page
22-241).
 If the low fuel indicator flashes, go to step 2.
 If the low fuel indicator does not flash, replace the gauge control module (tach) (see page
22-277).
2. Check for body electrical system DTCs.
 If any DTCs are indicated, do the indicated DTC’stroubleshooting.
 If no DTCs are indicated, go to step 3.
3. Do the fuel gauge sending unit test (see page 11-340).
Float
Position
Resistance
Terminal side of
male terminals
08/08/21 14:31:02 61SNR030_110_0341
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11-34111-341
Low Fuel Indicator Test
F
1/2
E LOW
11. Measure the resistance between fuel tank unit 4P
connector terminals No. 1 and No. 3 with the float
at E (EMPTY), LOW (LOW FUEL INDICATOR), 1/2
(HALF FULL), and F (FULL) positions.
If you do not get the following readings, replace the
fuel gauge sending unit (see page 11-338).
F
139.8 mm (5.5 in.) 1/2
72.1 mm (2.8 in.) LOW
19.5 mm (0.77 in.) E
8.9 mm
(0.35 in.)
() 19 to
21 205.8 to
215.8 537.5 to
707 772 to
788
12. Reconnect the fuel tank unit 4P connector.
13. Remove the No. 23 BACK UP (10 A) fuse from the under-hood fuse/relay box for at least 10 seconds,
then reinstall it.
14. Turn the ignition switch to ON (II).
15. Check that the pointer of the fuel gauge indicates F with the float at F.
 If the pointer of the fuel gauge does not indicate F, replace the gauge assembly.
 If the gauge is OK, the test is complete.
NOTE:  The pointer of the fuel gauge returns to the bottom of the gauge dial when the ignition switch
is turned to ACC or to LOCK (0), regardless of the
fuel level.
 Remove the No. 23 BACK UP (10 A) fuse from the under-hood fuse/relay box for at least 10 seconds
after completing troubleshooting, otherwise it
may take up to 20 minutes for the fuel gauge to
indicate the correct fuel level. 1. Do the gauge self-diagnostic function (see page
22-241).
 If the low fuel indicator flashes, go to step 2.
 If the low fuel indicator does not flash, replace the gauge control module (tach) (see page
22-277).
2. Check for body electrical system DTCs.
 If any DTCs are indicated, do the indicated DTC’stroubleshooting.
 If no DTCs are indicated, go to step 3.
3. Do the fuel gauge sending unit test (see page 11-340).
Float
Position
Resistance
Terminal side of
male terminals
08/08/21 14:31:02 61SNR030_110_0341
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µ
µ µ
µ
µ
µ
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
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