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Bilmerker => Tidlige elbiler: PSA => Emne startet av: Niram1969 . på torsdag 26. april 2018, klokken 07:27

Tittel: Saxo problem
Skrevet av: Niram1969 .torsdag 26. april 2018, klokken 07:27
Hi,
Just recently, I have noticed rather strange symptom starting my Saxo. I would slightly press accelerator pedal but the car would not move. I could hear faint grumbling coming (I presume) from either motor or reductor. I could also feel vibrations on the steering wheel. With releasing of the throttle and applying it again car would move normally. The only time I'm noticing that something is wrong is moving from standstill. When moving, I tried everything to reproduce any sort of misbehavior (rapid acceleration/braking) but with negative result. The only time I'm having a problem is starting from standstill. It seems that once locked, planetary gears in reductor works OK. Rate of occurrence is  once in 10 or maybe 20 starts. (but not at all last two days (!?) :o , I have no illusions that it repaired itself  :) ).

I have mentally prepared myself for motor removal, I have friend of mine sent me his broken gearbox (in case I would need spare parts). I would like to hear forum members opinion. Did anyone experienced similar behavior?

Any comforting voice is welcomed and appreciated,

//Marin
Tittel: Sv: Saxo problem
Skrevet av: timescapetorsdag 26. april 2018, klokken 08:52
I am not sure I understand exactly what you mean..
But

- any failure locked ? (read out failures). (Checkelec or Lexia. lexia will give you access to test different functions).
- Motor coal !
- Bad connection
- speeder potmeter failure
- 12V battery

How do the economy meter, (amp. meter in dashboard), behave when the failure is present ?

br.
Tittel: Sv: Saxo problem
Skrevet av: Niram1969 .torsdag 26. april 2018, klokken 09:28
Sitat fra: timescape på torsdag 26. april 2018, klokken 08:52
I am not sure I understand exactly what you mean..
But

- any failure locked ? (read out failures). (Checkelec or Lexia. lexia will give you access to test different functions).
- Motor coal !
- Bad connection
- speeder potmeter failure
- 12V battery

How do the economy meter, (amp. meter in dashboard), behave when the failure is present ?

br.

Hi,
No errors reported in Checkelec.
I replaced brushes. (no change in behavior) (replaced brushes were clean, without any damage, with more than 4mm of coal left). Collector is in mint condition.
Potentiometer looks OK. (it never happens that pressing pedal gives no result - when I press pedal, I could hear the electromotor turning, faint noise comes from reductor (or maybe one of the gimbals) but there is no transfer of the momentum to the wheels. So it is either that or the car starts normally.
12V battery measures OK.
Ammeter shows very small deflection to the right.

//Marin
Tittel: Sv: Saxo problem
Skrevet av: timescapetorsdag 26. april 2018, klokken 13:50
OK,
Then i sounds like the reduction gearbox..
Have you try to take the axles out or check the gearbox oil for metal spoons ?
Br.
Tittel: Sv: Saxo problem
Skrevet av: Niram1969 .torsdag 26. april 2018, klokken 19:27
Sitat fra: timescape på torsdag 26. april 2018, klokken 13:50
OK,
Then i sounds like the reduction gearbox..
Have you try to take the axles out or check the gearbox oil for metal spoons ?
Br.

I have replaced oil about two months ago after 100kkm. I have not found any metal debris. Oil was dark black but that is normal for the type.
Before taking the motor down, I will check axles. But if I have to chose, I would rather have gearbox issues than gimbals. It seem those are scarce with ludicrous price tag.

//Marin
 
Tittel: Sv: Saxo problem
Skrevet av: Niram1969 .tirsdag 29. mai 2018, klokken 09:33
Update:

I finally got the time (and courage  ) to take the motor down and perform the reductor inspection. And what did I found? Nothing!! All gears are in perfect condition. I put the missing pin in one planetary gear shaft but that was it. Case was very clean with no deposit of any kind.

