Any Idea how ODBII code P0751 translates into Volvo TCM code? I've got this one poping up after 1/2 mile drive. Car goes in limp mode - only third gear, lo lock-up.

Thank you guys,
I’d assume that P0751 translates to Volvo’s TCM-000B “Shift solenoid S1- Hydraulic fault”. The only think puzzles me is that first 2-3min ( ½ a mile or so) car’s shifting fine, until the transmission warms up. Make more sense solenoid to get stuck in OFF position when car is shifting cold. Or at least to remain jammed even when car is cooled down. My point is all mechanical and hydraulic system suppose to work better when car’s warm. Just the opposite of the car’s electronics. Unless there’s an internal leak somewhere on the path from solenoid to the gear clutch….

The tranny is slightly different than your engine which like to be warm. The high heat causes the solenoid to expand and restrict movement.

I suggest replacing the solenoid AND flushing the tranny with nice new fluid.

Klaus
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Common sense trumps a PhD

Make sense. I flushed the transmissin aprox. 1000 miles ago, changed the filter too. Didn't reset the TCM counter. Now tranny has 110k miles.

Interesting. The TCM doesn't have a counter, and the tranny doesn't have a filter. If you meant that you dropped the drain plug and poured 3 quarts out and refilled, that is not a flush. Your tranny holds close to 8 quarts of fluid. A good flush requires about 12 quarts of new fluid to be complete.

Klaus
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Common sense trumps a PhD

Volvo s80 transmission 4t65ev doesn’t have an oil drain plug. Every automatic transmission has oil filter and on most of them it has to be replaced at some point of time.
I did the tranny flushing according VADIS instruction with disconnecting oil return line and attaching transparent plastic tube on it and so on. I used even more then 12qrt oil.
As far as I know, the Volvo’s Transmission Control Module counts the hours the tranny was working while the oil temp is above the normal, trying to predict when the oil’s going to go bad and sending a message “trans oil change” before that happened.
When oil and/or tranny oil filter is changed, TCM has to be reset in order get the oil timer zeroed and to start new gear shifting adaptation cycle.

You should be able to reset the TCM by disconnecting the battery ground for 30 minutes.
My understanding of the autoboxes is limited to the 1993-2000 850/70 4 speed autos, where they do not have internal filters. There is a drain plug for them, but does not drain all of the fluid.

Klaus
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Common sense trumps a PhD

Common problem. The solenoid needs to be replaced. Fortunately it is not extremely difficult but I would farm it out to a mechanic or a friendly dealer.

Klaus
--
Common sense trumps a PhD

I use this site to find DTC definitions:

http://www.aboutautomobile.com/DTC/P0751

P0751 is a generic code applicable to all manufacturers. When a DTC is defined differently depending on the Mfr, the web site spells out those individual definitions.

Copied from the web site:

***
Definition of Diagnostic Trouble Code P0751
This Definition of P0751 is Applied to All Manufacturers
Powertrain: Shift Solenoid "A" Performance/Stuck Off
***

Hope that helps
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Dave in Virginia; 1998 V70 T5(M): IPD MOTRONIC+ ECU Upgrade, Sport Muffler, IPD Strut Tower Brace; VDO Boost Gauge, IPD Anti-Sway Bars, Rocha ABS Control Unit, Koni FDS Struts and Shocks/// 1988 245 DL Wagon// 1967 MGB Roadster