No announcement yet.

speed density code & function

  • Filter
  • Time
  • Show
Clear All
new posts

  • speed density code & function

    i recently managed to port the speed density code from PRJmod over into a 3B ECU with success to some extent. the car does start run and idle with MAF unplugged along with no MAF related fault codes. i changed up some things in the 3B code so the ECU only references 1 timing table and 1 lambda table because the ECU is equipped with multiple of each table by default. i than replaced one of the lambda tables by turning it into a VE table and added the IAT compensation table as well. it is just like PRJ's code. MAP sensor is input on AN5 just like the later ECU as well. the only real difference at the moment is that im running a motorola MPXH6300 MAP sensor and i know that the original code was setup for MPXH6400 sensors so the scaling is slightly different. i realized that the table at 0xB500 plays a major role in either the linearization of the MAP sensor or it has something to do with the transient state of fueling. over all the issue im having is that my motorola 300KPA sensor seems to trace around 200KPA when the car is at idle so i assume i have an error somewhere in the code function or something is interfering with the input on AN5. the circuit for AN5 in 3B is practically identical to the the AAN ECU so removing R660 is a must. slightly puzzled with the high reading of the MAP sensor and im hoping someone else has an understanding of the SD code and can help correct the issue.
    "The really good drivers got the bugs on the side windows." Walter Röhrl

  • #2
    no one? still looking at 0xB500 as it it read by DPTR directly after the ADC input is read. FVCO is the actual MAF value in RAM. would really like to know if this is MAP sensor linearization mapping or not because it is definitely being read when traced with ostrich emulator and if you mess with the values in that table the car gets very unhappy.
    code:00000130 E5 D9                    mov     A, ADDAT        ; Move MAP sensor signal to A
    code:00000132 F8                       mov     R0, A           ; Move MAP sensor signal from A to register 0
    code:00000133 90 B5 00                 mov     DPTR, #code_B500 ; Read from table
    code:00000136 93                       movc    A, @A+DPTR      ; table value+MAP Signal moved into A
    code:00000137 F5 DA                    mov     DAPR, A         ; D/A Converter Program Register
    code:00000139 88 4B                    mov     FVCO, R0        ; Move MAP signal into FVCO
    "The really good drivers got the bugs on the side windows." Walter Röhrl


    • #3
      Use MPX6400 or use "Find" in M232 Wiki for "If you use other MAP sensor" how many mods must do. For max $20 this is "madness"!!!

      Originally posted by vwnut8392 View Post
      FVCO is the actual MAF value in RAM.
      - There is no MAF or MAF values in Prjmod!!!!!! Read very carefully in CPU data sheet what is DAPR (not DPTR) (what doing every bit or combination of bits) and what is doing with data from ADDAT. Then and only then you will find what is this map (0xB500 to B5FF) and how precisely Dmitry organized working of his SD mod. Not just one VE map

      Small advice, don't touch this map.

      Best Regards!


      • #4
        well i was working on porting the speed density to the 3B ECU and i thought this was the problem because i have an MPXH6300 in my ECU. turned out after i took a break and looked at it again i didnt remove the code for MAF linearization and move the parts to reference the VE table and IAT fueling comp table. once i did that everything fell right into place and it works.
        "The really good drivers got the bugs on the side windows." Walter Röhrl


        • #5
          The DAPR B500 story must be a running gag meanwhile ^^


          • #6
            only problem i have now is on sharp throttle movements the fueling goes lean for a split second and if the car sits and idles for for like 3 minutes it just decides to go lean and shut off. of course it starts right back up after it shuts off. strange problem.
            "The really good drivers got the bugs on the side windows." Walter Röhrl