2002 MAZDA 6 low oil pressure

OUTLINE
F2–7
F2
End Of Sie
11 Generator
12 Oil pressure switch
13 Sedimentor switch
14 Instrument cluster
15 Neutral switch
16 Clutch switch
17 Coil
18 Brake switch
19 Brake switch 2
20 Cruise control switch
21 With cruise control system
22 PCM control relay
23 MAF/IAT sensor
24 Calibration resistor No.1
25 Fuel injector No.1
26 Calibration resistor No.2
27 Fuel injector No.2
28 Calibration resistor No.3
29 Fuel injector No.3
30 Calibration resistor No.4
31 Fuel injector No.4
32 CMP sensor
33 CKP sensor
34 EGR solenoid valve (vacuum)
35 EGR solenoid valve (vent)
36 VSC solenoid valve
37 Intake shutter solenoid valve (half)38 Intake shutter solenoid valve (full)
39 VBC solenoid valve
40 EGR control solenoid valve
41 Boost sensor
42 Accelerator position sensor
43 Idle switch
44 Fuel pressure sensor
45 ECT sensor
46 Fuel temperature sensor
47 Suction control valve
48 IAT sensor No.2
49 Cooling fan relay No.2
50 Cooling fan No.1
51 Refrigerant pressure switch (middle)
52 A/C switch
53 A/C amplifier
54 Cooling fan relay No.1
55 Cooling fan No.2
56 A/C relay
57 Refrigerant pressure switch (HI and LO)
58 Magnetic clutch
59 With A/C
60 Glow plug relay
61 Glow plug
62 Vacuum switch
63 Fuel warmer
64 With fuel warmer

FUEL SYSTEM
F2–49
F2
(2) Apply a slight amount of clean engine oil to
the sealing surface of the fuel pump unit.
(3) Align the fuel pipe on the fuel pump unit and
quick release connector so that the tabs of the
retainer are correctly fitted into the quick
release connector. Push the quick release
connector straight into the retainer until a click
is heard.
(4) Lightly pull and push the quick release
connector a few times by hand and verify that
it can move 2.0—3.0 mm {0.08—0.11 in} and
it is connected securely.
•If the quick release connector does not
move at all, verify that O-ring is not
damaged of that is has not slipped, and reconnect the quick release connector.
2. When the retainer is removed, perform the following procedure.
End Of Sie
FUEL TANK INSPECTIONA6E401242110202
Caution
•Disconnecting/connecting the quick release connector without cleaning it may possibly cause
damage to the fuel pipe and quick release connector. Always clean the quick release connector
joint area before disconnecting/connecting using a cloth or soft brush, and make sure that it is
free of foreign material.
Note
•This inspection is for two rollover valves and check valve (two-way) integrated in the fuel tank.
1. Remove the fuel tank with the fuel gauge sender unit. (See F2–45 FUEL TANK REMOVAL/INSTALLATION.)
2. Plug the fuel pipe of the fuel gauge sender unit.
3. Plug port C.
4. Connect the pump to port B.
5. Level the fuel tank.
6. Apply pressure of +2.0 kpa {+34 mmHg, +1.3
inHg} to port B.
(1) Verify there is airflow from port A.
•If there is no airflow, replace the fuel tank.
7. Apply pressure of –5.9 kPa {–44 mmHg, –1.7
inHg} to port B.
•If there is no vacuum, replace the fuel tank.
•If there is vacuum, turn the fuel tank
upside-down and proceed to next step.
8. Apply pressure of +2.0 kPa {+15 mmHg, +0.6
inHg} to port B.
(1) Verify there is no airflow from port A.
•If there is airflow, replace the fuel tank.
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OILOIL
PLASTIC FUEL HOSE QUICK RELEASE
CONNECTOR SEALING
SURFACE
A6E3912W006
B
C
APLUG
PLUG
CHECK VALVE
(TWO-WAY)
FUEL GAUGE SENDER UNIT
ROLLOVER VALVE
A6E40122034
B CA
PLUGPLUG
CHECK VALVE
(TWO-WAY)
FUEL GAUGE SENDER UNIT
ROLLOVER VALVE
A6E40122035

TROUBLESHOOTING
F2–169
F2
×: 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
Turbocharger malfunctionCarge air cooler malfunctionVBC system malfunctionGlow system malfunctionIncorrect fuel injection timingIncorrect idle speedCKP sensor is damaged (e.g.: open or short circuits)CKP sensor pulse wheel is damagedImproper gap between CKP sensor and pulse wheelSupply pump malfunctionSuction control valve malfunctionFuel pressure limiter malfunctionFuel line restriction or clogging

TROUBLESHOOTING
F2–171
F2
×: 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××××× ×
PCM control relay malfunctionECT sensor or related circuit malfunctionNeutral switch or related circuit malfunctionMAF/IAT sensor or related circuit malfunctionIAT sensor No.2 or related circuit malfunctionBoost sensor or related circuit malfunctionAccelerator position sensor or related circuit malfunctionAccelerator position sensor misadjustment
(including looseness)Idle switch or related circuit malfunctionIdle switch misadjustment (including looseness)Fuel pressure sensor or related circuit malfunctionImproper refrigerant charging amount

