Final Fix for Tranny Fault and Gear Circuit Faults P0915 and P0850

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malibulr4

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For months I was plagued with an intermittent tranny fault. It would happen when the car was warm. Put the car in Park and would get a tranny fault, a car not in park fault , and a bunch of flashing lights on the dash. Also weird clunking sounds at low speeds. Started with cleaning and swapping all things around the interior gear shifter....I have two LR4's so no issue with swapping parts for test purposes. Factory scan showed no faults in the transmission with solenoids etc. Final decided that it was the sliding gear selector and the circuit board that reads the sliding piece. I found a place in Vany Nuys Cal called Module Repair Pro and the owner said to bring it in.The problem was that I have never pulled a transmission pan OR yanked a valve body. I've done brakes, hubs, half shafts, water pumps, crossover pipes, and even did a front diff by myself, but heading in to the tranny seemed really daunting!

Went at it slowly. Didn't remove a thing, like the crossmember or exhaust, and did the karate chop on the side of the plastic pan to break the uptake tube from the filter. Valve body finally came out only after realizing that the connector sleeve has to come out first! Got the valve body out and replaced the rubber tubes and the double square rubber piece while the valve body was out. Separated the TCM from the valve body and delivered it to Module Repair Pro. Two days later he called and said it was done. It appears that he replaced the L shaped circuit board located on the other side of the sliding gear piece. Everything is back together, with the updated metal pan, and no faults for three days.
I've got 210,000 miles and was surprised to see a 2016 stamp on the old plastic tranny pan. Good news is that someone serviced the tranny around 100k.



A few tips.



The round connector sleeve takes more force to seat than you think. I used an extension to push it in further. The lock on the TCM will not seat until the sleeve is all the way in. Don't force the lock!

I switched over to regular bolts instead of Torx to hold the new metal tranny pan on. Just easier to use a small ratchet on them.

I could not torque the bolts that were too hard to reach so guessed based on the force needed to tighten the easy to reach ones.

Ended up using a gasket for a Ford. 18753 Felpro from local auto part store.

Used 6 or 7 quarts of ZF fluid to refill.....using FCP Euro so I can return the used oil and get more free oil of the other Rover.

Follow torque specs on bolts going from TCM to valve body, valve body to tranny, and pan to tranny.

I did not do the solenoids or rebuild the valve body with Sonnax. There are no shifting issues or codes so opted to not do it.

Abran was very helpful and so was Pfunk951 for answering a ton of questions.
 

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