Just thought I would let you all know that you can get into the maintenance mode on the gen 4 the same way as the gen 3 using the gas pedal shifter and brake sequence. Just tried it on mine after an oil change and started up the engine so I could check for leaks. Works like a charm.
Maintenance mode will run the engine at idle whether it needs it or not. It's useful after working under the hood and checking for leaks after oil and coolant changes. I will post the sequence tomorrow as I don't have it in front of me right now. Just don't drive it in maintenance mode as it disengages the traction control and that could damage the transaxle. To turn maintenance mode off just turn the car off and when you turn it on again the car will function as normal.
I've never heard of the "gas pedal shifter and brake sequence", I used to use the info button and headlights on/off 3 times on the Gen 3 and Prius+, but it doesn't work on the Gen 4.
Here's the procedure. press 2 times start buttuon press 2 times gas padel hold brake padel put P to N press 2 times gas padel hold brake padel put N to P press 2 times gas padel again put foot brake padel and start engine............ engine become inspecion mode/maintainencemode........ Hope this helps.
I've never had a problem with the ICE starting up on its own after putting the car in normal READY mode following an oil change to check for leaks, etc. After a few seconds, it just always starts up. I would think an easier procedure than "maintenance mode" would be to ask for cabin heat if the ICE doesn't start on its own after a few seconds.
Why would disengaging the traction control damage the transaxle? Many cars have a button that disengages the traction control at any time the driver desires.
Because the transaxle has powerful electric motors that develop large torque right away, and if a wheel breaks traction they can spin up to rotor-destroying speeds faster than you can react. The first-generation Prius had a "traction control" that was only there to protect the motors, and didn't do anything else that helped you with traction. Starting with Gen 2, the traction control can do the rest of the more useful things like applying the brake individually on the slipping wheel, so it is more deserving of the name "traction control". And the later generations have also continued to up the safe maximum motor rpm. But one function of the control is still to make sure the rotor magnets stay inside the case. In Gen 3 (maybe it started in Gen 2? not sure), there are two modes, distinguished by different numbers of go-pedal presses in the chicken dance. They separated out the run-engine-constantly and the disable-traction-control mode. The run-engine-constantly mode can be needed for some kinds of emission test. The TRAC-disable mode can be needed for speedo or dyno tests. The run-engine-constantly mode can be needed for some procedures that require you to get the engine all the way up to thermostat-open temperature or to fan-triggering temperature. I've used it for bleeding the cooling system after a coolant change. Haven't used it myself just for an oil change. There's a confusion in this thread back at post #4, somebody was confusing this maintenance mode (which runs the engine constantly) with a different thing entirely, getting the multifunction display to show some diag information.
Thanks for this. Note to those who own the Bentley manual/guide: this exact procedure is outlined in section 11-4 and is called "Inspection Mode" in the index.
