2002 MAZDA 6 engine coolant

ON-BOARD DIAGNOSTIC
F2–113
F2
DTC P0118A6E407001082215
Diagnostic procedure
DTC P0118 ECT sensor circuit high input
DETECTION
CONDITION•PCM monitors input voltage from ECT sensor while engine is running. If input voltage from ECT sensor is
above 5.0 V, PCM determines ECT sensor circuit high input.
POSSIBLE
CAUSE•ECT sensor malfunction
•Connector or terminal malfunction
•Short to power circuit in wiring between ECT sensor terminal A and PCM terminal 87
•Open circuit in wiring between ECT sensor terminal A and PCM terminal 87
•Open circuit in wiring between ECT sensor terminal B and PCM terminal 91
•PCM malfunction
STEP INSPECTION ACTION
1PERFORM DTC CONFIRMATION PROCEDURE
•Perform “DTC Confirmation Procedure”.
(See F2–85 DTC CONFIRMATION
PROCEDURE)
•Is same DTC present during KOEO or KOER
self-test?Yes Go to next step.
No Intermittent concern exists. Go to “Intermittent Concern
Troubleshooting”.
(See F2–227 INTERMITTENT CONCERN
TROUBLESHOOTING)
2INSPECT POOR CONNECTION OF ECT
SENSOR CONNECTOR
•Turn engine switch to OFF.
•Inspect for poor connection (damaged, pulled-
out terminals, corrosion, etc.).
•Is there any malfunction?Yes Repair or replace suspected terminal, go to Step 7.
No Go to next step.
3CLASSIFY ECT SENSOR MALFUNCTION OR
HARNESS MALFUNCTION
•Turn engine switch to ON (Engine OFF).
•Connect jumper wire between ECT sensor
connector terminals.
•Access ECT PID using WDS or equivalent.
•Is ECT PID below 1.0 V?Yes Replace ECT sensor, go to Step 7.
(See F2–76 ENGINE COOLANT TEMPERATURE (ECT)
SENSOR REMOVAL/INSTALLATION)
No Go to next step.
562
5462
ECT SENSOR
A
BPCM
87
91
B
A
9187 ECT SENSOR
HARNESS SIDE CONNECTORPCM
HARNESS SIDE CONNECTOR

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

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

F2–188
TROUBLESHOOTING
End Of Sie
13 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.
14 Inspect fuel injector.
(See F2–56 FUEL INJECTOR INSPECTION)
Is fuel injector okay?Yes Go to next step.
No Repair or replace as necessary.
15 Inspect EGR system operation.
Is EGR system operation normal?Yes Go to next step.
No Repair or replace malfunctioning part according to
EGR system operation results.
16 Inspect EGR water cooler for following:
•Coolant passage clogging/restriction
•Exhaust gas clogging/restriction
Is EGR water cooler okay?Yes Go to next step.
No Service as necessary.
17 Inspect IDM.
(See F2–84 INJECTOR DRIVER MODULE
(IDM) INSPECTION)
Is IDM okay?Yes Remove and inspect supply pump and common rail.
No Repair or replace as necessary.
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

TROUBLESHOOTING
F2–199
F2
NO.13 KNOCKING/PINGINGA6E408018881215
Diagnostic Procedure
13 KNOCKING/PINGING
DESCRIPTION•Excessive shrilly knocking sound from engine.
POSSIBLE
CAUSE•Poor fuel quality
•Air leakage from intake-air system
•Intake-air system restriction or clogging
•Variable swirl control (VSC) system malfunction
•Variable boost control (VBC) system malfunction
•Intake shutter valve stuck close
•VSC valve stuck close
•Glow system malfunction
•Low engine compression
•Improper valve timing
•Low coolant temperature
•Incorrect fuel injection timing
•Erratic signal from CKP sensor
•Erratic signal from CMP sensor
•ECT sensor or related circuit malfunction
•MAF/IAT sensor or related circuit malfunction
•IAT sensor No.2 or related circuit malfunction
•Boost sensor or related malfunction
•Fuel pressure sensor or related circuit malfunction
•Accelerator position sensor or related circuit malfunction
•Excessive fuel pressure
•Fuel return line clogging or restriction
•EGR system malfunction
•Exhaust system and/or catalyst converter restriction
•Turbocharger malfunction
•Charge air cooler malfunction
•Suction control valve malfunction (built-in supply pump)
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 Does engine run cold? Yes Go to symptom troubleshooting “NO.18 COOLING
SYSTEM CONCERNS—RUNS COLD”.
No Go to next step.
2 Inspect for following:
•Fuel quality (e.g.: including water
contamination, winter/summer blend)
•Fuel return line clogging and/or restriction
•Intake-air system restriction or clogging
•Exhaust system and/or catalyst converter
restriction or clogging
•Charge air cooler condition (restriction or
damaged)
Are all items okay?Yes Go to next step.
No Service as necessary.
Repeat Step 2.
3 Connect WDS or equivalent to DLC-2.
Access ECT PID.
Verify ECT PID is above 80 °C {176 °F}?Yes Go to next step.
No Inspect ECT PID.

