Mazda MX-6 1998, Workshop Manual

Page: 180 / 1282

TROUBLESHOOTING [ENGINE CONTROL FS]
14
EMISSION COMPLIANCE
DESCRIPTION
Emission compliance test is failed
POSSIBLE
CAUSE
• Vacuum lines leaks or blockage
• Spark plug malfunction
• Erratic or no signal from camshaft position sensor
• PCV valve malfunction or incorrect valve installation
• Exhaust system clogged
• Charcoal canister damage
• Improper engine compression
• Cooling system malfunction
• Leaks from intake manifold
• Inadequate fuel pressure
• EGR valve malfunction
• Fuel tank ventilation system malfunction
• Excessive carbon build up in combustion chamber
• Improper valve timing
Warning
Following troubleshooting flow chart contains fuel system diagnosis and repair procedures. Read
following warnings before performing fuel system service:
• 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 leaks are dangerous. Fuel can ignite and cause serious injuries 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.
or 0 1 -1 4 BEFORE REPAIR PROCEDURE
tr 0 1 -1 4 AFTER REPAIR PROCEDURE
STEP
INSPECTION ACTION
1
Check following:
• Vacuum lines for leaks or blockage.
• Electrical connections. Yes Go to next step.
• Proper maintenance schedule followed.
• Intake air system and air cleaner element
concerns: obstructions, leaks or dirty.
Are all items okay?
No Service as necessary.
Repeat step
1 .
2
Retrieve and record any continuous memory,
KOEO and KOER DTCs.
Are there any DTCs displayed?
Yes Go to appropriate DTC test.
No Go to next step.
3 Is any other drivability concern present?
Yes
Go to appropriate flow chart.
No Go to next step.
4 Connect NGS tester to DLC.
Access ECT PID.
Warm-up engine and run at Idle.
Verify ECT PID is correct.
• ECT PID.
d - 0 1 -4 0 A ENGINE COOLANT
TEMPERATURE SENSOR
INSPECTION [FS]
Is ECT PID correct?
Yes Go to next step.
No Check cooling system.
5 Is strong blue spark visible at each
disconnected hightension lead while cranking
engine?
Yes Check following:
• Spark plug(s) malfunction.
• CMP sensor improperly installated.
• Damage of trigger wheel on camshaft.
• Open or short circuit on CMP sensor.
• Open or short circuit between CMP sensor and PCM.
Repair or replace malfunctioning part. If okay, go to next
step.
No Check following:
• Hightension leads.
• Ignition coil and connector.
0 1 -0 1 A - 1 52