400V Tesla Controller (made by Eberspächer)

[Perrin21]

Hi, i am attempting to repair 4 400V controller from a Tesla.  The controller is triggering an error on the car and Tesla want £1500 for a replacement part.  From what i can see inside, the price of the replacement is about £1300 more than the parts inside so i am attempting to locate the fault source myself.  The controller is responsible for heating and also passes a signal to the power electronics module of the car to say its ok to activate the 400V systems.  Both parts seem to be refusing to function.

I have so far replaced the IXYS IXFL100N50P Mosfet as the old one was faulty, however i have also noticed a batch of failed resistors on the board.  i have been measuring them individually using my multimeter, is this the right way to measure them or must they be out of circuit?  As they are SMC resistors and very small i dont want to remove them if this can be avoided unless absolutely necessary.  There is an RC circuit that i believe is responsible for making the car activate and charge and it appears to lead to the large resistor on the board, this resistor has a small crack down the side so i need to locate a replacement. 

1) Could you please help me identify the large resistor value and wattage?  I think its 64 ohm but im new to reading the colour bars.  I need to find a replacement if you can provide a link. 

2) how do i test the MCP6031E is functioning correctly? 

3) Can you suggest anything that i should be looking for?

All help is gratefully received.

[goaty]

Could also be 68Ohm (gray color)

Opamp can be tested only for short maby but normally in operation or desolder and just replace. Chip is very cheap.

Also identify IC3 and IC2.
IC3 is driving gate, so maby this is fault.

[thinkfat]

You did check the fuse, didn't you?

Regarding the resistors - it's likely OK to test them in circuit, but they look good to me. They usually don't fail, and if, then you'd have some visual hint.

Check the capacitors for shorts. They're more likely to crack.

[Perrin21]

Hi thanks for your replies, yes i have tested and replaced the fuse.  Im checking with someone who has started to become helpful at Eberspächer to try and identify IC3 and IC2 along with some other components.  Id like to understand what's failed and why so that i can try to prevent it happening again.  I believe its caused by water ingress so sealing it up or water sealing the board may be an option.  happy to hear suggestions.  Heres my notes so far.

10R0 R21

64 OHM resistor blue, yellow black space bronze I think.

TCL T1003 V 051 W68 X2 just to see if they measure the same, mine seem odd but I'm not sure what they should measure. 

MCP6031E again this seems odd as some pins go to ground and I don't know if it's normal.

393 X2 SMD  R1 & R6
914 SMD R5
473 SMD R10
472 SMD R9
563 SMD R8
01C SMD R7

I'm measuring the resistors in circuit using my multimeter so I'm hoping that's a reliable way to measure them.  Other resistors on the board have measured correct using this method. 

I don't know how to check IC3, IC2, IC1, TR2, IC5, IC6 (if you have any info that might help me diagnose I'm greatful.  What is the part TR2 replacement? Just in case.   A schematic would make this easy.

Diodes and capacitors test fine, fuse tests fine.
Thanks for your help

[thinkfat]

Hi thanks for your replies, yes i have tested and replaced the fuse.  Im checking with someone who has started to become helpful at Eberspächer to try and identify IC3 and IC2 along with some other components.  Id like to understand what's failed and why so that i can try to prevent it happening again.  I believe its caused by water ingress so sealing it up or water sealing the board may be an option.  happy to hear suggestions.  Heres my notes so far.

10R0 R21

64 OHM resistor blue, yellow black space bronze I think.

TCL T1003 V 051 W68 X2 just to see if they measure the same, mine seem odd but I'm not sure what they should measure. 

MCP6031E again this seems odd as some pins go to ground and I don't know if it's normal.

393 X2 SMD  R1 & R6
914 SMD R5
473 SMD R10
472 SMD R9
563 SMD R8
01C SMD R7

I'm measuring the resistors in circuit using my multimeter so I'm hoping that's a reliable way to measure them.  Other resistors on the board have measured correct using this method. 

I don't know how to check IC3, IC2, IC1, TR2, IC5, IC6 (if you have any info that might help me diagnose I'm greatful.  What is the part TR2 replacement? Just in case.   A schematic would make this easy.

Diodes and capacitors test fine, fuse tests fine.
Thanks for your help

IC5 and IC6 look like Optocouplers. Maybe Vishay TCLT1000 series. https://www.vishay.com/docs/83515/tclt1000.pdf
Two terminals should read like a LED in diode mode on your DMM.

TR2 - no idea, it's invisible. From the pinout it looks similar to a LM2676 buck converter but I'm missing the inevitable inductor that goes with it.

[fzabkar]

MCP6031, Microchip, op amp, RRIO, high precision, 0.9uA, Vin = 1.8V - 5.5V:
http://ww1.microchip.com/downloads/en/devicedoc/22041b.pdf

If the op amp is operating in its linear region, then Vin- will be equal to Vin+.

