Mazda CX-7 2007 Workshop Manual page 261

STEP
6 VERIFY CURRENT INPUT SIGNAL STATUS
UNDER TROUBLE CONDITION
• Inspect the same PIDs as Step 5 while
simulating FREEZE FRAME DATA condition.
• Is there any signal which causes drastic
changes?
7 VERIFY CURRENT INPUT SIGNAL STATUS OF
FRONT HO2S
• Access the O2S11 for P2177 PID using the M-
MDS.
• Check the PID under following accelerator
pedal condition in NEUTRAL.
• Is the PID reading normal?
— –0.1— 0.1 A when idle
— More than 0.25 mA just after release of
accelerator pedal (lean condition).
8 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?
9 INSPECT FOR EXCESSIVE AIR SUCTION OF
INTAKE AIR SYSTEM
• Visually inspect for loosen, cracks or damages
hoses on intake-air system.
• Is there any malfunction?
10 INSPECT PURGE SOLENOID OPERATION
• Perform the Purge Control System Inspection.
(See01-03-78 ENGINE CONTROL SYSTEM
OPERATION INSPECTION[L3 WITH TC].)
• Does the purge control system work properly?
11 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].)
12 IDENTIFY CAUSE BY FUEL PRESSURE
SENSOR OR HIGH PRESSURE FUEL PUMP
• Is the vehicle accelerate performance
normally?
13 INSPECT FUEL PRESSURE SENSOR
• Inspect the fuel pressure sensor.
• Is fuel leakage found?
(See01-40-35 FUEL PRESSURE SENSOR
INSPECTION[L3 WITH TC].)
• Is the fuel pressure sensor normal?
14 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].)
15 INSPECT FUEL PRESSURE (LOW-SIDE)
• Connect the fuel pressure gauge between fuel
pump and high pressure fuel pump.
• Measure the low side fuel pressure.
(See01-14-5 FUEL LINE PRESSURE
INSPECTION[L3 WITH TC].)
• Is the low side fuel pressure within the
specified?
ON-BOARD DIAGNOSTIC [L3 WITH TC]
INSPECTION
Yes Inspect the sensor and related wiring harnesses repair or
replace it.
Then go to Step 20.
No Go to the next step.
Yes Go to the next step.
No Visually inspect for any gas leakage between the exhaust
manifold and the front HO2S.
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 source of air suction, then go to Step
20.
No Go to the next step.
Yes Go to the next step.
No Repair or replace the malfunctioning part according to
inspection result, then go to Step 20.
Yes Go to Step 15.
No Go to the next step.
Yes Go to the next step.
No Go to Step 14.
Yes Go to Step 15.
No Replace the fuel delivery pipe, then go to Step 20.
Yes Go to Step 20.
No Go to the next step.
Yes Go to the next step.
No Inspect for following:
• Fuel line restriction
• Fuel filter clogging
If okay replace the fuel pump. Then go to Step 20.
ACTION
01-02–219
01-02