Im having trouble with me 89 Toyota pickup 4wd auto trans. The truck sometimes does not want to pull off and I have to put it in low to take off then shift manually. Then there are times when the truck will take off with know problems. The truck will also some times struggle when going down the road and then other times will fly like i just dropped a new motor and tranny in it. The O/D light will sometimes flash but the truck will be actin fine, but for the most part it is when the truck is actin funny. The truck has been doing it for over 2 years it seems to me to be an electrical problem. Can anyone help.

 

That OD light flashing is a code for what's wrong. I'm not up on the codes for that though. Here's a start:
http://personal.utulsa.edu/~nathan-b...31diagnosi.pdf

After getting the code go through the trouble shooting section here for the A340H:
http://personal.utulsa.edu/~nathan-b...autotrans.html

 

Yeah, check the codes. Mine did the kinda the same thing, start out ok then shift to limp mode (not always) and not going over 2,800 r's. We checked codes and the #2 solenoid was bad, so I replaced all three. No codes. Now the tranny will drop a gear while cruising @ about 65mph when the engine temp gauge drops a notch???? wtf?

 

The temp sending unit that controls the tranny overdrive is on the backside of the engine. I replaced a few of these as my truck would do the same thing, downshift at 70 mph for no reason. Dealer ended up finding a wire joint in the engine bay that was the problem. That was 7 years ago. Been fine ever since.

 

shift solenoids. dacco detriot has them for 100.00. pretty easy job. my 89 did the same thing. on the 89 the diagnostic terminal is a single plug that is on the driver side wheel well next to the ignitor. just plug a wire in it and touch it to ground and the ODlight will flash your codes.

 

Im goin to check it out today ill let yall know what i find thanks for all the info i actually have a place to start now.

 

where is the best place to get the solenoids and speed sensors and about how much do they cost

 

Here's a cheap internet dealer:
https://www.1sttoyotaparts.com/partscat.html

 

Here's the plug that you ground, switch ignition on, don't start, with OD on, and the OD light will flash a code.

here's the codes.


Here's a cheap source.
http://www.bulkpart.com/Merchant2/me...e=A340solenoid

 

http://www.daccoinc.com/

there is a store locator if you want to try to get them locally. i got my solenoid kit from them for 100.00. it was the 1 and 2 shift solenoids only. my lock up and #4 were fine.
i had codes for my speed sensor as well but i pulled it and tested it and it was fine??? so i just replaced the solenoids and everything is just snazzy.

 

Have you tried unplugging the ECT unit and manual shift? This could rule out mechanical issues. The ECT unit is under the radio in front of the shifters, under the plastic trim. You will not have overdrive with the ECT unit unplugged.

 

i just got the code it is the no. 2 speed sensor thanks for all the info yall have been a great help! and i just got me another toyota today its an 86 but it has a blown head gasket i picked it up for $400 though so i figured that wasnt such a bad deal. i have an 83 parts truck im goin to swap out the front axle from so it should be pretty sweet. thanks again for the help ill probably need some more on my new project.

 

Speed sensor No. 2 is on the driver side of the tranny.

 

toyaholic i think i have the same problem that you did. Did you get the code for the number 2 sensor?

 

how do you test the #1 and #2 solenoid and the number #2 speed sensor. I want to make sure exactly what it is before I replace one cause it could be one or the other.

 

If you look in the FSM there will be a resistance test you can run to check it electricly but that may not tell you about a mechanical problem like a stuck or clogged valve which appearantly is a common problem with the A340 trannies. See the very end of this write-up: http://rigs.corequipment.com/Cebby/9...20Transtec.pdf

 

Solenoid no. 2 controls 1-2 up-shift
solenoid no. 1 controls 2-3 shift

 

 

Well I finally found the number 2 sensor at autozone. It was $81, and there ain't much to it. I am going to install it today along with a front seal. Maybe the sensor will be the right thing.

 

I replaced the number 2 speed sensor. and now im getting the number one solenoid code. does any one have a link to a site where i can find the number 1 and 2 solenoid package from dacco detroit i cant find it