BMW Limp Mode - Codes

[akajee]

Hi Guys,

On Saturday, my car went into limp mode. Gear light with exclamation on the inside.
I got a friend with software to check the codes.

There were a few:

7B DME has been around since he last checked the codes but I never got around to checking it out. Any Ideas on the cause?

44 DME was not there before. We cleared it took the car for a drive and it did not re-appear. Is this anything to worry about and what could have possibly caused this?

3B EGS happened once before but cleared itself after switching off and back on. This time it did not go out of limp mode until we cleared the code.

41 EGS was a new one. This was also cleared and the car is out of limp mode.

I suspect that the 3B EGS and 41 EGS codes relate to why the car went into limp mode but dont know what cause it. Any help would be appreciated.

Thanks

 

[FiRi@Rennzport]

What car and any mods?

 

[akajee]

What car and any mods?

Stock standard 325i, 2004 , steptronic

 

[FiRi@Rennzport]

Crap, 325 I got no help, but maybe some one here will have some info. Gl bru

 

[Blomhj]

P0720 Output Speed Sensor Circuit Malfunction

It's the internal Output shaft speed sensor. Probably the most common Autobox problem.

The speed sensor measures the output speed of the gearbox to be certain it's selected the correct gear. When this signal breaks down, it looses track of the gears, and defaults to sticking in 3rd gear.

 

[akajee]

P0720 Output Speed Sensor Circuit Malfunction

It's the internal Output shaft speed sensor. Probably the most common Autobox problem.

The speed sensor measures the output speed of the gearbox to be certain it's selected the correct gear. When this signal breaks down, it looses track of the gears, and defaults to sticking in 3rd gear.

any idea for cost and complexity of the OSS?

 

[Marco-Chung]

Have any problem when u driving the car??

 

[akajee]

So I hope that I got to the bottom of it.

I took the car to ZF South Africa for a diagnostic and it came up with the exact same error codes, funny (or not so funny) is that it went into limp mode on my way there....

There a great guy called Nico who evaluated the car and he is convinced that the box is overheating. We drove around with teh diagnostic machine plugged in and it monitored the temperature which went up to over 115 degrees. He recommended that I change the heat exchanger and the fan coupling.

He also says that he removes the gearbox thermostat as it is not need in South Africa due to the heat.

So that's my task for the weekend, will let you guys know if it sorts it out properly in a few weeks.

 

[Blomhj]

so basically the thermostat is a normally closed and when it reaches temp it opens ?

If you do the heat exchanger you just as might do the oil and the filter

 

[akajee]

so basically the thermostat is a normally closed and when it reaches temp it opens ?

If you do the heat exchanger you just as might do the oil and the filter

Let me first try this 2 parts and monitor. then we can take it from there.
That starts getting quite expensive at R450 per litre

 

[GPGrobler]

Why so expensive, where are you buying it from? :thinking:

 

[akajee]

Why so expensive, where are you buying it from? :thinking:

It was R223.00 per litre, no idea where I got R450.00 at G-drive.

 

[DieselFan]

If your gearbox has been overheating you should do the oil aswell. Liquimoly oil is around R180

 

[akajee]

I changed the thermostat, viscus and heat exchanger unit.
The Thermostat replacement cleared the 7B DME activation map cooling, that is gone.
You can hear the Viscus needed replacement and it also had some oil/gel which was one of the descriptions that I understood indicated that it was faulty.
I dont know what the heat exchanger achieved, but hey, I hope its cooling the box better.
I drove the car for about 40kms and no issues.

This morning on the way to work, it pops back into limp mode, same error.

The next part is the Output Speed Sensor which cost around R2520.00 but needs to come from Germany and wait time is 3 weeks.

In addition,
5l or 9L ATF oil - approximately R5000.00 @ BMW
Oil Filter - 470.98 @ BMW
Gasket - 290.38 @ BMW

So total damage is R8281.36 in addition to R1450.00 (heat exchanger) - APPROX R10 000.00

Called ZF and spoke to another guy who says that oil maybe low but they will need to check it but according to him, we changed the right parts so far and oil may just be a little too low.

Do I take the ***beep*** car to ZF and dump it there or take a chance....this is frustrating considering she is still so clean.

 

[zaleonardz]

My advice is to dump it at ZF

Yea its expensive, but you get proper backup and warentee.

Thus you have legal recourse.

 

[akajee]

My advice is to dump it at ZF

Yea its expensive, but you get proper backup and warentee.

Thus you have legal recourse.

That's what I thought as well...thanks

 

[akajee]

So I go back to ZF this morning to speak to Nico and book the car in if needed. He maintains that there is no issue on the box.

Before I leave, I hook up my DIS software and monitor the oil temperature. The drive is about 15-17kms. The temperature does not go above 101 degrees and before I changed the parts, it went over 117 degrees. no issues all the way.

Nico advises that I remove the thermostat beneath the expansion tank as that is only needed in colder countries and top up the ATF fluid .I did actually notice that my one was damaged when he showed me what it looked like.

I also bought some ATF fluid from them and it only costs R165+vat per litre as opposed to the BMW price.

So, I will try to top up the ATF fluid and remove that thermostat before pulling out more $$$ and see what happens.

 

[akajee]

Just an update. I have not yet removed that thermostat and the problem has not recurred. I only topped up the gearbox oil but only a litre (who knows how much actually fell out though when I opened it).

on the flip side , I got my software and cables sorted out and can read/clear codes and run diagnostics on the E30/46/90 using hte inpa/ediabas software

:coolShake::coolShake::coolShake::coolShake:

 

[akajee]

I just replaced my radiator on Thursday. It was not leaking and the car was not over heating but what did happen OCCASIONALLY, was the gearbox still went into limp mode due to overheating.

This happened only when I was stuck in traffic. I drove the car to Durban and it went well. Anyway, it appeared to be blocked pipes in the radiator.

So far, I sat in horrible traffic yesterday for 30 minutes or more and she did not complain.

Lets hope the problem is gone.:ty: