Toyota Repair: 89 camry le engine code

Question
I have an 89 camry le with engine code 11, which.in the cars manual means there is a faulty power supply. Does this mean the battery is bad? Or the alternator is bad?

Answer
Hello, Code 11 Momentary interruption in power supply to ECU (electronic control unit or computer) up to 1991. This could mean that the battery monetarily lost connection to the fuse block under the hood, make sure the battery terminals are clean and tight, it could also mean that there was an interruption the EFI fuse under the hood and the computer, I would check the efi fuse and try a new fuse, check all fuses both under the hood and inside at the left dash in the cover, look for any loose or corroded terminals of the fuses.