ECU Reset (Without Disconnecting Battery)
#43
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Join Date: May 2006
Location: 'Burbs Farmington Hills - go to school in Boulder, CO
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just for the sake of posting it, my manual for my automatic (06) xB sayd 5. EFI 15 A:.....
so in other words, the FI on 06 xBs #5, not #4 which was initially posted.
#4 is DOME 15 A........
thought it should be said.....
so in other words, the FI on 06 xBs #5, not #4 which was initially posted.
#4 is DOME 15 A........
thought it should be said.....
#46
bringing the thread back from the past... but thanks for the info... i'm dealing with a CEL and my car stuck in emergency mode that I can't clear... so i'm hoping the fuse pulling method works!!!
#48
From the drivers door, roll down the window, keep holding the button for 5 seconds after being down. Roll it back up and hold again for 5 seconds. You have to re-initialize the windows.
If not, take it to your dealer.
#50
be aware, im not sure if it was mentioned but your car computer (ECU) has to relearn everything, on a automatic it relearns the gears and shift points, it also relearns timing and fuel along with a lot of other things. 10 miles at 2200rpm with ac off same with ac on idle for 20 minutes (until its fully relearns) So i would not be going like a bad out of hell if you have a turbo or sc, as it will probably lean the hell out of you in some areas while its relearning the map.
Food for thoughts! Great Write Up!
Food for thoughts! Great Write Up!
#51
The ECU does not control the automatic transmission. If the automatic transmission is electronic like my Subaru's, it is controlled by a separate TCU that does continuously modify when to shift for the way it has most recently been drive. But I don't think the Scion automatic transmission is electronically controlled so has no TCU.
#52
The ECU does not learn, remember, forget, unlearn or relearn. It operates in real time using the inputs from the engine's sensors such as MAF, O2, knock.
The ECU does not control the automatic transmission. If the automatic transmission is electronic like my Subaru's, it is controlled by a separate TCU that does continuously modify when to shift for the way it has most recently been drive. But I don't think the Scion automatic transmission is electronically controlled so has no TCU.
The ECU does not control the automatic transmission. If the automatic transmission is electronic like my Subaru's, it is controlled by a separate TCU that does continuously modify when to shift for the way it has most recently been drive. But I don't think the Scion automatic transmission is electronically controlled so has no TCU.
Scion ECU (ECM) black boxes DO learn over time based on long term driving habits, and set one of several different performance modes for engine and transmission. This same "long term" adjustment (memory) is actually lost, and has to be relearned, when power is removed from the ECM...
Here's the wiring diagram for the Electronically Controlled Transmission in the xB Classic:
Automatic Transmission Control
Note that the electronically controlled transmission is directly controlled by the Engine Control Module (ECM/ECU)...
Read especially the last bit that describes in simple English how the ECM controls the transmission.
Yes, that is the same ECM that is reset and has to relearn from scratch through several complete cycles how it's driver drives, and sets engine and transmission to match that "style." Yes, the ECM also adjust and controls "real time" as events happen, but it also adjusts over a much longer period to a number of overall driving habits.
The box is much more sophisticated than most people give it credit for being...
Last edited by Tomas; 03-19-2012 at 12:31 AM.
#53
I should have been less certain and said if the transmission was electronically controlled it would learn. So the transmission is electronically controlled and can adjust to drivers, like the Subaru. You then indicate that the ECU also learns for the engine, but the link does not say that.
Are you also saying that the ECU also learns, remembers, forgets, unlearns and relearns the running of the engine? Rather than operating in real time using the inputs from the engine's sensors such as MAF, O2, knock? Are you contributing to the impression that the ECU must learn how to run the engine from the driver? Where do you get this from?
Do you also advocate disconnecting the battery to reset the ECU when changing octane, air filter, spark plugs or muffler? Do dealers know about this? Does the owners manual mention it?
