2002 MAZDA 6 sensor

F2–216
TROUBLESHOOTING
NO.20 FUEL ODOR (IN ENGINE COMPARTMENT)A6E408018881222
Diagnostic Procedure
End Of Sie
20 FUEL ODOR (IN ENGINE COMPARTMENT)
DESCRIPTION•Fuel smell or visible leakage.
POSSIBLE
CAUSE•Excessive fuel pressure
•Suction control valve malfunction (built-in supply pump)
•Fuel pressure limiter malfunction (built-in common rail)
•Fuel pressure sensor or related circuit malfunction
•Fuel leakage
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 Visually inspect fuel leakage at fuel injector and
fuel line.
Is there any fuel leakage?Yes Service as necessary.
No Go to next step.
2 Visually inspect for damaged or cracked fuel
filter.
Is fuel filter okay?Yes Go to next step.
No Replace fuel filter.
3 Inspect fuel pressure sensor.
(See F2–79 FUEL PRESSURE SENSOR
INSPECTION)
Is fuel pressure okay?Yes Go to next step.
No Repair or replace as necessary.
4 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)
5 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:
Remove and inspect common rail.
6 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)

TROUBLESHOOTING
F2–217
F2
NO.21 ENGINE NOISEA6E408018881223
Diagnostic Procedure
21 ENGINE NOISE
DESCRIPTION•Engine noise under hood.
POSSIBLE
CAUSE•Engine internal damage
•Timing belt displacement
•Fuel injector malfunction
•Loose attaching bolts or worn parts
•Improper drive belt tension
•Air leakage from intake-air system
•Incorrect injection timing
•Erratic signal from CKP sensor
•Erratic signal from CMP sensor
•Fuel pressure sensor or related circuit malfunction
•Boost sensor or related circuit malfunction
•Accelerator position sensor or related circuit malfunction
•MAF/IAT sensor or related circuit malfunction
•ECT sensor or related circuit malfunction
•EGR system or malfunction
•IAT sensor No.2 or related circuit malfunction
•Vacuum leakage
•Suction control valve malfunction (built-in supply pump)
•Air leakage from intake-air system
•Air in power steering fluid line
•Turbocharger operating noise
•Solenoid valve operating noise
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.
Note
•PCM checks fuel injection amount during a set interval while idling, and automatically corrects it to
maintain engine efficiency. It is normal that engine noise and vibration might be a little louder during
this process.
STEP INSPECTION RESULTS ACTION
1 Is squeal, click or chirp sound present? Yes Inspect engine oil level, solenoid valves installation or
drive belt.
No Go to next step.
2 Is rumble or grind sound present? Yes Inspect drive belt tension or power steering system
fluid level.
If okay, perform power steering fluid line air bleed.
No Go to next step.
3 Is rattle sound present? Yes Inspect location of rattle for loose parts.
No Go to next step.
4 Is hiss sound present? Yes Inspect for vacuum leakage and intake-air system
leakage.
No Go to next step.
5 Is rap or roar sound present? Yes Inspect exhaust system or loose parts.
No Go to next step.

F2–218
TROUBLESHOOTING
6 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 appropriate DTC test.
7 Access ECT PID.
Inspect ECT PID while warming up engine.
Is PID value correct?Yes Go to next step.
No Inspect ECT sensor and related wiring harnesses.
8 Access IAT PID.
Inspect IAT PID while running engine.
Is PID value correct?Yes Go to next step.
No Inspect IAT sensor and related wiring harnesses.
9 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.
10 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.
11 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.
12 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.
13 Remove parts necessary to inspect
turbocharger.
Note
•Do not remove turbocharger.
Inspect if turbocharger compressor wheel is
bent, damaged, or interfering with housing on
vehicle.
Is there any problem?Yes Replace turbocharger.
No Go to next step. STEP INSPECTION RESULTS ACTION

