Having body work done on a Gen 2

About the only concern would be if there is any significant deposits built up in the throttle body. Normal operation results in carbon "goop" slowly building up where the throttle blade rests - which restricts airflow some. The ECM will adapt by opening the throttle slightly more to maintain idle. The more goop there is, the more the ECM adapts.

Now when you disconnect the 12V, the ECM resets back to the "as new" settings, including throttle. If the throttle is very restricted, the ECM won't know this and the engine might not start.

Short form- clean the throttle body. Also you have to reset the auto window functions on the LF door. (closed window, hold the switch up for several seconds; open window, hold the switch down for several seconds.)

Posted via the PriusChat mobile app.

 

Whenever I've (intentionally) disconnect the 12 volt, albeit on our 3rd gen, the next few start-ups feature an unusual rev-up. I suspect the computers are reestablishing parameters, maybe including throttle body response. So maybe no problem? Somehow I can't see a car being disabled by a relatively common event like battery disconnect.

What makes you think they'll disconnect the 12 volt though? Did they say anything about it?

Disconnecting the battery might be a good idea though, especially if the repair drags on for a few days, and/or they have the car "open", dome light on and so forth. To avoid running down the battery.

My 2 cents: if there's no practical reason to disconnect the battery, leave it as-is, but hook up a lowish amperage smart charger, for the duration of the repair. If that's not in the cards, then yeah, disconnect the neg cable will protect the battery from run-down.

 

i think the service manual recommends it when doing body work.

do body shoppes read service manuals? probably not. do they follow safety proceedures? probably just whatever they have done forever.

 

Do you have a picture of the door to be repaired?

In general, for a car with readily available salvage yard parts, like your Prius, if a door was to be taken off, then the door would be replaced. Otherwise, no reason to take off a door for body work.

If they have to do any welding, then the shop will MIG weld.
In that case, the battery is disconnected. MIG welding uses an electrical arc between the gun and the body, to quickly and locally heat up the metal.

Even if there is rust, the body shop may not weld.
Depending on the area, some will cut out the rusted metal, treat the remaining metal, then use automotive adhesive to bond the new panel. Automotive adhesive is now used extensively in many areas in vehicles. When done correctly, the overall bond/strength might/could be better than welding (the two pieces of metal are bonded over 1-3", verses the small, spaced out, spot welds.

Good Luck.

 

In terms of concerns for the Prius, as long as they don't have to do any work near the Hybrid battery, or near any high power wires, no special considerations with the Prius.

Also, fwiw, as per shop policy, some shops always disconnect the battery.
All it takes is that one car, where many of the car computer decide to go, for what ever reason, for the shop to very quickly loose days, weeks, months worth of profits.
Some cars, like Mercedes Benz and BMW, have extremely outrageous prices to replace various computers. On a MB, since ~2000, even the tail lights are controlled through an on car network connection.

 

Pretty much with any "modern" car -- hybrid or ICE -- you take a chance when you disconnect the battery that when you reconnect there could be a steep learning curve. My mechanic's knowledge is somewhat limited, but the rigs all "learn" idle settings, etc. for your particular vehicle and for a 10-year-old car, those settings are probably much different than when it was first put into service.

When I put a new battery in my 2002 Toyota Corolla in 2014, the thing idled very poorly. Had to leave it idling in the driveway for 15 minutes or so until the car "relearned."

In my experience, most body shops will disconnect the battery. Nowadays, one of the first things I see in the manuals, even for minor repairs that have nothing to do with the electrical system -- 1) Disconnect 12v.

 

I would not let a body work guy mess around with the 12 volt.

They will unbolt it…..not necessary and dangerous.

Take the red plastic cover on top of the battery off.

On the black plastic fuse housing on top of the battery there’s 2 black cables that just plug in. A thick one a thin one. They terminate to white plugs that have lock levers. Press the lock lever down with small screwdriver and it just unplugs.

unplug those 2 cables.

easy and safe and fast. There diferent sized so only fit in there holes.

Then the 12 volt is completely disconnected from the car.

Thick wire is the main B+ cable to the front jumppoint.

Thin wire is 12 volt sensing wire to the inverter.

whendone just plug them back in.