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Q: Gauges fluctuate wildly then car turns off.

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I've been having this issue for the past few months where the gauges in my car begin to fluctuate wildly, rpm, speed, fuel all start changing within the span of a few seconds they go from min to max while driving. The battery light turns on then the car turns off. This happens once the car has been on for a period of time which can vary from a few minutes to about an hour. I have replaced the battery and checked all of the grounds in the system to make sure they are wrench tight. I have also replaced the idle control valve since the car sometimes accelerates and decelerates on its own while idleing thought this did not fix the issue. Recently i tried taking it to a mechanic to connect to the onboad diagnostics tool and i have error messages for tps circuit low voltage (P0122) which i replaced, fuel level sensor circuit low voltage (P0462), TPS sensor circuit intermittent low voltage (P1122). I am at the end of my rope changing sensors and testing the different leads of the PCM.

My car has 48000 miles.
My car has an automatic transmission.

Hello. Though there are a lot of common issues that can cause this, the most common is a voltage issue. Low voltage will cause each of these symptoms and codes you are getting. I usually start by testing the ignition switch. It is the most common failure to cause this. The switch fails internally and causes these circuits to act up. If for some reason the ignition switch is not the issue then it may be a problem with the body control module or an internal short in the fuse box. If you want to have this repaired, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose this.

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