Auto ECU Pin 104

[Devilsfutbol17]

How does Pin 104 effect the drive-ability of the car?

 

[rts91tsi]

The code in the A/T ECU looks at the inhibitor switch bit to add the transmission load, and also to determine which idle table to use, either park or drive, for the state of the bit. It also looks at the bit to determine whether or not to update o2 feedback. That's as much as I could find in the code.

 

[Devilsfutbol17]

Thank you for the information.

A manual ECU or any version of ECMLink removes that pins normal feature in an automatic. So how does the car's Park and Neutral behavior change when you use a manual ECU or ECMLink?

Do cars with manual ECU's or ECMLink still idle fine in Park and in Neutral?

Does it give the car the ability to start while the transmission is in Drive?

 

[rts91tsi]

Technically the A/T and M/T ECU's hardware is the same, and it's the bin that is different, which determines the difference in configuration. For example, I'm using a M/T ECU with the E932(A/T) bin.

Here is a screen shot from the XDF that I converted to line up with the A/T code(disregard my miss-spelling of neutral in my definition, it's been fixed). You'll notice the difference between the idle speed table for "Drive" and "Park/Neutral". The M/T bin will give the same idle speed(based off ECT) as the "Park/Neutral" table.

As far as starting while in drive, I don't know. Hopefully someone running the M/T bin or ECMLink will chime in.

 

[Devilsfutbol17]

Thank you once again for your response.

So with the M/T ECU in the automatic car, there will be no difference in the target idle speed between Park/Neutral and Drive?

If that’s correct, does it cause any problems? Why would there be a need to have a difference in idle speed between Park/Neutral and Drive?

 

[rts91tsi]

Perhaps I didn't explain clearly enough.

Using an ECU with a M/T bin will only allow/give the value from the "Park/Neutral" idle speed table (which has the same values as the M/T bin) to be accessed for park, neutral, and drive. When you place the shifter in drive you are putting load on the engine, which will more than likely cause the idle speed to drop. This is why the A/T code has the added logic to compensate for the load on the engine when placed in drive.

 

[Devilsfutbol17]

Yeah I am following you. That clears up my questions. I understand how the M/T ECU will work in my car now. I know people do it, I just wanted to know exactly what the difference in drivability would be and why.

Thank you for your help, it is much appreciated.

 

[undefined0000]

I ran my automatic with a manual computer, and actually with auto injectors at first because I didn't know it was a MT computer. I only noticed that the idle would creep up when I put it in park/neutral and that was it. I would set the idle with the car in drive so it wouldn't stall out on me, if you set a 750 idle with it in park, it will probably stall when you try to drive it. The M/T ecu also won't pull timing in between shift.

 

[Devilsfutbol17]

Cool thanks, yeah I figured I would just bump the idle up a bit.