Newbie from Mongolia- O/D light blinking

[CrazyMongol]

As for the code 86, the manual points either to a bad harness or a bad TCM, or ECM. I would take a look around while you are down there for signs of wear or dirt of something to explain this.

MoGas and Semlin, you are my heroes... I really hope it is just bad connections, as getting any parts into Mongolia is a nightmare!

ok, guess it's a really dumb question, but I hope that as I am a newbie, you'll let me get away with it...

Tried to look on the acronym list, couldn't find what is TCM or ECM, could you help me with it?

 

[CrazyMongol]

are there lots of Toy dealers out your way?

not really, need to dig in piles of S*&% to find out something worthy

 

[semlin]

not 100% sure but i believe TCM = transmission control module and ECM = engine control module. Both expensive computer items you do not want to break. hopefully it is a loose connector or frayed wires. has anyone been down there recently workintg on it?

 

[CrazyMongol]

went under the car now for two hours, disconnected and cleaned, try to see if there's anything disconnected, and it all seemed fine to me. took the a short ride, and the "O/D off" blinked again...
When I'll finish here at the office, I'll take to a place where I can lift the car up, so I can get a better visual, and can reach the connections better to clean them up... I'll keep you all posted, I can't see this bulb blinking at me anymore...

 

[CrazyMongol]

Hopefull last update

put the car on the lift, disconnected both No. 2 sensor, and the other sensor on the tranny (not sure what it is, but if I'm already there...) cleaned them both, all connections seemed to be fine, then disconnected all wires goes to TCM and ECM, cleaned and checked them, disconneted the 10 AMP dome fuse, and went on a 20 min. ride, and guess what? no more blinking lights on my dash! Thanks allot LC gods!

 

[CrazyMongol]

Special thanks to Semlin and MoGas- keep on the great job! You are life savers

 

[semlin]

right back at you. what kind do you drink in Mongolia?

also, for future reference, was the no. 2 sensor at the front or back?

 

[OZCAL]

I love this place .

 

[CrazyMongol]

Too happy, too soon...

ok, took a day off yesterday to celbrate the national "no more O/D off blinking" day, and took the dog to the river (therefore haven't been in the forum, I'm getting addicted). Well, it took some time, but the f*&^%# light went on blinking again!!! Tomorrow I am taking my dog (more than 70 kg of teeth and muscle) to the local Toyota dealer to get some better explanations as to what is going on, I don't mind to change ECM, TCM and tranny, just can't see these light anymore, they are coming to me in my dreams...

Semiln- I am not sure whether No. 2 was sensor was at the front or at the back, the one that points forward though was in the back and up, hardly accesible. I guess that tomorrow (with the kind help of my dog ) I'll get back to you with an answer on that one...

The only thing keeps me in Mongolia is that it is one of the only places on earth where the beer is cold and the women are ! We have great locally brewred beer called Khan Brau, you should come over and check it out!

 

[semlin]

mongol, sorry to hear about that. You should pull the codes again to be sure they are the same ones and that both returned.

the no. 2 sensor does point forward so it must be at the back.

I am away from my service manual until Monday now so I can't give you the toyota step by step diagnosis guide until then. Basically you need to check for specified resitance /continuity across a few TCM circuits and the switches to figure out where the problem lies but I don't know the numbers. There is at least one test that isolates it either to the TCM or harness so you should definitely do these test before buying a new TCM. Maybe someone else can check in the AT section of the 94 manual and set these out for you.

 

[Mickldo]

If you don't want to see the O/D light flashing why don't you pull it out!









Just kidding, somebody had to say it.
Don't you hate electrical problems, you search and search for hours to find a connector thats dirty or some other minor problem.
Hope you have luck at the Toyota dealership.

 

[CrazyMongol]

Thanks Semlin,

You have half-brighten my day, because it seems like I am getting now just one code- 8 blinks, 1 sec pause and then 6 blinks.

I hope it is a good sign... Would it be code 86 then?

 

[CrazyMongol]

If you don't want to see the O/D light flashing why don't you pull it out!

Just kidding, somebody had to say it.
Don't you hate electrical problems, you search and search for hours to find a connector thats dirty or some other minor problem.
Hope you have luck at the Toyota dealership.

Yes, mechnical problems are easy to solve, some gear to pull, 5 kg hummer will mostly do, and on top of it, it all makes sense. With electricity, ther's no logical way to figure it out...

As for the luch with the dealership... well, I got the dog, they'll need the luck this time

 

[e9999]

a bit of tape on the light will do nicely, and easy enough to do...

 

[semlin]

ok here are the diagnostic steps for code 86

1. check for continuity between the ECM connector NE0 terminal and TCM connector NE terminal. If no continuity replace tyhe TCM to ECM wire harness.

2. if continuity check voltage between TCM connector NE and ground. voltage should be less than 5 volts. If this is OK problem is the ECM. if voltage is bad replace the TCM [note edit].

given that youa;sp had code 61 which is defective speed sensor, and code 86 which is described as "severed engine speed sensor or short circuit -- severed wire harness or short circuit", you might also consider replacing the rest of the harness before you replace an ECM or TCM, but above is what the manual says.

 

[CrazyMongol]

Thank you Semlin, I will check and will inform over the thread.

 

[semlin]

oops on item 2 I say ECM is the problem either way. i think that if the voltage is bad it is the TCM but I will check tonight.

 

[Romer]

BTW Crazymongol - Happy Birthday. Good luck in finding your problem.

 

[CrazyMongol]

Thanks Romer!

I would have been a happy birthday if I would solve the problem. Hope I'll get to solve it before the next birthday

 

[CJF]

C-Mongol,

Looks like you're focusing on wiring and getting good help with that. I just want to make sure you can really rule out the sensors themselves at this point. Have you actually pulled them to see if they're fouled with fluid or something? Or, guys, is there an FSM test for them?

On my 91 the speed sensor circuit went out, according to the cruise control diagnostic system. (We only have one sensor and it's only used for the cruise control.) Pulled the sensor (sticking into the T-case), and it was obvious that an o-ring seal had failed and allowed the sensor to get fouled with gear oil. Replaced the offending o-ring and then the sensor (I tried just cleaning it first but no luck) and got my cruise control back.

Good luck,

Curtis