Mazda CX-7 2007 Workshop Manual page 357

SYMPTOM TROUBLESHOOTING [L3 WITH TC]
Diagnostic procedure
STEP INSPECTION
1 Is the engine overheating?
2 Is the engine runs cold?
3 Connect the M-MDS to the DLC.
Perform the self-test function using the M-MDS.
Turn the ignition switch to the ON position.
Retrieve any DTCs.
Is a DTC displayed?
4 Inspect for the following.
• Fuel quality (proper octane, contamination,
winter/summer blend)
• Charge air cooler condition (restriction or
damaged)
• Air cleaner element (clogging or restriction)
• Intake-air system leakage
• PCV valve installation
• Vacuum line leakage or blockage
• Fuel leakage at fuel system
• Charcoal canister damaged
• Exhaust system and/or three-way catalytic
converter restriction
Are all items normal?
5 Perform the EGR system operation inspection.
(See01-03-78 ENGINE CONTROL SYSTEM
OPERATION INSPECTION[L3 WITH TC].)
Does the EGR system operate properly?
6 Perform the TP sweep inspection.
(See01-03-78 ENGINE CONTROL SYSTEM
OPERATION INSPECTION[L3 WITH TC].)
Does the electronic throttle control system work
properly?
7 Perform the Variable Swirl Control System
Operation Inspection.
(See01-03-78 ENGINE CONTROL SYSTEM
OPERATION INSPECTION[L3 WITH TC].)
Does the variable swirl system work properly?
8 Perform the Wastegate Control System
Operation Inspection.
(See01-03-78 ENGINE CONTROL SYSTEM
OPERATION INSPECTION[L3 WITH TC].)
Does the variable swirl system work properly?
9 Perform the Evaporative Emission (EVAP)
System Leak Inspection.
(See01-03-78 ENGINE CONTROL SYSTEM
OPERATION INSPECTION[L3 WITH TC].)
Does the variable swirl system work properly?
10 Remove and shake the PCV valve.
Does the PCV valve rattle?
11 Perform the spark test.
(See01-03-78 ENGINE CONTROL SYSTEM
OPERATION INSPECTION[L3 WITH TC].)
Is a strong blue spark visible at each cylinder?
RESULTS
Yes Go to symptom troubleshooting "NO.17 COOLING
SYSTEM CONCERNS - OVERHEATING."
No Go to the next step.
Yes Go to symptom troubleshooting "NO.18 COOLING
SYSTEM CONCERNS - RUNS COLD."
No Go to the next step.
Yes DTC is displayed:
Go to appropriate DTC test.
No No DTC is displayed:
Go to the next step.
Yes Go to the next step.
No Service if necessary.
Repeat Step 4.
Yes Go to the next step.
No Inspect or replace the malfunctioning parts, according
to the inspection results.
Yes Visually inspect the throttle body (damaged/
scratching.) If normal, go to the next step.
No Inspect or replace the malfunctioning parts, according
to the inspection results.
Yes Go to the next step.
No Inspect or replace the malfunctioning parts, according
to the inspection results.
Yes Go to the next step.
No Inspect or replace the malfunctioning parts, according
to the inspection results.
Yes Go to the next step.
No Inspect or replace the malfunctioning parts, according
to the inspection results.
Yes Go to the next step.
No Replace the PCV valve.
Yes Go to the next step.
No Inspect or replace the malfunctioning parts, according
to the inspection results.
ACTION
01-03–57
01-03