Idle will raise when stopped

Hello all I have a Hybrid TRD off road Tundra and it has been prettty flawless so far but it will jump idle when stopped at stop signs. I can not figure out what is causing it because sometimes it will jump back down to normal and other times it doesn't. I am sure dealers will say it is because of the larger tires but I am running 275 70 20s and they are like an inch taller than originals. The originals Falkens are not good for off road so I am wondering if anyone else has had this issue? I will probably have the dealer look at it next oil change.

 

You mean your engine is on even you’re stopped? In the hybrids I owned in the past, the engine was only ever idling when the hybrid battery was low and the engine was charging it up. AC uses up a lot of battery and if you’re in a lot of traffic, it’s easy to get the engine kicking on to charge up the battery instead of recovery energy from braking.

 

I’ll be the first to ask. What does tire size have to do with engine idle speed? I have heard, but can’t verify that idle speed can fluctuate at times when the engine switches between port/direct injection to help clean the back side of the intake valves.

 

Idle has nothing to do with tire size, I was just saying the dealership would probably try to blame it on that. We have been having some unbearable heat and it doesn't do it all the time. Just sometimes and it will eventually drop the idle back down then go into Hybrid mode which is like an electric golf cart. I call it that but you get the idea.

 

Ok. Got it.

 

I have a hybrid and it idles almost at 1k, sometimes, and then back down others, on both hot and cold engines. Was the same when I had stock tires and also with 35's. I only have 2k miles on the truck so not really worried at this point, might just be how it is.

 

A few things to try, in case you haven't already done so:

• Switch from ECO to NORMAL drive mode
• Switch the AC to manual (not AUTO)

 

Yeah, I think it is a normal thing after reading the owners manual. I believe when it it is hot it serves as a fail safe to ensure the truck doesnt burn to the ground from the electric motor stuff overheating.

 

I will go with the multiple computers said " start the bitch up we need to cool and charge these select items" . My wifes 2019 Lexus .....walk out in the garage at 10:00 PM and that car is doing something. Bizarre. hope it doesnt burn the house down

 

Mine appears to do it when the battery level is low

 

Most likely your A/C compressor cycling on and off which is perfectly normal under certain circumstances. The idle speed will be bumped up slightly to accommodate to load of the compressor engaging

 

Yes around two bars and it is hotter than hell. Also notice it clicks or sounds weird while doing it

 

Definitely getting the battery too low is kicking the engine on. I saw that the hybrid has electric fans and electric water pump so the engine doesn’t need to be on to cool the system coolant.

The hybrid compressor is electric and not powered by the engine is not needed to power the AC. Our gas trucks need to idle up because the compressor runs on a belt of the engine and needs more power when cycling on. My previous Tacoma had the largest idle change I’ve ever seen when the compressor kicks on.

 

I'm talking about the electric motor and battery systems not the engine. In the hybrid it kicks on the engine when the battery is low or it doesn't go into fully electric mode. In ideal conditions the hybrid mode should always engage when stopped unless all parameters aren't met. These parameters have to do with ambient Temps, pressures and battery health at time.

 

Yes, the battery would get hot if the cabin gets hot. It’s air cooled with air from the cabin and I would expect after driving around with the AC on it would probably cool down enough to be ok.

Next time it happens, just check your battery gauge. I can guarantee that when the battery ticks down to two bars the engine will kick on.

Just for clarity, hybrid mode is when both the engine and motor are working together. When the engine is off and disengaged, Toyota calls this EV mode.

 

I break it apart by iForce (engines and turbos) and Max (Hybrid Battery EV) the truck has two gauges and two bars but you are right when the Max guage's battery shows two bars it will kick the engine on.