Monitoring Auto Trans Fluid Thermal Degradation

[ptommo59]

There is a parameter used on the new 150kw Prado/Hilux/Fortuner ECU that tracks the estimated thermal degradation of the Auto Trans Fluid which from reading online would be a good indication of when it should be changed if you are not doing it based on km's..

The info I have read indicates that a figure of >49999 is bad and the ATF should be changed and a Scantool used to reset the estimated figure to baseline.

There is also a Torque Converter Temperature Raise History value but I haven't found any info on what that tells us, so not sure how useful it is.

The relevant codes for Scangauge II:

ATF Thermal Degradation Estimate

TXD 070022162B
RXF 04620516062B
RXD 3010
MTH 000100010000
Name ATD

Torque Converter Temperature Raise History

TXD 070022162C
RXF 04620516062C
RXD 3008
MTH 000100010000
Name TCR

and Torque Pro:

OBD2 Mode and PID: 22162B
Long name: ATF Thermal Degradation Estimate
Short name: ATF Degrad
Min value: 0
Max value: 65535
Scale: x1
Unit: –
Equation: A*256+B
OBD Header: 700

OBD2 Mode and PID: 22162C
Long name: Torque Converter Temperature Raise History
Short name: TCT Raise
Min value: 0
Max value: 255
Scale: x1
Unit: –
Equation: A
OBD Header: 700

Would be interesting to see what sort of values everyone is seeing at various km and usage (my Nov 21 Prado at approx 25000km with a trans cooler fitted at startup are ATD 293 and TCR 0 haven't monitored while driving yet).

[hiluxxury]

Thanks for this - its good info. Similar parameters have been around a while on other Aisin transmissions - my XC60 has them available as well