FBH The end of the SAGA ? - Page 30

cosmin · 19th January 2020, 09:11

Here are both boards, same error.
Resoldered the near CPU resistors and the ones next to CAN tranceiver. No change.
Removed the big 390uF capacitors and checked the circuits and passing points beneath them. All ok.
Measured ALL resistors by placing test pins directly on board, not on top of resistors. All ok.
Same thing with small smd transistors and diodes.
Measured as much as i can find, all passing points on boards. All seem to be ok.

On this one was broken the 1 ohm power resistor and the 44N05 transistor next to him. I hoped that was it, but no success. Until i discover the short power transistor, he blowed me 2 times the 1ohm resistor i replaced, so now i had to create it from 5pcs 5,1ohm 1206 resistors.

On second board initially i had the eror "metering pump shortcircuit" after it ticks 2-3 times on every start sequence.
After many tests and resolderings, now i have the same "glow plug/flame monitor interruption" error.
Maybe after i solve the glow plug issue, comes back the metering pump error too. I suppose there's a specific order of error checkings, and if he finds a glow plug error, the other system checkings are stopped.
I replaced the BTS141 too, but error remains. Transistor was good.

Pete73 · 19th January 2020, 10:51

What are the ohm readings in WTT in test mode?

Did you try the trick to earth finger to pin 19 when running test to glow pin?

The ohm values should jump around if that pin can detect anything.

If so, then I still think that you have a bad solder joint or a cut trace somewhere

The metering fault comes when you start the diagnostics, if not connected, with a vendor specific board you will always get it until you have it in the car, that is what I got with BMW thermotop Z. (I have an BMW X5).

Looking at the pics and the 10k, are you sure that you have a solid connection to circuit from it, as in several places there is still loads of varnish on all of them?

BR Pete

Pic with PIN 19 marked

I marked all the related resistors with red dots in pic..

Pete73 · 19th January 2020, 11:42

Hmm, the one with blowing 1ohm resistor near the thermal sensor..

Seems that you have a bad short there, and that resistor is in line with the pin 19 too, you have to find that short first, the glow plug measurement will not work before.

And int the first pic, just under the electrolytic cap, the 49.9k looks like a bad solder joint.

cosmin · 19th January 2020, 12:33

Quote:

Originally Posted by Pete73

Looking at the pics and the 10k, are you sure that you have a solid connection to circuit from it, as in several places there is still loads of varnish on all of them?

I marked all the related resistors with red dots in pic..

You where right Pete! I resoldered all the resistors inside the red square you marked and now is working fine!
Thank you very much! I couldn't think about this in a million years, without your help.

The short circuit was inside the 44N05 transistor, and replaced at that time but the glow plug error was still there.

Now, after the first board solved, i made the same resistor re-soldering on second board too, but no success.
Tomorrow i will test it again with WTT and let you know.

Pete73 · 19th January 2020, 12:42

Excellent!

I had the similar situation too, with persistent "nagging" of one forum member I desoldered all of them and replaced them, and voila!

The cold solder joint might be the 2nd most common problem with them, must be the heat + the ROHS solder, just can not take the heat variance.

Good news! Enjoy the warm mornings!

Keep the 1ohm, do not go over the original, it just will not work. If you still get heat and blown resistor, you have too high current in that circuit.

BR Pete.

P.S. all this is FrenchMike´s fault, he made us fixing them.

So he deserves that "thank you".

cosmin · 20th January 2020, 13:51

On second board, problem is not solved by re-soldering the resistors in that area. I get same glow plug interruption error.

Pete73 · 20th January 2020, 14:03

Quote:

Originally Posted by cosmin

On second board, problem is not solved by re-soldering the resistors in that area. I get same glow plug interruption error.

Measure the voltage on pin 19 when not running glow test and when running the test, gives some idea is the line totally dead..

cosmin · 20th January 2020, 15:09

I measured 3,35V in test mode and 0V when not running the test. I get same value on the functional board.
So the CPU is ok.

Pete73 · 21st January 2020, 03:48

Quote:

Originally Posted by cosmin

I measured 3,35V in test mode and 0V when not running the test. I get same value on the functional board.
So the CPU is ok.

Did you try the earthing trick? Did the values jump up/down?

I still think you have a bad resistor somewhere and you did put the 1 ohm resistor back near the mosfet?

cosmin · 21st January 2020, 04:22

I touched the wire soldered to pin 19, in test mode. The values do not change in WTT.
On this board, the 1ohm resistor is ok, it wasn't defective.

