Q: Why isn't my car reading it's rpm?

asked by on January 28, 2017

It just started not reading it's rpm. Everything else seems fine. But I do need an oil change and probably an all around tune up. I'm a single mom though with very little savings.

My car has 190000 miles.
My car has an automatic transmission.

Hi There, This could be related to a couple of possibilities. The [instrument voltage regulator]((https://www.yourmechanic.com/services/instrument-voltage-regulator-replacement) regulates the voltage supplied to the various gauges in your vehicle’s dash. When this is not working properly, this may cause the gauges in your dash to dim or flicker erratically or in some cases provide false readings.

This may also be caused by a faulty transmission speed sensor. The speed sensor reads the rotational speed of the reluctor wheel, located within the transmission. The speed sensor also controls the anti-lock braking system. Driving with a bad speed sensor usually causes the ABS to malfunction and can lead to loss of braking power and/or an accident. When this is not working properly, you may also notice the transmission hesitating to shift gears, erratic tachometer readings, the speedometer not working properly or the odometer not working properly. I would recommend having an expert from YourMechanic come to your location to diagnose and inspect your vehicle.

Was this answer helpful?
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

module or unit?

Hi there. From the description you have provided, your vehicle Check Engine Light on with lots of warnings and exterior lighting acting weird, sounds like there may be a charging system related problem. I would recommend not driving your vehicle...

"Service 4WD" shows on the dash

Hi there. Check the harness wires from the transfer case to the output shaft speed sensor. See if the speed sensor wires are burned and shorted into the harness. This could cause the 4wd to engage when ever and at...

My chevy hhr is having sluggish accerlation and knocking sounds in the front and rear wheels

Hello, thank you for writing in. The vehicle may be having engine issues, or it may be having wheel/suspension issues. The first thing to determine is if the noise occurs as long as the car is on, or if it...

Related articles

The Best Used Cars to Buy If You Have 3 or More Kids
If If you have three or more kids, you could probably get by with a mid-size sedan if all you want to do is take them from Point A to Point B. Realistically, though, having kids means music lessons, athletics,...
The Best Used Cars to Buy for Senior Citizens
Everyone Everyone needs a way to get around. You need to get groceries, get to doctors’ appointments, visit with family and more. However, senior citizens have very different needs when it comes to buying a used car than other demographics....
A Buyer’s Guide to the 2012 Chevrolet Captiva Sport
The The 2012 Chevrolet Captiva Sport is a brand new vehicle and is an eco-conscious crossover SUV for the environmentally friend consumer. It comes standard with many features, but also has many available options so it can suit any buyer’s...