That's me in the corner... That's me in the spot light... LOSING MY TRANSMISSION!
 

That's me in the corner
That's me in the spot light
Losing my transmission
Trying to keep up with you
And I don't know if I can do it
Oh no, I've said too much
I haven't said enough

I thought that I heard it rattling
I thought that I felt it slip
I think I thought I saw TCIL flash

Every start up
from every stop... light..
I'm feeling hesitation
Like it don't want to go, no,
I'm losing my transmission
When I put it in Park,
the engine revs 1200,
it never did before,
I think this tranny's dead and done for.

Nice im drunk to

I wasn't drunk. I was bummed. May as well sing the blues away. After 15 years, (but only 59K miles) it finally happened to me... tranny troubles.

The truck hesitates to go forward after applying the accelerator from a standing start.

The truck revs to 1,200 RPM for a second when put into Park.

When shifted from Drive to Park three times in a row in relatively quick succession, the TCIL flashed, and remained flashing until fourth gear was reached when driving (nervously) down the road immediately afterward.

The codes that came up seem unrelated... P0720 Speed Sensor output circuit malfunction (my ABS light is on, again, and I know I need to replace the left front speed sensor), P1139 Water in Fuel Indicator Circuit Malfunction (no wonder I never seem to get water in the fuel) and P1249 (Wastegate Control Valve performance). None appear to be directly transmission related.

When moving slowly, the slow engagement to go forward really manifests itself.

Hummm...my post didn't actually post...

anyway, let us know what you find out Y2...

My bad that was drunk me posting :-X03
Sorry to hear your trans gave out.

Time for code reading to see whats going on only 59k, have you ever done a trans oil change? If thats the original trans oil it probably is bad.

You could have a hit there if you could get past the copyright laws. The income generated could help offset the cost of repairs for your transmission. You just need to find a few middle aged, slightly overweight guys with ball caps on to sing it.

The lyrics invoke a lot of emotion, laughter and crying at the same time. The best part is that it does not need to be produced for PowerStroke specific audiences. This song could be the anthem for anyone and everyone with an automatic transmission!

I am thinking something along these lines.


If you need an agent, I might be able to help you out with that. My fee is only 74.99%, so you should have at least a few bucks left over.

On a serious note, I hope it is something simple and you can get it sorted out quickly.

Keep us posted.

The codes that came up seem unrelated... P0720 Speed Sensor output circuit malfunction (my ABS light is on, again, and I know I need to replace the left front speed sensor), P1139 Water in Fuel Indicator Circuit Malfunction (no wonder I never seem to get water in the fuel) and P1249 (Wastegate Control Valve performance). None appear to be directly transmission related.

I've changed the transmission fluid 4 times in 59K miles. That's about every 15K miles. Two of the changes involved removing the bell housing cover plate, hand spinning the crank, finding the plug, draining the torque converter fully type of changes. One of the changes was the use a clear tube into a bucket and let the pump drive out all the fluid type of change. And one of the changes was a quick pan drop only. Still, I think the fluid (and internal filter) has been changed more than most people do for such low mileage use.

The P0720 is transmission related. That code is for the Output Shaft Speed sensor/circuit on the top of the extension housing. It could be a faulty sensor, wiring, or debris that has attracted to its magnet. The OSS works in conjunction with the TSS (turbine shaft speed) sensor and VSS to determine trans range, shift points, and TCC lock up.

Thanks Roland... I hadn't looked the code up, and assumed the speed sensor fault was for my known bad wheel speed sensor. There was an asterisk on my OSS in the PID monitoring menu indicating an out of range condition. I'm going to monitor it on my drive today to pick up a trailer. Hope I make it home.

^^^^ what he said. It can have ill effects on a tranny not shifting correctly. Is your speedometer all bouncy? Also a free and easy thing to do right now is to check the wire harness going to the tranny to make sure theres no oil or water inside the conector.

I know this sounds strange, but right now I'm suspecting one of my alternators. That is the most recent change I've done, and I would not be the first person to have OSS problems diagnosed to alternator AC RF interference.

My OSS reads about 900 RPM faster than my engine RPM when the TCC is locked up.

I am wondering out loud if driving it this way could cause damage, especially towing.

Me too. I drove it, but didn't end up towing that trailer after all. Stop and go traffic is dicey, but long haul driving seems OK. I have to use the truck one more day before I can park it and switch to the (hate to say it, but more reliable) GMC.

If I have to pull the trans to fix a little thing, then I might as well break the trans, because the day I pull it is the day a built tranny is going in it's stead. Right now, I need the truck to work for me more than I need to work for the truck.

Just following up so that others may be helped in the future...

It was, indeed, one of my alternators... as I suspected.

The OSS sensor is a hall effect sensor (just like the camshaft position sensor) that is sensitive to EMF, and in particular, sensitive to the AC RFI emitted from the alternator before it is rectified to DC.

The alternator works and produces it's rated output, as verified by bench testing, but it is emitting a level of electronic interference that just about disabled the transmission, and set several other non related codes.

I'm interested in how and why this occurs with one alternator over another. The condition is often diagnosed as a bad diode in the rectifier, but having had the alternator apart, I'm not convinced that any of the diodes are bad.

Interestingly enough, the ground of the alternator attaches to the same bracket that holds the metal fluid cooling lines to the transmission, and that connection occurs PRIOR to the cooling lines transitioning to flexible rubber portions. In other words, the cooling lines antenna a solid metal continuous connection from the lower alternator case ground to the transmission housing itself. The cooling lines also run parallel and in close proximity to the positive leads to the starter.

I'm trying to find similar experiences from others in the past. However, not too many folks trying to resolve a transmission problem head to the alternator first. By the time they get to the alternator, many other things end up getting replaced (sensors, wiring, PCM, transmission, and sometimes the truck itself).

For now, I've unplugged the lower alternator until I have more time to play around with the possibilities. In the meantime, the transmission is, and has always been, just fine. The interference with the OSS caused a lot of misbehaviors when starting from a stop in Drive (delay before moving) and when placed into Park (temporary elevated idle). Manually shifting 1, 2, D was a successful work around, but disconnecting the alternator is much better. No more codes, no more problems.

By the way, those with dual alternators should know that a code will initially set (P1105 or 1103, forgot which) in the first drive cycle after the lower alternator is disconnected, but after the second drive cycle or battery disconnect reconnect without the lower alternator connected, the PCM will automatically revert to assuming it only came with one alternator, and function accordingly without setting anymore lower alternator codes.