Hello e46fanatics,
our ECU, the Siemens MS43, is limited to read 1024kg/h of air. After applying the MAF hack, this value doubles to 2048kg/h and therefor enough flow for bigger MAFs.
A cheap alternative for the HPX PMAS MAF is manufactured by Bosch with the part number 0 280 218 067 (or 0 986 280 219) and is installed on the Audi (R)S4 B5's 2.7 V6 biturbo engine and is able to measure upto 1800kg/h.
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The MAF sensor module comes preinstalled in a 3.5 inch housing and has a 5 pin connector (Audi part number 1J0973775A) with the following pinout:
Pins 2, 3 and 5 should be self explaining, you can just connect them to the OEM MAF wires, or create a new 4-wire loom and run it to the cable distribution box located under the intake manifold.
Pin 4 need a solid 5.00 volts supplyvoltage, as this is the reference for the MAF output signal. This is absolutly crucial for the MAF to work properly!
The MS43 has two integrated 5V outputs, one for the electronic accelerator pedal and one for the electronic throttlebody, which you will preferly use, because you can tap into the wire right in the distribution box.
By the way, this is pin 7 at the middle ECU connector (X60003) for the voltage U_DKG according to the manual (brown/white, 0.5mm²)
If anybody is concerned about the MAF drawing too much current, during operation it only needs 1,1mA :thumbsup:
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Now that you have the connection from the MAF to the ECU, the next part is applying the MAF hack (512k file) and editing the sensor definition (64k file)
You have two options to double the MAF limit:
In addition to that, you need to set "C_MAF_KGH_R_LS_MES_MAX" to 1800kg/h.
Today I discovered, that "C_ABC_INC_MAF_MON" and many other constants lay within checksum 4's area. This means you can only edit this value in the 512k full flash. (Look over here for details)
______________________________________________
The user jd_improved was kind enough to share his sensor definition and allowed me to publish it in form of an Excel, respectivly CSV, file, that you can download from my Google Drive over here. Just copy and paste the new values over the existing ones :thumbsup:
I will also provide an updated 512k file with the MAF hack for all M54 engines, correct checksums and the RS4 MAF characteristic already applied and the corresponding XDF file for editing it with Tuner Pro for the lazy people.
______________________________________________
Note 1: Credits belong to Daniel_F. for his amazing files, jd_improved and volter for the Bosch characteristic and the RomRaider team for the MAF axis values!
Note 2: The RS4 MAF measures backflow in the section below 1.00 volts and therefor it's zeroed out in the table, since the MS43 can't understand .
Note 3: The XDF file published by MS43info on the 16th Feb. contains an error in the MAF voltage axis, I corrected it with the correct values from the RomRaider axis.
Note 4: This is not the holy grail, so let me know if there is room for improvement. Malfunction can happen, but that's why this board exists, let's figure this out together!
Have a nice day :craig:
our ECU, the Siemens MS43, is limited to read 1024kg/h of air. After applying the MAF hack, this value doubles to 2048kg/h and therefor enough flow for bigger MAFs.
A cheap alternative for the HPX PMAS MAF is manufactured by Bosch with the part number 0 280 218 067 (or 0 986 280 219) and is installed on the Audi (R)S4 B5's 2.7 V6 biturbo engine and is able to measure upto 1800kg/h.
______________________________________________
The MAF sensor module comes preinstalled in a 3.5 inch housing and has a 5 pin connector (Audi part number 1J0973775A) with the following pinout:
- Pin 1 - IAT sensor output (not used)
- Pin 2 - voltage input 12V (red?)
- Pin 3 - common ground (black)
- Pin 4 - voltage input 5V (brown/white)
- Pin 5 - MAF sensor output (yellow)
Pins 2, 3 and 5 should be self explaining, you can just connect them to the OEM MAF wires, or create a new 4-wire loom and run it to the cable distribution box located under the intake manifold.
Pin 4 need a solid 5.00 volts supplyvoltage, as this is the reference for the MAF output signal. This is absolutly crucial for the MAF to work properly!
The MS43 has two integrated 5V outputs, one for the electronic accelerator pedal and one for the electronic throttlebody, which you will preferly use, because you can tap into the wire right in the distribution box.
By the way, this is pin 7 at the middle ECU connector (X60003) for the voltage U_DKG according to the manual (brown/white, 0.5mm²)
If anybody is concerned about the MAF drawing too much current, during operation it only needs 1,1mA :thumbsup:
______________________________________________
Now that you have the connection from the MAF to the ECU, the next part is applying the MAF hack (512k file) and editing the sensor definition (64k file)
You have two options to double the MAF limit:
- First is to do it manually with a HEX editor and changing the bytes 0x3D8A3 and 0x3D8C7 from "4E" (1024kg/h) to "3E" (2048kg/h) and double the conversion in the Tuner Pro MAF table to "0.03125*X"
- Second is downloading RomRaider and the MS43 definition .XML file, flick the switch under the "Forced Induction" section and use the special MAF table right next to it.
In addition to that, you need to set "C_MAF_KGH_R_LS_MES_MAX" to 1800kg/h.
Today I discovered, that "C_ABC_INC_MAF_MON" and many other constants lay within checksum 4's area. This means you can only edit this value in the 512k full flash. (Look over here for details)
______________________________________________
The user jd_improved was kind enough to share his sensor definition and allowed me to publish it in form of an Excel, respectivly CSV, file, that you can download from my Google Drive over here. Just copy and paste the new values over the existing ones :thumbsup:
I will also provide an updated 512k file with the MAF hack for all M54 engines, correct checksums and the RS4 MAF characteristic already applied and the corresponding XDF file for editing it with Tuner Pro for the lazy people.
______________________________________________
Note 1: Credits belong to Daniel_F. for his amazing files, jd_improved and volter for the Bosch characteristic and the RomRaider team for the MAF axis values!
Note 2: The RS4 MAF measures backflow in the section below 1.00 volts and therefor it's zeroed out in the table, since the MS43 can't understand .
Note 3: The XDF file published by MS43info on the 16th Feb. contains an error in the MAF voltage axis, I corrected it with the correct values from the RomRaider axis.
Note 4: This is not the holy grail, so let me know if there is room for improvement. Malfunction can happen, but that's why this board exists, let's figure this out together!
Have a nice day :craig: