Skip the auto shop - Our mechanics make house calls

Q: problems with changing gears

asked by on

my transmission will sometime not shift gears and my check engine light come on it takes along time to shift gears my rpm goes up to over 30 and stop put it in neutral and move the gear stick back in drive then it will change but sometimes it don't do it it shifts the way it suppose to

My car has 164000 miles.
My car has an automatic transmission.

Hi there. The transmission is loosing power to the sensors and solenoids inside the transmission case. Go under the vehicle with the wheels chocked and check the transmission harness. Look for any debris, oil, moisture, broken or bent pins. If there is nothing wrong with the harness, then with the ignition switch on and the engine off, check for power at the harness with a digital volt ohm meter (DVOM). Also check for a ground in the harness with the DVOM. If there is power and ground, then the harness inside the transmission may be broken and is shorting out and needs replaced. Plus, check the circuit for the downshift solenoid to the transmission.

If the downshift solenoid is not functional, then the transmission may also lock out the shifting. If there is no power or ground, then turn the key off and check the battery terminals and the fuse box for any loose wire and blown fuses. If all wires and fuses are okay, then check for power and ground at the computer. If there is no power to the computer, then there is a broken wire between the computer and the fuse box. If there is power, check for power coming out of the computer. If there is power coming out of the computer then change the harness to the transmission. If there is no power coming out of the computer, then the computer has failed and need replaced. If you need further assistance diagnosing your vehicle, then seek out a professional, such as one from YourMechanic, to help you with 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

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: I have a squeaking / chipping noise coming from under the jeep at 15 mph and when I slow down adding pressure to the brakes it sto

It is not uncommon to hear a chirping, or squeaking noise, coming from the brakes. Sometimes, it is just normal for the pads to make some noise, other times it can signal that it is time for the brake pads...

Q: Transmission slips while going downhill, when braking or coasting

Hello there, issues shifting when going downhill is a bit unusual for the 1998 K2500. There are a few possible causes for the transmission to slip when going downhill. The likely would be that the transmission fluid level is low,...

Q: Car dying and lights on

Hello. Thanks for writing in. Lets start by discussing the dead battery. When the lights were left on, the battery was drained. After jump starting it and allowing the alternator to recharge it, the battery should be fine. Have you...

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...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.