2002 MAZDA 6 engine overheat

F2–168
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
Improper engine coolant levelWater and anti-freeze mixture is improperCooling system malfunction (Radiator, hose,
over-flow system, thermostat, etc.)Cooling fan system malfunctionEngine or transaxle mounts are improperly installedCooling fan No.1 or No.2 seat are improperFuel qualityEngine overheatingIntake-air system clogging or restrictionAir leakage from intake-air systemVSC system malfunctionVacuum leakage

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

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

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

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.

F2–178
TROUBLESHOOTING
End Of Sie
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
F2–179
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