F2–178
TROUBLESHOOTING
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NO.5 ENGINE STALLS-AFTER START/AT IDLEA6E408018881207
Diagnostic Procedure
18 Verify test results.
•If okay, return to diagnostic index to service any additional symptoms.
•If malfunction remains, replace PCM. (See F2–64 PCM REMOVAL/INSTALLATION) STEP INSPECTION RESULTS ACTION
5 ENGINE STALLS-AFTER START/AT IDLE
DESCRIPTION•Engine stops unexpectedly.
POSSIBLE
CAUSE•Poor fuel quality
•Intake-air system restriction or clogging
•Engine overheating
•A/C system improper operation
•Immobilizer system (PATS) and/or circuit malfunction (if equipped)
•PCM control relay malfunction
•Glow system malfunction
•Inadequate fuel pressure
•Fuel pressure sensor related circuit malfunction
•Suction control valve malfunction (built-in supply pump)
•Fuel pressure limiter malfunction (built-in common rail)
•Fuel leakage
•Fuel line clogging or restriction
•Fuel filter clogging or restriction
•Incorrect fuel injection timing
•Erratic signal from CKP sensor
•Erratic signal from CMP sensor
•Supply pump malfunction
•Fuel injector malfunction
•Low engine compression
•Improper valve timing
•Exhaust system and/or catalyst converter restriction or clogging
•EGR system malfunction
•ECT sensor or related circuit malfunction
•Accelerator positions sensor or related circuit malfunction
•Accelerator positions sensor misadjustment
•MAF/IAT sensor or related circuit malfunction
•V-reference voltage supply circuit malfunction
•IDM or related circuit 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
1Note
•The following test should be perform for
vehicles with immobilizer system. Go to
Step 10 for vehicles without immobilizer
system.
Connect WDS or equivalent to DLC-2.
Do following conditions appear?
•Engine is not completely started.
•DTC B1681 is displayed.YesBoth conditions appear:
Go to Step 4.
NoEither or other condition appears:
Go to next step.
2 Is coil connector securely connected to coil? Yes Go to next step.
No Connect coil connector securely.
Return to Step 1.
3 Does security light illuminate? Yes Go to next step.
No Inspect instrument cluster and wiring harness.

TROUBLESHOOTING
F2–181
F2
End Of Sie
NO.6 CRANKS NORMALLY BUT WILL NOT STARTA6E408018881208
Diagnostic Procedure
28 Inspect IDM.
(See F2–84 INJECTOR DRIVER MODULE
(IDM) INSPECTION)
Is IDM okay?Yes Go to next step.
No Repair or replace as necessary.
29 Inspect EGR system operation.
Is EGR system operation normal?Yes Remove and inspect supply pump and common rail.
No Repair or replace malfunctioning part according to
EGR system operation results.
30 Verify test results.
•If okay, return to diagnostic index to service any additional symptoms.
•If malfunction remains, replace PCM. (See F2–64 PCM REMOVAL/INSTALLATION) STEP INSPECTION RESULTS ACTION
6 CRANKS NORMALLY BUT WILL NOT START
DESCRIPTION•Starter cranks engine at normal speed but engine will not run.
•Refer to symptom troubleshooting “No.5 Engine stalls” if this symptom appears after engine stall.
•Fuel is in fuel tank.
•Battery is in normal condition.
POSSIBLE
CAUSE•Poor fuel quality
•Intake-air system restriction
•Fuel line restriction
•EGR system malfunction
•Glow system malfunction
•Fuel pressure sensor or related circuit malfunction
•Suction control valve malfunction (built-in supply pump)
•Fuel pressure limiter malfunction (built-in common rail)
•Fuel leakage
•Fuel filter clogging
•Incorrect fuel injection timing
•Erratic signal from CKP sensor
•Erratic signal from CMP sensor
•V-reference supply circuit malfunction
•ECT sensor or related circuit malfunction
•Supply pump malfunction
•Fuel injector malfunction
•Immobilizer system (PATS) and/or circuit malfunction (if equipped)
•Low engine compression
•Improper valve timing
•IDM or related circuit malfunction
•PCM control repay 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
1Note
•The following test should be perform for
vehicles with immobilizer system. Go to
Step 10 for vehicles without immobilizer
system.
Connect WDS or equivalent to DLC-2.
Do following conditions appear?
•Engine is not completely started.
•DTC B1681 is displayed.YesBoth conditions appear:
Go to Step 4.
NoEither or other condition appears:
Go to next step.
2 Is coil connector securely connected to coil? Yes Go to next step.
No Connect coil connector securely.
Return to Step 1.

