Hey Guys,

Does anyone have any details on the electronic throttle?

is it PWM or DC or something else?

I am trawling through the code trying to understand how it all works...

Cheers
D.

 

Just some notes (the memory locations are for 53040010):

0x80AB42 could be the sensor in the throttle body (X FSM refers to this as the TP Sensor)
0x80AB44 could be the AccelPedal (X FSM refers to this as the APP sensor)

I logged both and there is a slight lag in the readings of 80AB42 over the readings from 0x80AB44.

0x80AB44 is inverted, ie "1023-80AB44 = 80AB42"

 

^ although I am not sure how the throttle tables come into play...

has anyone actually verified their function (apart from - "the car feels better...")

 

When I first dug into the Evo 10 ROM, I couldn't find the APP ADC input. However, I think I found it this morning. Based on my interpretation of the OBD-II routines. APP_main is ADC_0F, and APP_sub is ADC_02.

I have yet to link it to the "throttle" tables though. One axis for the "throttle" tables is rpm, but the other is a bit of a challenge to trace back. Now that I'm pretty sure about the ADC inputs for APP, I will probably just follow around the APP ADC value to see where it goes in the ROM.

 

why two ADC's?

 

Backup and for consistency check. Need to prevent lawsuits where people claim the car just took off without them touching the throttle pedal. :-)

 

oh so in the FSM there are two sensors?

 

Yep, two APP sensors and two TPS sensors, both sets are labeled as "main" and "sub" with "sub" being the backup. Based on the FSM OBD descriptions of the APP CELs, it appears that the APP sub uses a narrower voltage range than the APP main (full scale voltage for APP sub appears to be about 1/2 the full scale voltage of the APP main).

I've got an Excel file with pretty much all the ADC inputs figured out. Do you want me to email it to you?

 

Hrmmm.

Well maybe I found the TWO TPS's then.

Like I said 42 and 44 ( +8 for you ROMID ) come out to basically the same, 44 is "1023 - 42" ... but 42 has some delay over 44, they are individual ADC's as far as I can tell...

 

I've got ADC_08 (80AB54) and ADC_06 (80AB52) as the two TPS ADC RAM values. MUT TPS is derived from ADC_06. The ADC_08 value is used much more extensively through the ROM though. NOT values are calculated for both. Have no idea how the NOT values are being utilized.

 

Yeah that's what I have got too..

Funny we are both looking at this code at the same time.

ok now I have APP mapped out I might be able to work out that R0 input to the Throttle Map lookup sub

 

Nice. I think this is an area of tuning that can definitely affect drivability for the better, so looking forward to you interpretation of the r0 input.

 

Definitely. I've been tweaking the rates on my car.

 

Does tweaking the throttle maps make a difference? I'm curious because my initial assumption was that the throttle maps set the TPS position vs the APP position. However, I just logged TPS and APP, and its pretty much 1:1 all the time, so if those are throttle maps, they do not represent the relationship between TPS position and APP position. Perhaps the maps set the speed or acceleration of the TPS vs the speed of the APP? That would be more consistent with the appearance of the throttle maps.

 

Yeah that's what I have found too. (logging them side by side that is)

Mrfred - Can you just double check that only 3 out of the 7 parent routines (to Throttle_Map_Lookup) are active? ie aren't disabled by ECU_OPTION bits?

I logged the R0 inputs for those 3 parents and they are all static.. ie R0 doesn't change. Which is very very bizzare!