A340F Solenoid failure symptoms and replacement

A couple of weeks ago, on a coldish morning, I noticed that my '97 DX Alltrac was sluggish to get away from a stop sign. The engine rev'ed higher than usual, and the van moved forwards, but as if it really wasn't in as big a hurry as I was. Since my '94 came back from a trip to Mt Rainier just last summer with a roasted transmission and I had to replace it with one from my donor van, another transmission swap was not on my agenda, especially heading into winter. But it had been fine minutes earlier, as I had headed out from home, so this wasn't a problem that got worse gradually - it was sudden. I tried putting the shifter in the "L" position, and it was fine. I went about my business shifting manually and got to where I was going and home again, but it put a cramp in my attitude for the day. The issue went away for a week, and then returned, also on a cold morning.
Once I had a chance to do a little research online and in my FSM, it became reasonably clear that my trouble was with one of the three solenoids inside the transmission, just inside the pan. My CEL has been on for a while since I have a clogged EGR port that I've been procrastinating about, but when I read the codes, sure enough, a new one had appeared: P0753 - trouble with the #1 solenoid that is responsible for shifting into 1st gear. Aha. A classic electrical problem. The older Previa auto transmissions don't have these solenoids.
Toyota wants about $140 for the part, if I remember correctly. Various ebay sources offer all three in a no-brand-name make for around $60. A domestic company called Rostra makes a kit, and prices vary from $90 to $300. I found an ebay ad by some guy who had bought the kit, never used it, and was cleaning house - I won the auction for $50.
It's a mess to drop the pan, but it was an opportunity to get almost a gallon of fluid exchanged and renew the filter. The new ones went in without a hitch. The electrical connectors are different, and there are wires that wind up needing to be tied out of the way, but otherwise the Rostra units were a bolt-in fit. And the old #1 solenoid measured 120 ohms, rather than the 12 or so that it should. So my confidence that I had a fix was high before I even poured the new fluid in. I've been driving it for a week now with no trouble.

I expect that many a mechanic would tell a customer that their apparently slipping transmission was dead and needed replacement. No telling how many Previas have gone to the shredder for want of one of these solenoids. All in all this was a really easy fix.

Old #1 solenoid:

Attachment 3111

New one:

Attachment 3112

the other two old ones:

Attachment 3113

The new ones:

Attachment 3114

Here's a link to Rostra's installation instructions. My van has the "earlier" version of the A340F

Good job. I did the same thing on my corolla... spent $10 at the junk yard for solenoids... fixed the 3rd gear start problems
The A340F is basically a hand me down from the 4Runner/T100... that's something you can also get parts from at the junk yard too

the A46DE/DF also has solenoids, but they are very different and at different locations

I remember when my transmission was out when the motor was being rebuilt. I kept telling myself that I should get off work early and take the transmission to an ATRA shop. But the shop who did my work convinced me that they'll look at it and put in new seals/filter/fluid.

Beginning of the year, I would put my previa into drive and the it felt like I was in neutral til it grabbed a bit later. Then when I was driving it, the lower gears would not shift right away and suddenly, boom, I'm in 3rd gear.

I took it the shop and they said it feels like the gears are going bad.

I thought it was solenoid too, so I searched online, but I never got a code for it.

I then took it to the shop where I wanted to take it in the first place and he gave me a the $1200 for a full rebuild and to this day, I can't be happier about it. All new gears, solenoids, torque converter and even added a shift kit.

When I went to get my van, the Transmission shopped showed me the front drum, which was burnt and all the clutches breaking down.



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