(https://s19.postimg.cc/slaiewa8f/Image00001.jpg) (https://postimg.cc/image/slaiewa8f/)
No damage at all!


(https://s19.postimg.cc/572j2z00v/Image00003.jpg) (https://postimg.cc/image/572j2z00v/)
Sunk shaft (pin missing)

(https://s19.postimg.cc/3s0ye96nj/Image00002.jpg) (https://postimg.cc/image/3s0ye96nj/)
Fixed.




(https://s19.postimg.cc/ym87by9pb/ex_rew.png) (https://postimg.cc/image/ym87by9pb/)
(https://s19.postimg.cc/3s0ye8ji7/min_ex_fw.jpg) (https://postimg.cc/image/3s0ye8ji7/)
Excitation looks OK, throttle responsiveness is good.

Right now, everything points to collector (90%) or chopper board (10%).
If I'm thinking rationally (may not be the case with everything going on), it is not short circuited wingdings. My guess is that IGBT would fail if that is the case. I have just finished 500km trip (300km high speed highway). Car endured everything without (noticeable) problem. I have even tried to force it to fail - maximum accelerations (red zone wherever possible, in my configuration thats about 30kW into motor)), maximum speed, high speed regen (150A) - nothing. Damn thing just rolls without objections.
If that will be that case (motor collector issue), I'll be very disappointed. I was always very light footed, my average energy consumption is less than 124Wh/km, original brushes replaced after 80kkm (not because of the wear, 4mm left).
Now I'm thinking, what are my options? Motor replacement? Are those used SA13 available at all?

//Marin



Tittel: Sv: Saxo problem
Skrevet av: Niram1969 .torsdag 07. juni 2018, klokken 12:58
Update:
After taking motor apart just to find nothing, I did the same with the Sagembox. I took out contactor, chopper board, IGBT, everything! I replaced few of notorious 100uF/50V caps (one leaked a little but measured OK), cleaned all contacts and put everything back up together.

One week and 650km after - not a single "false" start. Even when provoked, the car starts fine. I'm glad that it works but I'm not quite happy for not finding root cause.

What really got me angry and frustrated is fresh reductor oil leak. Previously dry engine is now oil stained. I guess that I didn't tighten inner reductor cover enough.  I soooo don't want to take it down again by myself... :'(

//Marin
Tittel: Sv: Saxo problem
Skrevet av: Niram1969 .mandag 18. juni 2018, klokken 07:37
New update:

Problem resurfaced again, so I'm back to square one. I did some investigation and this is what I found.



This is the armature voltage when the problem appears (car not moving forward, vibrations felt on sterring wheel and the whole chassis).



And this is armature voltage when the car starts normally.


I was mislead earlier because I was looking at single signal, rather then full burst.

So at least I think I found root cause. But I still do not know what is causing it. I think I can rule out engine. That only leaves IGBT, chopper board or ECU. Only. :)

//Marin
Tittel: Sv: Saxo problem
Skrevet av: timescapemandag 18. juni 2018, klokken 10:59
1. where are you measuring ? (what is armature voltage ?)
2. Your pictures shows 100hz (50hz dob. rectified) noise .. ?

Wild guess...
Do the controller think the car is running and try to regen bracke ?
What happens if you push the car when you have the failure ?

br.
Tittel: Sv: Saxo problem
Skrevet av: Niram1969 .mandag 18. juni 2018, klokken 11:46
Sitat fra: timescape på mandag 18. juni 2018, klokken 10:59
1. where are you measuring ? (what is armature voltage ?)
2. Your pictures shows 100hz (50hz dob. rectified) noise .. ?

Wild guess...
Do the controller think the car is running and try to regen bracke ?
What happens if you push the car when you have the failure ?

br.

1. Pictures represent collector voltage
2. Picture should represent PWM voltage delivered to motor.  It looks dirty but I think it is just how digital scope represents too much data on small resolution screen. When time base is reduced, signal is nicer and cleaner, but then you miss those pauses in signal.

