Page 162 of 909
F2–10
FUEL SYSTEM
End Of Sie
OUTLINEA6E401201006201•The fuel system is essentially carried over from that of the current MPV (LW) MZR-CD (RF Turbo) engine
model. (See MPV Wordshop Manual Supplement 1737-1*-02D.)
×:Applicable
*1: With fuel warmer
End Of Sie
FUEL SYSTEM
ItemMazda6
(GG, GY)Current
MPV (LW)
Remark for new model
MZR-CD (RF Turbo)
Fuel tank×Same function as MPV (LW) MZR-CD (RF Turbo) engine model
Shape has been changed
Fuel gauge sender unit×Same function as MPV (LW) MZR-CD (RF Turbo) engine model
Shape has been changed
Fuel filter bodyFuel filter×Same function as MPV (LW) MZR-CD (RF Turbo) engine model
Priming pump×Same function as MPV (LW) MZR-CD (RF Turbo) engine model
Fuel warmer
*1×Same function as MPV (LW) MZR-CD (RF Turbo) engine model
Common rail injection system×Same function as MPV (LW) MZR-CD (RF Turbo) engine model
Page 163 of 909
FUEL SYSTEM
F2–11
F2
STRUCTURAL VIEWA6E401201006202Engine room side
.
1
2
3
4
5
6
7
9
8
10
11
12
10
A6E40122031
1 Fuel warmer
2 Sedimentor switch
3 Supply pump
4 Suction control valve
5 Common rail
6 Priming pump7 L.H.D.
8 Fuel injector
9 Priming pump
10 Fuel filter
11 R.H.D.
12 Sedimentor switch
Page 182 of 909
F2–30
LOCATION INDEX
Fuel tank side
.
End Of Sie
21
A6E40002004
1 Fuel tank
(See F2–45 FUEL TANK REMOVAL/
INSTALLATION)
(See F2–49 FUEL TANK INSPECTION)
2 Nonreturn valve
(See F2–50 NONRETURN VALVE INSPECTION)
3 Sedimentor switch
(See F2–52 SEDIMENTOR SWITCH INSPECTION)
4 Fuel filter
(See F2–50 FUEL FILTER COMPONENT
REMOVAL/INSTALLATION)
(See F2–51 FUEL FILTER COMPONENT
DISASSEMBLY/ASSEMBLY)
5 Fuel warmer
(See F2–51 FUEL WARMER INSPECTION)6 Priming pump
(See F2–52 SEDIMENTOR WATER DRAINING)
7 Supply pump
(See F2–53 SUPPLY PUMP REMOVAL/
INSTALLATION)
(See F2–54 SUPPLY PUMP INSPECTION)
8 Suction control valve
(See F2–54 SUCTION CONTROL VALVE
INSPECTION)
9 Common rail
(See F2–54 COMMON RAIL INSPECTION)
10 Fuel injector
(See F2–55 FUEL INJECTOR REMOVAL/
INSTALLATION)
(See F2–56 FUEL INJECTOR INSPECTION)
Page 202 of 909

F2–50
FUEL SYSTEM
NONRETURN VALVE INSPECTIONA6E401242270201
Note
•Nonreturn valve is integrated in the fuel tank. Therefore, before inspecting the nonreturn valve perform the
follwing:
1. Remove the fuel gauge sender unit. (See F2–45 FUEL TANK REMOVAL/INSTALLATION.)
2. Siphon the fuel from the fuel tank.
Note
•The nonreturn valve is normally closed by the spring force.
3. Verify that the nonreturn valve is closed.
•If it is stuck open, replace the fuel tank.
4. Verify that the nonreturn valve opens when pulled up by a finger.
•If it does not open, replace the nonreturn valve.
End Of Sie
FUEL FILTER COMPONENT REMOVAL/INSTALLATIONA6E4012348022011. Disconnect the negative battery cable.
2. Complete the “BEFORE REPAIR PROCEDURE”. (See F2–45 BEFORE REPAIR PROCEDURE.)
3. Remove in the order indicated in the table.
L.H.D.
R.H.D.
.
4. Install in the reverse order of removal.
5. Complete the “AFTER REPAIR PROCEDURE”.
(See F2–45 AFTER REPAIR PROCEDURE.)
6. Start the engine and verify that fuel does not leak
from the fuel system.
•If fuel leaks, reinstall the fuel filter.
End Of Sie
1
4
23
A6E40122010
1 Connector
2Fuel hose
3 Installation nut
4 Fuel filter body
4
1
2
3
A6E40122011
Page 203 of 909

FUEL SYSTEM
F2–51
F2
FUEL FILTER COMPONENT DISASSEMBLY/ASSEMBLYA6E4012348022021. Disassemble in the order indicated in the table..
