pcmhacking.net

Hi everyone a bit new still to ecu pcm hacking however im wondering if someone might point me in the right direction to communicate via this hidden port inside a 4jx1 ecu.

Im planning on playing around with it but im not too sure where to start.

Any help is greatly appreciated.

The biggest highest density chip would be a Motorola HC11 processor. The 3 row header in the white box with ABC looks like a standard Delco/Delphi header that would contain address and data bus lines. The blue connector, I dont know. I'd pick the pinouts for a HC11 processor, such as the F1 footprint and see if that main chip lines up. If it does look for the BDM pins and get a USB-BDM-NT interface and try and read it. But these are not a well known PCM and you might run in to walls and get no answers quickly. The above is about the extent of my knowledge on this one.

Thank you for the reply Antus its going to be a work in progress for sure

Actually i just realised this is the tdi which is later then i was thinking so less likely to be a hc11. I found some details here discussing that you can do some fuel trims with a tech 2. The bdm comment still stands as it has that 3 row header but it clicked that thd hc11 is too early for bdm. http://forum.australia4wd.com/index.php ... rs-to-ecu/

Do you want to communicate for logging or to read the flash?

Looks to be a 2mbit flash chip next to the processor, you could desolder if you have the equipment or perhaps try a test clip

ejukated wrote:Do you want to communicate for logging or to read the flash?

Looks to be a 2mbit flash chip next to the processor, you could desolder if you have the equipment or perhaps try a test clip

well for now i have given up on the tuning part i have partial maps from desoldering the ic however

now my projects have taken me in a slightluy different directing and i am trying to figure out why it seems the only units that will actually communicate with these cars is a tech2

i have a few different readers and none will get coms with them and i have even tried some console commands on an elm terminal without alot of luck

so... if anyone can help out? or thinks they might have handy tips it would be much appreciated.

A gm mdi interface will work with the gm tech2win tool which is a software tech2 emulaor. You should be able to find one from about $220 but there are (or were) fakes in the market. Most other J2534 interfaces dont include the ALDL protocol which is useful to have for 1990s/2000s GM.

its funny I tried to connect to a 2015 Transtron today & it came back as saying couldn't communicate & still has me staggered as to why, but there have been a few changes in the controller especially in series 1 so it could be a Bosch or EDC17.

Anyone had issues with Kess saying this ecu needs a different protocol(335) with 2015 even though it is definitely a Transtron ecu?

aussielegend,

I am sure my cheapy actron scanner has communicated with these ECU's before. I have a mate which has this motor and we needed to address a couple of codes previously. I might be wrong as I do not know too much about these vehicles but it would not surprise me if the system was this ECU, might you i was not tuning it but more diagnosing a fault.

cheers
oldn64

Hi Aussielegend,

The Injectors can be programmed via a Tech2 for minor fuel changes that affect individual cylinder power. So if you have an ageing Injector that has gone out of factory spec (maybe a blocked nozzle with only 5 of 6 jets spraying), then you can potentially trick the ECU into thinking that the Injector is a lower delivery class than its Trim Code as printed on top of the Solenoid. eg. say your Injector Trim Code is 48, which correlates to a B2 Injector, but its in cylinder #4 which appears to have a lower power output when using the Tech2 Injector Balance Test. So you want that particular injector to give more power than its currently allowing, so you can set it to be a B1 Injector and work your way down slowly to the lowest factory delivery Injector of A1. If going all the way down to A1 and doing the Balance test each time, and it still has a lower output (rpm drop is less than other cylinders when that injector is turned off), then you need to replace or repair the Injector.

So it can be a blocked nozzle (less than 6 jets working), or it could be something more sinister like a broken amplifier spring, or a damaged plunger in the barrel. The worst case scenario is a broken poppet spring which really means a replacement injector.

BTW - Any chance you have the numbers as printed on top of the chips of the ECU Motherboard, as I'm working on a potential Immobilizer workaround and it would save me pulling the cover of one of my spare ECU's?

Cheers!
P.S. I am not aware of other Tech Tools working 100% on these 4jX1 ECU's, but recently a mechanic told me that his $5000 Scan Tool allowed him to read the Holden Jackaroo / Isuzu Trooper ECU live stream data, but it still didn't help him to get the car started!