Toyota Finds ECU Flaw, But Not The One You Would Think

Wow I really don't know the Snow ball is getting bigger, heavier and worse , poor toyota customers is like a hide cancer Oh my....

LOL!!!

Like I said ... just as likely to get a stall condition...


The most probable cause is multi-input processing error.

ECU's in today's autos work like a big "look up table", i.e., for a given air temperature, throttle command, engine temp, engine load, RPM, oxygen sensor, anti-knock sensor, etc, then set the fuel injectors, valve timing, and ignition timing to predetermined values. The true number of inputs is very large and the range of the sensor inputs is even larger.

For example, for a single output such as ignition timing and two inputs, air temp and RPM, the calculations look like; the air temperature range is from -20F to +120F = 140 inputs. Combined with RPM from 1000 to 6000 in resolution of 100 RPM is 50, resulting in 140 x 50 = 7,000 data points that must be individually tested.

If we consider adding oxygen sensor inputs, 200 in all, then the total number of calculations goes to 7,000 x 200 = 1,400,000.

When all of the inputs are considered over their full expected operating range, the total number of calculations that must be validated is in the billions.

Add into this the possibility and uncertainty of any sensor sending slightly erroneous data when the sensor is starting to fail intermittently and The Problem, IMHO, is that the extent of these calculations has now grown too large for testing, either in software or on the road, to ever test each and every unique combination.

And thus, it is highly likely that there is an error in the ECU calculations for some very obscure combination of inputs (like full throttle on a 72F day with the knock sensor slightly out of spec and the engine at 3250 RPM). Then, and only then, does the calculation result in a error that commands full throttle.

I agree, however I think Toyota released the Corolla with the last Corolla's ecu (didn't dyno test and recalibrate with the new slightly different hardware) So there are probably some engine speeds where harmonics force more or less air than expected into the engine causing it to flood or starve... causing it to stall. Simple solution really, remap the ecu for each and every engine/car configuration.

I agree, however I think Toyota released the Corolla with the last Corolla's ecu (didn't dyno test and recalibrate with the new slightly different hardware) So there are probably some engine speeds where harmonics force more or less air than expected into the engine causing it to flood or starve... causing it to stall. Simple solution really, remap the ecu for each and every engine/car configuration.

lol half hour internet crash.

Has Toyota learned nothing from the "sudden acceleration" debacle. Why are they dicking around think about a recall. Just do it. get it over with and avoid months of bad press. Damn this company is dumb.

WTF? Stop it already Toyota, I want to read about "automotive" news again, not about all your problems! Please, just copy the Germans again and don´t take it further!

Poor Toylex fanboys. Getting it extremely hard at the moment. Every time I read some news about the former quality giant, I say to myself, now they have reached the bottom. But then again they surprise me with something new.

Good luck!