Are you also saying that the ECU also learns, remembers, forgets, unlearns and relearns the running of the engine? Rather than operating in real time using the inputs from the engine's sensors such as MAF, O2, knock? Are you contributing to the impression that the ECU must learn how to run the engine from the driver? Where do you get this from?
Do you also advocate disconnecting the battery to reset the ECU when changing octane, air filter, spark plugs or muffler? Do dealers know about this? Does the owners manual mention it?
Last edited by vintage42; 03-19-2012 at 12:44 AM.
#54
I should have been less certain and said if the transmission was electronically controlled it would learn. So the transmission is electronically controlled and can adjust to drivers, like the Subaru. You then indicate that the ECU also learns for the engine, but the link does not say that.
Are you also saying that the ECU also learns, remembers, forgets, unlearns and relearns the running of the engine? Rather than operating in real time using the inputs from the engine's sensors such as MAF, O2, knock? Are you contributing to the impression that the ECU must learn how to run the engine from the driver?
Do you advocate disconnecting the battery to reset the ECU when changing octane, air filter, spark plugs or muffler? Do dealers know about this? Does the owners manual mention it?
Are you also saying that the ECU also learns, remembers, forgets, unlearns and relearns the running of the engine? Rather than operating in real time using the inputs from the engine's sensors such as MAF, O2, knock? Are you contributing to the impression that the ECU must learn how to run the engine from the driver?
Do you advocate disconnecting the battery to reset the ECU when changing octane, air filter, spark plugs or muffler? Do dealers know about this? Does the owners manual mention it?
There are, to my understanding, two different sets of adjustments made by the ECM both for the engine and the transmission: Short term and long term.
Obviously both engine and transmission respond and make adjustments based on current inputs, but it is my understanding that these instant changes are also moderated by long term trends that the ECM learns over time. Exactly what these trends are and how they interact with current inputs are very cloudy, and they are a proprietary feature of the Toyota firmware.
The background information originally provided to the sales organization when these vehicles were introduced did state that both engine and transmission responses were modified by not just current inputs, but by learned habits. I'm much more inclined to accept the word of the folks who developed the hardware and firmware than I am the word of someone who said the ECM didn't even control the transmission.
Should you find reliable info that says something contrary, you are certainly more than welcome to present it.
(I believe the experience of the forced induction folks will also reinforce the idea that the ECM learns over time and makes long-term engine adjustments, as one of the "problems" some encounter appears to be trend adjustments made by the ECM...)
#55
From the ECM description...
Emphasis added --Tomas
Control System
∗ SFI system The SFI system monitors the engine condition through the signals, which are input from each sensor to the engine control module. The best fuel injection volume is decided based on this data and the program memorized by the engine control module, and the control signal is output to TERMINALS #10, #20, #30 and #40 of the engine control module to operate the injector. (Inject the fuel). The SFI system produces control of fuel injection operation by the engine control module in response to the driving conditions.
∗ ESA system The ESA system monitors the engine condition through the signals, which are input to the engine control module from each sensor. The best ignition timing is detected according to this data and the memorized data in the engine control module, and the control signal is output to TERMINALS IGT1, IGT2, IGT3 and IGT4. This signal controls the ignition coil and igniter to provide the best ignition timing for the driving conditions.
∗ IAC system The IAC system increases the RPM and provides idling stability for fast idle–up when the engine is cold and when the idle speed has dropped due to electrical load, etc. The engine control module evaluates the signals from each sensor, outputs current to TERMINAL RSD, and controls the idle air control valve.
∗ Fuel pump control system The engine control module operation outputs to TERMINAL FC and controls the C/OPN relay. Thus controls the fuel pump drive speed in response to conditions.
∗ SFI system The SFI system monitors the engine condition through the signals, which are input from each sensor to the engine control module. The best fuel injection volume is decided based on this data and the program memorized by the engine control module, and the control signal is output to TERMINALS #10, #20, #30 and #40 of the engine control module to operate the injector. (Inject the fuel). The SFI system produces control of fuel injection operation by the engine control module in response to the driving conditions.
