Revised Diagnostic Troube Code P0300 Table
File In Section: 6E - Engine Fuel & EmissionBulletin No.: 61-65-43
Date: September, 1996
SERVICE MANUAL UPDATE
Subject:
Section 6E - Engine Controls - Revised DTC PO3OO Diagnostic Table
Models:
1996-97 Buick LeSabre, Riviera
1996 Buick Park Avenue
1995-97 Chevrolet Camaro
1996 Oldsmobile Eighty Eight, LSS, Ninety Eight
1997 Oldsmobile Eighty Eight, LSS, Regency
1995-97 Pontiac Firebird
1996-97 Pontiac Bonneville
with 3.8L Engine (VINs 1, K - RPOs L67, L36)
This bulletin is being issued to revise the DTC PO3OO - Engine Misfire Detected diagnostic table in Engine Controls, Section 6E. The previous diagnostic table included a step instructing the technician to disconnect the MAF sensor while monitoring the misfire information on the scan tool. The misfire information on the scan tool will stop updating with the MAF sensor disconnected. The revised table removes steps instructing the technician to disconnect the MAF sensor.
Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table.
2. A faulty injector or injector circuit will cause a misfire DTC to be set. The DTC P1200 chart diagnoses any problems with the injector circuits.
3. The Misfire Current Cylinder # counter may normally display a small amount of activity (0 - 10 counts) but should not steadily increment during an entire 200 revolution test sample period.
4. Depending on the cause of the misfire, the Misfire History Cylinder # counter will display a very large number for the misfiring cylinder(s); values for the non-misfiring cylinders will be less than 1/2 as great as the misfiring cylinder(s). When investigating a misfire, always start with the components associated with the cylinder(s) that has the largest number of counts stored in the Misfire History Cylinder # counter.
5. through 12. Checks for conditions that can cause a random cylinder misfire.
13. through 22. Checks for conditions that can cause a non-random or single cylinder misfire.
DTC PO3OO - Engine Misfire Detected