F2–220
TROUBLESHOOTING
NO.22 VIBRATION CONCERNS (ENGINE)A6E408018881224
Diagnostic Procedure
22 VIBRATION CONCERNS (ENGINE)
DESCRIPTION•Vibration from under hood or driveline.
POSSIBLE
CAUSE•Loose attaching bolts or worn parts
•Cooling fan No.1 or cooling fan No.2 seat are improper
•Engine or transaxle mounts are improperly installed
•Components malfunction such as worn parts
•Erratic signal from CMP sensor
•ECT sensor or related circuit malfunction
•Accelerator position sensor or related circuit malfunction
•MAF/IAT sensor or related circuit malfunction
•Idle switch or related circuit malfunction
•Incorrect adjustment of accelerator position sensor and/or idle switch
•Fuel injector malfunction
•Vacuum leakage
•Improper tension or damaged drive belts
•Improper balance of wheels or tires
•Driveline malfunction
•Suspension 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 following components for loose attaching
bolts or worn parts:
•Cooling fan No.1
•Cooling fan No.2
•Cooling fan No.1 and cooling fan No.2 seat
•Drive belt and pulley
•Engine mounts
•Exhaust system
Are all items okay?Yes Go to next step.
No Readjust or retighten engine mount installation
position.
Service as necessary for other parts.
2 Inspect vacuum leakage.
Are vacuum hoses okay?Yes Go to next step.
No Service as necessary.
Repeat Step 2.

TROUBLESHOOTING
F2–221
F2
End Of Sie
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.
4 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)
5 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.
6 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.
7 Inspect fuel injector.
(See F2–56 FUEL INJECTOR INSPECTION)
Is fuel injector okay?Yes Inspect following systems:
•Wheels
•Transaxle and mounts
•Driveline
•Suspension
Service as necessary.
No Repair or replace as necessary.
8 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

F2–222
TROUBLESHOOTING
NO.23 A/C DOES NOT WORK SUFFICIENTLYA6E408018881225
Diagnostic Procedure
End Of Sie
23 A/C DOES NOT WORK SUFFICIENTLY
DESCRIPTION•A/C compressor magnetic clutch does not engage when A/C switch is turned on.
POSSIBLE
CAUSE•Improper refrigerant charge amount
•Open A/C switch magnetic clutch
•Open circuit between A/C relay and A/C magnetic clutch
•Poor GND of A/C magnetic clutch
•Improper A/C magnetic clutch clearance
•Refrigerant pressure switch is stuck open
•A/C relay is stuck open
•Improper A/C cut-off control
•Open circuit between A/C switch and PCM through both refrigerant pressure switch and A/C amplifier
STEP INSPECTION RESULTS ACTION
1 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
YesNo DTC is displayed:
Go to appropriate DTC test.
2 Disconnect A/C compressor connector.
Start engine and turn A/C switch to ON.
Is there correct voltage at terminal of A/C
compressor magnetic clutch connector?
Specification
More than 10.5 VYes Inspect for GND condition of magnetic clutch on A/C
compressor.
If GND condition is okay, inspect magnetic clutch coil
for open circuit.
No Go to next step.
3 Disconnect refrigerant pressure switch
connector.
Connect jumper wire between terminals of
refrigerant pressure switch connector.
Turn engine switch to ON.
Turn A/C switch on and set blower fan at any
speed.
Measure PCM terminal 84 voltage.
Is voltage below 1.0 V?Yes Inspect refrigerant pressure switch operation.
If switch is okay, go to next step.
No Inspect for following:
•A/C switch is stuck open
•Open circuit between refrigerant pressure switch
and PCM terminal 84
•Open circuit of blower motor fan switch and
resistor (if blower motor does not operate)
•Evaporator temperature sensor and A/C amplifier
4 Inspect A/C cut-off operation.
Does A/C cut-off work properly?Yes Go to next step.
No Repair or replace malfunctioning part according to A/C
cut-off system inspection results.
5 Remove jumper wire from switch connector.
Reconnect connector to refrigerant pressure
switch.
Start engine and turn A/C switch on.
Does fan operate?Yes Inspect for stuck open A/C relay.
Replace if necessary.
No Inspect following and repair or replace as necessary:
•Refrigerant charging amount
•Seized A/C compressor
6 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)

