P0339 and P0727 - related or not?

[Rigmaster]

Trying to help a friend with his 2001 525iT automatic. It's just recently thrown a CEL and he says it shifts poorly and downshifts abruptly.

I just drove the car after reading the codes + resetting the CEL and it does not shift nearly as smoothly as my 2000 528iT, and it does downshift fairly abruptly when slowing at a light or stop sign.

Generic OBD Code reader shows P0339 (Crank Pos sensor A circuit intermittent) and P0727 (Engine speed input circuit no signal).

Now, I don't have a problem telling him to replace the Crank pos sensor if it's a likely cause of the problem, but I'm wondering if it is.

The only thing I found with a quick search is a guy who had the same codes, took it to a couple of shops and ended up having the DME main relay replaced which fixed the problem (??!!)- I tried swapping the DME main relay (Sky Blue) from this car with the one in my car and it makes no difference- the CEL popped up again almost immediately and the car still shifts poorly. I disconnected the battery for ~30-40 minutes to "reset" the tranny too.


Any input from the peanut gallery???


My friend is ready to sell the car if he thinks he needs a new tranny.....

Thanks!

[edjack]

If the crank position (aka speed) sensor is intermittent, it may be causing the transmission code. In any event, the sensor will probably soon fail, which will prevent the engine from running, and will strand the driver.

[rf900rkw]

Without valid data from the DME, the EGS is going to use a default shift map that is very firm and late (meaning early downshifts). If your friend thinks non-optimal shift scheduling is an internal transmission problem worthy of selling the car, I'll be happy to take it at a broken transmission price.

[Rigmaster]

Without valid data from the DME, the EGS is going to use a default shift map that is very firm and late (meaning early downshifts). If your friend thinks non-optimal shift scheduling is an internal transmission problem worthy of selling the car, I'll be happy to take it at a broken transmission price.

Yeah, that's what I was thinking too. I told him that if it was my car, I'd replace the Crank pos sensor and hopefully that would cure it, but I told him I wasn't sure that was the problem- but the symptoms and codes pointed towards that.


I've referred him to a good local indy BMW shop, so hopefully they'll take care of it for him.


Thanks.

[e34gasm]

My 2000 528iT pulled this on me today. Did you ever find out what it was? Preface: I already know my alternator is toast. I put the battery on a charger (disconnected from systems on the rest of the car) so I could make the short run to school. Got a 'thump' as the tranny went to limp mode. Turned the car off, thinking this might clear the tranny error. Car won't start. It turns over fine, and there's juice still on the battery (11.9V), even with the dying alternator. FINALLY, after trying a dozen times, it starts up and throws P0335 Crankshaft Position Sensor A Circuit and P0727 engine speed sensor. I've heard about DME having hallucinations when something wonky goes on with the power supply. I'm hoping that when I replace the alternator tonight, the errors stop happening. Mr. Murphy go home!

Good grief, what happened to my paragraph formatting? I'm not the sort of dolt that would vomit all that out in one paragraph. Even the internet breaks on me!

[oleguaa]

i have 01 525i and I have some problems with it.
Does anyone know? what does p0339 and p0727 codes mean?

thanks

[larrym3711]

My OBD (generic) list i get this:
P0339-crankshaft position sensor A, circuit intermittent.
P0727-engine speed input circuit, no signal.

larrym3711
2001 540iA Sport

[oleguaa]

Do you know where does it located?(crankshaft position sensor)

[pikachukiat]

bump. anyone follow up with a solution? it woudl be nice to know if clearing the DME is the solution before going to the dealer for a $300 repair job that doesnt repair it.

Crank pos sensor located right next to the starter - on the block next to bellhousing driver side.

[rf900rkw]

P0339 - CPS signal intermittent.

Fix -- figure out what is cause the computer to complain about the intermittent signal and fix it.

[MHRX5]

I have a 2002 BMW X5 3.0, I love this car, when its running right, It runs really strong. However I have been battling oil leaks and some vacuum leaks for some time. I recently rebuilt the top end about 50K ago, Im at 298,000 at the moment. On a very hot day a few days ago I backed up a slight hill and parked. Upon returning to my car I started it and it immediately died, I restarted it and again, three more times it just died then I saw a display "STOP! OIL PRESS" or something like that. I assumed my oil was low and the oil sending unit was registering lower oil level because I was parked at an angle. I added 2 quarts and it would stay running. Then the "TRANS FAILSAFE PROG" has been constant, I can drive the car but it shifts hard.

Now I can't drive the car at all, the idle is very rough and it's backfiring in the intake, I hear whistling and hissing vacuum leaking, all that goes away when I increase throttle to over 1500RPM it runs very smooth.

I am now getting P0141 O2 Sensor Heater Circuit, P0339 Crankshaft Position Sensor "A" Circuit, P0727 Engine Speed Input Circuit No Signal.

I still really like this car, I know its aging and as time goes on more parts will need to be replaced, at the moment I just want to get it running right again. My plan is to change the Crankshaft Position sensor, the Engine Speed Sensor, the Intake and Exhaust Cam Position sensors and possibly delete my CCV system completely.

Any advise from anyone who encountered similar symptoms or is smarter than I would be appreciated. I will document my progress in hopes it will help others in the future.

[MHRX5]

I ordered off EBAY the X8R aluminum DISA Valve replacement and it went back together great and now I have very smooth idle and no popping in the intake but it was still hard to start.

x8R-DISA-Fix.png
I reset the codes and then got new ones, P0141 O2 Sensor Heater Circuit, P0339 Crankshaft Position Sensor "A" Circuit, P0727 Engine Speed Input Circuit No Signal but at least it is idling correctly now.

I will replace the Speed Input Sensor when it comes in, I also have an old Crankshaft Position Sensor from when I rebuilt the top end so I will try that.

Im looking for a way to verify if a sensor is good or bad, any suggestions?

[MHRX5]

Problem solved! Today is an exciting day, I had an old Crankshaft Position Sensor laying around and just decided to give it a shot, took out the old one and got a new O-ring and inserted it, reassembled everything and cleared the codes and it started immediately. It ran smooth and the P0339 and P0727 are now gone. I drove it around and those codes did NOT reappear. I still get a P0056 HO2S Heater Control Circuit and some random System Too Lean codes but Im pretty certain I need to change my Bank 2, Sensor 2 O2 Sensor and those issues will go away. I will report back when that is solved.

So the possible solution to a P0727 Engine Speed Input Circuit No Signal (TRANS FAIL SAFE PROG) is to first change the Crank Position Sensor and maybe that will fix the problem.

[gmak]

Congratulations! Sometimes the BMW gods throw us a bone!