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Hi there, i have searched the forums quite a bit and havent found any explanation for some parameters in the auto section of the enhanced 1.4 vs ecotec tunes. I had a couple of questions. My car goes into gear (reverse and drive) pretty harsh, is there any way of reducing this pressure, would garage shift or anything like time limits etc have an affect on how it goes into gear?

also what is 1-2 upshift pressure mod time limit? what does it do? im just a little curious when it comes to the transmission stuff as there hasnt been much chat about it recently.

Thanks in advance.

that normally happens when someone has been under the pan screwing up the hex nut on the end of the pressure control solenoid...... if your force motor tables are already at zero at 0kph then im not sure what else you can do... other than remove the pan and back off the hex nut again

Jayme wrote:that normally happens when someone has been under the pan screwing up the hex nut on the end of the pressure control solenoid...... if your force motor tables are already at zero at 0kph then im not sure what else you can do... other than remove the pan and back off the hex nut again

Which force motor table should i be looking at? I haven't adjusted anything in the tune just yet. I turned the solenoid 1/4 turn a year ago, but it hasn't been a problem till now. Sometimes it goes in soflty and slow, other times it slams in there. Any ideas? Cheers

hoosedamoose wrote:My car goes into gear (reverse and drive) pretty harsh, is there any way of reducing this pressure, would garage shift or anything like time limits etc have an affect on how it goes into gear?

Get a data log of shifting in to and out of gear a few times. Have a look at the force motor current, if its max (lowest pressure) like Jayme mentioned there is no further tuning possible.

hoosedamoose wrote:also what is 1-2 upshift pressure mod time limit? what does it do? im just a little curious when it comes to the transmission stuff as there hasnt been much chat about it recently.

The PCM is controlling the force motor based on a a number of tables and modifiers. Once a shift has been commanded (look at the requested gear while logging) the PCM monitors the RPM and decides when it has started to drop that the shift begins and when it rises the shift has finished.

During a shift you can modify the pressure so the shift is softer as it engages, go to far and it will have too much slip. The tables are all labelled along the lines of pressure ramp 1 and pressure ramp 2. The ramp 1 tables operate first and then ramp 2, there are various time and ramp rate tables.

The pressure modifier time limit defines how long all this is allowed to happen for, if the shift is unusually slow or the PCM does not detect it properly then the time limit will put an end to the ramp rates and go back to normal.

You can log this and see what happens, at WOT the force motor current will be maximum. On a 1-2 shift you will likely see a dip during the shift as the ramp tables work.

Edit: Screen cap of a log showing the force motor current in blue at WOT...