Read/Write/Clone Suzuki Alto 2009+ 33920-68K01 (Bosch 0 261 S04 260) ECU/ECM

It's time to experiment with a remap, so I had the need to read, write and clone the engine computer in my Suzuki Alto (GFC31S, K10B).  Unfortunately, the instructions given in Ksuite don't seem to cover this variant of the ECU, but I've worked it out so that you don't have to.  Actually, I've worked it out twice, because I seem to have forgotten to document it the first time, so here goes...

ECU: Bosch 0 261 S04 260 Motronic
MCU: Infineon TriCore TC1762
Ksuite Plugin: 340 - Bosch ME17.8.xx IROM TC1762

Connections:

ECU Pinout:

E01-1: Red
E01-9 Red
E01-52: Orange
E01-55: Green
E01-56: White
C01-6: Black
BOOT: Grey (see below)

All connections above match what is in the Ktag connection instructions, other than the black and grey wires.

BOOT Pad: 

The next thing to deal with is the BOOT pad on the PCB.  You'll need to connect to a pad on the PCB, either by soldering a small piece of wire or by holding a probe on the pin.  I've done both, as I opened a spare ECU that I purchased from a wrecker in order to attempt to read it, but preferred not to open my original ECU if I could avoid it.  To achieve that, I got some assistance from my father to make up a jig so that a hole could be drilled in the ECU in the correct location to access the BOOT pad on the PCB without opening it, which is the method I used to read the original ECU.

Side note, for those that are interested, the BOOT pad on the PCB connects to pin 87 (P4.1) of the TriCore TC1762 IC.  Port 4 (P4.x) pins are used to configure the boot settings for the TriCore chip, which tells the chip where you want it to boot from (eg. you can boot from flash, the CAN bus, or over serial (ASC0 pins)).  I found the BOOT pin that Ktag wants by trial and error, testing all pads on the PCB that connect to the P4.x pins on the TriCore IC, until one worked.  Search the TriCore TC1762 datasheet for BOOT and HWCFG if you wish to learn more.

The BOOT pad is shown in the image below, at the top, right of centre:

Ksuite:

1. Connect the Ktag to your PC
2. Connect a 12V DC power supply to the Ktag and turn it on
3. Start Ksuite
4. Click PROTOCOLS
5. Under the K-TAG section of the menu on the left, select BOOTLOADER TRICORE
6. From ECU LIST, select BOSCH ME17 SUZUKI
7. Click OK
8. Read the instructions, but skip the connection instructions
9. Click OK
10. Select "340 - BOSCH ME17.8.xx IROM TC1762"
11. Click Read to read the ECU Maps & EEPROM.

Other Notes:

The EEPROM is inside the TC1762 IC, it's not a separate chip in these ECUs.

Using Ksuite to write the EEPROM (EPR file) and Maps/Firmware/Code (MPC) file individually to a spare ECU resulted in the EEPROM being corrupted.  I discovered this after putting the spare ECU in the car, expecting it to start, but it didn't (immobiliser light stayed on).  After reading back the code and EEPROM from the spare ECU and comparing those files with the copies of the original (using HxD) the EEPROM data was found to be corrupt.

To work around this issue, I read the ECU (Maps and EEPROM) into a single file and then wrote that file to the spare ECU that I purchased from the wreckers.  This worked, and the car starts when the spare ECU is installed.

As an experiment, I've had a company do a "Stage 1" tune (remap) of the ECU, so I need to write the modified maps to the spare ECU to try it out.  I'm not sure how good it will be, as it was all done remotely, but it seems a fair few people do it, so I thought I'd give it a go.  If it kills the engine, it won't be a huge loss, since it's done a little over 220,000K's, so a newer engine probably wouldn't hurt.  If you want a copy, leave a comment below with your e-mail address and I'll be in touch (comments on this blog are moderated, so it won't be published but I'll be able to see it).

Update (29/07/2022): I can confirm that programming only the MPC file works, as I have programmed the spare ECU with a remapped MPC file.  I haven't experimented further with the EEPROM programming, to work out if I messed it up or if Ksuite or the associated hardware did.  I plan to re-visit this issue soon.

I can't say that I've noticed much difference with the remapped ECU, though on the first test drive I did notice that I was speeding everywhere by around 3-5km/h, so maybe there is a difference.  Further, less subjective testing is needed.  I'm also considering sending the original MPC file to another online tuning company and getting them to have a go at it as well.