Mazda CX-7 2007 Workshop Manual page 374

SYMPTOM TROUBLESHOOTING [L3 WITH TC]
STEP INSPECTION
3 Inspect the spark plugs for the following:
• Cracked insulator
• Heat range
• Air gap
• Worn electrode
Is the spark plug normal?
4 Inspect the compression pressure at the
suspected malfunctioning cylinder.
Is the compression pressure correct?
(See01-10-9 COMPRESSION INSPECTION[L3
WITH TC].)
5 Install all the spark plugs.
Perform the spark test at the suspected
malfunctioning cylinder.
Is a strong blue spark visible?
(Compare with normal cylinder.)
6 Access and monitor the FUEL_PRES PID.
Is the FUEL_PRES PID value within the
specification?
(See01-40-6 PCM INSPECTION[L3 WITH TC].)
7 Inspect the fuel pressure sensor.
(See01-40-35 FUEL PRESSURE SENSOR
INSPECTION[L3 WITH TC].)
Is the fuel pressure sensor normal?
8 Inspect the high pressure fuel pump.
(See01-14-19 HIGH PRESSURE FUEL PUMP
INSPECTION[L3 WITH TC].)
Is the high pressure fuel pump normal?
9 Inspect the spark plug for the following.
• Heat range
• Air gap
Is the spark plug normal?
10 Perform the KOER self-test function using the M-
MDS.
(See01-02-10 KOEO/KOER SELF TEST[L3
WITH TC].)
Is the suspected cylinder injector circuit related
DTC (P0201, P0202, P0203 or P0204) present?
11 Is the air cleaner element free of blockage?
12 Perform the spark test.
(See01-03-78 ENGINE CONTROL SYSTEM
OPERATION INSPECTION[L3 WITH TC].)
Is a strong blue spark visible at each cylinder?
13 Access and monitor the FUEL_PRES PID.
Is the FUEL_PRES PID value within the
specification?
(See01-40-6 PCM INSPECTION[L3 WITH TC].)
14 Inspect the fuel pressure sensor.
(See01-40-35 FUEL PRESSURE SENSOR
INSPECTION[L3 WITH TC].)
Is the fuel pressure sensor normal?
15 Inspect the high pressure fuel pump.
(See01-14-19 HIGH PRESSURE FUEL PUMP
INSPECTION[L3 WITH TC].)
Is the high pressure fuel pump normal?
01-03–74
RESULTS
Yes Go to the next step.
No Replace the spark plug.
Yes Go to the next step.
No Repair or replace the malfunctioning parts.
Yes Go to the next step.
No Repair or replace the malfunctioning parts.
Yes Inspect the suspected cylinders fuel injector for the
following:
• Open or short circuit in the fuel injector
(See01-14-27 FUEL INJECTOR INSPECTION[L3
WITH TC].)
No Go to the next step.
Yes Go to the next step.
No Replace the delivery pipe.
Yes Replace the delivery pipe.
Retest Step 6
If the FUEL_PRES PID indication is other that the
specification, replace the high pressure fuel pump.
No Replace the high pressure fuel pump.
Yes Go to the next step.
No Replace the spark plug.
Yes Go to appropriate the DTC test.
(See01-02-13 DTC TABLE[L3 WITH TC].)
No Inspect the suspect cylinder fuel injector for the
following:
• Resistance
(See01-14-27 FUEL INJECTOR INSPECTION[L3
WITH TC].)
Yes Go to the next step.
No Replace the air cleaner element.
Yes Go to the next step.
No Repair or replace the malfunctioning parts.
Yes Go to step 16.
No Go to the next step.
Yes Go to the next step.
No Replace the delivery pipe.
Yes Replace the delivery pipe.
Retest Step 13.
If the FUEL_PRES PID indication is other that the
specification, replace the high pressure fuel pump.
No Replace the high pressure fuel pump.
ACTION