2002 MAZDA 6 cooling

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

F2–172
TROUBLESHOOTING
×: Applicable
End Of Sie
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
A/C relay (A/C control siganl) circuit malfunctionA/C magnetic clutch or related circuit malfunctionCooling fan No.1 system malfunctionClutch slippageAir in power steering fuluid lineVSS or related circuit malfunctionBrake draggingLoose partsImproper balance of wheel or tiresDriveline malfunctionSuspension malfunctionImmobilizer system and/or circuit malfunctionCoolant heater system malfunction

TROUBLESHOOTING
F2–173
F2
NO.1 MELTING OF MAIN OR OTHER FUSESA6E408018881203
End Of Sie
1 Melting of main or other fuses
[TROUBLESHOOTING HINTS]
Inspect condition of fuse.
Damaged fuse Related wiring harness
MAINMAIN fuse
•BTN fuse
•FAN fuse
•AD FAN fuse
•IG KEY 2 fuse
IG KEY 1IG KEY 1 fuse
•Engine switch
—ENGINE fuse
FUEL PUMPFUEL PUMP fuse
•Fuel warmer
•PCM control relay
BTNBTN fuse
•ROOM fuse
IG KEY 2IG KEY 2 fuse
•Engine switch
ROOMROOM fuse
•DLC-2
ENGINEENGINE fuse
•PCM
INJINJ fuse
•PCM
•IDM
•MAF/IAT sensor
•VSC solenoid valve
•VBC solenoid valve
•EGR control solenoid valve
•EGR solenoid valve (vacuum)
•EGR solenoid valve (vent)
•Intake shutter solenoid valve (half)
•Intake shutter solenoid valve (full)
GLOWGLOW fuse
•Glow plug relay
—Glow plug
—GLOW SIG
ENG+BENG+B fuse
•PCM
FANFAN fuse
•Cooling fan relay No.2
AD FANAD FAN fuse
•Cooling fan relay No.1
Shorted harness
Repair shorted harness and replace fuseFuseDeterioration
Replace fuse

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.

TROUBLESHOOTING
F2–179
F2
4 Connect WDS or equivalent to DLC-2 and
retrieve DTC.
DTC
B1213, B1342, B1600, B1601, B1602, B1681,
B2103, B2431Yes Go to appropriate DTC test.
No Go to next step.
5 Is there continuity between PCM GND terminals
65, 85, 103, 104 and GND?Yes Go to next step.
No Repair or replace wiring harness.
6 Measure voltage between PCM GND terminals
65, 85, 103, 104 and coil terminal C.
Is the voltage below 1.0?Yes Go to next step.
No Repair or replace wiring harness.
7 Turn engine switch to ON.
Access VPWR PID.
Is VPWR PID okay?
Specification
Battery voltageYes Go to next step.
No Repair or replace wiring harness.
8 Disconnect coil connector.
Turn engine switch to ON.
Is there battery voltage at coil connector terminal
D (harness-side)?Yes Inspect for following:
•Open or short circuit between coil terminal A and
PCM terminal 80
•Open or short circuit between coil terminal B and
PCM terminal 28
No Repair or replace wiring harness between coil
connector terminal D and fuse panel.
9 Is there continuity between PCM terminal 57 and
starter relay?Yes Go to next step.
No Repair replace wiring harness.
10 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 10.
11 Is engine overheating? Yes Go to symptom troubleshooting “NO.17 COOLING
SYSTEM CONCERNS-OVERHEATING”.
No Go to next step.
12Note
•Ignore DTC P0122, P0123, P0222 or
P0223 while performing this test.
Disconnect accelerator position sensor
connector.
Measure voltage at accelerator position sensor
connector VREF terminal (terminal D) with
engine switch ON.
Specification
4.5—5.5 V
Is voltage okay?Yes Go to next step.
No Go to symptom troubleshooting “NO.26 CONSTANT
VOLTAGE”.
13 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 for 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.
14 Does engine start normally after warm-up? Yes Inspect glow system operation.
(See T–19 RELAY INSPECTION)
Replace any malfunctioning part as necessary.
If glow system is okay, go to next step.
No Go to next step. STEP INSPECTION RESULTS ACTION

