[BlackLine]

Sunday night i was down in cincy, and on the way back my check engine light came on, i thought nothing of it but my gas mileage was crap, its about a 60-70 mile drive back and i used 1/2 tank of gas!! well i undid the mod and the check engine light went away. i just used my buddies scanner and got a P1182 code WOT or anyone know what that is?

 

[John]

p1182 super charger inlet pressure sensor performance

 

[MotorMouth]

P1182 Supercharger Inlet Pressure Sensor Performance ECM.

From ***'s DTC list. This happened on my car when I first bought it. Turns out the vacuum lines were switched around on the bypass valve canister. Dealership tried to tell me it dose not come that way from the factory but at the same time said that they would "absorb the cost" and not charge me. The car sat on the floor for two months withthe hood open, my guess is that somone unhooked them and they were plugged in wrong.

Might have a vacuum line backwords. I would check the lines for the correct routing and un-do the boost mod. Drive it for a bit with the stock vacuum line routing to make sure it is not a problem with the car.

 

[John]

Anything you do to change the inlet pressure out of the factory range will set this code. Thats where the piggy back or ecu programing comes in.

 

[clownhair]

I get this code from time to time and that is without the vacuum lines moved around. I figured it was from having a smaller pulley but now your getting it as well.

 

[[email protected]]

we've got the fix and we are ready to release...NO CODES with a much smaller pulley than stock our vendor forum should be going up on here and cobalt SS today or tommorrow.

 

[MotorMouth]

we've got the fix and we are ready to release...NO CODES with a much smaller pulley than stock our vendor forum should be going up on here and cobalt SS today or tommorrow.

That's good news for all

 

[clownhair]

whats that? Oh its the sound of the hordes madly throwing their money at you. You better hurry this mob is restless.

 

[mailmars]

Sunday night i was down in cincy, and on the way back my check engine light came on, i thought nothing of it but my gas mileage was crap, its about a 60-70 mile drive back and i used 1/2 tank of gas!! well i undid the mod and the check engine light went away. i just used my buddies scanner and got a P1182 code WOT or anyone know what that is?

Start paying attention to your catalytic converter.. I bet that puppy was cherry red by the time you got it home.. That rich for that period of time....oooooch.....

Mark

 

[BlackLine]

mark, is this piggyback ecu going to give us the abillity to adjust things?

also is the catback due for release soon also?

 

[mailmars]

Had lunch today with a friend that consults to GM and EDS on some of the firmware. It appears that automobile manufactures, being the conservitive creatures that they are have some interesting limitations. Does 8 bit counters mean anything? 8 bits is 0xf in hex and is basicly 16. The problem with this is that it starts at 0 so the max decimal value is 15. One of those small counter locations stores and set the boost variable for the fuel and timing state machines. While the engine is still in vacuum my uderstanding is that it is set to 0x0 and has a inactive bit set. There is a seperate code path when the engine is running in vacuum. When the active bit is set high it uses another path ( another logic route through the state machine ) I also took away from the lunch conversation that there is not a lot of out of range checking on some of the state machines. Thier opinion was that if something broke and sends stuff out of range other conditions would catch them. In short, it might get a little hairy pushing the boost over 15psi... Just a guess but as my friend stated, the limit has to be somewhere...On a side note.... The tables can read 3 digits past the decimal point the state machine only uses the integer.

Mark

Oh yea... The boost/vacuum, timing, fuel pulse/rate, air flow, etc., are used all over the place. As stated, you would not believe which modules has use for some of the powertrain info.

 

[Barry]

Had lunch today with a friend that consults to GM and EDS on some of the firmware. It appears that automobile manufactures, being the conservitive creatures that they are have some intersting limitations. Does 8 bit counters mean anything? 8 bits is 0xf in hex and is basicly 16. The problem with this is that it starts at 0 so the max decimal value is 15. One of those small counter locations stores and set the boost variable for the fuel and timming state machines. While the engine is still in vacuum my uderstanding is that it is set to 0x0 and has a inactive bit set. There is a seperate code path when the engine is running in vacuum. When the active bit is set high it uses another path ( another logic route through the state machine ) I also took away from the lunch conversation that there is not alot of out of range checking on some of the state machines. There opinion was that if something broke and sends stuff out of range other conditions would catch them. In short, it might get a little hairy pushing the boost over 15psi... Just a guess but as my friend stated, the limit has to be somewhere...On a side note.... The tables can read 3 digits past the decimal point the state machine only uses the integer.