TROUBLESHOOTING
F2–197
F2
13 Inspect if turbocharger turbine wheel is
damaged, cracked or interfering with housing on
vehicle.
Note
•Inspect all fins on each turbine wheel.
Is there any problem?Yes Replace turbocharger.
No Go to next step.
14 Is any engine oil found inside turbocharger
turbine housing?YesExcessive amount of oil is found:
Replace turbocharger.
Small amount of oil is found:
Wipe oil off of vehicle, then go to next step.
No Go to next step.
15 Is any engine oil found inside turbocharger
compressor hosing?Yes Wipe oil off of vehicle and install all removed parts in
Step 10. Then, go to next step.
No Turbocharger is okay.
Install all parts removed in Step10.
Then, go to next step.
16 Perform EGR system inspection.
Is EGR system okay?Yes Go to next step.
No Repair or replace malfunctioning part according to
EGR system operation results.
17 Inspect idle speed.
(See F2–34 IDLE SPEED INSPECTION)
Is idle speed correct?Yes Go to next step.
No Repair or replace malfunctioning part according to idle
speed inspection results.
18 Inspect adjustment of accelerator position
sensor and idle switch.
(See F2–72 ACCELERATOR POSITION
SENSOR INSPECTION)
(See F2–70 IDLE SWITCH INSPECTION)
Are accelerator position sensor and idle switch
adjusted correctly?Yes Go to next step.
No Adjust accelerator position sensor and idle switch
correctly.
(See F2–73 ACCELERATOR POSITION SENSOR
ADJUSTMENT)
(See F2–71 IDLE SWITCH ADJUSTMENT)
19 Visually inspect CKP sensor and teeth of pulse
wheel.
Are CKP sensor and teeth of pulse wheel okay?Yes Go to next step.
No Replace malfunctioning parts.
20 Measure gap between CKP sensor and teeth of
pulse wheel.
Specification
1.5—2.5 mm {0.059—0.098 in}
Is gap within specification?Yes Go to next step.
No Adjust CKP sensor position.
21 Visually inspect CMP sensor and teeth of pulse
wheel.
Are CMP sensor and teeth of pulse wheel okay?Yes Inspect following PIDs:
(See F2–65 PCM INSPECTION)
•ECT
•IAT
•MAF
•MAP
•RPM
If PID value is not as specified, repair or replace
malfunctioning parts.
If PID value is okay, go to next step.
No Replace malfunctioning parts.
22 Inspect fuel pressure sensor.
(See F2–79 FUEL PRESSURE SENSOR
INSPECTION)
Is fuel pressure okay?Yes Go to next step.
No Replace common rail.
23 Inspect suction control valve.
(See F2–54 SUCTION CONTROL VALVE
INSPECTION)
Is suction control valve okay?Yes Go to next step.
No Repair supply pump.
(See F2–54 SUPPLY PUMP INSPECTION) STEP INSPECTION RESULTS ACTION

TROUBLESHOOTING
F2–201
F2
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14 Is any engine oil found inside turbocharger
compressor hosing?Yes Wipe oil off of vehicle and install all removed parts in
Step 10. Then, go to next step.
No Turbocharger is okay.
Install all parts removed in Step10.
Then, go to next step.
15 Perform EGR system inspection.
Is EGR system okay?Yes Go to next step.
No Repair or replace malfunctioning part according to
EGR system operation results.
16 Inspect glow system operation.
(See T–19 RELAY INSPECTION)
Is glow system operation normal?Yes Go to next step.
No Repair or replace malfunctioning part according to
glow system operation results.
17 Visually inspect CKP sensor and teeth of pulse
wheel.
Are CKP sensor and teeth of pulse wheel okay?Yes Go to next step.
No Replace malfunctioning parts.
18 Measure gap between CKP sensor and teeth of
pulse wheel.
Specification
1.5—2.5 mm {0.059—0.098 in}
Is gap within specification?Yes Go to next step.
No Adjust CKP sensor position.
19 Visually inspect CMP sensor and teeth of pulse
wheel.
Are CMP sensor and teeth of pulse wheel okay?Yes Inspect following PIDs:
(See F2–65 PCM INSPECTION)
•ECT
•IAT
•MAF
•MAP
•RPM
If PID value is not as specified, repair or replace
malfunctioning parts.
If PID value is okay, go to next step.
No Replace malfunctioning parts.
20 Is engine compression correct?
(See B2–8 COMPRESSION INSPECTION)Yes Go to next step.
No Inspect for following:
•Damaged valve seat
•Worn valve stem and valve guide
•Worn or stuck piston ring
•Worn piston, piston ring or cylinder
•Improper valve timing
Service as necessary.
21 Inspect suction control valve.
(See F2–54 SUCTION CONTROL VALVE
INSPECTION)
Is suction control valve okay?Yes Inspect following:
•Boost sensor
•MAF/IAT sensor
•IAT sensor No.2
•Fuel pressure sensor
•Accelerator position sensor
No Repair supply pump.
(See F2–54 SUPPLY PUMP INSPECTION)
22 Verify test results.
•If okay, return to diagnostic index to service any additional symptoms.
•If malfunction remains, replace PCM. (See F2–64 PCM REMOVAL/INSTALLATION) STEP INSPECTION RESULTS ACTION