(added 11/20. It may have been my Coolant Temp idiot light, but this does not change the fact that my engine did shut itself down to avoid damage).i have never heard of our trucks having a fail safe with the oil system ie low oil presure or low oil level and it shutting the truck down to save the motor.
I know there is a failsafe for A/T oil temp. A few months ago I had dealer top off my coolant reservoir. Filled it to 'full' line. Drove about 5 miles, car stalled. Automatic transmission fluid temperature warning light was on. Wouldn't start. A few minutes later it started, warning light off, drove 10 blocks, shut down again, warning light on.
Googled and found posts about an over-full reservoir triggering this reaction. Don't remember if it just triggers the sensor or if it actually causes an overheating situation. Res. topped off causes level to rise above 'full' line as coolant heats up and expands.
Removed 2 or 3 or whatever inches of fluid from the reservoir, had Advance Auto reset OBDI. All is well.
This was before I installed a separate tranny cooler, so coolant and AT fluid shared the same radiator. Wonder what would happen now with separate coolers?
(added 11/20. It may have been my Coolant Temp idiot light, but this does not change the fact that my engine did shut itself down to avoid damage).Nope no safety measures there either... This truck is useing 20 year old technology... There are no fail safe measures... The only thing remotely like that would be the non interference motor. Again you are talking about technology that high end cars such as BMW, Mercedes, Audi, and the likes have only started implementing in the last 5 year's... They have also tried thever best(and done very well at it) to make their cars dealer only serviceable.
You got something else going on there. No way will topping off a coolant reservoir overheat your trans... That even defies logic, let alone reality.
plane and simple your wrong... our vehicles are running on 20 year old technology first of all, thes trucks were designed and brought to life in 1996, the design process too at least three years start to finish, its 20year old tech.OP's 2002 is 11 years old. My 1999 is 14 years old. They are not limited by 20 year old technology.
I understand what you are saying.
I am correct. I know I am correct because I experienced this. Before we start flinging poo at each other I want to reiterate that I do not know if it actually causes an overheating situation or if it just triggers the temperature sensor.
Re defiance of logic, because we are talking about a mechanical object with sensors and nothing is ever perfect there there will always be an opportunity for an unexpected consequence in the system, which in this case would be the triggering of a sequence of ECU commands because it receives a notice that the A/T fluid is getting dangerously hot even though the A/T fluid is not dangerously hot. The ECU is being told "warning! warning! fluid too hot!". I do not know if the fluid is actually getting too hot or if the temperature sensor is being triggered in another way and telling yelling at the ECU to shut 'er down when in fact the fluid temperature is fine. I am unequivically asserting that as long as the ECU gets this warning it will shut the engine down.
The A/T temp warning light was triggered and my engine stopped running. It started again 5-10 minutes later because it had been sitting and it cooled down. It conked out 3 minutes and 10 blocks later because the sensor triggered again so the A/T temp warning light lit up and the engine shut down to protect itself from me, the driver. My outboard engine does the same thing if the oil reservoir gets too low.
It is not particularly sophisticated technology. You add a protocol which triggers when a sensor reaches a predetermined limit. It reaches the limit, triggers a response from the engine management system, which cuts electricity to the spark plugs so they stop firing or cuts electricity to the EFI relay so the fuel injection stops working or tells whatever component or system to stop doing what it does bc there is a problem. When I pull the EFI fuse my truck won't start.
Why can't the ECU receive a tap on the shoulder when a temperature sensor exceeds a certain temperature? Why can't the ECU then cut power to the ______ (fill in name of component here)? It is a basic binary decision tree, an If-Then sequence of events, which is how a computer works (If I remember correctly). It processes the particular If-Then decisions defined by the coding (software) programmed into it. This is what a computer does, process If-Then commands.
My 1999 limited will produce a temperature reading on a ScanGauge. My Transmission temperature sensor and ECU were built in such a way that they can produce specific temperature readings, not just trigger certain events when a predetermined level is reached. I know the Earlier 3rd Gens do not produce a temperature reading on a ScanGauge. I don't know if this is because of ECU reprogramming or of it is because Toyota started installing revised temperature sending units in the 99 model year.
So the capability of my 1999 engine to do what it did exists.
I will ferret out the Googles I found about the over full reservoir and A/T temp sensor and post the links. Can't find them right now.