Mark

Oh yea... The boost/vacuum, timming, fuel pulse/rate, air flow, etc., are used all over the place. As stated, you would not believe which modules has use for some of the powertrain info.

I was just thinking that

 

[riz906]

hu ? tell about this piggy back ! more boost and raise the rev limiter Woo.

 

[D3XXFR]

Had same issue.....oh well W00T FOR PSI-FI!

 

[WopOnTour]

Had lunch today with a friend that consults to GM and EDS on some of the firmware. It appears that automobile manufactures, being the conservitive creatures that they are have some interesting limitations. Does 8 bit counters mean anything? 8 bits is 0xf in hex and is basicly 16. The problem with this is that it starts at 0 so the max decimal value is 15. One of those small counter locations stores and set the boost variable for the fuel and timing state machines. While the engine is still in vacuum my uderstanding is that it is set to 0x0 and has a inactive bit set. There is a seperate code path when the engine is running in vacuum. When the active bit is set high it uses another path ( another logic route through the state machine ) I also took away from the lunch conversation that there is not a lot of out of range checking on some of the state machines. Thier opinion was that if something broke and sends stuff out of range other conditions would catch them. In short, it might get a little hairy pushing the boost over 15psi... Just a guess but as my friend stated, the limit has to be somewhere...On a side note.... The tables can read 3 digits past the decimal point the state machine only uses the integer.

Mark

Oh yea... The boost/vacuum, timing, fuel pulse/rate, air flow, etc., are used all over the place. As stated, you would not believe which modules has use for some of the powertrain info.

Much of what you are saying WAS perhaps true in the old 8-bit ECM days, which essentially ended with the release of the P4-ECM in 1996. All are now operating at 16-bit or better. (Motorola/RISC/PowerPC instruction sets)Where as an 8bit OBDI ECM typically had tables/maps limited to 16x16 (256 cells or sites) Todays ECMs have very few issues with "bit" limitations or quantization error. In short our ECM can be calibrated to run on almost any boost level- given the appropriate tools to alter these maps/tables.
Does your buddy have any experience with the Motorola BDM tool-box??
Regards
WopOnTour

 

[CarNut]

.... Does 8 bit counters mean anything? 8 bits is 0xf in hex and is basicly 16. The problem with this is that it starts at 0 so the max decimal value is 15...

Doesn't make sense. 8 bits will count 0 - 255 or 0 - 127 with a sign bit. To fill an 8 bit register with 1's you need to specify 0xff. The "0x" means nothing to the hardware. It just just a prefix to the shell (software) that reads your keyboard inputs that says the number you are entering is in hex format. So 0xf stored in an 8 bit register will only get you 00001111.

Knowing they used 8 bit registers doesn't tell you much. We can probably assume they're not using standard integer or floating point formats. If they allocated 4 bits to the integer portion and the rest to decimals, they could store up to 15.94 (only .0625 resolution, there is not enough room to store 3 significant decimals). They could be storing 0 - 31.9 psi (absolute pressure) with .125 resolution. Then the high bit would essentially indicate boost. Or, they may simply be storing the uncalibrated bits from the A to D converter. In any case there will be an upper limit to the value that can be stored but we have no easy way to determine it.

I suspect your friend was just making up a simple example to explain the limitations of storing values in digital memory. His point that there isn't much range checking is more significant. This could explain behavior where the codes generated don't make sense. In fairness though, 8 bits is probably enough resolution for most vehicle sensors. Using more bits when they are not needed/used would slow down the system.

 

[Blue04RedLine]

Doesn't make sense. 8 bits will count 0 - 255 or 0 - 127 with a sign bit. To fill an 8 bit register with 1's you need to specify 0xff. The "0x" means nothing to the hardware. It just just a prefix to the shell (software) that reads your keyboard inputs that says the number you are entering is in hex format. So 0xf stored in an 8 bit register will only get you 00001111.

Knowing they used 8 bit registers doesn't tell you much. We can probably assume they're not using standard integer or floating point formats. If they allocated 4 bits to the integer portion and the rest to decimals, they could store up to 15.94 (only .0625 resolution, there is not enough room to store 3 significant decimals). They could be storing 0 - 31.9 psi (absolute pressure) with .125 resolution. Then the high bit would essentially indicate boost. Or, they may simply be storing the uncalibrated bits from the A to D converter. In any case there will be an upper limit to the value that can be stored but we have no easy way to determine it.