Can you tell us the markings on the other chips which you wish us to identify?

[Perrin21]

OK so i have replaced the MCP6031E Opamp (short to ground), the Main Mosfet (blown), the large resistor (cracked) and still no response when connected to the car.  I am looking now at IC3 IGBT gate driver, however i cannot seem to identify the part as it only has 6Z9R written on it.  Does anyone have a link to the replacement part?

Thanks so much for your help.

[goaty]

... and still no response when connected to the car.

If there is some kind of communication missing, the driver chip probably isn´t responsible for it. Is there some data lines ?

[DaJMasta]

Could it be something farther up the chain?  Could the module dying have taken the upstream communications line driver?

Not exactly sure if it's possible with the communication architecture, but could be worth looking into if you've ruled the stuff on the board out.

[thinkfat]

OK so i have replaced the MCP6031E Opamp (short to ground), the Main Mosfet (blown), the large resistor (cracked) and still no response when connected to the car.  I am looking now at IC3 IGBT gate driver, however i cannot seem to identify the part as it only has 6Z9R written on it.  Does anyone have a link to the replacement part?

Thanks so much for your help.

Looks more like GZ9P to me.

PS: could be not a part number at all, just as well a date and lot code.
If you already know that it's a gate driver (likely) then just search mouser.com for "IGBT gate driver SOT-23-5". I think they're all similarly spec'd and you just need to check whether you need an inverting or non-inverting type.

[Perrin21]

like this? https://uk.farnell.com/texas-instruments/ucc27533dbvt/driver-gate-dual-35v-5a-5sot23/dp/3005813?st=IGBT%20gate%20driver%20SOT-23-5

[fcb]

This doesn't look super complicated.  I would reverse-engineer the whole circuit, you will be able to work out exactly what everything does and create suitable tests for it.  And for £1300 it's got to be worth an evening!

[Perrin21]

sadly, im skilled with a soldering iron and im grasping the basics of components as i delve deeper but reverse engineering the board is way out of my comfort zone.  I wouldn't know where to start.  I just know that this little IC is shorting to ground on 2 pins and im fairly sure it shouldn't be.  for £4 id like to swap it out but i dont know what it is?  The markings are G9ZP and its 5 pin. 

[fcb]

OK.  Are IC3 and IC4 the same, what are all the markings.

Concur that IC3 looks like a gate drive. Find where all the 5 pins go (we can see that pin 6 drives the gate via R21).  Even if you can produce a list of all the points (netlist) that would help (e.g. R21 west - TR3#1, R21 east - IC3#6).

Also, there appears to be two seperate circuits here. Might be worth treating them as two seperate problems, also I suspect that the heater circuit being u/s won't stop the car from booting up - probably concentrate on the other one first.  Did you say liquid damage?

[Perrin21]

For anyone playing along at home, Ive confirmed IC3 to be MCP1402-EOT https://uk.farnell.com/microchip/mcp1402t-e-ot/driver-mosfet-500ma-non-inv-smd/dp/1439711?st=MCP1402T-EOT

Thanks to everyone who helped along the way.

[Perrin21]

Annoyingly ive replaced IC3 and put the controller all back together and it still doesn't work.  Theres no sign of life at all.  I was about to give up then i got my fourth wind and pulled it back out again.  Determined i have mapped out the entire circuit board in the hope that someone can help me to track down this fault.  I have replaced IC3, IC1, TR3, R21, IC5 and IC6, the fuse is fine and tested the board for continuity.  Ive noticed the Zener diode ZD1 is measuring 3.1 Ohm in both directions (not sure if it should but it seems wrong to me) , ive also noticed i can'easure the impedance of C13 and C12 but i will need to check this again.  I have been considering swapping out TR2 because i dont know how to measure it to check if its faulty.  Im unable to put any power through the circuit until its back in the car as i dont have a power supply, if you know how i can test it let me know (ive looked at the data sheet and as im new to looking at them its a bit confusing so some help would be amazing.  Ive tried to colour code the circuits to make them easier to follow.  How do i know what capacitors to replace with what values if they are SMD type?   Im getting desperate now.  They want £1500 for a new controller that contains £50 in components and ive replaced almost everything and everything ive removed has measured wrong compared to the replacement part. 

https://photos.app.goo.gl/sryowFgsb4rxMwhc9

Ive noticed the following

IC4 has continuity between pins 2 and 3 (where it goes in and out) Should it be?
I am trying to identify IC4 (it says AUGK on the top, any suggestions what the part is?

[fcb]

ZD1 appears to be part of the power supply for the main heater drive circuit.