F2–180
TROUBLESHOOTING
15 Is there any restriction in exhaust system or
catalyst converter?Yes Repair or replace as necessary.
No Go to next step.
16 Access RPM PID.
Is RPM PID indicating engine speed during
cranking engine?Yes Go to next step.
No Go to Step 19.
17Note
•The following test should be performed on
the vehicles with A/C system. If the
following test cannot be performed due to
engine stalling, go to next step.
•Go to next step for the vehicle without A/C
system.
Connect pressure gauge to A/C line.
Turn blower and A/C switches on.
Is pressure within specifications?Yes Go to next step.
NoA/C is always on:
Go to symptom troubleshooting “NO.24 A/C ALWAYS
ON OR A/C COMPRESSOR RUNS
CONTINUOUSLY”.
Other symptoms:
Inspect following:
•Refrigerant charging amount
•Cooling fan No.1 and/or cooling fan No.2 operation
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 Depress accelerator pedal slightly.
Crank engine.
Does engine start now?Yes Inspect idle speed.
(See F2–34 IDLE SPEED INSPECTION)
No Go to next step.
20 Inspect for fuel leakage from fuel pipe.
Is any fuel leakage found on fuel pipe?Yes Repair or replace as necessary.
No Go to next step.
21 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.
22 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.
23 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
•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.
24 Inspect fuel pressure sensor.
(See F2–79 FUEL PRESSURE SENSOR
INSPECTION)
Is fuel pressure okay?Yes Go to next step.
No Replace common rail.
25 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)
26 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.
27 Inspect fuel injector.
(See F2–56 FUEL INJECTOR INSPECTION)
Is fuel injector okay?Yes Go to next step.
No Repair or replace as necessary. STEP INSPECTION RESULTS ACTION

F2–184
TROUBLESHOOTING
NO.7 SLOW RETURN TO IDLEA6E408018881209
Diagnostic Procedure
7 SLOW RETURN TO IDLE
DESCRIPTION•Engine takes more time than normal to return to idle speed.
•Engine speed continues at fast idle after warm-up.
POSSIBLE
CAUSE•Thermostat is stuck open
•Fuel injection timing is incorrect
•Erratic signal from CKP sensor
•Erratic signal from CMP sensor
•ECT sensor or related circuit malfunction
•Accelerator position sensor or related circuit malfunction
•Idle switch or related circuit malfunction
•MAF/IAT sensor or related circuit malfunction
•Fuel pressure sensor or related circuit malfunction
•Incorrect adjustment accelerator pedal position sensor and/or idle switch
•Incorrect idle speed
•Excessive fuel pressure
•Supply pump malfunction
•Suction control valve malfunction (built-in supply pump)
•Fuel pressure limiter malfunction (built-in common rail)
•Fuel injector malfunction (incorrect fuel regulate pressure)
•Neutral switch or related 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
1 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 for 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.
2 Access ECT PID.
Start and warm-up engine to normal operating
temperature.
Is ECT PID reading between 82—112 °C {180—
233 °F}?Yes Go to next step.
NoECT PID is higher than 112 °C {233 °F}:
Go to symptom troubleshooting “NO.17 COOLING
SYSTEM CONCERNS-OVERHEATING”.
ECT PID is less than 82 °C {180 °F}:
Go to symptom troubleshooting “NO.18 COOLING
SYSTEM CONCERNS-RUNS COLD”.

TROUBLESHOOTING
F2–185
F2
End Of Sie
3 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.
4 Inspect cooling fan No.2 control system
operation.
Does cooling fan No.2 control operate properly?Yes Go to next step.
No Repair or replace malfunctioning part according to
cooling fan No.2 control system operation inspection
results.
5 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)
6 Inspect adjustment of neutral switch.
(See F2–69 NEUTRAL SWITCH INSPECTION)
Is neutral switch adjusted correctly?Yes Go to next step.
No Adjust neutral switch correctly.
7 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.
8 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.
9 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
•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.
10 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)
11 Remove thermostat and inspect operation.
(See E–9 THERMOSTAT REMOVAL/
INSTALLATION)
(See E–10 THERMOSTAT INSPECTION)
Is thermostat okay?Yes Go to next step.
No Replace thermostat.
12 Inspect IDM.
(See F2–84 INJECTOR DRIVER MODULE
(IDM) INSPECTION)
Is IDM okay?Yes Go to next step.
No Repair or replace as necessary.
13 Inspect fuel injector relief pressure.
Is fuel injector relief pressure okay?Yes Remove and inspect supply pump and common rail.
No Replace fuel injector.
14 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