bayu.mks

Dear all

Sorry.

I just want to asking regarding Grade Logic Control (in AT ) in Honda (CRV, Stream, etc )

How that things work ? using a sensor or work by others mechanical ?

Thank You

sugarloafpkwy

I don't think anyone has any idea what you're talking about.

If you mean what controls shifting in an automatic transmission then it's a combination of electronic and mechanical controls.

thompels

I mean regarding the shifting in AT. Cause if Honda Transmission use Grade Logic Contorl, it will keeps our transmission in position 2nd to get more power in climbing hill road. maybe in other transmission will change to 3rd gear. I just wondering how it works? how this AT with Grade Logic Control know that the car is on climbing situation, so it can keep the gear. Base on what ?

thx

thompels

I mean regarding the shifting in AT. Cause if Honda Transmission use Grade Logic Contorl, it will keeps our transmission in position 2nd to get more power in climbing hill road. maybe in other transmission will change to 3rd gear. I just wondering how it works? how this AT with Grade Logic Control know that the car is on climbing situation, so it can keep the gear. Base on what ?


pls look
http://automobiles.honda.com/m...=True


thx

thx

drdisco69

The service manual doesn't make much mention of it. It appears that the ecu just compares how much throttle is being applied versus how much the car is accelerating, and bases gear choice on that. I think it uses the coolant temperature sensor and the ATF temperature sensor to detect more load on the engine and trans as well, helping to determine the appropriate gear.

Sorry I don't know any more, but I'd like to see what other people make of this.

thompels

thanks for reply.

What the meaning of calulation of gradient ?

thx

drdisco69

Gradient is the angle of a hill, so it uses the extra load to figure out how steep of a hill it's climbing.

I wonder if the barometric pressure sensor is sensitive enough to detect a tiny change in elevation like a moderate hill would give. It says it uses the sensor in determining the gradient, so I guess so.

thompels

Sorry,

what is barometric pressure ? soory i really don't understand it.
and where the position of these sensor ?
is it under the machine so it can read the road level, likte tiny camera ??

sorry,

thx

drdisco69

Barometric pressure is the air pressure. It changes with the altitude, obviously, and the ecu needs to correct for the less dense air at higher altidudes above sea level. The sensor is inside the ecu, and by monitoring the readings of this sensor, the ecu can determine whether the car is going up a hill or down, depending on whether the air pressure is falling or rising. The closer to sea level you get, the more dense the air gets.

thompels

is it possible fot the barometric prrssure to know the level of road ? If possible how?

thx

drdisco69

Not directly, it can only sense the air pressure, and by that it can determine the level of the car above sea level.

thompels

Thx,

but how the grade logic control to keep the 3rd gear when drining in up hill level. Not change to 4th gear like other usual AT ? thx

drdisco69

Well like the diagram shows, the ecu controls the shift solenoids that determine the gear the transmission is in, so it just does whatever it wants.