Skip the auto shop - Our mechanics make house calls

Q: Speed sensor keeps going bad and Check Engine Light is on.

asked by on

What makes this car speed sensor keep going bad I have changed it 4times car does great until check engine light comes on then it stays in 2nd or 3rd gear

My car has 170000 miles.
My car has an automatic transmission.

A: This may potentially be related to a faulty...

This may potentially be related to a faulty transmission control module. As you may know, every time a gear change is required, the car's computer activates a transmission solenoid, which directs transmission fluid into the valve body to engage the correct gear. When this is faulty or not working properly, this can cause a delay in gear shifting or, in some cases, cause the car to not shift at all.

The speed sensors help to monitor the speed of the output shaft in the transmission which then relay this information to the transmission control module. It may be possible that the sensors are now working correctly, but the module is essentially making the signal of the sensor useless. I would recommend having an expert mechanic, such as one from YourMechanic, come to your location to determine why the Check Engine Light is on with the speed sensor and replace the sensor as needed.

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: Car sputters in First or Second gear

The wet weather was a good hint toward an ignition misfire. The water will make the spark plugs and wires too short to ground. You would most likely be able to hear a snapping noise from the plug wires in...

Q: Locked up

This is most likely a locked up caliper which can happen when the hydraulic brake pistons tend to drag a bit. When this happens, an intense heat is created resulting in the brake fluid reaching a boiling temperature. As this...

Q: how to set up the engine speed sensor on a puma 2.4 tdi motor

Hello. It does not appear that a 2.4 Land Rover engine requires a reset procedure for the crank position sensor. Most crank position sensors are hall effect or magnetic type, and operate by reading a signal from the reluctor wheel...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
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 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...