power at rear wheels pid

[mtnman]

I'm getting a divide by zero error for the "Power at rear wheels" (CALC.POWER_RW) PID. Has anybody used this PID? Am I missing other PIDS that this relies on? I've got sae.vss included and it appears to be the only PID in the equation.

[Tordne]

Have you checked that your vehicle has a value (other than 0) for it's weight. I think that is used for this calculation also.

[Trippin]

Calc PIDs require two or more different PIDs to be active. To find out which ones you need, right click on the CALC PID and select "more info".

Hope this helps.

[Elowe65]

I kept getting the same deal. I tried everything.

Not sure if I fixed it the right way but the only way I got it to work was to manually insert my vehicles weight in the formula.

I went to C:\Program Files\EFILive\V7\Configuration\sae.generic

opened it in notepad, went to;

*CLC-00-902
kW 0.0 750.0 .0 "(3411.014622)*{SAE.VSS.kph}*dx({SAE.VSS.kph},6)/12960.0"
hp 0.0 1000.0 .0 "(7520)*{SAE.VSS.mph}*dx({SAE.VSS.mph},6)/8226.63"

Inserted the weights (3411.014622 and 7520 in this case)

saved and closed.

Now it works just fine (for this application only).

I think it is supposed to read this info from the customer details, but mine never did.

Like I said, this may not be the right way but it worked for me.

Just keep in mind that the sae.generic file is over written when the software is updated.

[mtnman]

Inserted the weights (3411.014622 and 7520 in this case)

7520 lbs? what are you driving? The GMC website shows my 2500HD CC curb weight of 5907 lbs. Are you carrying a 1613 lbs payload or a dually with diesel engine? Although the dually is shown to be 6552lbs (I dont know if that's with the diesel engine or not).

[Trippin]

I kept getting the same deal. I tried everything.

Not sure if I fixed it the right way but the only way I got it to work was to manually insert my vehicles weight in the formula.

I went to C:\Program Files\EFILive\V7\Configuration\sae.generic

opened it in notepad, went to;

*CLC-00-902
kW 0.0 750.0 .0 "(3411.014622)*{SAE.VSS.kph}*dx({SAE.VSS.kph},6)/12960.0"
hp 0.0 1000.0 .0 "(7520)*{SAE.VSS.mph}*dx({SAE.VSS.mph},6)/8226.63"

Inserted the weights (3411.014622 and 7520 in this case)

saved and closed.

Now it works just fine (for this application only).

I think it is supposed to read this info from the customer details, but mine never did.

Like I said, this may not be the right way but it worked for me.

Just keep in mind that the sae.generic file is over written when the software is updated.

Oops, I just assumed you had entered the weight in when you set it up.

[Elowe65]

Oops, I just assumed you had entered the weight in when you set it up.

I thought/figured it would be that easy too.

For some reason I could never get it to save these settings. I tried I don't know how many times, but each time I re-opened scan-tool, the PID would be invalid again.

It was just easier to set them this way.

Someway or another, I always seem to figure out the hard way around things.

[mtnman]

What does the "dx" represent in the equation?

*CLC-00-902
kW 0.0 750.0 .0 "2657*{SAE.VSS.kph}*dx({SAE.VSS.kph},6)/12960.0"
hp 0.0 1000.0 .0 "5858*{SAE.VSS.mph}*dx({SAE.VSS.mph},6)/8226.63"

I've hardcoded my weight values and when scanning the values range from -154 to 101, averaging at 0 HP. How accurate is this equation? Am I inputing the value wrong or something?

[Elowe65]

What does the "dx" represent in the equation?

*CLC-00-902
kW 0.0 750.0 .0 "2657*{SAE.VSS.kph}*dx({SAE.VSS.kph},6)/12960.0"
hp 0.0 1000.0 .0 "5858*{SAE.VSS.mph}*dx({SAE.VSS.mph},6)/8226.63"

I've hardcoded my weight values and when scanning the values range from -154 to 101, averaging at 0 HP. How accurate is this equation? Am I inputing the value wrong or something?

dx()

Syntax: dx(PID,frame_count)

Arguments: {PID}: a PID name. frame_count (optional): an expression.

Return value: The rate of change of the value of {PID} from the current frame-frame_count to the current frame.


Go here to read up on the formula.

http://forum.efilive.com/showthread.php?t=3