Mazda Mazda6 Workshop Manual Supplement page 345

Diagnostic Procedure
STEP INSPECTION
1 Is idle speed stable?
2 Is engine overheating?
3 Perform self-test function using WDS or
equivalent.
Turn engine switch to ON.
Retrieve any DTC.
Is DTC displayed?
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?
5 Does engine run normal after warm-up?
6 Note
• 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?
7 Inspect hose bands between following parts:
• Turbocharger compressor housing and air
cleaner
• Turbocharger compressor housing and
charge air cooler
Are hose bands loose?
8 Inspect for improper operation, kinks, clogging or
disconnection on guide blade actuator.
Is guide blade actuator okay?
9 Perform EGR system inspection.
Is EGR system okay?
10 Inspect idle speed.
(See F2–34 IDLE SPEED
Is idle speed correct?
TROUBLESHOOTING
RESULTS
Yes
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
INSPECTION)
No
ACTION
Go to next step.
Go to symptom troubleshooting "NO.8 ENGINE RUNS
ROUGH/ROLLING IDLE".
Go to symptom troubleshooting "NO.17 COOLING
SYSTEM CONCERNS—OVERHEATING".
Go to next step.
DTC 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
No DTC is displayed:
Go to next step.
Go to next step.
Service as necessary.
Repeat Step 4.
Inspect glow system operation.
(See T–19 RELAY INSPECTION)
Replace any malfunctioning part as necessary.
If glow system is okay, go to next step.
Go to next step.
Go to next step.
A/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
Retighten hose bands.
If concern is resolved, complete inspection.
If concern still exists, go to next step.
Go to next step.
Turbocharger is okay.
Go to next step.
Repair or replace as necessary.
If concern is resolved, complete inspection.
If concern still exists, turbocharger is okay.
Go to next step.
Go to next step.
Repair or replace malfunctioning part according to
EGR system operation results.
Go to next step.
Repair or replace malfunctioning part according to idle
speed inspection results.
F2
F2–193