Q: Car won't start, is it my ECU?

asked by on October 10, 2016

So, my car battery died because I left the keys in the ignition for 2 weeks, not in the on position, just in the ignition. So we jumped it & all was well. Unfortunately I didn't drive it or let it run long enough, so in the morning it was dead again. So my boyfriend jumped it again, this time he crossed the cables & it caused a spark of course. He then put them on the correct way & the car started. We drove around fine but the radio wasn't working. I found that it blew the radio fuse. The radio came on but I have no sound with the radio, only sound on the right side when a cd is in. Well now the car tries to start but it won't fully turn over. Could it be the ECU? We got the P1122 code for the throttle control actuator & are going to look into the fuel pump & I will be getting a new battery but I just need to know what else it could be? Please help, I just got the car 2 months ago & have only driven it twice.

My car has 120000 miles.
My car has an automatic transmission.

Hi, thanks for writing in. While it could be the ECU, it could also be a great many other things. It is most likely not any one component but is probably a combination of faults. Many years ago you could get away with crossing the cables with little more damage than an alternator, but the electronics in modern cars are very sophisticated and are easily damaged by voltage spikes. You probably have a surge protector on your computer at home to protect it from just the sort of thing that happens to the electronics in your car if you get your cables crossed. There is no easy answer for this problem and simply replacing every component that shows up in the list of codes can get very expensive and very likely won’t solve all of your problems. This is one case where you really need someone with experience to sort it out. Here at YourMechanic, we can have a technician come to your home or office to inspect and diagnose this issue for you, and make or suggest the necessary repairs.

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