2002 MAZDA 6 air filter

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

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.

F2–182
TROUBLESHOOTING
3 Does security light illuminate? Yes Go to next step.
No Inspect instrument cluster and wiring harness.
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.
11Note
•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”.
12 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. STEP INSPECTION RESULTS ACTION

F2–186
TROUBLESHOOTING
NO.8 ENGINE RUNS ROUGH/ROLLING IDLEA6E408018881210
Diagnostic Procedure
8 ENGINE RUNS ROUGH/ROLLING IDLE
DESCRIPTION•Engine speed fluctuates between specified idle speed and lower speed and engine shakes excessively.
•Idle speed is too slow and engine shakes excessively.
POSSIBLE
CAUSE•Poor fuel quality
•Air leakage from intake-air system
•Intake-air system restriction
•Incorrect idle speed
•Engine overheating
•Cooling fan No.1 system malfunction
•A/C system improper operation
•EGR system improper operation
•EGR water cooler malfunction
•Fuel leakage
•Inadequate fuel pressure
•Fuel pressure sensor or related circuit malfunction
•Suction control valve malfunction (built-in supply pump)
•Fuel pressure limiter malfunction (built-in common rail)
•Fuel filter clogging
•Fuel line restriction
•Incorrect fuel injection timing
•Erratic signal from CKP sensor
•Erratic signal from CMP sensor
•ECT sensor or related circuit malfunction
•Idle switch misadjustment
•Idle switch or related circuit malfunction
•Accelerator position sensor misadjustment
•Accelerator position sensor or related circuit malfunction
•MAF/IAT sensor malfunction
•Neutral switch or related circuit malfunction
•Supply pump malfunction
•Fuel injector malfunction
•Low engine compression
•Improper valve timing
•Engine compression excessive unbalance for each cylinder
•Unbalanced fuel injection amount for each cylinder
•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 Inspect for following:
•Fuel quality (e.g.: including water
contamination, winter/summer blend)
•Fuel line/fuel filter clogging
•Loose bands on intake-air system
•Cracks on intake-air system parts
•Intake-air system restriction
•Vacuum leakage
•Cooling fan No.1 system operation
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.

F2–190
TROUBLESHOOTING
NO.10 LOW IDLE/STALLS DURING DECELERATIONA6E408018881212
Diagnostic Procedure
10 LOW IDLE/STALLS DURING DECELERATION
DESCRIPTION•Engine stops unexpectedly at beginning of deceleration or recovery from deceleration.
POSSIBLE
CAUSE•Intake-air system restriction or clogging
•Poor fuel quality
•A/C system improper operation
•Inadequate fuel pressure
•Suction control valve malfunction (built-in supply pump)
•Fuel pressure limiter malfunction (built-in common rail)
•Fuel leakage
•Fuel line restriction or clogging
•Fuel filter restriction or clogging
•Incorrect fuel injection timing
•Incorrect idle speed
•Erratic signal from CKP sensor
•Erratic signal from CMP sensor
•Supply pump malfunction
•Fuel injector malfunction
•Low engine compression
•Improper valve timing
•Glow system malfunction
•EGR system malfunction
•MAF/IAT sensor or related circuit malfunction
•ECT sensor or related circuit malfunction
•Fuel pressure sensor or related circuit malfunction
•Neutral switch malfunction or related circuit malfunction
•Accelerator position sensor or related circuit malfunction
•Idle switch or related circuit malfunction
•Incorrect adjustment accelerator position sensor and/or idle switch
•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 Does engine idle rough? Yes Go to symptom troubleshooting “NO.8 ENGINE RUNS
ROUGH/ROLLING IDLE”.
No Go to next step.
2 Inspect for following:
•Fuel line/fuel filter clogging or restriction
•Intake-air system restriction or clogging
•Fuel quality (e.g.: include water
contamination, winter/summer blend)
Are all items okay?Yes Go to next step.
No Service as necessary.
Repeat Step 2.
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.
4 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.