2. Assemble in the reverse order of removal.
Sedimentor Switch Installation Note
1. Apply a small amount of fuel to a new O-ring.
2. Tighten the sedimentor switch enough to the fuel
filter by hand.
Fuel Filter Installation Note
1. Apply a small amount of fuel to the fuel filter O-ring.
2. Tighten the fuel filter approx. 3/4 by hand after the O-ring contacts the priming pump.
End Of Sie
FUEL WARMER INSPECTIONA6E401234802203For Cold Areas
1. Remove the fuel warmer. (See F2–51 FUEL FILTER COMPONENT DISASSEMBLY/ASSEMBLY.)
2. Verify that the resistance between terminal A and
the fuel warmer body is within the specification
when vacuum of –31.3— –38.0 kPa {–235— –
285 mmHg, –9.2— –11.2 inHg} is applied to port
A of the fuel warmer.
•If as specified, carry out the “Circuit Open/
Short Inspection”.
•If not as specified, replace the fuel warmer.
Specification
Circuit Open/Short Inspection
1. Inspect for open/short circuit in the following
wiring harnesses.
•If there is open/short circuit, repair or replace
wiring harnesses.
Open circuit
•If there is no continuity, the circuit is open. Repair
or replace the harness.
—Fuel warmer terminal A (harness-side) and
GND
—Fuel warmer terminal B (harness-side) and
power supply
Short circuit
•If there is continuity, the circuit is shorted. Repair or replace the harness.
—Fuel warmer terminal B (harness-side) and GND
End Of Sie
1 Connector
2 Fuel hose
3 Priming pump
4Fuel filter
(See F2–51 Fuel Filter Installation Note)
5Sedimentor switch
(See F2–51 Sedimentor Switch Installation Note)
6 Drain plug
7 Fuel warmer
R
17.6—26.5
{1.8—2.7,
13.0—19.8}
7
5
4
3
6
1
2
N.m {kgf·m, ft·lbf}
A6E40122036
Ambient temperature (°C {°F}) Resistance (ohms)
20 {68} 0.5—1.5
FUEL WARMER
B
A6E40122013
A B FUEL WARMER
HARNESS SIDE CONNECTOR
A6E40122014
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F2–52
FUEL SYSTEM
SEDIMENTOR WATER DRAININGA6E4012348022041. Disconnect the negative battery cable.
2. Complete the “BEFORE REPAIR PROCEDURE”. (See F2–45 BEFORE REPAIR PROCEDURE.)
3. Loosen the drain plug located at the bottom of the fuel filter.
4. Pump the priming pump and drain the water.
5. After all the water has been drained, tighten the drain plug.
6. Complete the “AFTER REPAIR PROCEDURE”. (See F2–45 AFTER REPAIR PROCEDURE.)
7. Reconnect the negative battery cable.
End Of Sie
SEDIMENTOR SWITCH INSPECTIONA6E401213840201
Note
•Perform the following test only when directed.
1. Disconnect the negative battery cable.
2. Complete the “BEFORE REPAIR PROCEDURE”. (See F2–45 BEFORE REPAIR PROCEDURE.)
3. Drain fuel from the fuel filter. (See F2–52 SEDIMENTOR WATER DRAINING.)
4. Remove the sedimentor switch.
5. Inspect for continuity of the sedimentor switch
using an ohmmeter.
•If as specified, inspect the following and carry
out the “Circuit Open/Short Inspection.”
•If not as specified, replace the sedimentor
switch.
Specification
6. Install the sedimentor switch.
7. Reconnect the negative battery cable.
8. Complete the “AFTER REPAIR PROCEDURE”.
(See F2–45 AFTER REPAIR PROCEDURE.)
Circuit Open/Short Inspection
1. Inspect the following wiring harnesses for open or
short (continuity check).
Open circuit
•If there is no continuity, the circuit is open.
Repair or replace the harness.
—Sedimentor switch terminal B (harness-
side) and GND.
—Sedimentor switch terminal A (harness-
side) and instrument cluster terminal 1C.
Short circuit
•If there is continuity, the circuit is shorted.
Repair of replace the harness.
—Sedimentor switch terminal A (harness-
side) and GND.
—Sedimentor switch terminal B (harness-
side) and power supply.
