2017 mkz 3.0 awd P0299

[mkzeasy17]

Im receiving a p0299 but I only get this when im flooring it, I can drive normal and wont pop up. It reads turbo A underboost condition, has anyone had this same issue and if so what was the remedy. I see it could be turbo but it could be a vacuum line or something else. Thank you all in advance!

 

[bbf2530]

Im receiving a p0299 but I only get this when im flooring it, I can drive normal and wont pop up. It reads turbo A underboost condition, has anyone had this same issue and if so what was the remedy. I see it could be turbo but it could be a vacuum line or something else. Thank you all in advance!

Hi mkzeasy17 and welcome to the Lincoln Forums.

Take a look at these links: Google Search

As you mentioned and can see, there are various possible causes, such as boost leaks from cracked hoses or loose clamps, a faulty wastegate or bypass valve, a clogged intercooler, or a malfunctioning boost pressure sensor etc.

Therefore, you would first need to properly troubleshoot, diagnose the cause, and correct it.

Generally speaking, the vehicle can be driven. However, if the issue gets worse, damage can occur, and/or the engine may go into limp mode. If you get a flashing CEL, pull over and turn off the engine as soon as safely possible, and avoid driving it.

In the meantime, since this problem currently only occurs when you “floor it”, do not floor it until it is fixed.

I’m sure others will also jump in to help, so keep us updated and good luck.

 

[mkzeasy17]

Hi mkzeasy17 and welcome to the Lincoln Forums.

Take a look at these links: Google Search

As you mentioned and can see, there are various possible causes, such as boost leaks from cracked hoses or loose clamps, a faulty wastegate or bypass valve, a clogged intercooler, or a malfunctioning boost pressure sensor etc.

Therefore, you would first need to properly troubleshoot, diagnose the cause, and correct it.

Generally speaking, the vehicle can be driven. However, if the issue gets worse, damage can occur, and/or the engine may go into limp mode. If you get a flashing CEL, pull over and turn off the engine as soon as safely possible, and avoid driving it.

In the meantime, since this problem currently only occurs when you “floor it”, do not floor it until it is fixed.

I’m sure others will also jump in to help, so keep us updated and good luck.

Thank you, ill check those other potential issues and see if corrected, the issue goes away. I appreciate the reply!

 

[Action]

You get the code when you "floor" the accelerator or go to Wide Open Throttle. (WOT)
At WOT the engine or PCM is expecting the highest boost possible from the turbo(s) in short order.
That isn't happening.
There may be some boost or no boost at all.
When less than WOT, the PCM is not expecting as much or very little boost.

The diagnosis question becomes, is it a turbo mechanical problem. Or turbo control issue.
Included in the control is the sensor.
The waste gate and vacuum line is part of that as well.

The turbo issue can be lack of oil, excessive wear. lack of cooling causing wear or warpage.

As stated above, further diagnosis is necessary.

Action