My Trans. Failsafe story

[ggj13557]

I was finally able to pull the codes and here they are:


Code Description Retrieval Time
P1632 Smart Alternator Faults Sensor/Circuit Malfunction 2012-08-30 18:52:36
P1639 Vehicle ID Block Corrupted or Not Programmed 2012-08-30 18:52:36
P1638 Can Link ECM/INSTM Circuit / Network Malfunction 2012-08-30 18:52:36

Any suggestions?

[SlickGT1]

Ok now monitor your voltage while revving it a bit. Like 1500rpm - 2000rpm. I have a feeling our voltage regulator is acting up.

[ggj13557]

The accelerator is unresponsive so there is no way to rev the engine unless there is another way.

[ggj13557]

Battery voltage was 11.5 prior to starting the engine and 12.5 after starting the engine.

[ggj13557]

Now it's 10.4 prior to starting the engine and 12.5 after starting the engine.

[SlickGT1]

Run it for a bit and see what the voltage settles at. See if it spikes at any time.

Honearly those P codes are not complete to diagnose these cars. You need something more BMW oriented. Like INPA, or DIS.

The other two codes are throwing me off.

[JonK]

Thanks for the post.
I do have 2005 4.4i X5 with little over 110,000 miles. I start having triple warning light that pointed to the TC Actuator plus Trans. Safe warning with grinding gear noise and sometimes A/C stopping for few seconds. When car start jerking it got pretty scarey.

I pulled the actuator out and found out the plastic gear was worn but not as bad as other posts. Turned the gear 180 degree but I was still having problem.

The voltage while engine running was little above 14V nothing abnormal. I couldn't even find voltage sparks upto 17V.

However, I am glad that I followed this post and decided to change the voltage regulator, given the fact that most of time what goes wrong is voltage regulator. I got on eBay for $70 plus shipping. What did I have to lose until I pay close to $1,000 for actuator and not getting the results...

I have done alternator and regulator replacement for e46 twice. What a pain in the aaas, and decided to take a crack by encouraged by the fact that newer X5 4.4 doesn't use the water cooled actuator. In the morning I jacked the car up to get ready. I called my mechanic he said he would do it for $240. I said "deal!" and took the car to the mechanic and sat there for 4 hours while they were working on my car.
I found out I have an engine oil leak coming from drivers side and that showed my alternator with oil. (I suspect that will be oil pump gasket like my e46.)

It was messy job even for my experienced mechanic. His assistance Louis was able to take out the alternator under the car but didn't have enough clearance to pull it out. So the started disassembling the coolant hoses and finally about to pull out radiator. I wanted to tell my "Soup Nazi" mechanic that he could pull out electric fan behind the radiator for enough clearance, but too intimated to tell him. He hates "Do It Yourselfers..." Fortunately he decided to replaced the regulator while the alternator is stuck on the bottom frame. It was replaced in about 4 hours and I haven't got the triple warning plus trans safe last 48 hours.

I suggest that you have a high mileage BMW you change the voltage regulator as preventive maintenance. It is unusual that Alternator shoots out high voltage sparks occasionally instead of lower voltage or just simply crapping out. But obviously it happens on our high power AMP on later model E53 4.4i.

$320 plus 3 weeks of agony I am a happy man. I am have to have a trustworthy mechanic on my side who won't rip me off. Next day I had him change transmission fluid and TC fluid replaced at practically at cost. Darn that 1liter TC fluid was $68. 5 G Pentosin 1 was about $85 off eBay. Both old fluid was in decent shape... I could feel the difference how well the shifts.



I have changed

[SlickGT1]

Yea if it goes over 14v, that is enough of over-voltage to become a problem to our very sensitive electronics.

[JonK]

I don't get TFS warning lights, but I could still hear griding noise on turns and when 4X4 kicks in. As I said my gear is worn but not as but.

I took a plunge and ordered a gear($131). There are a couple of vendors out there on eBay for around $140. I will put DIY and keep you posted if it has fixed the problem.