Code: EGR and CTS conversions

[EagleMark]

I've been looking through other old ECM masks and there's even a bigger questions as to CTS conversions?

But thinking of what 1project2many said about weird things happening when using MAX? Looked at conversions in calculated values, then hex! Min is 00 and max is FF, which would be right, right? But doesn't 00 and FF also mean nothing? Like when you burn a chip sometimes stock hex filler space is 00 then when burned it's FF...

I looked through some very old XDF/ECU files written by rBob, some enable temps were clearly noted to use a hex string below FF!

[jim_in_dorris]

Okay try this again. I just finished grading 2 classes worth of finals, so the brain is a little fried right now.

Mark. 00 to FF hex is 0 to 255 decimal for a total count of 256.

if you are looking at an A/D converter which is measuring 0 to 5 V, then you have 5/256 or .02 volts per count.

if you look at temp range of -40 to 152 degrees for a total of 192 degrees (I assume that this is IAT) then you have 192/256 or .75 degrees per count

This works out as .75 degrees for every .02 volts.

Different ranges will have different results but will be similiar. HTH.

If you don't raise the EGR Qual temp to something that the coolant doesn't reach, then it exits differently. That may be why your truck runs poorly when you raise that value.

[EagleMark]

Thanks Jim, most of that I knew.

Just had to question 00 and FF as it would always be the top and bottom. 3 reasons why were what 1project2many said about never going Max, but going above temp that would disable, second is old XDF files clearly state to use a hex to disable that was not max FF, third is looking at stock chips filler space is 00 and burned chips are FF.

[EagleMark]

Well I did some testing today, had to find why this happened but was more interested in hex numbers that actually worked instead of the conversion to decimal. With correct hex it should be possible to create correct conversion.

Findings EGR Enable Temp:
1. Tests were done on fresh ADSU chip read from my factory ECM, in a factory ADSU vehicle while emulating with AutoProm.
2. Tests were all done warmed up and data showed 88c as Coolant temp. Varied up/down by 1c throughout tests.
3. EGR temperature to disable had drastic effects when "EGR - VE Comp Table" was zeroed out.
4. EGR CTS to enable 36h would die when revved up.
5. EGR CTS to enable 35h would run fine when revved up.
Conclusion: EGR is enabled/disabled at 35h/36h.

Findings Closed Loop Enable Temp:
1. Tests were done on fresh ADSU chip read from my factory ECM, in a factory ADSU vehicle while emulating with AutoProm.
2. Tests were all done warmed up and data showed 88c as Coolant temp. Varied up/down by 1c throughout tests.
3. Closed loop was entered at 91h
4. Closed Loop was exited at 94h
Conclusion: Conversion could be figured out that 91 to 94h = 88c.

Findings Closed loop entry at cold start:
1. Tests were done on fresh ADSU chip read from my factory ECM, in a factory ADSU vehicle while emulating with AutoProm.
2. Closed loop was entered at 69c when warming up.
3. Closed loop Enable Temp is 40h. Conversion in mask to enable Closed Loop is 8c
4. All timers for Closed Loop had long expired so I believe 69c is accurate.
Conclusion: Conversion is way off!

Both tests were done multiple times to insure accuracy.

Intresting note. I have tweaked my ASDU file for many things including entering CL sooner and my hex is 26 compared to stock 40

[EagleMark]

I am going to test CTS when Closed Loop is entered again when vehicle cools off completely. 69c seems high?

But! if the conversion is removed and left at X the temp is 64c

40 hex is decimal 64. Is it possible these don't need a conversion?

[jim_in_dorris]

Mark, that is correct. you are not looking at an A/D conversion for enable, but what temp is enable. (That is an awkward sentence) In that particular case, no conversion should be applied.

Mark. on your first test, were you changing location LD1B3 to 35 and 36 Hex? Stock is 132 decimal, hex 84 at that location. I am trying to use your values to walk through the code and see what is different. 88c would be 171 A/D counts or AB hex.

[EagleMark]

So why do all these masks have a conversion?

And in which case does it need a AD conversion?

This is strange, some look completely sane with no conversion and some are completely wrong without a conversion?

Closed Loop Enable looks sane with no conversion at 64c and close to what I found at 69c

HiWay Min Coolant looks InSane at 133c

[jim_in_dorris]

I think that we need to look at each individual case and determine how it is used. If we are comparing directly to A/D counts it's one way, and if we are comparing to already converted values its the other way.

[EagleMark]

Mark. on your first test, were you changing location LD1B3 to 35 and 36 Hex? Stock is 132 decimal, hex 84 at that location. I am trying to use your values to walk through the code and see what is different. 88c would be 171 A/D counts or AB hex.

Missed your edit above...

Yes LD1B3, stock ASDU is 84h

The 88c was what my coolant temp was reading in ADX file at time of test.

Attached is a clean read of ASDU, FYI it is identical to the one we have listed in $42 info thread as ASDU-$42-5.7L-Auto.bin‎

[jim_in_dorris]

Sorry I missed this yesterday, busy grading and prepping for next quarter. What I really need to know Mark is what were you changing to 35/36 hex to cause your problem? I really believe you are using a correct bin, just not sure what location in that bin you are changing. Also at this point, I need to verify that L00E3 is the output of the A/D converter for coolant temp. also mark what location are you using to read the coolant temp?

EDIT!!! I was hunting thru the $42hack.asm and saw something that made me think. I know I have seen a table that related coolant temperatures to voltage output of the sensor. I need to look at that table, can you find it please.