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

asked by on

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
  1. Home
  2. Questions
  3. Why isn't my car reading it's rpm?

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: Is it better to just change trans fluid instead of flushing the whole system?

When it comes to vehicles over 5 years or 60,000 miles, my preference is to drain the transmission through the pan and replace the filter, especially if the transmission has never been serviced. The sales pitch is of course that...

Q: Throttle body position sensor

The rumbling noise may be coming from the loose catalyst in the exhaust piping. It would need to be verified by a road test to listen to the noise. If the catalyst is breaking up in the exhaust then the...

Q: Car ran hot and now it will crank, but will not start.

Hi there. From the description you have provided, your vehicle will crank, but will not start, needs to be properly diagnosed. Replacing parts without diagnosing, can be costly and time consuming. The fact you got the engine to start after...

Related articles

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...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.