I dont think that the car tries to regen brake. I lifted the car and could easily spin wheel in both directions with no apparent resistance.
Pushing the car during error - tried that numerous times. Does not help. Switching between forward and reverse sometimes helps. What really puzzles me is - once started, car runs without problems. Even in drive, switching between drive and regen is OK. The only case when this happens is when the car stops and the motor current is 0. If I apply little throttle just before car fully stops and hold it with handbrake - it will start. So, now I'm driving it like that. No fun there. Waiting at traffic lights with handbrake on and feeding 5A into motor.  :-[

//Marin

P.S. I even replaced speed sensor. No change in behavior.
Tittel: Sv: Saxo problem
Skrevet av: timescapeonsdag 20. juni 2018, klokken 13:22
Have you calibrated the speeder pedal ?
Tittel: Sv: Saxo problem
Skrevet av: Niram1969 .onsdag 20. juni 2018, klokken 14:33
Sitat fra: timescape på onsdag 20. juni 2018, klokken 13:22
Have you calibrated the speeder pedal ?

I don't know how it's done. Does it require dedicated hardware (Elit)?

//Marin

P.S. I have replaced ECU. Little improvement but "false" starts are still present.
Tittel: Sv: Saxo problem
Skrevet av: elektroluxonsdag 20. juni 2018, klokken 16:15
Calibrating accellerator is a automatic part of reprogramming the CPU. You will need PSA diagnostic, and in the prosess the CPU will adapt to the pedals signal. If this signal is not similar during following start ups the pcu will not engage Contactor and car will not start.

This is a safety issue so car is not started with accelerator pushed down.
Tittel: Sv: Saxo problem
Skrevet av: Niram1969 .mandag 09. juli 2018, klokken 11:57
(hopefully) Final update:

I have received new chopper board, replaced my (suspectedly failed) one. I started the car and immediately after pressing accelerator, yellow error light appeared. Car would not move. Reason - Permanent fault - Function: drive current chopper.

Before I put my board back in, I took another look at it. And bingo, I found (at least one) error. Zener diode CR37 (6V2) was shorted. I replaced it, put everything back and, voila - car works! :) I have tried to reproduce problem but was not able to. So It seems that the problem is finally resolved.
It was just 02.15h :) so I examined donor board and found mechanical damage. Can someone tell me the component markings for CR46 (diode, probably a zener type)?



//Marin
Tittel: Sv: Saxo problem
Skrevet av: timescapemandag 09. juli 2018, klokken 19:05
CR46 = 6V2 zener :)

br.
Tittel: Sv: Saxo problem
Skrevet av: Niram1969 .mandag 09. juli 2018, klokken 21:02
Thank you!

//Marin
Tittel: Sv: Saxo problem
Skrevet av: Björn Nymanfredag 31. januar 2020, klokken 23:25
Sitat fra: Niram1969 . på mandag 09. juli 2018, klokken 11:57
(hopefully) Final update:

I have received new chopper board, replaced my (suspectedly failed) one. I started the car and immediately after pressing accelerator, yellow error light appeared. Car would not move. Reason - Permanent fault - Function: drive current chopper.

Before I put my board back in, I took another look at it. And bingo, I found (at least one) error. Zener diode CR37 (6V2) was shorted. I replaced it, put everything back and, voila - car works! :) I have tried to reproduce problem but was not able to. So It seems that the problem is finally resolved.
It was just 02.15h :) so I examined donor board and found mechanical damage. Can someone tell me the component markings for CR46 (diode, probably a zener type)?



//Marin

Hello Marin,

Nice work with repairing the chopper unit!

I bought a Citroen Berlingo a few days ago. And it might have a similar fault. I'm getting these errors from Checkelec:
Permanent fault - Function: drive current chopper
Permanent fault - Speed sensor

Do you think both these errors could be related to the Zener that you replaced?
What's the easiest way to open up the chopper unit and have a look at the PCB?