Dtc P0300 [Z6] - Mazda 3 Workshop Manual

Mazda 3 Workshop Manual – Engine + Wiring Diagrams + Diagnostic Trouble Codes
Note
• Large bubbles are normal since
they are remaining air coming out
from engine coolant passage.
INSPECT ENGINE COMPRESSION
• Inspect engine compression.
8
(See COMPRESSION INSPECTION
• Is it normal?
VERIFY TROUBLESHOOTING OF DTC
P0140 COMPLETED
• Make sure to reconnect all disconnected
connectors.
• Clear the DTC from the PCM memory using
the WDS or equivalent.
9
• Perform the "HO2S heater, HO2S, and
TWC Repair Verification Drive Mode".
(See OBD DRIVE MODE
• Is the PENDING CODE for this DTC
present?
VERIFY AFTER REPAIR PROCEDURE
• Perform the "AFTER REPAIR
PROCEDURE".
10
(See AFTER REPAIR PROCEDURE
• Are any DTCs present?
DTC P0300
• The PCM monitors the CKP sensor input signal interval time. the PCM calculates the
change of interval time for each cylinder. If change of interval time exceeds the
preprogrammed criteria, the PCM detects misfire in the corresponding cylinder. While
the engine is running, the PCM counts the number of misfires that occurred at 200
crankshaft revolutions and 1,000 crankshaft revolutions and calculates the misfire
DETECTION ratio for each crankshaft revolution. If the ratio exceeds the preprogrammed criteria, the
CONDITION PCM determines that a misfire, which can damage the catalytic converter or affect
emission performance, has occurred.
Diagnostic support note
• This is a continuous monitor (Misfire).
Downloaded from
[Z6].)
[Z6].)
[Z6].)

DTC P0300 [Z6]

Random misfire detected
https://carmanualshub.com/
Yes Go to the next step.
Implement engine overhaul for repairs, then
No
go to the next step.
Replace the PCM, then go to the next step.
Yes
(See PCM REMOVAL/INSTALLATION
No Go to the next step.
Go to the applicable DTC inspection.
Yes
(See DTC TABLE [Z6].)
No DTC troubleshooting completed.
- automotive repair manuals website
[Z6].)
B3E010200300W01