Mazda CX-7 2007 Workshop Manual page 336

SYMPTOM TROUBLESHOOTING [L3 WITH TC]
STEP INSPECTION
10 Connect the M-MDS to the DLC-2.
Access and monitor following PIDs using the
data monitor function.
• ACSW
• APP
• ECT
• MAF
• MAP
• PSP (PCM terminal 2T)
Do the PIDs indicate the correct values under
trouble condition?
(See01-40-6 PCM INSPECTION[L3 WITH TC].)
11 Inspect for restriction in the exhaust system and
three-way catalytic converter (TWC).
Is there any restriction?
12 Remove and shake the PCV valve.
Does the PCV valve rattle?
13 Perform the spark test.
(See01-03-78 ENGINE CONTROL SYSTEM
OPERATION INSPECTION[L3 WITH TC].)
Is a strong blue spark visible at each cylinder?
14 Access and monitor the FUEL_PRES PID.
Is the FUEL_PRES PID value within the
specification?
(See01-40-6 PCM INSPECTION[L3 WITH TC].)
15 Is the vehicle accelerate performance normally?
16 Inspect the fuel pressure sensor.
(See01-40-35 FUEL PRESSURE SENSOR
INSPECTION[L3 WITH TC].)
Is the fuel pressure sensor normal?
17 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].)
18 Connect the fuel pressure gauge between the
fuel pump and the high pressure fuel pump.
Measure the fuel pressure line of the low
pressure side.
(See01-14-5 FUEL LINE PRESSURE
INSPECTION[L3 WITH TC].)
Is the fuel pressure within the specification?
19 Inspect fuel injector for each cylinder.
(See01-14-27 FUEL INJECTOR
INSPECTION[L3 WITH TC].)
Are the fuel injectors normal?
20 Measure the compression pressure for each
cylinder.
(See01-10-9 COMPRESSION INSPECTION[L3
WITH TC].)
Are compression pressures within the
specification?
21 Verify test results.
• If normal, return to the diagnostic index to service any additional symptoms.
• If a malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform the
repair or diagnosis.
— If the vehicle is repaired, troubleshooting is completed.
— If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later
calibration is available. Retest.
End Of Sie
01-03–36
RESULTS
Yes Go to the next step.
No Inspect and repair or replace suspected parts and the
related harnesses.
If the malfunction remains, perform the intermittent
concern troubleshooting procedure.
(See01-03-76 INTERMITTENT CONCERN
TROUBLESHOOTING[L3 WITH TC].)
Yes Replace the malfunctioning part.
No Go to the next step.
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.
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 delivery pipe.
Yes Troubleshooting is completed.
Go to Step 21.
No Go to the next step.
Yes Go to the next step.
No Inspect for the following:
• Fuel line restriction
• Fuel filter clogging
If normal replace the fuel pump.
Yes Go to the next step.
No Replace the suspected fuel injector.
(See01-14-23 FUEL INJECTOR REMOVAL/
INSTALLATION[L3 WITH TC].)
Yes Replace the injector driver module.
If the problem remains, overhaul the engine.
No Inspect for the following:
• Damaged valve seat
• Worn valve stem and valve guide
• Worn or stuck piston ring
• Worn piston, piston ring or cylinder
• Improper valve timing
Service if necessary.
ACTION