∗ ESA system The ESA system monitors the engine condition through the signals, which are input to the engine control module from each sensor. The best ignition timing is detected according to this data and the memorized data in the engine control module, and the control signal is output to TERMINALS IGT1, IGT2, IGT3 and IGT4. This signal controls the ignition coil and igniter to provide the best ignition timing for the driving conditions.
∗ IAC system The IAC system increases the RPM and provides idling stability for fast idle–up when the engine is cold and when the idle speed has dropped due to electrical load, etc. The engine control module evaluates the signals from each sensor, outputs current to TERMINAL RSD, and controls the idle air control valve.
∗ Fuel pump control system The engine control module operation outputs to TERMINAL FC and controls the C/OPN relay. Thus controls the fuel pump drive speed in response to conditions.
Last edited by Tomas; 03-19-2012 at 01:14 AM. Reason: to add link
#57
As to when might I recommend resetting? When any change of vehicle equipment that might affect the engine or transmission customizations that have been made in ECM memory, and that includes change in tire diameter, change in air intake, or other similar changes that will cause a sudden, semi-permanent change in the engine or transmission's operating environment.
Some folks like to reset with change of seasons, but I feel that seasonal changes are certainly gradual enough that the ECM can easily keep up.
Some folks believe it is reasonable idea to reset when one moves to a new area, because changes in altitude and topography require re-learning. There is some good thought in that, and I can see the logic: Why build the new memory on the old, why not just start from scratch with a reset?
Some suggest it for extended vacations in totally different environments. (I would probably not - but at the same time I would not be averse to resetting when I get back home...)
Some even suggest resetting once a year - often in the spring when they go through everything on the car anyway - simply to clear the memory and reboot the ECM computer. Spring cleaning. I can understand the logic in that, too.
All the ECM reset does is erase the customization based on previous experience and bring everything back to factory settings. It might save a little bit of learning time or, more importantly, clear any errors or anomalies that might have crept in. It is akin to rebooting any other computer: It gives it a fresh start without any of the minor errors that might have accumulated over its runtime..
Turning the ignition off does not re-boot the ECM computer - it merely goes into a "sleep" mode - although it does wake up about 5 hours later and run some checks, such as those it does on the fuel system during extended downtime.
A reboot comes most easily from a temporary removal of ECM power (pulling fuse or disconnecting battery), and that is the quickest way to get back to a cleared memory and factory settings.
Many folks do not like to reboot the ECM by disconnecting the battery because other devices in the vehicle also have volatile memories that are lost when this is done (trip odo, radio, etc.).
Last edited by Tomas; 03-19-2012 at 06:02 PM.
#58
Is there a differnce between the efi fuse and efi relay? Do these have different effects on the car? Etc? A member on here told me to pull my efi relay to check if its blown which could possibly be causing my check engine light to keep coming on. I'm throwing two codes p0304 and p2196 and I've changed plugs coils injectors and o2 yet my light continues to come on. Ill pull this fuse along with the relay just to check but I was wondering if they are the same thing or different???
#59
hahah, yah Vintage, there is a reason i work for Toyota =P
The ECU does relearn, stock pushed numbers. For Fuel Trim, Timing, Shift Patterns and Points, knock value, then adjust them over time to better suite your driving needs. The transmissions actually have a separate ECU module to read all of these different senarios. It is the same as if you got cracked in the head and forgot your name, then your friends and family force you to remember =) However if you have a Piggy Back ECU it 100% Truly learns, because you are forcing values that are not original.
Dustin
The ECU does relearn, stock pushed numbers. For Fuel Trim, Timing, Shift Patterns and Points, knock value, then adjust them over time to better suite your driving needs. The transmissions actually have a separate ECU module to read all of these different senarios. It is the same as if you got cracked in the head and forgot your name, then your friends and family force you to remember =) However if you have a Piggy Back ECU it 100% Truly learns, because you are forcing values that are not original.
Dustin