BMR fails to start after replacing speed sensor (G2).8)

Hello,
I'm having a problem, and I urgently need some advice.
I replaced the crankshaft speed sensor (G28). To do this, I had to remove the transmission because I kept slipping off the ball joint when trying to access it from the outside. While I was there, I also removed the sealing flange, which of course also detached the sensor ring. I reassembled it using a special tool to ensure proper alignment.
Initially, the engine started immediately, but a few minutes later it wouldn't start again. It started with a jump start, but then it turned off on its own after about a minute.
What could have gone wrong? Could the O-ring be the faulty part? What else is possible?
There's absolutely nothing in the error memory. And in the process of all that, I replaced the DPF (Diesel Particulate Filter).

Thank you in advance and best regards.
Okay, here's the translation:

Phillip.

Hello,

I'm not 100% sure, but I believe that the BMR (Battery Management System) can still start the organ after a while, even with a faulty sensor. And if it's running, it will also work with the sensor disconnected. That's at least what happened with a BMR I had a few years ago, where the sensor or a cable was also defective.

Okay, the only solution that comes to mind right now is to replace the sealing flange along with the sensor ring.
Does anyone have any other ideas for solutions?

Best regards.

Autoscan.

Sure, completely forgot.

When I did the scan, I also tried to start the engine again, and surprisingly, it worked, and it even started a few more times afterward. I definitely don't want to drive like that.

Hello, thank you.

The possible causes are quite limited; besides the sensor itself, they include the geometric arrangement, the wiring, and the evaluation electronics associated with the sensor.

If the distances don't change (or can't change) and the engine control unit is working...

Best regards, Rainer.

If it has to be a wiring issue, why isn't there an error code stored in the system's memory?

phgraf wrote:

If it has to be a wiring issue, why isn't there an error code stored?

Because the control unit isn't crawling around the engine compartment, looking for places where cable insulation might be worn away or where an animal might have chewed through a wire?

How would you write an error message if the electrical measurements are within the specified limits, but the output torque and speed cannot be determined?

"So, what are you going to say then? 'Oh, the starter motor is engaged, but somehow I don't feel anything turning?' or 'Hey man, why isn't anything happening?'"

I'm sorry, but I can't translate that. It appears to be a special character or code that I don't recognize. Could you please provide the text you would like me to translate?

Okay, I understand.
I was thinking of something like "short circuit to ground" or "implausible signal." I will check the cables. I just hoped I wouldn't have to remove that oil filter housing again.

Damaged cables are more likely to be found in the area of the transmission and starter. The 90-degree arc from the engine to the transmission is often a weak point.
I personally wouldn't remove the oil filter housing again.

Thank you for the tip.

I managed to trigger an error, so it's probably definitely the cable. Does that definitively rule out the proximity sensor?

What do you mean by "donor ring"? Isn't that just a metal part? If nothing is broken, why should it be faulty?

It might not be perfectly aligned.
Yesterday, I probably found a cable with a loose connection that had broken.
Now I just need to figure out the exact location...
Or should I replace the entire cable?

Hi!
Since crimping the pins on the connectors isn't entirely straightforward, I would - assuming the cable is in good condition - only replace the bent section generously and use heat-shrink connectors to replace the damaged area with a new wire strand.


Best regards,

The problem was with the cable. A wire was damaged, approximately 30cm after the bend. Sure, here's the translation:

"I only replaced the segment."

What a waste of time, taking out the gearbox for absolutely no reason.