Diagnosing Buick driveability concerns

July 22, 2024
A 2017-2018 Buick Envision with a 2.5L or 2.0L engine or 2014-2018 Regal with a 2.0L engine may have a MIL on with DTC P2097 but with no driveability concerns.

A 2017-2018 Buick Envision with a 2.5L or 2.0L engine or 2014-2018 Regal with a 2.0L engine may have a MIL on with DTC P2097 but with no driveability concerns.

There are many things that can cause this DTC and care must be taken when diagnosing this code. When performing the diagnostics listed here, the purge solenoid vacuum source line should be disconnected and blocked off at the vacuum source (intake manifold).

1. Idle the engine in Park with your foot off the brake pedal.

2. Idle the engine with your foot on the brake pedal to keep the vehicle from moving and place the transmission into Drive.

3. Drive at a steady speed of 50 mph or more without using the cruise control. After completing this, in the service bay with the vehicle in park, take note of the long-term fuel trim value. Using the accelerator pedal, raise engine speed from idle to about 2,000 rpm and hold it there for two minutes and monitor any changes in the long term fuel trim value. If the long term fuel trim value was high, then dropped into a normal range of minus 13% to 13% and stays there, the concern may be a vacuum leak, skewed MAF sensor, modified/damaged air box or a non-OEM air filter. Swap as many parts from a known good vehicle to rule out specific components. If no change, perform an AFIT test on all fuel injectors to see if any lean injectors can be found. If no individual lean injectors can be found, replace all four injectors.

4. If the long term fuel trim value was in a normal range (minus 13%-+13%) and never stayed outside of the normal range, ask the customer if he/she drives in heavy stop and go city traffic. Drive with the customer and see if they are a digital driver. A digital driver is one who gets up to their desired speed, then lets off the throttle and lets the vehicle coast down a few miles per hour then gets back onto the throttle to get back up to their desired speed. These driving habits can induce P2097.

About the Author

Motor Age Staff

Motor Age has been publishing technical content for professional automotive technicians since 1899. Our writers have decades of experience and scores of ASE certifications, and they continue to teach new generations of technicians via classrooms all around the globe, as well as through the books and training manuals they've authored. 

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