19th January 2020, 09:11	#291
cosmin Newbie BMW Join Date: Sep 2016 Location: Pericei Posts: 15 Thanks: 3 Thanked 0 Times in 0 Posts	Here are both boards, same error. Resoldered the near CPU resistors and the ones next to CAN tranceiver. No change. Removed the big 390uF capacitors and checked the circuits and passing points beneath them. All ok. Measured ALL resistors by placing test pins directly on board, not on top of resistors. All ok. Same thing with small smd transistors and diodes. Measured as much as i can find, all passing points on boards. All seem to be ok. On this one was broken the 1 ohm power resistor and the 44N05 transistor next to him. I hoped that was it, but no success. Until i discover the short power transistor, he blowed me 2 times the 1ohm resistor i replaced, so now i had to create it from 5pcs 5,1ohm 1206 resistors. On second board initially i had the eror "metering pump shortcircuit" after it ticks 2-3 times on every start sequence. After many tests and resolderings, now i have the same "glow plug/flame monitor interruption" error. Maybe after i solve the glow plug issue, comes back the metering pump error too. I suppose there's a specific order of error checkings, and if he finds a glow plug error, the other system checkings are stopped. I replaced the BTS141 too, but error remains. Transistor was good. Last edited by cosmin; 19th January 2020 at 09:53..

19th January 2020, 10:51	#292
Pete73 Newbie X5 Join Date: Dec 2019 Location: Uusimaa, Finland Posts: 18 Thanks: 0 Thanked 5 Times in 5 Posts	What are the ohm readings in WTT in test mode? Did you try the trick to earth finger to pin 19 when running test to glow pin? The ohm values should jump around if that pin can detect anything. If so, then I still think that you have a bad solder joint or a cut trace somewhere The metering fault comes when you start the diagnostics, if not connected, with a vendor specific board you will always get it until you have it in the car, that is what I got with BMW thermotop Z. (I have an BMW X5). Looking at the pics and the 10k, are you sure that you have a solid connection to circuit from it, as in several places there is still loads of varnish on all of them? BR Pete Pic with PIN 19 marked I marked all the related resistors with red dots in pic.. Last edited by Pete73; 19th January 2020 at 11:36..

21st January 2020, 04:22	#300
cosmin Newbie BMW Join Date: Sep 2016 Location: Pericei Posts: 15 Thanks: 3 Thanked 0 Times in 0 Posts	I touched the wire soldered to pin 19, in test mode. The values do not change in WTT. On this board, the 1ohm resistor is ok, it wasn't defective. Last edited by cosmin; 21st January 2020 at 09:23..

19th January 2020, 11:42	#293
Pete73 Newbie X5 Join Date: Dec 2019 Location: Uusimaa, Finland Posts: 18 Thanks: 0 Thanked 5 Times in 5 Posts	Hmm, the one with blowing 1ohm resistor near the thermal sensor.. Seems that you have a bad short there, and that resistor is in line with the pin 19 too, you have to find that short first, the glow plug measurement will not work before. And int the first pic, just under the electrolytic cap, the 49.9k looks like a bad solder joint.

19th January 2020, 12:42	#295
Pete73 Newbie X5 Join Date: Dec 2019 Location: Uusimaa, Finland Posts: 18 Thanks: 0 Thanked 5 Times in 5 Posts	Excellent! I had the similar situation too, with persistent "nagging" of one forum member I desoldered all of them and replaced them, and voila! The cold solder joint might be the 2nd most common problem with them, must be the heat + the ROHS solder, just can not take the heat variance. Good news! Enjoy the warm mornings! Keep the 1ohm, do not go over the original, it just will not work. If you still get heat and blown resistor, you have too high current in that circuit. BR Pete. P.S. all this is FrenchMike´s fault, he made us fixing them. So he deserves that "thank you".

20th January 2020, 13:51	#296
cosmin Newbie BMW Join Date: Sep 2016 Location: Pericei Posts: 15 Thanks: 3 Thanked 0 Times in 0 Posts	On second board, problem is not solved by re-soldering the resistors in that area. I get same glow plug interruption error.

20th January 2020, 15:09	#298
cosmin Newbie BMW Join Date: Sep 2016 Location: Pericei Posts: 15 Thanks: 3 Thanked 0 Times in 0 Posts	I measured 3,35V in test mode and 0V when not running the test. I get same value on the functional board. So the CPU is ok.