Car needs fixing

[tw]

Originally Posted by sexobon

Yes, which is why monster might try (if she hasn't already) disconnecting then reconnecting the positive battery cable to see if a power interuption restores default software settings.

First, do not disconnect the positive cable. Good workmanship dictates disconnecting the negative cable.

Second, that can create other problems. For example, if she did not have the radio code, then the radio would no longer work. And radio presets may be lost. Other problems can also be created by that solution that typically would not solve anything.

Third, better is to identify the fuse that powers that circuit. But if the computer needs resetting, well, that is a function that already exists inside that computer; called a watchdog timer.

This type of problem cannot be solved without a wiring diagram due to the unique nature of that design. What existed even 50 years ago does not exist inside that car.

What xoxoxoBruce has described is often known as a CAN network. Designed by Intel long before the IBM PC existed. The design featured an 8051 single chip computer that was standard in all PC keyboards. It also existed long before the first IBM PC. Now one wire can replace tens or 100 wires. Fixing that door light is virtually impossible without the wiring diagram.