End Of Sie
Float Continuity
Up Yes
Down No
UP
DOWN
FLOATA
B
A6E40122015
1O 1M 1K 1I 1G 1E 1C 1A
1P 1N 1L 1J 1H 1F 1D 1B INSTRUMENT CLUSTER CONNECTOR
SEDIMENTOR SWITCH
HARNESS SIDE CONNECTOR
A
B
A6E40122016
Page 322 of 909

F2–170
TROUBLESHOOTING
×: Applicable
Troubleshooting item
1 Melting of main or other fuses
2 MIL illuminates××
3 Will not crank
4 Hard start/long crank/erratic start/erratic crank× × ××××× ×
5 Engine stalls After start/at idle×××××××××
6 Cranks normally but will not start× × ×××× × ×
7 Slow return to idle××××
8 Engine runs rough/rolling idle× × ×××× ××
9 Fast idle/runs on××
10 Low idle/stalls during deceleration× × ×××× ×
11Engine stalls/quits Acceleration/cruise× ××××× ×
Engine runs rough Acceleration/cruise× ××××× ×
Misses Acceleration/cruise× ××××× ×
Buck/jerk Acceleration/cruise/ deceleration× ××××× ×
Hesitation/stumble Acceleration× ××××× ×
Surges Acceleration/cruise× ××××× ×
12 Lack/loss of power Acceleration/cruise× ××××× ×
13 Knocking/pinging××××
14 Poor fuel economy×××××××
15 Emissions compliance× ×××××××
16 High oil consumption/leakage
17 Cooling system concerns Overheating×
18 Cooling system concerns Runs cold
19 Excessive black smoke××××
20 Fuel odor (in engine compartment)×
21 Engine noise××××
22 Vibration concerns (engine)×××
23 A/C does not work sufficiently
24 A/C always on or A/C compressor runs continuously
25 A/C does not cut off under wide open throttle conditions
26 Constant voltage×
Fuel injectors malfunction (Leakage or clogging,
inoperative)Fuel leakage from fuel system (including insulator,
fuel injector)Fuel filter restriction or cloggingCMP sensor is damaged (e.g: open or short circuit)CMP sensor pulse wheel is damagedIDM or related circuit malfunctionExhaust system restriction or cloggingCatalyst converter malfunctionEGR system malfunctionEGR water cooler malfunctionV-reference voltage supply circuit malfunction
Page 328 of 909

F2–176
TROUBLESHOOTING
NO.4 HARD START/LONG CRANK/ERRATIC START/ERRATIC CRANKA6E408018881206
Diagnostic Procedure
4 HARD START/LONG CRANK/ERRATIC START/ERRATIC CRANK
DESCRIPTION•Starter cranks engine at normal speed but engine requires excessive cranking time before starting.
•Battery is in normal condition.
POSSIBLE
CAUSE•Poor fuel quality
•Intake-air system restriction or clogging
•Starting system malfunction
•Inadequate fuel pressure
•Fuel pressure limiter malfunction (built-in common rail)
•Suction control valve malfunction (built-in supply pump)
•Engine overheating
•Glow system malfunction
•Fuel filter clogging or restriction
•Fuel line clogging or restriction
•Fuel leakage
•Exhaust system and/or catalyst converter restriction or clogging
•Incorrect fuel injection timing
•Erratic signal from CKP sensor
•Erratic signal from CMP sensor
•ECT sensor or related circuit malfunction
•Accelerator position sensor or related circuit malfunction
•Accelerator position sensor misadjustment
•MAF/IAT sensor or related circuit malfunction
•Fuel pressure sensor or related circuit malfunction
•Supply pump malfunction
•Fuel injector malfunction
•Low engine compression
•IDM or related circuit malfunction
•EGR system malfunction
Warning
The following troubleshooting flow chart contains the fuel system diagnosis and repair
procedures. Read the following warnings before performing the fuel system services:
•Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always keep
sparks and flames away from fuel.
•Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injury or death
and damage. Fuel can also irritate skin and eyes. To prevent this, always complete “BEFORE
REPAIR PROCEDURE” and “AFTER REPAIR PROCEDURE” described in this manual.
STEP INSPECTION RESULTS ACTION
1 Inspect for following:
•Fuel quality (e.g.: include water
contamination, winter/summer blend)
•Fuel line/fuel filter clogging
•Intake-air system restriction
Are all items okay?Yes Go to next step.
No Service as necessary.
Repeat Step 1.
2 Is engine overheating? Yes Go to symptom troubleshooting “NO.17 COOLING
SYSTEM CONCERNS-OVERHEATING”.
No Go to next step.
3 Connect WDS or equivalent to DLC-2.
Turn engine switch to ON.
Retrieve any DTC.
Is DTC displayed?YesDTC is displayed:
Go to appropriate DTC test.
Communication error message is displayed:
Inspect following:
•Open circuit between PCM control relay and PCM
terminal 53 or 79
•Open circuit PCM control relay and PCM terminal
69
•PCM control relay stuck open
•Open or poor GND circuit (PCM terminal 65, 85,
103 or 104)
•Poor connection vehicle body GND
NoNo DTC is displayed:
Go to next step.