Ecu Reset?

[///Matt]

A good buddy @ Autohaus of Clayton BMW said that clearing out my ECU (Engine Control Unit - Bosch model) would get my 97 540i back on track. Apparently all that octane boost and fuel injector cleaner was confusing my engine's computer into thinking that a higher octane gas was the norm. Now my acceleration is dwindling and MPG's aren't so good.... If anyone knows how to clear this out please let me know.

Regards,

[billB]

Originally posted by ///Matt@Dec 22 2004, 05:18 AM
A good buddy @ Autohaus of Clayton BMW* said that clearing out my ECU (Engine Control Unit - Bosch model) would get my 97 540i back on track.* Apparently all that octane boost and fuel injector cleaner was confusing my engine's computer into thinking that a higher octane gas was the norm.* Now my acceleration is dwindling and MPG's aren't so good.... If anyone knows how to clear this out please let me know.

Regards,

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I am not sure on what u mean by clearing the ECU? I thought ECU was very similar to the "EPROM" chip in your PC loaded with specific factory values by defaults. One thing for sure, you can perform certain upgarding procedures by flashing the chip (similar to flash BIOS on PCs) through "EEPROM" chips. The link below does BMW upgrade/performance etc. But this is not your question? or is it?
http://www.eurospeedperformance.com/Products/eco.htm

But for BMW ECUs to memorize/remember what type/grade of gas I used in the past? You got me!! I can say fuel through the ECU will trigger engine code/ fault when and if there is a mismatch, or sharp deviations from certain predefined values already burned into the chip. I am thinking in terms of additive mixture adaptation VALUE and its relation with the constant readings/signal of O2 sensors i.e lean/rich values--0.0ms vs. 0.2ms gets translated into too much air and/or too little fuel thus enrich etc.

ANYONE WISHES TO SHED SOME LIGHT ON THIS AND TAKE IT FURTHER? May be predefined fuel calibration values? Fuel trim etc?
regards
billb

[BeelZibub]

Think what he's getting at is a computer reset - Just disconnect the battery neg lead for 10 mins then connect it back and start, she will then reconfigure the computer according to what all the carssensors are telling her now.

This is a good option for a lot of things and is always worth a try but I wouldn't be too sure in this case. However, I have had to drop from my usual 97ron (uk super premium spec) to 95ron fuel this last 2 weeks (for whatever reason) and now my car runs like abag of Sh**e. This shouldn't be a problem for either of us as these things have knock sensors to monitor and adjust according to the fuel being used.

PS If you have been constantly using octane boost and have now stopped you will see a significant drop in MPG and power - that's what octane boost is for - boosting power and MPG.

[billB]

Since knocking can be attributed to one or more of the following:
A.lower actain like in ///Mat's or bad fuel.
B.advanced timing.
C.Extreme temp and overheating.

Can we reprogram the chip/MAP to "make it" think its reading the correct values?

[BeelZibub]

Originally posted by billB@Dec 22 2004, 03:05 PM
Since knocking can be attributed to one or more of the following:
A.lower actain like in ///Mat's or bad fuel.
B.advanced timing.
C.Extreme temp and overheating.

Can we reprogram the chip/MAP to "make it" think its reading the correct values?

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My above post was indeed 3 points

1: That I think his mate was refering to a computer reboot - which usually recalibrates/sets everything and I don't think it will work in this case.

2: That lowering the octane of the fuel shouldn't be a problem as the knock sensors are there to handle this. However, obviously fuel economy and power will be effected.

3: Although point 2 is true, both of us seem to have suffered probs since lowering the octane rating of our fuels(Thankfully though I treated her to a full tank of super premium at lunch time) - I wait to see if she gets back to her old self or I will have to do some proper diagnostics on her - Which I really can't be bothered to do.

[grtmoby]

What he will do is called "Reset Adaptation Values". These are values learnt by the computer through various inputs of which the way you press the acc. pedal, fuel octane....etc. This is not to be confused with ECU reset (sometimes called Battery Reset) that is mentioned earlier by BeelZibub.

[billB]

Originally posted by BeelZibub+Dec 22 2004, 05:09 PM--><div class='quotetop'>QUOTE(BeelZibub @ Dec 22 2004, 05:09 PM)</div><div class='quotemain'>

My above post was indeed 3 points

1: That I think his mate was refering to a computer reboot - which usually recalibrates/sets everything and I don't think it will work in this case.

2: That lowering the octane of the fuel shouldn't be a problem as the knock sensors are there to handle this. However, obviously fuel economy and power will be effected.

3: Although point 2 is true, both of us seem to have suffered probs since lowering the octane rating of our fuels(Thankfully though I treated her to a full tank of super premium at lunch time) - I wait to see if she gets back to her old self or I will have to do some proper diagnostics on her - Which I really can't be bothered to do.

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[/b]

<!--QuoteBegin-grtmoby@Dec 22 2004, 10:18 PM
What he will do is called "Reset Adaptation Values". These are values learnt by the computer through various inputs of which the way you press the acc. pedal, fuel octane....etc. This is not to be confused with ECU reset (sometimes called Battery Reset) that is mentioned earlier by BeelZibub.

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Per grtmody there is a chip learning process of past experience i.e gas type.octain etc. I know some BMW transmission has this ability of "remembering" your driving habits, hence shifting in adaptation/anticipation of your next move.

To BeelZ there is no such thing; it is a matter of resetting the chip.

I agree with Beelz because these chips are already pre-programmed with factory default values. As such the engine is running with a reference points/values. MAKES SENSE?