Has anyone re-located the controller in a 2002 e4? If so, where? I have repeatedly gotten the -41 error code so picked up a heat sink on ebay to see if it helps. My problem is I cannot get the controller and heat sink to fit because I had to push the controller back a couple inches for with the lithium battery I have from @Inwo
From cold start, How long does it take before your -41 show up?
When you get your error, to a quick test tap and see if any of your battery terminals are warm or screaming hot. If so, remove that cable, clean real well and reinstall.
Otherwise, Do you still have your controller bolted to the mounting plate? Is there thermal paste between the bottom of the controller and the plate? How warm is the backside of that plate when it goes to -41?
What other changes have you done to the car beyond the new battery?
- Bigger wheels?
- Lift Kit?
- Motor?
- Adjusted/tweaked controller?
- Magic Magnet?
Jack up your back wheels and give them a spin to make sure your parking brake is not dragging.
Let me see if I can find the temp sensor in a T1/T2.
I’m working a theory with another build but we are working with a T4 (which is laid out a bit different.
Relocating it should not have made more heat. It may be connection heat, or possibly heat due to the improved performance.
A fan blowing on the plate should help if controller has low thermal resistance to the mounting plate.
The heat sink would only delay overheating. The heat needs a path out of the oven.
Like you suggest, relocating it.
It usually only comes up if i try to get above 30 mph.
Yes still attached to the mounting plate. No paste. I will check how warm it gets next time i drive it.
Yes, 23 inch tires, 4 inch lift, upgraded motor. I believe the controller was tweaked to allow for the higher speeds. I also have 2 rear facing seats so more weight.
The issue is not from relocating the controller as a result of the battery. I have always had this issue but finally trying to resolve it. The code came up even before the lift and tires. But usually only above 30mph
Idea that comes to mind is that initially the heat had a short path from controller to upper frame under dash. Now that I had you use spacers between controller and frame, the path has been cut.
I need to look at your pictures. Possible a larger sheet of aluminum extending every which way there is room will dump more heat.
An overheating T1 or T2 is your GEMs way of saying “Step 2 of 4, I got this bro.”
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That gap between the controller and mounting plate is not conducting heat very well.
You might want to pull the controller back off, clean both surfaces, use more than 3 bolts to mount it back on that plate flat.
If you still need more cooling it looks like you can sneak at least a 1 inch thick finned heat sink in there.
But I would still look at why you seem to be generating more heat than usual. Since this was happening before your battery swap it might be worth getting a look at your controller numbers.
I agree, that can’t help but overheat. The controller is not making thermal contact with the plate. Air is a terrible conductor.
Also, it’s hard to determine, but there may be a washer between conductors on the power terminals. Washers other than copper are not allowed between conductors.
I would sugest a thicker plate or heatsink, but that will just add another layer of resistance to heat transfer.
Possibly, replace the heat transfer plate with thicker, stiffer, flatter one. Then add heat transfer compound. 1/4" thick is the norm, but more rigid the better.
I have some scrap Tesla heat transfer pad left over that i could send to fill the gap, but eliminating the gap is much better.
Aluminum 180 W/m-K conductivity
Air .03
Paste or pad about 5 (keep it thin)
Just enough to keep air out.
Sorry but like (Jar-Jar Gem) has stated -41 is very common in older original controllers. After so many heat cycles they just can’t perform.
A newly remanufactured controller from FSIP usually does the trick. So it could be that all the heat sinks or fans in the world might not fix your problem. So my advice is Get a new controller and try again and if that dosent work take the controller out sell it on EBay & push your 2002 off a cliff. Use the money from your controller to buy yourself a 2008+car
which controllers will work with a 2002?
Early 2002’s came with a T1 and late model 2002s came with T-2 controllers. If you remove the controller, you’ll notice serial number or model number and at the very end of the number, he will either say T1 or T2
If I had to place a bet based on your picture, I would guess that your car has a T2 controller and I say that because the small plug looks black and I’m pretty sure the early cars that had a T-1 had a gray plug
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There is away to upgrade to t4 or t5 but I have not done it