Intermittent Limp Mode without check engine light or scan codes?

SONATALUVR

MEMBER
2006 HYUNDAI SONATA
3.3L
V6
2WD
AUTOMATIC
78,000 MILES

My low-mileage vehicle listed above has been going into Limp Mode intermittently since 2018, and my Hyundai dealer has not been able to find anything to fix because there are never any scan codes, and the check engine light doesn't come on.

I didn't know about Limp Mode until recently, so the description of the symptoms I gave probably didn't help.

I've had my car towed to two Hyundai dealers four times for this issue and spent about $3,000, but there was no fix.

During the pandemic, I didn't need a reliable car much, but now I do.

Most recently, the dealer has recommended replacing the spark plugs and optionally the "TPS and complete software update" for about $1,100. But the dealer has not said these items will fix the Limp Mode issue, so I have been hesitant to move ahead with the work.

What tests and repairs would you recommend?

Thank you very much for providing this service!

Andrea

Monday, November 21st, 2022 AT 3:01 AM

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
52,185 POSTS

This can be caused by an intermittent transmission or throttle body issue. I would service the throttle body first to see if that helps. With the problem being sporadic the computer may not pick up on the problem with a trouble code FYI.

Here are two guides to help us fix the problem:

https://www.2carpros.com/articles/reduced-power-limp-mode

and

https://www.2carpros.com/articles/throttle-actuator-service

Here is how to do the job on your car. Check out the images (below). Please let us know what you find. We are interested to see what it is. Also did the dealer do a CAN scan?

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

Let me know.

Image (Click to make bigger)