You can buy these diagnostic tools these days that you stick into a slot on most modern vehicles and it runs a diagnostic program to tell you what ails it. Are these any good? My 2008 Nissan Titan pickemup truck that is my only vehicle... 210k miles... cruise control stopped working, the "set" light flashes. And the radio just turns off and on by itself! The cd player doesn't work correctly. The fuel gauge has shown an erroneous reading a few times. Something ain't right. I checked my battery and connections, seems to be fine. As for the cruise control set light, I found mention of a couple of parts it could be; not sure if these other electronic errors are related. I don't currently have a mechanic I trust, just wondering about these devices. I took my gf's little Ranger truck in for it running hot and it ended up costing her $2,500! I probably would have scrapped the truck. Point is, the mechanic's stories didn't add up from time to time and I don't trust him. After first being pretty enthused about him. My little town is woefully lacking in a good mechanic.
Check your grounds at the frame and engine block. Sounds like an intermittent power interruption which is commonly a bad ground cable or connection IME. Replace any corroded cables. I would also test the battery. If it’s failing you could have all kinds of weird symptoms in a computerized vehicle.
In my experience. I spent some years as a heavy equipment mechanic in the logging industry in northern Maine, ran a couple auto repair shops, and many years after that as a factory representative in the heavy duty and automotive industry, starting in the mid-late 70’s so I got to play with all the early computerized rolling equipment and it was a chit show at times lol. I learned how to use a multimeter for a voltage drop test and how to check for bad grounds pretty quick as cables and connectors were major issues here in the rust belt. It’s always the best place to start with intermittent issues like you described, especially when equipment gets a little age and some miles built up. There were a lot more component failures early on too, but a lot of that was caused by loose connections. Computers need constant voltage or they can do weird things.
Yawner before you buy one take it by O’Reilys, NAPA, Autozone or a similar place they all have a scanner/code reader they will scan all codes for you for free. You can also read online most vehicles have a procedure cycle key x times, press gas/brake pedal x times and the codes will show up on the dashboard. It’s not perfect as many times one problem will cause numerous codes to show up, a good mechanic can decipher what is most likely and work from there. Most/many so called mechanics are actually overpaid parts changers!
Been a auto tech for about 18 years now, and have used pretty much nothing else except snap on scanners Tried a few code readers and get frustrated that they don't always pull all the codes my snap on one does, or give a data stream But they are stupid expensive!!!! One option is that often dealers take old units in trade that are worth what they are in plastic (virtually nothing) but still very good units Example: have a solus pro about 12 years old, trade in value is about $400 towards $5000 of a new one I use this one at home, not updateable, good to 2014(?) Lets me do something instead of just staring at the light or throwing parts at it With that said it sucks you don't have any trustworthy shop around you,
