Skip the auto shop - Our mechanics make house calls

Q: Check Engine light comes on and goes off

asked by on

The light in the speedometer red needle is not working. Also, the Check Engine light comes on and goes off.

A: If the speedometer is not working but the r...

If the speedometer is not working but the rest of the instrument cluster is, the issue is probably the vehicle speed sensor. This sensor is the main input to the control module for speedometer control. The problem could also be with the wiring or the speedometer itself. There are hundreds of reasons the Check Engine Light might be on. The powertrain control module (PCM) takes inputs from dozens of sensors. It then uses this information to control outputs such as fuel delivery and emissions equipment. If the PCM detects a problem anywhere in the system it will illuminate the Check Engine Light. A failed vehicle speed sensor could cause both of the problems you are having. A trained professional, such as one from YourMechanic, will be able to inspect your vehicle's speedometer issue and Check Engine Light to give you a definitive answer for what repairs are 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: Immobilizer keeping car from starting.

Your car may need the service harness and relay installed into the wiring of your ignition switch; the tech bulletin is RJT 1678, to get the parts list and directions. This part is a fix to a few different problems...

Q: Gas pedal sticking

I have seen this issue before. Your gas pedal is connected to the throttle plate via a cable. If the throttle plate becomes dirty, it will get stuck and harder to move. You will feel this in the gas pedal....

Q: Blowing fuse for turn, ABS, and Hvac fan, Also will start in any gear

Hello, thanks for writing in about your Chrysler Town & Country. If it will start in any gear, then there is more than likely a fault in the neutral safety circuit. It can be as simple as the neutral safety...

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...
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...
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.