TCU TurboLamik

Hi,

I'm running a TCU V2 (firmware 10.75) on a ZF 8HP50, connected to a Link G4X via CAN (Type CAR = 6, custom ECU, base RX ID 1536 / TX ID 1600).

Problem: The "Transmission Oil Temp" received over CAN (TX stream BaseTX+2, byte 3) reads noticeably higher than the "Oil Temp (C)" shown in TunerPro over serial, and the gap grows as the gearbox warms up - e.g. TunerPro shows about 61 C while the CAN side shows around 80 C. The CAN raw byte appears to rise roughly 1.5x faster than the serial value.

What I've already checked:

• The ADX "Oil Temp (C)" uses X - 40, and the CAN spec is also unsigned8, 1 C/bit, offset -40 - the conversions are identical on both sides, so the raw values themselves must differ.
• Other channels on the same CAN stream (gear, torque, speed) decode correctly in the Link.

Questions:

1. Are the serial "Oil Temp (C)" and the CAN "Transmission Oil Temp" taken from the same internal variable? Or does the CAN value use a different source (e.g. a calculated clutch/friction temperature, or a Fahrenheit-scaled value)?
2. Which of the two should I trust as the actual sump oil temperature?
3. The 10.77 changelog mentions "fixed gearbox temp in Jeep (can type 80)". Do 10.77 or 10.78 also change the oil temp sent on the standard TCU CAN stream (type 6)?

Thanks a lot - the TCU otherwise works great.