Too Much E85?
This bulletin applies to a number of GM products including 2013-2015 Cadillac ATS/2012-2015 SRX, 2012-2017 Buick LaCrosse/Regal/Verano, 2012-2017 Chevy Caprice, 2016-2018 Captiva/ 2011-2017 Equinox/2012-2018 Impala and 2011-2017 GMC Terrain.
Some customers may complain about reduced engine power and the MIL on. The reduced engine power message on the display may clear after cycling the ignition key. Technicians may find DTC P228C (fuel pressure regulator control performance-low pressure) set in the ECM as current or history. Technicians might also find a prior repair of the high pressure fuel pump. The condition may be caused by excessive use of E85 fuel, causing a plunger internal to the fuel pump to stick.
1. Take a sample of fuel from the fuel system in a clean glass or metal container.
2. Inspect for contaminants. Place the container on a level surface for approximately five minutes in order to allow any particles/contaminants to settle. If contamination is found, inspect the fuel tank and strainer for buildup or blockage. In needed, completely clean the fuel system and add E-10 fuel. If no contamination is found and/or further diagnostics leads to a high pressure fuel pump concern, replace the high pressure fuel pump and related lines.
3. Advise the customer to run a tank of premium or Top Tier E-10 through the system to effectively clean all fuel system components after the repair.