Had an intermittent problem with my Cruise Control engaging. The CC light would come on when the CC on/off button was pressed. When the CC would engage the "set" light would come on and the speed would hold. On occasion the CC would not engage. I looked are reread the owners manual.....NOTHING! I was double checking to make sure there was nothing different with the hybrid. (I have owned Toyota for a very long time...since 88') Took it to the dealer.............."Sorry sir, we could not reproduce the problem"! Frustrating!!!!!!!!!!!!! But, PROBLEM IDENTIFIED AND SOLVED! Since the Hybrid is new to me, "shifting" is a little bit different. There is a "B" on the shifter which is mentioned for "downshifting". There is no mention that once you are done with downshifting that you must shift back to "D" for normal operation. The only mention is not to run in "B" for an extended amount of time. So, when you are in the "B" position, the CC with disengage. To re-engage, you must shift back into "D" and press the CC lever up to "resume" or down to "set" the CC again. I'm I the only "dummy" with a new car here??? LOL!
There's no reason for shifting to B. It's pretty useless. It's not recommended to use B in a normal city traffic. It's intended for long stretch of down hill road. When you're going on a long stretch of down hill road, you can just release the accelerator and let it cost. It will regen until the battery is full. When the battery is full, The Prius will automatically engage engine brake which is the same as shifting to B but you can still use everything the D has to offer, cruise control, accelerate, brake with regen or friction. I take I5 down the grapevine all the time. It's a 10 mile stretch of 6% down hill. I just turn on CC and let it brake for me. I've shifted to B before to try it out. It's really really useless.
Shifting to "B" does "down-shift"... But, since I am new to this hybrid, I wanted to understand all functions of this vehicle. There is a road I take that has some steep switch backs that empties to a down hill slope. Shifting into "B" did increase engine braking which is useful in this situation which is not useless. If there was no reason for shifting into "B", then it would not have been engineered into the Prius. As the function of gears and key positions is mimicked differently in the Prius compared to a "normal" transmissions or key positions, lower gears such as "B" are also included. My issue was/is why was I having intermittent problems with my CC engaging. I started to take note of my actions that lead up to the CC not engaging. There was no mention of this in the owners manual and a trip to the dealer did not provide an answers. Purpose of this tread - to share my experiences and findings with this forum to better inform its members. The information and opinions (Positive and Negative) collected in this forum helps keep all of us informed. ....your response is appreciated.
Are you finding that the CC does not engage at all, that your having to push the set button again. Or is it that you set the CC only to have the car slow down 3-5 MPH then have the CC kick in, causing you to go into the power section until your back up to the set speed. ???? This describes my issue with the CC
For me...when it is shifted into "B" the CC is locked out until you shift back into "D". Once in drive, the CC works like normal. Hope this helps.
It is doing what it should since they don't want you driving around in 'B', thus the CC lockout in "B".
But, they don't tell you that in the book and the dealer doesn't know either....had to find it out for myself.
Even though we have two Gen III Prii, I have never found a use for drive B and didn't know that CC didn't work in B. Welcome to the group and thank you for posting your question/discovery.
Yep. The 2nd gen also prevented cruise control from engaging if driving in B. Cpruadio is correct, B is pretty useless. Don't bother with it. I can concur w/cpraudio's assertions (at least on my 2nd gen) about the car basically putting itself into B mode (and spinning the ICE, if needed) when the HV battery gets too full. I see it frequently where I live now when coasting down a hill (as observed by looking at ICE RPM on my ScanGauge and amount of current going in/out of the HV battery). I've seen it on the drive between LA and the Bay Area on long downhill stretches as well. Hobbit wrote up http://www.techno-fandom.org/~hobbit/cars/b-mode.html re: B mode on the 1st and 2nd gen.
