EFIDynoTuning Forum

Engine dies coming to a stop, downshifts seem a bit more noticable. Fluid still nice and clean and not burnt. Gonna drop the trans pan this weekend and inspect. Would like to have TCC solenoid on hand when I go back together with it.
Any recommendations on quality solenoid brands?

00 F150 2wd 4.6 4r70

I would say Motorcraft. No other.

check the main bulkhead connector and make sure there's not trans fluid in there, if there is that means the seal is leaking and it could be shorting it out

make sure the filter didn't fall out and has a retainer

if its a custom tune on it make sure the 2-1 downshift tq modulation table is set to all 1s below 10 mph

A little back story on the problem. It has been very cold recently. (Into the negatives) I start my truck and idle it every morning before I move it. I noticed a bit of a high pitched hum that seems to be pressure related to trans that only happens at cold ambient temps. If above 30 I don't notice it. Best way to describe something similar in sound is almost like an alternator hum thru speakers at times but not rpm dependent.

I will be dropping the pan tonight and will inspect and test harness and connections. I am also gonna pull connector from the eec and check there as well. I live in the rust belt now. No telling what I will find.

I do believe it to be either a short or an internal leak on the TCC solenoid.

I also have an aftermarket pan I have had for a while to go on it with a drain plug.

I will take a look at the calibration file. I haven't touched trans parameters in years on it.

I never understand why people say 'if there's fluid in the connector, it's leaking and shorting out'. Transmission fluid is dielectric, and all of the electronic parts inside the pan are fully submerged in it. How will some seepage int he plug cause shorting, but not the components that are fully submerged in it?

no idea, i never understood it either until i experienced it myself

I've always chalked it up to one of them things beyond my knowledge.

Dropped the trans pan. Nothing crazy in the pan. Not bad for 300k+ miles. TCC solenoid was intact. No cracks. Didn't find any issues. Replaced it anyway as I had a new one. Put it back together with a new trans pan, filter fluid.
Still doing the same thing. Took a look at the harness connector at trans bulkhead. Had some fluid. Cleaned it up best I could with brake clean. Checked eec connector. No issues.
Bumped the idle up a bit. No change.
I looked for the 2-1 torque modulation table and I don't see it. Im using the latest cvaf1 xdf.

Edit
Something else I noticed as well. Going into from park or neutral to reverse is fine, into drive is rough and may stall. If I keep it running in drive sitting still, foot on brake, and shift from drive to 2 it is easy on it but if I go to 1st it clunks. Going back to 2 is easy, into d is clunks. I say clunk but what I really mean harder than normal engagement.
I'm starting to thing this is cross talk hydraulically. Maybe a leak at the vb gasket? Maybe something beyond my knowledge of 4r70s? We shall see