No.15 Emission Compliance - Mazda CX-7 2007 Workshop Manual

SYMPTOM TROUBLESHOOTING [L3 WITH TC]
NO.15 EMISSION COMPLIANCE[L3 WITH TC]
15 EMISSION COMPLIANCE
DESCRIPTION Fails emissions test.
• Poor fuel quality
• Vacuum lines leakage or blockage
• Cooling system malfunction
• Engine overheating
• Spark plug malfunction
• Air leakage from intake-air system
• Variable swirl system malfunction
• Wastegate control system improper operation
• Turbocharger malfunction
• Charge air cooler malfunction
• Inadequate fuel pressure (high-pressure side)
• PCV valve malfunction or incorrect valve installation
• EGR system malfunction
• Exhaust system and/or three-way catalytic converter restriction
• Fuel tank ventilation system malfunction
• Charcoal canister damage
• Air cleaner element clogging or restriction
• Throttle body malfunction
• Improper operation of electronic throttle control system
• Relief valve malfunction (built-in delivery pipe)
• Suction control valve malfunction (built-in high pressure fuel pump)
• Improper air/fuel mixture ratio control operation
• Erratic or no signal from CMP sensor
• Erratic signal from CKP sensor
• Front or rear HO2S or related circuit malfunction
• ECT or related circuit malfunction
• MAF sensor or related circuit malfunction
• IAT sensor No.1 or related circuit malfunction
• IAT sensor No.2 or related circuit malfunction
• Fuel pressure sensor or related circuit malfunction
• Accelerator position sensor or related circuit malfunction
POSSIBLE CAUSE
• TP sensor or related circuit malfunction
• Manifold absolute pressure (MAP) sensor or related circuit malfunction
• VSS or related circuit malfunction
• Fuel line restriction
• High pressure fuel pump malfunction
• Fuel injector or related circuit malfunction
• Incorrect fuel injection timing
• Three-way catalytic converter (TWC) malfunction
• Engine internal parts malfunction
• Excessive carbon is built-up in combustion chamber
• Improper engine compression
• Improper valve timing
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
• Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injury or
Caution
• Disconnecting/connecting the quick release connector without cleaning it may possibly
01-03–56
keep sparks and flames away from fuel.
death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete
"BEFORE REPAIR ROCEDURE" and "AFTER REPAIR PROCEDURE" described in this
manual.
(See01-14-4 BEFORE REPAIR PROCEDURE[L3 WITH TC].)
(See01-14-4 AFTER REPAIR PROCEDURE[L3 WITH TC].)
cause damage to the fuel pipe and quick release connector. Always clean the quick release
connector joint area before disconnecting/connecting, and make sure that it is free of
foreign material.
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