So the 400V traction battery supply is dropped to perhaps 5 or so volts by the resistor chain (R4/R11/R20?) and the 'LED'.  You would probably have to test ZD1 out of circuit to be sure if it worked.  One way round it would look like a diode (A>K), to test if is working the other way connect via a say 4K7 to 12V supply (it should end up with perhaps 4V7 or 5V1 or something across it (the MCP4031 has a Vmax of 5V5 - so unlikley more than that unless there is a regulator th there).  If this is toast then your heater circuit won't work (and possibly won't give the car the control signal it is expecting back).

I'm trying to understand the entire operation of the board.  I get the the main heater is PWM'd at 400V via the big MOSFET and this is controlled via IC6 optocoupler from the top part of the circuit (and likely via the multiway).  Also I get that there is likely a control signal returning to the car via the other (IC5 optocoupler) - perhaps derived from the PTC co-efficient of the heater element), hence precision opamps.

I don't get the 2nd 'htrloop' - perhaps a valve?  This appears to be driven from something else and via that big resistor. Be good to understand what that is.

Also, does the cabin fan connect to the 4 pin molex connector?  This might be driven via the half-bridge driver (TR2). 

[Perrin21]

ive updated the picture as IC3 was marked incorrectly.  if IC2 ( has failed its game over as that is the processor that has software from Eberspächer on it so i can't get that chip from them as i dont have access to that.  The board has 2 functions.  1 is the heater circuit and the other (more important to me) is the circuit that is a loop around the car that tells the power electronics module all of the connectors are connected and its ok for the contactors to activate the full traction battery .  Apparently shorting PL2 will over ride the circuit and allow the car to start and charge if that helps but im not 100% sure how so that's the circuit i need to fix.  Both of the white wires are measuring correct and ive even changed the large 68 Ohm fuse to be sure.  . 

[fcb]

If IC2 is small Microchip PIC (12F?) then you would have a problem if that is toast. It does look like IC2 is connected to send/receive via the optocouplers.  The 400V heater circuit is only live presumably when the main contactor is engaged, which can't happen until the PL2 signal is good?  So fix that side first, forget the 400V heater control, the car couldn't talk it it until it has 400V anyway.

[Perrin21]

IC2 is https://ww1.microchip.com/downloads/en/DeviceDoc/41294b.pdf (HV615-I) so has Eberspächer programming.  Yes if that's dead im SOL. and will have to buy a new controller.  how do i test it with a multimeter when i dont know what they have made it do?  you mentioned in an earlier post the MCP4031, did you mean MCP6031E?  Do you think TR2 may be toast?  Theres no unusual shorts to ground on it, if i remove it i guess i could take some measurements.  I have hot air , desoldering station and soldering iron so can easily get things out.  Ive also got some solder paste so im getting used to that.  this board is teaching me a lot, i hope i can make it work.  I can't afford a new one and my traction battery is going down daily which is a potential disaster.

[fcb]

That would make sense. It’s a version of PIC12F615. I wouldn’t worry about the 400V side yet.

I’m on my phone now, so can’t easily see pix. My thought is that the opto-coupler from the 400V to h-bridge is probably got PWM on it to drive the h-bridge (fan speed) - When you fix the enable logic then it should be easy enough to check if the microcontroller is working (that micro is probably not getting CAN bus, but probably a PWM or low speed serial data to set the fan/htr.

So imagine you short out PL2 (assuming you’ve read this on some Tesla forum), what components do you short? Can you test these? This should give you a clue.

[Perrin21]

Thanks for helping.  Ive made some more changes to the schematic ive made and corrected a few issues so it may make better sense. 

Ive also found out the zener diode value and some of the other capacitors that were testing bad so ive ordered replacements along with IC4.

im assuming when you say to concentrate on the 400v side you are referring to the cluster i am working on at the bottom of the board, is that correct?  Or should i be focused on the top of the board?  Up there everything looks as it should but i haven't tested TR2 for functionality.   

Out of curiosity, i have some blue thermal pads i got off eBay, are they sufficient for using on TR3 to the aluminium outer case or do i need a thermal grease?  what's recommended? here's the details of what i have already.

100x100x1mm Thermal Pads for use with Laptops, PC, XBOX OR PlayStation

0.5mm Easily cut to Size to fit your application

High Performance Thermal Conductivity 6.0W/mk
Specific Gravity: 2.85 g/cm3
Hardness: 30 Shore C
Continuous Use Temp: -40～+220 ºC
Dielectric Breakdown Voltage: >5 Kv
Tensile Strength: 55Kg/c㎡
Dielectric Constant: 5.5ºC-in2/W
Volume Resistivity: ＞3.1*10″Ω.cm
Flame Rating: V-0
Thermal sink, insulation, pressure endurance, stickiness, fill in, Anti-vibration.