problem??? help plzzz - Toyota Yaris Forums

yarringyaris · 05-25-2010, 04:14 AM

So while driving my toyota yaris' which is brand new. while crusing at about 1.5rpm going about 20mph i get random surges in acceleration, its noting significant but i personally can feel it when im on the brake or gas pedal.

anyone have any inputs??

Yaris Hilton · 05-25-2010, 10:56 AM

Normal. Cruising at 20 MPH requires only a fraction of a horsepower to maintain speed on level ground. The throttle's right on the edge of cutting back to idle. The ECU switches in and out of DFCO (Deceleration Fuel Cut Off) mode, causing the surging. When the engine's coasting with no power, no fuel is being injected at all and the pumping losses produce a drag. Then it switches back to slightly above idle power and surges ahead.

The changes in drag you feel when you're on the brake are due to the transmission shifting, if you've got an automatic.

TheSilkySmooth · 05-25-2010, 12:26 PM

Agree with YH. Also, the car will run better as it breaks in. Surging at low speed will be normal on most any car.

05-25-2010, 04:14 AM	#1
yarringyaris Drives: 2011 yaris sedan Join Date: Apr 2010 Location: san mateo Posts: 2	problem??? help plzzz So while driving my toyota yaris' which is brand new. while crusing at about 1.5rpm going about 20mph i get random surges in acceleration, its noting significant but i personally can feel it when im on the brake or gas pedal. anyone have any inputs??

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05-25-2010, 10:56 AM	#2
Yaris Hilton Half a Bubble Off Plumb Drives: 2009 Yaris Sedan Join Date: Mar 2009 Location: Bristol, Tennessee, USA Posts: 1,593	Normal. Cruising at 20 MPH requires only a fraction of a horsepower to maintain speed on level ground. The throttle's right on the edge of cutting back to idle. The ECU switches in and out of DFCO (Deceleration Fuel Cut Off) mode, causing the surging. When the engine's coasting with no power, no fuel is being injected at all and the pumping losses produce a drag. Then it switches back to slightly above idle power and surges ahead. The changes in drag you feel when you're on the brake are due to the transmission shifting, if you've got an automatic.

05-25-2010, 12:26 PM	#3
TheSilkySmooth Drives: 08 3DR 5M Bayou Blue; 09 Fos Join Date: Oct 2008 Location: New Hampshire Posts: 622	Agree with YH. Also, the car will run better as it breaks in. Surging at low speed will be normal on most any car.