BUICK, CADILLAC, CHEVROLET, GMC

PIP5385

2016-03-22 · NHTSA 10113954

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 with the steps to diagnose and repair vehicles that may have Service Engine Soon lamp or reduced engine power message came on and was cleared after cycling the key. Also technician may find a P228C set as current or history, and a prior history of High Pressure Fuel Pump replacement, and the customer has been using E85 fuel. If the Diagnostic Trouble Code is current follow Service Information instruction for the repair. If the code is set in history and there are no current drivability concerns take a large fuel sample and let it sit for a couple of hours looking for contamination. Verify the fuel pressure using a scan tool the actual and desired fuel pressures are very close to the same. If contamination is found in the tank then completely flush the fuel system and add e-10 fuel. Also remove the high pressure fuel pump inlet line from both ends. Using regulated air down to about 60 pounds per square inch or lower, blow through the inlet side of this pipe / hose. Inspect for restriction in the check valve built into this hose. If restricted then replace the pipe run a tank of premium fuel through the vehicle and reevaluate the concern.

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.