1999 volvo V70 XC @110000miles

a few months ago my reverse started acting up. It would slowly reverse on a flat surface it you let it idle, but it you gave it gas the engine would rev and nothing would happen for a few seconds and then the trans would shudder and then finally move in reverse. All forward gears worked fine. No codes. It kept getting worse over time.

I took the tranny out and did a rebuild myself including the valve body. The B4 underdrive brake band was broken and the clutch plates where pretty worn out. The fluid wasn't as bad as i thought it would be.

Now with the rebuilt tranny back in after driving around for about 10 minutes i get the flashing up arrow and the CEL. Codes are P1816 and P0734. Clear the codes and drive and they come back.

I know that i could have done something wrong so i start with the easiest tests. I test the Ohms of the solenoids:

S1 = 15 Ohms
S2 = 17 Ohms
SL = 18 Ohms
Line Pressure = 5 Ohms

I tested with 2 different digital meters to make sure i was getting good results. My question is, if S2 and SL are both out of spec, shouldn't a code be thrown? I can feel the shift from 1st to 2nd, but i don't really feel a shift from 2nd to 3rd, but i don't get the code that responds to 3rd gear ratio.

Could the following be a possible scenario: S2 and SL resistance is close enough to spec that no code is thrown, but S2 is stuck on, so gear 1 and 2 work, but 3rd and 4th can't be engaged since they require S2 to be off.

 

Not a tranny expert but from an electronics perspective, the ohms of the solenoids are telling you about connectivity - ie shorts or open circuits. Since you have consistent readings, it sounds like all is good for connections. Now when you apply voltage to the solenoids, you should get a voltage drop - and if that's out of range (say one is stuck on or off) then it would make sense the voltage would be off and you get a code.