Is 9365095 a OS setup for the 4L80E

[EDH]

I have a 96 chevy truck with a 7.4l and 4l80 swap. The ECU serv# is 16250279 and the operating system is 9365095. It appears to shift all gears fine but will not lock the converter under any circumstances. Should the HP tuners Tools be able to force a converter lock? Do I have the correct OS for a 4L80E. Thanks for any help.

[Jon S.]

That is a 1998 Vortec PCM, with a 1998 OS. You shoiuld be able to read / tune it with HPT.

[EDH]

Thanks Jon S. I have been able to read it and tune it. The issue is nothing will make the convertor lock up except applying ground to the tcc wire at the pcm. I get a momentary "apply en" but never a "lock" in the scanner. It up/down shifts all gears fine. I removed the brake signal from the pcm since I read many instances of faulty brake switches not allowing convertor lock. I have also shut off misfire detection. Still no convertor lock.

[Jon S.]

My apologies for misunderstanding your original post.

I have zero experience tuning the Vortec PCM - but have a few these tunes on file just for reference.

Are you certain the PCM is from a 7.4L 4L80 truck ? Again, I don't know for certain, but OS 9365085 or OS 16263425 was often used in full-size trucks with the 4L80.

Check your TC apply and release speeds, and confirm that the PCM's calculated speed is correct.

Regarding the TCC brake input to the PCM ... not sure with the Vortec PCM, but with later PCMs (0411) if this input was absent the torque converter would not lock (i.e. the PCM had to "see" the brake pedal status switching - or it would inhibit TC lockup).

[EDH]

I tried it with the brake input connected and disconnected with no difference. The calculated speed input is correct. We have ran the vin on the pcm and it also showed it was a 7.4L 4L80e vehicle. Probably going to run a stand alone trans controller to take over converter lock up on decel.

[Jon S.]

Just to be clear ... I was under the impression that the TC was not locking at all - which is a completely different issue than unlocking on deceleration.

If the TC does lock at steady state cruising, but then unlocks under deceleration - this is normal for a truck tune.

Typically if the TC is locked, it will unlock again if the TPS % falls below about 2% or 3%.

You can adjust these parameters to keep the TC locked on deceleration (like a car tune) - but I don't believe that HPT has these parameters available for the Vortec PCM. Do you have access to other tuning software ?

[EDH]

Correct, it never locks. But if it did, I would like to have converter lock on light decel.

[mecanicman]

Sounds like you have a 4l60 o/s. 4l60 uses 2 solenoids to control the converter and 4l80 uses one.

[EDH]

I wouldn't think so unless a 7.4L came with a 4l60 at one point. It also up/down shifts perfectly.

[mecanicman]

Under calibration details, controller details, what is the number for segment 7?

[mecanicman]

or just post the file.

[EDH]

16241014 for the seventh segment. Thanks

[EDH]

Here is the tune and some logs. I lowered the tcc apply/release table significantly and now I have an issue where the converter will rapidly lock and unlock at certain loads.

[Russ K]

The Torque Convertor min & max duty cycle tables are missing. Ask support to add them.

Russ Kemp

[EDH]

Thanks Russ, I will do that.