Mazda 6 Workshop Manual page 231

Diagnostic Procedure
STEP INSPECTION
1 Is the idle speed stable?
2 Is the engine overheating?
3 Perform the self-test function using the WDS or
equivalent.
Turn the engine switch to the ON position.
Retrieve any DTC.
Is the DTC displayed?
4 Inspect for the following:
• Fuel quality (such as 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 the items normal?
5 Does the 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
the engine stalling, go to the next step.
• Go to next step for the vehicle without A/C
system.
Connect the pressure gauge to the A/C line.
Turn the blower and the A/C switches on.
Is the pressure within the specifications?
7 Inspect the hose bands between the following
parts:
• Turbocharger compressor housing and air
cleaner
• Turbocharger compressor housing and
charge air cooler
Are the hose bands loose?
8 Inspect for improper operation, kinks, clogging
or disconnection on the guide blade actuator.
Is the guide blade actuator normal?
9 Inspect the EGR system operation.
(See F2–232 EGR Control System
Is the EGR system operation normal?
10 Inspect the idle speed.
Is the idle speed correct?
TROUBLESHOOTING
RESULTS
Yes Go to the next step.
No Go to the symptom troubleshooting "NO.8 ENGINE
RUNS ROUGH/ROLLING IDLE".
Yes Go to symptom troubleshooting "NO.17 COOLING
SYSTEM CONCERNS—OVERHEATING".
No Go to the next step.
Yes DTC is displayed:
Go to the appropriate DTC test.
Communication error message is displayed:
Inspect for the following:
• Open circuit between the PCM control relay and
• Open circuit between the PCM control relay and
• Stuck open PCM control relay
• Open or poor GND circuit (PCM terminal 65, 85,
• Poor connection at vehicle body GND
No No DTC is displayed:
Go to the next step.
Yes Go to the next step.
No Service if necessary.
Repeat Step 4.
Yes Inspect the glow system operation.
Replace the any malfunctioning part if necessary.
If the glow system is normal, go to the next step.
No Go to the next step.
Yes Go to the next step.
No A/C is always on:
Go to the symptom troubleshooting "NO.24 A/C
ALWAYS ON OR A/C COMPRESSOR RUNS
CONTINUITY".
Other symptoms:
Inspect the following:
• Refrigerant charging amount
• Cooling fan No.1 and/or cooling fan No.2 operation
Yes Retighten the hose bands.
If the concern is resolved, complete the inspection.
If the concern still exists, go to the next step.
No Go to the next step.
Yes Turbocharger is normal.
Go to the next step.
No Repair or replace if necessary.
If the concern is resolved, complete the inspection.
If the concern still exists, turbocharger is normal.
Go to the next step.
Yes Go to the next step.
Inspection.)
No Repair or replace the malfunctioning part according to
the EGR control system inspection results.
Yes Go to the next step.
No Repair or replace the malfunctioning part according to
the idle speed inspection results.
ACTION
PCM terminal 53 or 79
PCM terminal 69
103 or 104)
F2
F2–219