Trouble code P0758 Shift solenoid B

[waldo2]

1997 Land Cruiser, 1FZFE engine, automatic, US Model.

I have no second gear. Goes right from first to third. If I shift down from drive it goes right to first. Code reads P0758 shift solenoid B.

Finding the parts is difficult. I'm on a budget. The dealer wants 700 bucks for one and there are three of them (while you're in there). Tried a few cheap from China options and they don't look right , so went to Partsouq. 100 bucks. OK I'll try replacing the faulty one.
They give the part number as 85420-30200 (shift solenoid A and B are the same) When I go to order it changes the part number to 85420-21090. ?? OK maybe it's updated part.

I drain the tranny , remove the pan, and there it is, the second one from the front is supposed to be Solenoid B. I change it but the new part looks different. It fits and it measures the correct Ohms so I put it all back together and the problem is still there . No second gear. The fault code is gone. No codes at all but no second gear either.

Very frustrated at this point. Now I am reading to check the ECU? Any Ideas appreciated

 

[baldilocks]

Rostra Transmission Toyota A140 A240 A340 Jeep AW4 Shift Solenoid Kit

Check out the deal on Rostra Transmission Toyota A140 A240 A340 Jeep AW4 Shift Solenoid Kit at Oregon Performance Transmission

www.oregonperformancetransmission.com

Rostra is legitimate. In the mean time if you have to drive your 80 you can disconnect the wire harness from the trans driver side and shift manually. This works on the A442f anyway.

 

[Malleus]

Your part numbers are correct.

Your next step should be to check your subharness for continuity. Check the wire terminals from one end to the other. If that checks out, yes, you need to look at the ECM.

The transmission controller is integrated into the single unit next to the glovebox. The first thing I'd do is open the case and visually check the board to make certain there is no evidence of leaking capacitors. You don't need any special training to inspect it. If it looks OK, it probably is. If there is a component fault, it'll be apparent.

If that looks OK, you need to check continuity from the subharness to the ECM terminals, which is what the service manual means for you to do when it says check the ECM – you're checking continuity, not ECM function. You're actually checking the engine harness continuity from the engine–transmission connector housings (near the starter) to the ECM.

You need a multimeter with backprobes, so that you can check the wiring with the connector housings in place on the ECM connectors. Backprobes are needle attachments that allow you to contact the rear end of the terminals. Don't pierce the insulation if you can help it.

If all that checks out, you have one of two faults: 1) the valve body piston is stuck, 2) the TCM circuit is FUBAR.