My check engine light was on and it pointed to the Throttle Position Sensor. Code 0403 I took it to the dealership and they tested the trottle position sensor and said it was perfectly normal. They reset the ECU and I went on my way. It stayed off for 2 days and then last night it came back on. The car has been running NO differently the whole time, with the engine light on or off. There seem to be no symptoms. Anyway I reset the ECU again last night and have driven it about 40 miles since resetting without it coming back on. Once last night I also got the code 0505 which is says there is no problem recorded or detected. Is the check engine light just coming on because of something electrical or something. The dealership checked everything out and said they found nothing wrong with it. Any help would be greatly appreciated. Thanks

 

Yes, the check engine light just coming on because of something electrical or something. We have to figure out what the "or something" is. If the Check Engine Light goes on there should be one or more Diagnostic Trouble Codes stored in the Engine Control Unit. Do the readout and post your results here.