F2–192
TROUBLESHOOTING
End Of Sie
NO.11 ENGINE STALLS/QUITS, ENGINE RUNS ROUGH, MISSES, BUCK/JERK, HESITATION/STUMBLE,
SURGES
A6E408018881213
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
11ENGINE STALLS/QUITS, ENGINE RUNS ROUGH, MISSES, BUCK/JERK, HESITATION/STUMBLE,
SURGES
DESCRIPTION•Engine stops unexpectedly at beginning of acceleration or during cruise.
•Engine stops unexpectedly while cruising.
•Engine speed fluctuates during acceleration or cruising.
•Engine misses during acceleration or cruising.
•Vehicle bucks/jerks during acceleration, during or deceleration.
•Momentary pause at beginning of acceleration or during acceleration.
•Momentary minor irregularity in engine output.
POSSIBLE
CAUSE•Poor fuel quality
•Glow system malfunction
•Air leakage from intake-air system
•Intake-air system restriction or clogging
•Engine overheating
•A/C system improper operation
•Turbocharger malfunction
•Variable swirl control (VSC) system malfunction
•EGR system malfunction
•Neutral switch or related circuit malfunction
•Cooling fan No.1 or cooling fan No.2 seat are improper
•Fuel line clogging or restriction
•Fuel filter clogging or restriction
•Incorrect fuel injection timing
•Erratic signal from CKP sensor
•Erratic signal from CMP sensor
•ECT sensor or related circuit malfunction
•Boost 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
•IAT sensor No.2 or related circuit malfunction
•VSS or related circuit malfunction
•Incorrect adjustment accelerator position sensor and/or idle switch
•Incorrect idle speed
•Inadequate fuel pressure
•Fuel pressure sensor or related circuit malfunction
•Suction control valve malfunction (built-in supply pump)
•Fuel pressure limiter malfunction (built-in common rail)
•Supply pump malfunction
•Fuel injector malfunction
•Low engine compression
•Improper valve timing
•Exhaust system and/or catalyst converter restriction
•Clutch slippage
•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.

TROUBLESHOOTING
F2–193
F2
Diagnostic Procedure
STEP INSPECTION RESULTS ACTION
1 Is idle speed stable? Yes Go to next step.
No Go to symptom troubleshooting “NO.8 ENGINE RUNS
ROUGH/ROLLING IDLE”.
2 Is engine overheating? Yes Go to symptom troubleshooting “NO.17 COOLING
SYSTEM CONCERNS—OVERHEATING”.
No Go to next step.
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.
4 Inspect for following:
•Fuel quality (e.g.: including water
contamination, winter/summer blend)
•Fuel line/fuel filter clogging and/or restriction
•Intake-air system restriction or clogging
•Exhaust system and/or catalyst converter
restriction
•Cooling fan No.1 or cooling fan No.2 seat
Are all items okay?Yes Go to next step.
No Service as necessary.
Repeat Step 4.
5 Does engine run normal 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.
6Note
•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 CONTINUITY”.
Other symptoms:
Inspect following:
•Refrigerant charging amount
•Cooling fan No.1 and/or cooling fan No.2 operation
7 Inspect hose bands between following parts:
•Turbocharger compressor housing and air
cleaner
•Turbocharger compressor housing and
charge air cooler
Are hose bands loose?Yes Retighten hose bands.
If concern is resolved, complete inspection.
If concern still exists, go to next step.
No Go to next step.
8 Inspect for improper operation, kinks, clogging or
disconnection on guide blade actuator.
Is guide blade actuator okay?Yes Turbocharger is okay.
Go to next step.
No Repair or replace as necessary.
If concern is resolved, complete inspection.
If concern still exists, turbocharger is okay.
Go to next step.
9 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.
10 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.

TROUBLESHOOTING
F2–195
F2
NO.12 LACK/LOSS OF POWER-ACCELERATION/CRUISEA6E408018881214
Diagnostic Procedure
12 LACK/LOSS OF POWER-ACCELERATION CRUISE
DESCRIPTION•Performance is poor under load (e.g., power down when climbing hills).
POSSIBLE
CAUSE•Poor fuel quality
•Air leakage from intake-air system
•Intake-air system restriction or clogging
•Engine overheating
•A/C system improper operation
•Improper operation of A/C cut-off control
•Variable boost control (VBC) system malfunction
•Variable swirl control (VSC) system malfunction
•EGR system malfunction
•Vacuum leakage
•Clutch slippage
•Exhaust system and/or catalyst converter restriction
•Fuel line or clogging or restriction
•Fuel filter clogging or restriction
•Incorrect fuel injection timing
•Erratic signal from CKP sensor
•Erratic signal from CMP sensor
•ECT sensor or related circuit malfunction
•Boost 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
•IAT sensor No.2 or related circuit malfunction
•Incorrect adjustment accelerator position sensor and/or idle switch
•Incorrect idle speed
•Inadequate fuel pressure
•Fuel pressure sensor or related circuit malfunction
•Suction control valve malfunction (built-in supply pump)
•Fuel pressure limiter malfunction (built-in common rail)
•Supply pump malfunction
•Fuel injector malfunction
•Low engine compression
•Improper valve timing
•Cooling fan No.1 or cooling fan No.2 seat are improper
•Turbocharger malfunction
•Charge air cooler malfunction
•Brake system dragging
•Intake shutter valve malfunction
•Guide blade valve 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 idle speed stable? Yes Go to next step.
No Go to symptom troubleshooting “NO.8 ENGINE RUNS
ROUGH/ROLLING IDLE”.
2 Is engine overheating? Yes Go to symptom troubleshooting “NO.17 COOLING
SYSTEM CONCERNS—OVERHEATING”.
No Go to next step.