F2–224
TROUBLESHOOTING
NO.25 A/C DOES NOT CUT OFF UNDER WIDE OPEN THROTTLE CONDITIONSA6E408018881227
Diagnostic Procedure
End Of Sie
25 A/C DOES NOT CUT OFF UNDER WIDE OPEN THROTTLE CONDITIONS
DESCRIPTION•A/C compressor magnetic clutch does not disengage under wide open throttle.
POSSIBLE
CAUSE•Accelerator position sensor malfunction
•Accelerator position sensor misadjustment
•Loosely installed accelerator position sensor
STEP INSPECTION RESULTS ACTION
1 Does A/C compressor disengage when A/C
switch is turned off?Yes Go to next step.
No Go to symptom troubleshooting “NO.24 A/C ALWAYS
ON OR A/C COMPRESSOR RUNS
CONTINUOUSLY”.
2 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:
Inspect adjustment of accelerator position sensor.
If accelerator position sensor adjustment is not
correct, adjust accelerator position sensor.
3 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)

TROUBLESHOOTING
F2–225
F2
NO.26 CONSTANT VOLTAGEA6E408018881228
Diagnostic Procedure
26 CONSTANT VOLTAGE
DESCRIPTION•Incorrect constant voltage.
POSSIBLE
CAUSE•Constant voltage circuit malfunction
•Accelerator positions sensor or related circuit malfunction
•Fuel pressure sensor or related circuit malfunction
•Boost sensor or related circuit malfunction
•ECT sensor GND circuit malfunction
•MAF/IAT sensor GND circuit malfunction
•IAT sensor No.2 GND circuit malfunction
•Fuel temperature sensor GND circuit malfunction
Note
•Accelerator position sensor, fuel pressure sensor and boost sensor use constant voltage.
STEP INSPECTION RESULTS ACTION
1 Disconnect appropriate sensor connectors
(accelerator position sensor, boost sensor and
fuel pressure sensor) where constant voltage
circuits inspection failed.
Turn engine switch to ON position.
Measure voltage between following appropriate
sensor connector terminals:
•Constant voltage terminal and GND terminal.
Is constant voltage above 6.0 V?Yes Repair constant voltage circuit short to power in
harness.
No Go to next step.
2 Is voltage across battery terminals above 10.5
V?Yes Go to next step.
No Inspect charging system.
3 Turn engine switch to OFF.
Leave appropriate sensor connectors
disconnected where constant voltage inspection
failed.
Measure voltage between positive terminal and
GND circuit at appropriate sensor vehicle
harness connector.
Is voltage above 10.5 V and within 1.0 V of
battery voltage?Yes Go to next step.
No Go to Step 8.
4Note
•Purpose of this step is to determine if
WDS or equivalent is communicating with
PCM.
Turn engine switch to ON.
Attempt to access ECT PID.
Can ECT PID be accessed?Yes Go to Step 7.
No Go to next step.
5 Turn engine switch to OFF.
Disconnect accelerator position sensor and
PCM connectors.
Turn engine switch to ON.
Measure voltage between PCM connector
terminals 104 and 53/79.
Is voltage greater than 10.5 V?Yes Go to next step.
No Repair open circuit between PCM terminal 53/79 and
PCM control relay.
6 Leave accelerator position sensor and PCM
connectors disconnected.
Measure resistance between PCM connector
terminals 104 and 90.
Is resistance greater than 10,000 ohms?Yes Inspect sensor connector for constant voltage again.
No Repair constant voltage circuit short to GND.
7 Turn engine switch to OFF.
Leave accelerator position sensor
disconnected.Disconnect PCM connector.
Measure resistance between PCM connector 90
and constant voltage circuit at appropriate
sensor connector.
Is resistance less than 5.0 ohms?Yes Inspect sensor connector for constant voltage again.
No Repair open constant voltage circuit.