CADILLAC, CHEVROLET, GMC

PIP5062B

2013-09-23 · NHTSA 10113269

A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.

Manufacturer summary

Original wording in English

This Preliminary Information communication provides information to the technician on the steps to diagnose and repair vehicles that have check engine light and a misfire. Technician will find a P0300 set. If the misfiring cylinder is creating NO or very low power, technician will need to follow these diagnostics steps. 1) Swap the ignition coil and spark plug with another cylinder. 2) Inspect the plug when out for wet or dry condition. 3) Perform an injector test with a scan tool. 4) If the plug is wet then check for a leaking or stuck open injector. 5) If the plug is dry then enrich the intake air with propane. If the severity of the misfire is less with enrichment, suspect a weak or inoperative injector driver in the Engine Control Module and replace as needed. 6) Perform a cylinder leakage test to determine if there is a valve sealing concern. If there is a valve sealing concern see the latest version of PIP5029 for recommendations.

Repeated filings are grouped only when make, bulletin number, publication date and complete summary agree. Original record numbers are retained. Older publications remain available, and an explicit later version is shown when established. Pre-1994 vehicle associations are separated from default results; an unspecified year does not mean all model years apply.