Mazda 6 2002 Workshop Manual page 222

Diagnostic procedure
STEP
1 VERIFY FREEZE FRAME DATA HAS BEEN
RECORDED
• Has FREEZE FRAME DATA been recorded?
2 VERIFY RELATED SERVICE INFORMATION
AVAILABILITY
• Check for related Service Information
availability.
• Is any related Service Information available?
3 VERIFY RELATED PENDING CODE OR
STORED DTCS
• Turn ignition key to OFF then ON (Engine
OFF).
• Verify related pending code or stored DTCs.
• Is other DTCs present?
4 VERIFY CURRENT INPUT SIGNAL STATUS
(IGNITION KEY TO ON /IDLE)
• Access BOO, ECT, IAT, MAF, RPM, TP and
VSS PIDs using WDS or equivalent.
(See F–45 PCM
• Is there any signal that is far out of
specification when ignition switch is ON and
engine runs at idle?
5 VERIFY CURRENT INPUT SIGNAL STATUS
UNDER TROUBLE CONDITION
• Inspect same PIDs as in Step 4 while
simulating FREEZE FRAME DATA condition.
• Is there any signal which causes drastic
changes?
6 INSPECT SPARK PLUG CONDITION
• Turn ignition key to OFF.
• Remove spark plug from suspected cylinder.
• Inspect spark plug condition:
— Cracks
— Ecess wear
— Gap
— Wet
• Is any problem found on spark plug?
7 VERIFY HIGH-TENSION LEAD CONDITION
• Remove high-tension lead.
• Inspect high-tension lead condition and
resistance.
— Cracks
— Spark shorts to cylinder head through high-
tension lead insulator
• Is high-tension lead okay?
8 INSPECT FOR AIR SUCTION AT INTAKE-AIR
SYSTEM
• Inspect for air leakage at following:
— Around connection of dynamic chamber and
intake manifold
— Around connection of intake manifold and
cylinder head
• Is air leakage found?
9 INSPECT FUEL INJECTOR HARNESS
• Remove intake air system parts.
• Disconnect fuel injector connector on
suspected cylinder.
• Connect NOID LIGHT to fuel injector connector
terminals.
• Inspect dim of light during cranking.
• Does noid light illuminate?
ON-BOARD DIAGNOSTIC
INSPECTION
INSPECTION.)
Yes Go to net step.
No Record FREEZE FRAME DATA on repair order, then go to
net step.
Yes Perform repair or diagnosis according to available Service
Information.
• If vehicle is not repaired, go to net step.
No Go to net step.
Yes Go to appropriate DTC troubleshooting.
(See F–67 DTC TABLE.)
No Go to net step.
Yes Inspect suspected circuit and/or part according to
inspection results. Then go to Step 12.
(See F–45 PCM INSPECTION.)
No Go to net step.
Yes Inspect suspected circuit and/or part according to
inspection results. Then go to Step 12.
(See F–45 PCM INSPECTION.)
No Go to net step.
Yes • If spark plug is wet, fuel flooding is suspected. Go to
step 12.
• If spark plug has a cracks, ecessive wear or improper
gap, replace faulty spark plug. Then go to Step 12.
No Go to net step.
Yes Go to net step.
No Replace high-tension lead, then go to Step 12.
Yes Repair or replace suspected part, then go to Step 12.
No Go to net step.
Yes Go to net step.
No Inspect for fuel injector harnesses.
Repair or replace it if necessary, then go to Step 12.
ACTION
F–125
F