Transmission Codes

[JMI]

Been getting the "Trans Program" warning intermittently and took car into a recommended tranny shop. They scanned the codes and said it showed "Speed Sensor - 27". He said that was a little vague and was hesitant to recommend changing the speed sensor out. At least they are not a shop where they throw parts at a problem and hope for the best. But I'm beginning to feel a tinge of desperation and am inclined to go that way.
Anyone familiar with "Speed Sensor - 27"?
Any suggestions?

Thanks

Jim

[fujioko]

I assume the “speed sensor” is the same one that is also used for the speedometer. Anyway these sensors tend to go bad often enough. A good way to determine if the sensor is faulty is to take the car on the freeway and engage the cruse control. A faulty sensor will make the cruse control surge momentarily ever few minuets.

The sensor typically costs about $45.00 and takes about 15 min to replace. You’ll need to back the car up on ramps to service the sensor which is located on the differential.

My advice is based on general knowledge and I’m certainly not familiar with the auto-box codes.

Good luck!

[Bill R.]

speed sensor inside the transmission , second is the torque converter stall speed is exceeded. What that code indicates it that the crank position sensor on the engine determines engine rpm and the transmission speed sensor reads the transmission rpm. The computer knows how much slippage should be between the engine rpm and trans rpm, if it gets a differing reading then it triggers this code. Since the transmission speed sensor or pulse sensor is fairly easy to change i would change it first , its not terribly expensive either. Order one from bma and change it out along with a fluid change then clear the codes and see if it comes back.

Been getting the "Trans Program" warning intermittently and took car into a recommended tranny shop. They scanned the codes and said it showed "Speed Sensor - 27". He said that was a little vague and was hesitant to recommend changing the speed sensor out. At least they are not a shop where they throw parts at a problem and hope for the best. But I'm beginning to feel a tinge of desperation and am inclined to go that way.
Anyone familiar with "Speed Sensor - 27"?
Any suggestions?

Thanks

Jim

[JD525IA]

in the area of the tranny. There should be a speed sending unit (sensor) on the top rear part of the tranny. It is there to tell the ECU/computer exactly what the output shaft is seeing for speed.

The speedometer gets is readings from the sensor located on rear differential, not the tranny. The transmission troubleshooting page on BMWE34.net says that the tranny speed sensor (pulse generator) gets dirty or can go bad, causing the Trans Program. Link below:

http://www.bmwe34.net/e34main/trouble/TransProgram.asp

If a mechanic has checked for thrown codes, then I would give that a shot. The part is about $130 last time I checked,but the tranny has to be lowered to access it.

Check it out.

JD

[Bill R.]

trans pan towards the rear of the transmission

in the area of the tranny. There should be a speed sending unit (sensor) on the top rear part of the tranny. It is there to tell the ECU/computer exactly what the output shaft is seeing for speed.

The speedometer gets is readings from the sensor located on rear differential, not the tranny. The transmission troubleshooting page on BMWE34.net says that the tranny speed sensor (pulse generator) gets dirty or can go bad, causing the Trans Program. Link below:

http://www.bmwe34.net/e34main/trouble/TransProgram.asp

If a mechanic has checked for thrown codes, then I would give that a shot. The part is about $130 last time I checked,but the tranny has to be lowered to access it.

Check it out.

JD

[JMI]

Thanks, guys, that is a weath of information. Will try the cruise control idea and if (when) I get the "Trans Program" warning again I will discuss changing one or both sensors with the tranny guy.

Thanks again

Jim

[fujioko]

Jim,

The cruse control method is for checking the speedometer speed sensor and not the transmission speed sensor. That was my error in assuming they were the same. I guess it’s true when you assume………

Anyway, it looks like the pros got you on the right track. Listen to them and not me. Good luck!

[JMI]

Bill R and company,

While doing a little more research I came across this:

http://www.bimmer.info/forum/showthread.php?t=13455

It is the same tranny as mine - ZF 4HP22

Looks simple enough to change

Will let you guys know how it works out.

Thanks for all the help

Jim

[JMI]

Changed out the "Pulse Generator/Magnetic Pickup" this afternoon and will let the car sit overnight. Will start it up in the morning and see how it goes.

Not too optimistic at this point, but never do I give up hope

[JMI]

Changing out the "Pulse Generator" turned the trick!

Thanks for the help!