Mazda Mazda6 Workshop Manual Supplement page 328

NO.4 HARD START/LONG CRANK/ERRATIC START/ERRATIC CRANK
4 HARD START/LONG CRANK/ERRATIC START/ERRATIC CRANK
• Starter cranks engine at normal speed but engine requires excessive cranking time before starting.
DESCRIPTION
• Battery is in normal condition.
• Poor fuel quality
• Intake-air system restriction or clogging
• Starting system malfunction
• Inadequate fuel pressure
• Fuel pressure limiter malfunction (built-in common rail)
• Suction control valve malfunction (built-in supply pump)
• Engine overheating
• Glow system malfunction
• Fuel filter clogging or restriction
• Fuel line clogging or restriction
• Fuel leakage
• Exhaust system and/or catalyst converter restriction or clogging
• Incorrect fuel injection timing
• Erratic signal from CKP sensor
• Erratic signal from CMP sensor
• ECT sensor or related circuit malfunction
• Accelerator position sensor or related circuit malfunction
POSSIBLE
• Accelerator position sensor misadjustment
CAUSE
• MAF/IAT sensor or related circuit malfunction
• Fuel pressure sensor or related circuit malfunction
• Supply pump malfunction
• Fuel injector malfunction
• Low engine compression
• IDM or related circuit malfunction
• EGR 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
• Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injury or death
Diagnostic Procedure
STEP
1 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?
2 Is engine overheating?
3 Connect WDS or equivalent to DLC-2.
Turn engine switch to ON.
Retrieve any DTC.
Is DTC displayed?
F2–176
TROUBLESHOOTING
sparks and flames away from fuel.
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.
INSPECTION RESULTS
Yes Go to next step.
No Service as necessary.
Repeat Step 1.
Yes Go to symptom troubleshooting "NO.17 COOLING
SYSTEM CONCERNS-OVERHEATING".
No Go to next step.
Yes DTC 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
No No DTC is displayed:
Go to next step.
A6E408018881206
ACTION