I suspect your friend was just making up a simple example to explain the limitations of storing values in digital memory. His point that there isn't much range checking is more significant. This could explain behavior where the codes generated don't make sense. In fairness though, 8 bits is probably enough resolution for most vehicle sensors. Using more bits when they are not needed/used would slow down the system.

I...am soooo lost right now. I didn't read past the first paragraph of that thing.

 

[mailmars]

Much of what you are saying WAS perhaps true in the old 8-bit ECM days, which essentially ended with the release of the P4-ECM in 1996. All are now operating at 16-bit or better. (Motorola/RISC/PowerPC instruction sets)Where as an 8bit OBDI ECM typically had tables/maps limited to 16x16 (256 cells or sites) Todays ECMs have very few issues with "bit" limitations or quantization error. In short our ECM can be calibrated to run on almost any boost level- given the appropriate tools to alter these maps/tables.
Does your buddy have any experience with the Motorola BDM tool-box??
Regards
WopOnTour

Yep..... There are still a lot of 8 bit counters... The bus and logic paths are 16 bits. I do FPGA work for this company and we use 64 bit logic paths but depending on the value, how it is used, how it is mapped, the counter type, etc., depends on how I map the counter. Counter width and other tables are dependant on the logic design of that specific state machine and are totally independent of the logic path/data bus width. It is nothing more than a place to stuff a value. I can't think of any reason but I could make a table location 3 bits if I wanted to and still have a 64bit path.

Mark

 

[mailmars]

Doesn't make sense. 8 bits will count 0 - 255 or 0 - 127 with a sign bit. To fill an 8 bit register with 1's you need to specify 0xff. The "0x" means nothing to the hardware. It just just a prefix to the shell (software) that reads your keyboard inputs that says the number you are entering is in hex format. So 0xf stored in an 8 bit register will only get you 00001111.

Knowing they used 8 bit registers doesn't tell you much. We can probably assume they're not using standard integer or floating point formats. If they allocated 4 bits to the integer portion and the rest to decimals, they could store up to 15.94 (only .0625 resolution, there is not enough room to store 3 significant decimals). They could be storing 0 - 31.9 psi (absolute pressure) with .125 resolution. Then the high bit would essentially indicate boost. Or, they may simply be storing the uncalibrated bits from the A to D converter. In any case there will be an upper limit to the value that can be stored but we have no easy way to determine it.

I suspect your friend was just making up a simple example to explain the limitations of storing values in digital memory. His point that there isn't much range checking is more significant. This could explain behavior where the codes generated don't make sense. In fairness though, 8 bits is probably enough resolution for most vehicle sensors. Using more bits when they are not needed/used would slow down the system.

No not reallly.... The counter location is 8 bits with first 4 bits (nibble) being used for a ratio and and second nibble being used for actual boost.... My bad.. forgot to explain what happened to 1st nibble in the octet.


Sorry 'bout that..... Thats why I don't teach..


Mark

 

[WopOnTour]

Yep..... There are still a lot of 8 bit counters... The bus and logic paths are 16 bits. I do FPGA work for this company and we use 64 bit logic paths but depending on the value, how it is used, how it is mapped, the counter type, etc., depends on how I map the counter. Counter width and other tables are dependant on the logic design of that specific state machine and are totally independent of the logic path/data bus width. It is nothing more than a place to stuff a value. I can't think of any reason but I could make a table location 3 bits if I wanted to and still have a 64bit path.

Certainly! Dividing down is easy with a wide enough path!!.(The Redline ECM is 32 bit BTW)
All I'm saying is your buddy was explaining a POTENTIAL method of creating this memory call, but having worked with it for a number of years I can tell you-it just dont work that way! Why? Motorola baby! So unless your boy has had a lot of first hand experience programming 68xyz embedded automotive micro-controllers (EDS? Ross Perot? Texas??- I doubt it, but if he has ever lived in Romulus...maybe ...)

"How thing's Work" (ie boost control) just cannot be summarized by a simple 8 bit register explaination.
Find out if your buddy knows anything about THIS stuff
http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=MPC562&nodeId=018rH3bTdG8648
http://www.freescale.com/files/microcontrollers/doc/app_note/AN2000.pdf
as this is the embedded processor in the RL ECM
If he knows this stuff or has access to the BDM tools, please let us know
I've got a few cut apart I can send him
WopOnTour