Tesla Small Drive Unit TMPHS value [SOLVED]

[tensa]

Hi All,
Looking for help with the Tesla Small Drive Unit using a v6 board running software v5.27.

For some reason the tmphs keeps jump up when I floor the throttle and dropping back down when the car idles. It goes as high as 90 degrees for about 1 second then drops back down to about 38-45 degrees. The tmpm value stays constant around 36-42 since the cooling pump is running.

The problem is this means the default 85 tpmhsmax value keeps being triggered resulting in a TPMHSMAX error. I have increased it to 105 to make the car drivable at slow speeds.

What is expected and recommended here?

[tom91]

Air pockets in your cooling system most likely. Alot of people have reported this behaviour with the SDUs and vac filling coolant systems and making sure its designed right usually resolve this issue.

[mane2]

I've had TMPHSMAX error pretty quickly when I had air in the cooling system. It took less than 1km driving to go over 85c. Waiting 30 seconds it went down, but quickly came back when starting to drive. Could drive only 100 meters and wait 30 seconds..

[tensa]

I've had TMPHSMAX error pretty quickly when I had air in the cooling system. It took less than 1km driving to go over 85c. Waiting 30 seconds it went down, but quickly came back when starting to drive. Could drive only 100 meters and wait 30 seconds..

Did you manage to fix it?

[mane2]

Did you manage to fix it?

Sure, just filled again it and went back driving. This time, I took the coolant bottle with me. Recommend going steep hills up and down, helps getting the air out.

[jrbe]

Use a vacuum fill for coolant systems to get all the air out. Especially important if your coolant system has high and low areas to trap air.