RomRaider

Hi Guys,

I'm trying to locate the pins to unbrick a Nissan TB48 ECU. The only pin I'm unable to trace is the WatchDog Timer.... I have a quick question though as I've been reading myself into a frenzy. Is the WDT pin on a 7055 chip Pin 124 "WDTOVF" or pin 221 "PL5/ADTRG1".

Cheers!

It's usually PL5 , but I haven't done an exhaustive study of all possible ECUs. If you have a ROM dump or better a working ECU it's possible to confirm by checking which pin it toggles.

I vaguely recall some people have had success without generating the WDT signal but forcing nRES high via a low-ish resistor (10-22 ohms ?) but I never tried and wouldn't really recommend it. Proceed at your own risk.

If you take straight, high-res photos of both sides of the PCB someone may be able to assist identifying the testpoints.

hi,

I am also looking unbricking my ecu. I did some search and found some info about 7055.

RES pin 58 /reset
PL5 pin 221 Watchdog
MD0, MD1, MD2 pins 59, 55, 50 /mode pins
TxD1 pin 165 /transmit data
RxD1 pin 166 /receive data
FWE pin 56 /flash write enable <-- no need

What part of processor needs power? 5v or 12V? <-- underneath ecu are 2x6 test spots. There is spots for GND, +5v, +12v batt, RST, MD1, TxD1, TxD2 and watchdog.
And 7055 datasheet tells that there is couple boot mode options where you use FWE and MD2 and or without MD0? <---- Datasheet tells to use in boot mode MD0 and MD2, but not working for me yet.

the WDTOVF pin has nothing to do with the external watchdog IC and signal found on pin PL5. Forget WDTOVF completely.

Don't apply +12V to the mcu. Thoroughly read https://nissanecu.miraheze.org/wiki/Bootmode
as well as unbrick thread .

How are you guys bricking your ECUs ? This is uncommon. I've never bricked one even during development...

Bin file attached. Any chance of finding what pin the wdt monitors would be great! I'm at a bit of a loss now.... I've found all of the other pins.

This ECU was bricked due to a USB cable being pulled mid flash via Uprev. Don't ask!

This is where I got today:

I made with 555 chip square wave for PL5, pin 221. Works well when RST released it stays in +5v. I tried different MD_ configurations but nothing worked to get communications. I only got echo but nothing more. Next I will try some another rs232 cable but I think its the same.

Pic of the setup in attachment

Thanks for having a look!

I tried pin 221 (PL5) but I couldn't get RES to go high, even with my 555 squarewave that I know works well on a previous ECU.

It's just dawned on me that I didn't apply power to IGN.... Going to have another crack at it tonight.

I found with my previous 7055 that I unbricked last week (V35 VQ35DE ECU) I had to use 7055 preset instead of generic boot device in Renesas flash tool kit otherwise it wouldn't connect.

SUCCESS!



Retried with IGN powered and hey presto! ***idot!***

Pins attached for future reference!

Cheers!

Well done, glad you were able to unbrick. Would you be able to add your pin info to https://nissanecu.miraheze.org/wiki/Ecu_hw ,if it matches one of the "types" , or if yours is different we can add a new type with PCB photos.

Today I got it!

I didnt have proper cable but I opened the blue "vag-com" cable and jump wired from FTDT chip. It worked for me