Tranny 'clacking'

[sfo1]

I have an '08 w/@30k on the clock. Today, while diving in the City I start up a pretty steep hill and catch a red light, and stop. When the light turns green, I hit the gas and I get this quick "clack, clack, clack" sound, more electronic sounding that mechanical. Scared the crap out of me but the car moved. I actually went around the block to try to replicate on the same hill; did it again, and again.

Anyone have an idea what this is? Car was in drive and ECT on '2nd.' BTW, does the ECT have two or three settings? Manual describes three; power, off and second. I only have two; power and second (no middle setting).

 

[planetalaska]

Hill Start Assist Control at work?

 

[Carl L]

Mine does this too so I guess they all do. Not sure what "hill assist" does but these trucks roll backwards when in gear which seems odd. My M5 has hill start and it holds the car still on inclines for 2-3 seconds after lifting off the brakes.

Yeah, ECT is 3 settings: power, 2nd and NORMAL (when neither is illuminated in the dash).

 

[tempestv8]

If there was wheel spin due to slippery conditions, the sound that you heard could simply be the electronic traction control doing what it does to limit wheel spin. Does it sound similar to when you activitate HDC?

 

[sfo1]

If there was wheel spin due to slippery conditions, the sound that you heard could simply be the electronic traction control doing what it does to limit wheel spin. Does it sound similar to when you activitate HDC?

No slippage; it was dry pavement. It was the hill/start assist. The indicator lit up and I repeated the condition easily. I turned off the assist, but the scenario repeated. The on/off didn't seem to change the experience.

 

[bjowett]

It could be the hill assist or the VSC. Given your description, I think the vehicle stability control may be activating (best guess). The stability control uses yaw and g load sensors to determine what the vehicle is doing. The system tends to be a little overly sensitive, so a steep hill with a little acceleration could be activating it, or the sensors could be bad. Have your Toyota dealer inpspect the VSC system and/or perform a "zero point calibration".

 

[mark71]

how do you turn off the hill start assist?