Skip the auto shop - Our mechanics make house calls

Q: Reduce Engine power and nothing happens when pushing the gas pedal

asked by on

My truck starts but When started a Service 4x4 sign comes on and the Reduce engine power and when you go to step on the gas nothing happens. We took it in and the code ran was the Throttle position Sensor and we changed it out but it continues to have the Reduce engine power thing come on and when i push on the gas pedal its like its not connected because the engine doesnt rev or anything

My car has 172000 miles.
My car has an automatic transmission.

A: Hi and thanks for contacting YourMechanic. ...

Hi and thanks for contacting YourMechanic. The service 4x4 light indicates a loss of communication to the throttle position sensor, and a reduction in power is a prime indicator that the transfer case position sensor or selector switch has failed. When this happens, the computer gets a reading that the transfer case is not in the right gear, so it forces the throttle position sensor to make the engine run at a lower rate to prevent damage to the transfer case. Changing out the throttle position sensor is helpful, but not required in this situation. I would recommend replacing the transfer case position sensor or selector switch. This will fix the issue of the service 4x4 light and restore the power to the engine. If you need assistance in investigating and repairing this issue, a YourMechanic certified technician can come to your location to perform a Reduced Power light is on Inspection on your vehicle.

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!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: rpm's cutting engine power

Hello. This is normal for this truck. Due to the design of the control systems and the variable valve timing, the computer will attempt to adjust everything during this type of maneuver. Using an aftermarket computer programmer can make this...

Q: Can't shift into drive or reverse

The most common problem with hard shifting from park is the brake light switch. The way it is set up you have to have your foot on the brake for the park switch release to engage. These brake light switched...

Q: Engine is not turning over; clicking noise from starter

The symptoms you describe on your GMC Sierra lead me to believe that the issue lies with the battery, starter or the wiring that joins these two components together. It is also possible to have issues with all three. You...

Related articles

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 Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...