Camry cruise control doesn’t brake / hold speed on descents

Discussion in 'Toyota Hybrids and EVs' started by Braddles.au, May 20, 2019.

  1. Braddles.au

    Braddles.au DEFAnitely using an EBH

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    My dear old dad passed away last Tuesday. I am driving his 2010 Camry Hybrid HL (Australian spec) atm.
    My NVW30 Prius will maintain cruise control set speed on descents; sometimes quite aggressively.
    By contrast the Camry does little to rein in the speed. The braking effect feels like the gentle resistance when you lift off the accelerator. I was set on 110km/h but sped to over 120 on a descent before I braked (which cancelled the CC). As I slowed I was overtaken by a new Volvo SUV police car (that didn’t pull me over!)
    2.4 l engine plus 105kW motor should be capable. It maintained speed going up the steep ascents on the M1 from Newcastle to Sydney in a manner that my Prius struggles with so it should be able to brake too.
    Or does the Camry’s CC just not work that way?
     
  2. bisco

    bisco cookie crumbler

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    sounds like our 2008. the '13 is better, but still lacking for some reason. hopefully, they got it right on gen 3.
     
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  3. ChapmanF

    ChapmanF Senior Member

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    My Gen 1 Prius cruise control would not hold speed on descents unless I shifted to B mode.

    It was as if the cruise control in Gen 1 was simply transplanted from a regular car, designed only to work the go pedal, so it would have no descent-holding effect unless B was selected, to slow more aggressively when the go pedal is released.

    Then I got my Gen 3 liftback, and discovered it will not even allow B and cruise to be selected together, which irritated me, until I realized the Gen 3 cruise control now has descent-speed-holding built in, so without selecting B it has the same behavior as the Gen 1 cruise control in B.

    Could the Camry setup be more like the Gen 1? Does it have a B selection, and does it allow selecting that mode when cruise is on?
     
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  4. Trollbait

    Trollbait It's a D&D thing

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    The Camry hybrid does have a B 'gear', though it may not be labeled as such. The current one even has a range of B-ness by way of selecting different gears on the shifter.

    The hybrid is a variant of the ICE Camry, so it easily could have the same cruise control as the standard model. In a fist gen Camry hybrid, the odds of this are higher.
     
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  5. NR427

    NR427 Member

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    My 2015 would hold the speed going downhill. I'm not sure about the older ones.
     
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  6. CamryDriver

    CamryDriver Active Member

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    My 2018 LE Camry Hybrid scared the pants off me the first time it "Jake Braked" going down a steep hill. I'd say the cruise does a great job maintaining speed overall. The radar feature is sweet as well.

    Can't speak to the older versions.
     
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  7. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Old-school cruise control is all about reading the speed and then controlling the engine (via throttle) until the speed hits the setpoint. That's great when you're cruising on flat land or up hills, but you don't get a brake effect when going downhill.

    Many new cruise controls read the speed and then tell the transmission what to do to seek the setpoint. The transmission in turn controls the engine via throttle.

    When the transmission is running the show, downshifting for braking effect is on the menu, when it wasn't before.
     
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  8. ChapmanF

    ChapmanF Senior Member

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    Gen 1 Prius re-used a cruise control that only acted the first way (as if it controlled the engine throttle), but the transmission could be put in a mode (B) where it would treat "no go pedal pressure" as "please slow down" and the end effect would sort of work out as you wanted.

    Kind of funny, because the actual logic making up the Gen 1 cruise control was found in the hybrid-vehicle ECU, not in the engine controls or acting on a real throttle ... but it was just as if they sort of copy-pasted some existing cruise logic from a different model onto the HV ECU circuit board.

    Then in the later generations they integrated it better.
     
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  9. Braddles.au

    Braddles.au DEFAnitely using an EBH

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    Thanks for all of the replies.
    1. This old CC clearly doesn't use the MG aggressively to maintain speed. It only adopts the 'standard' throttle-off regen (or thereabouts).
    2. I haven't selected B during CC operation. I suspect that it would cancel CC so I would be better of using the brakes/regen anyway.
    3. 110 km/h is at an indicated 118 km/h, so I was safe from plod.
    In my Prius I would often cancel CC on steep climbs, in the Camry I'll cancel CC on steep descents.
     
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