You're turn.
they do what they are programmed to do. Just because you and i cannot reprogram the ecu doesn't mean it cannot be manufactured by Toyota with different parameters/instructions.if our ECUs are so smart then how come they can not be re-flashed and played with
is that truck '99 or later?i have ran my truck till the AT/temp light came on on the dash and continued the run it(while parked and at idle to let it cool down) and this took me at least 15min for the temp to drop enough to shut off the light. my truck did not shut down, it did not stall ect, it kept running.
you can keep searching all you want, i even encourage you to go to a dealer or any other toyota tech and ask their opinion, but they will all tell you what i am telling you, the system can not and will not do that. i will not argue with you over your motor shutting down, but it was not because the trans was too hot, or that they over filled the coolant expansion tank. they systems are not linked, there is not sensor in the coolant system other than coolant temp sensors, and they do not have any control over the running of the motor other than to signal rich A/F mixtures when cold and just fired up, and normal A/F mixtures when the motor reaches normal operation temps.
if your motor shut down on you like you say it did, and i have no reason to think you are a liar, so i will believe it did, then it shut down for some other reason not related to either the trans temp or the coolant temp or level. NEITHER of those two(or three) will affect if the motor runs or not. again our trucks do not have any fail safes like that and if anyone tells you they do, they are wrong/misinformed or other wise. -i dont even think the new toyotas do.
if your motor shuts down unexpectedly for some reason it might have thrown a code, did you check engine light come on? if so what was the code that triggered the light? if no check engine light came on, that would tell me that you experienced a problem with the ignition system.
-even BMW (i use them because i worked a dealer for a while as well as an independent shop and know there systems pretty well) will throw a code if the motor is shut down due to a safety precaution/fail-safe. it will store the code and tell you what happened(if you read the codes). -if you had no codes i can assure you that there is no way that the ECU took over and shut the motor down out of is AI thinking.
(added 11/20. It may have been my Coolant Temp idiot light, but this does not change the fact that my engine did shut itself down to avoid damage).all of them agree that toyota has no fail safes for this motor.
just because you find a document saying something exists does not mean it actually does.
My 4Runner Brother, Thats all I've got right now. My experience + Toyota Factory Manual with authentic translation errors.
Does your father in law have access to the 2002 Electric Wiring Diagram? Will he please look at Engine Control diagrams, which I think are in the System Circuits section listed in the index? Please ask him to see if there is text after the diagrams. Does that text have the heading 'SYSTEM OUTLINE' with 4 sub categories, 1. INPUT SIGNAL, 2. CONTROL SYSTEM, 3. DIAGNOSIS SYSTEM, 4. FAIL- SAFE SYSTEM (capital letters from copy/paste, not me yelling).
If he can and that is there will he please explain what 4. FAIL- SAFE SYSTEM refers to/describes/means/yadda yadda? Please ask him what "...malfunction occurs in any system…" ...fail-safe system either…" "…or else stops the engine" means. I would really appreciate it if he would be willing to do this because I would love to understand it.
If he does not have access to the manual would you please forward the screenshot I posted? I think I can send you all 9 pages of the Engine Control section if you pm me. Can I attach images and such in pm's?
recap:
First I'd like to confirm this info is in the 2002 Official Factory Electrical Wiring Diagram manual.
second: If so, what is it telling us.
Thanks
thekid, just for the record -- kyle isn't a tech *for* toyota, but he knows a lot about the 4runner
he just stated in another thread he works for a family-owned mechanic shop that started in the 50s.
i also PMed them [MENTION=94888]EatonKyleH[/MENTION] to get his take on this, i know he is darn good with both wiring diagrams and electrical systems across the board, plus he is a tech for toyota, so maybe his imput would help shed more light here. if i am wrong i will look silly i know, but it wont be the first time and probably wont be the last time. but i dont think im wrong(no one ever does).
thekid, just for the record -- kyle isn't a tech *for* toyota, but he knows a lot about the 4runner
he just stated in another thread he works for a family-owned mechanic shop that started in the 50s.
oh... for some reason i thought he worked for toyota... ok my bad... see what i said about being wrong, i was wrong, and i feel silly... :brick::doh:
hey i have my combat life saver certs, and emergency wilderness first aid ect, and my wife is a OR nurse im sure we coulda done the surgery for you a lot cheaper... just sayin network bro network