Mazda 2002 6 Workshop Manual page 238

STEP
3 VERIFY RELATED PENDING AND STORED
DTCS
• Turn ignition key to OFF, then ON (Engine
OFF).
• Verify pending and /or stored DTCs using WDS
or equivalent.
• Is DTC P0443 also present?
4 IDENTIFY TRIGGER DTC FOR FREEZE FRAME
DATA
• Is DTC P0133 on FREEZE FRAME DATA?
5 VERIFY CURRENT INPUT SIGNAL STATUS
• Warm up engine.
• Access O2S11 PID using WDS or equivalent.
• Inspect PID under following accelerator pedal
conditions (in PARK (ATX) or NEUTRAL
(MTX)).
• Is PID reading okay?
— More than 0.55 V when suddenly depress
accelerator pedal (rich condition).
— Less than 0.55 V just after release of
accelerator pedal (lean condition).
6 INSPECT INSTALLATION OF FRONT HO2S
• Inspect if front HO2S is loosely installed.
• Is sensor installed securely?
7 INSPECT GAS LEAKAGE FROM EXHAUST
SYSTEM
• Visually check if any gas leakage is found
between exhaust manifold and front HO2S.
• Is there any gas leakage?
8 INSPECT LONG TERM FUEL TRIM
• Access LONGFT1 PIDs
• Compare it with FREEZE FRAME DATA
recorded at Step 1.
• Is it below FFD value?
9 INSPECT FUEL LINE PRESSURE (Excessive
fuel line pressure)
• Turn ignition key to OFF.
• Inspect fuel line pressure while engine running.
(See F–20 FUEL LINE PRESSURE
INSPECTION.)
• Is fuel line pressure okay?
10 INSPECT FUEL LINE PRESSURE (Low fuel line
pressure)
• Turn ignition key to OFF.
• Inspect fuel line pressure while engine running.
(See F–20 FUEL LINE PRESSURE
INSPECTION.)
• Is fuel line pressure okay?
11 INSPECT FUEL LINE FROM FUEL PUMP TO
FUEL DELIVERY PIPE
• Visually inspect fuel line for any leakage.
• Is any fuel leakage found?
ON-BOARD DIAGNOSTIC
INSPECTION
Yes Go to DTC P0443 troubleshooting procedures, then go to
Step 13.
No Go to next step.
Yes Go to next step.
No Go to troubleshooting procedures for DTC on FREEZE
FRAME DATA.
(See F–67 DTC TABLE.)
Yes Go to step 8.
No Go to next step.
Yes Go to next step.
No Retighten sensor, then go to Step 13.
Yes Repair or replace any faulty exhaust parts, then go to Step
13.
No Replace sensor, then go to Step 13.
Yes Engine is driven under rich condition. Go to next step.
No Engine is driven under lean condition. Go to step 10.
Yes Go to next step.
No Inspect fuel pump maximum pressure and fuel return pipe
for clogging.
(See F–25 FUEL PUMP UNIT
• If any problem is found, repair or replace suspected
parts.
• If all items above are okay, replace fuel pump unit.
Then go to Step 13.
Yes Go to step 13.
No Go to next step.
Yes Replace suspected fuel line, then go to Step 13.
No Inspect fuel filters for following:
• Restriction or clogging at fuel filter (high-pressure side)
• Foreign materials or stain inside fuel filter (low-pressure
side)
Perform following actions according to result.
• If restriction or clogging is found at fuel filter (high-
pressure side), replace fuel filter.
• If foreign material or stain is found inside fuel filter (low-
pressure side), clean of fuel tank and filter.
• If all items above are okay, replace pressure regulator.
Then go to Step 13.
ACTION
INSPECTION.)
F–109
F