Skip the auto shop - Our mechanics make house calls

Q: What does the powertrain malfunction/reduced power (RTT) Warning Light mean?

asked by on

What does the powertrain malfunction/reduced power (RTT) Warning Light mean?

The Powertrain malfunction/reduced power is a warning that is illuminated when the vehicle is experiencing a condition - that if driven can cause damage to the engine, transmission or drivetrain. The warning is to let you know to decrease the load on the vehicle (typically speed) and is close to defaulting into a limp home mode for protection if it has one. Typically with this warning a code is set in one of the component located in the powertrain (engine control, transmission or traction control/ABS). It is possible that if it keeps occurring that it can activate another warning. If the problem resolves itself the warning may go away.

For example, if you have a heavy load, perhaps towing a trailer, and are going up a hill, and the transmission is starting to overheat. To avoid further damage the warning “Powertrain malfunction/reduced power” is illuminated to warn you to take steps like ease off the load to avoid overheating the transmission. If you decide to ignore this warning the vehicle may go into a limp home mode where the computers will cut back on the throttle and operate in a safe mode it knows is safe till the issue has been resolved, and the transmission temperature has cooled down.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  • Home
  • Questions
  • What does the powertrain malfunction/reduced power (RTT) Warning Light mean?

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: My 2010 Ford Explorer power trans light came on

The power train warning light generally will come on when the computer has detected a fault within the transmission control system. When this happens, the transmission control system puts the vehicle into a "limp mode" which helps to prevent further...

Q: Four-wheel-drive won't go into gear

Hello, there seems to be two common reasons behind why your Dodge Dakota will not engage its’ four wheel drive. The first reason is due to the wiring harness for the four wheel drive selector switch. Over time rubbing on...

Q: How does the active park assist system work?

Parallel parking is no fun, even if you’re an experienced veteran. If your car has the active park assist (APA) system, then you’ve got some extra help to make the process easier. This is an automated system that actually scans...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...