F2–202
TROUBLESHOOTING
NO.14 POOR FUEL ECONOMYA6E408018881216
Diagnostic Procedure
14 POOR FUEL ECONOMY
DESCRIPTION•Fuel economy is unsatisfactory.
POSSIBLE
CAUSE•Incorrect idle speed
•A/C system improper operation
•Intake -air system clogging or restriction
•Engine cooling system malfunction
•Poor fuel quality
•Improper coolant level
•Erratic signal from CKP sensor
•Erratic signal from CMP sensor
•Fuel pressure sensor or related circuit malfunction
•ECT sensor or related circuit malfunction
•Boost sensor or related circuit malfunction
•Accelerator position sensor or related circuit malfunction
•Incorrect adjustment idle switch
•MAF/IAT sensor or related circuit malfunction
•IAT sensor No .2 or related circuit malfunction
•VSS or related circuit malfunction
•Turbocharger malfunction
•Charge air cooler malfunction
•Low engine compression
•Improper valve timing
•Exhaust system and/or catalyst converter clogging
•Incorrect fuel injection timing
•Fuel injector malfunction
•Supply pump malfunction
•Fuel leakage
•Fuel line clogging or restriction
•Fuel filter clogging or restriction
•Brake dragging
•EGR system malfunction
•Vacuum leakage
•Clutch slippage
•Variable boost control (VBC) system malfunction
•Coolant heater 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.: including water
contamination, winter/summer blend)
•Fuel line/fuel filter clogging and/or restriction
•Fuel line leakage
•Intake-air system restriction
•Exhaust system and/or catalyst converter
restriction
•Charge air cooler condition (restriction or
damaged)
•Vacuum leakage
Are all items okay?Yes Go to next step.
No Service as necessary.
Repeat Step 1.
2 Is brake system functioning properly? Yes Go to next step.
No Inspect for cause.

TROUBLESHOOTING
F2–203
F2
3 Perform self-test function using WDS or
equivalent.
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.
4Note
•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.
5 Access ECT PID.
Drive vehicle while monitoring PID.
Is PID within specification?Yes Go to next step.
No Inspect for coolant leakage, cooling fan No.1 and
cooling fan No.2 operations or thermostat operation.
6 Inspect idle speed.
(See F2–34 IDLE SPEED INSPECTION)
Is idle speed okay?Yes Go to next step.
No Go to symptom troubleshooting “NO.7 SLOW
RETURN TO IDLE”.
7 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.
8 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)
9 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.
10 Inspect fuel injector.
(See F2–56 FUEL INJECTOR INSPECTION)
Is fuel injector okay?Yes Go to next step.
No Repair or replace as necessary.
11 Perform turbocharger inspection.
(See F2–38 TURBOCHARGER INSPECTION)
Is turbocharger okay?Yes Go to next step.
No Replace turbocharger.
12 Inspect guide blade valve operation.
(See F2–229 ENGINE CONTROL SYSTEM
OPERATION INSPECTION)
Is there any problem?Yes Repair or replace as necessary.
No Go to next step.
13 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. STEP INSPECTION RESULTS ACTION

TROUBLESHOOTING
F2–205
F2
NO.15 EMISSION COMPLIANCEA6E408018881217
Diagnostic Procedure
15 EMISSION COMPLIANCE
DESCRIPTION•Fails emissions test.
POSSIBLE
CAUSE•Poor fuel quality
•Vacuum leakage
•Air leakage from intake-air system
•Intake-air system restriction or clogging
•Variable swirl control (VSC) system malfunction
•Variable boost control (VBC) system malfunction
•Intake shutter valve stuck close
•VSC valve stuck close
•Turbocharger malfunction
•Guide blade valve malfunction
•Charge air cooler malfunction
•Glow system malfunction
•EGR system malfunction
•EGR water cooler malfunction
•Low coolant temperature
•Engine overheating
•Inadequate fuel pressure
•Fuel pressure limiter malfunction (built-in common rail)
•Suction control valve inspection (built-in supply pump)
•ECT sensor or related circuit malfunction
•MAF/IAT sensor related circuit malfunction
•IAT sensor No.2 or related circuit malfunction
•Fuel pressure sensor or related circuit malfunction
•Incorrect adjustment accelerator position sensor and/or idle switch
•Accelerator position sensor or related circuit malfunction
•Idle switch or related circuit malfunction
•Fuel line rclogging or restriction
•Supply pump malfunction
•Fuel injector malfunction
•Incorrect fuel injection timing
•Incorrect idle speed
•Erratic signal from CKP sensor
•Erratic signal from CMP sensor
•Boost sensor or related circuit malfunction
•Neutral switch or related circuit malfunction
•VSS or related circuit malfunction
•Low engine compression
•Improper valve timing
•Base engine malfunction
•Exhaust system and/or catalyst converter restriction
•Catalyst converter 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 Is engine overheating? Yes Go to symptom troubleshooting “NO.17 COOLING
SYSTEM CONCERNS—OVERHEATING”.
No Go to next step.
2 Does engine run cold? Yes Go to symptom troubleshooting “NO.18 COOLING
SYSTEM CONCERNS—RUNS COLD”.
No Go to next step.