Mazda CX-7 2007 Workshop Manual page 235

STEP
8 VERIFY CURRENT INPUT SIGNAL STATUS OF
FRONT HO2S
• Connect the M-MDS to the DLC-2.
• Start the engine and warm it up completely.
• Access the O2S11 PID.
• Read the O2S11 PID under following
accelerator pedal condition (in NEUTRAL).
— –0.1— 0.1A when idle.
— More than 0.25 mA just after release of
accelerator pedal (lean condition).
• Is the PID normal?
9 VERIFY CURRENT INPUT SIGNAL STATUS OF
MAF SENSOR
• Connect the M-MDS to the DLC-2.
• Start the engine.
• Access the MAF PID.
• Verify that the MAF PID changes quickly
according to engine speed.
• Is the PID normal?
10 INSPECT INTAKE-AIR SYSTEM FOR
EXCESSIVE AIR SUCTION
• Visually inspect the hose in intake-air system
for looseness, cracks or damages.
• Is there any malfunction?
11 INSPECT IGNITION COIL WIRING HARNESSES
• Inspect the ignition coil related wiring harness
condition (intermittent open or short circuit) for
all cylinders.
• Are wiring harness conditions normal?
12 INSPECT IGNITION SYSTEM OPERATION
• Perform the spark test.
(See01-03-78 ENGINE CONTROL SYSTEM
OPERATION INSPECTION[L3 WITH TC].)
• Is strong blue spark visible at each cylinder?
13 INSPECT ENGINE COMPRESSION
• Inspect the engine compression.
(See01-10-9 COMPRESSION
INSPECTION[L3 WITH TC].)
• Is there any malfunction?
14 INSPECT FUEL PRESSURE (HIGH-SIDE)
• Access and monitor FUEL_PRES PID.
• Is the FUEL_PRES PID value within the
specified?
(See01-40-6 PCM INSPECTION[L3 WITH
TC].)
15 IDENTIFY CAUSE BY FUEL PRESSURE
SENSOR OR HIGH PRESSURE FUEL PUMP
• Is the vehicle accelerate performance
normally?
16 INSPECT FUEL PRESSURE SENSOR
• Inspect the fuel pressure sensor.
(See01-40-35 FUEL PRESSURE SENSOR
INSPECTION[L3 WITH TC].)
• Is the fuel pressure sensor normal?
17 INSPECT HIGH PRESSURE FUEL PUMP
• Replace the high pressure fuel pump.
• Monitor FUEL_PRES PID.
• Is the FUEL_PRES PID value within the
specified?
(See01-40-6 PCM INSPECTION[L3 WITH TC].)
ON-BOARD DIAGNOSTIC [L3 WITH TC]
INSPECTION
Yes Go to the next step.
No Visually inspect for the exhaust gas leakage between the
exhaust manifold and front HO2S.
• If there is no leakage, replace front HO2S.
(See01-15-2 EXHAUST SYSTEM REMOVAL/
INSTALLATION[L3 WITH TC].)
Then go to Step 20.
Yes Go to the next step.
No Replace the MAF/IAT sensor, then go to Step 20.
Yes Repair or replace the malfunctioning part, then go to Step
20.
No Go to the next step.
Yes Go to the next step.
No Repair the wiring harnesses, then go to Step 20.
Yes Go to the next step.
No Repair or replace the malfunctioning part according to
spark test result.
Then go to Step 20.
Yes Go to the next step.
No Overhaul the engine, then go to Step 20.
Yes Go to Step 18.
No Go to the next step.
Yes Go to the next step.
No Go to Step 17.
Yes Go to Step 18.
No Replace the fuel delivery pipe, then go to Step 20.
Yes Go to Step 20.
No Go to the next step.
ACTION
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01-02