RomRaider

Hi, I am having a similar problem that Mart had with his 06 STI ECU. I have all the required pins(I think) powered up and grounded and am not able to get a scan tool device to communicate with the ECU. Any help would be appreciated.

Here's a pic of the ECM connector, from left to right it should be B137, B136, B84, B135, B134



12VDC

B134 #5 -- ign switch

B137 #2 -- power supply

B137 #3 -- power supply

B137 #10 -- back-up power supply

GND

B134 #22 -- power supply ground

B136 #17 -- power supply ground

Also have B137 #8 and #9 and B84 #1 grounded, not in IO but found in wiring diagram, seemed #8,9 were ECM grounds and B84 #1 is the ground to determine if ECU is MT trans, which is what this ECU came out of from the junkyard.

SSM/GST

B134 #21 -- Data link connector -- pin#10 on OBD2 data link connector per wiring diagram

pic of it wired up



I'm sure I've missed something very simple, just haven't stumbled onto it yet.

Thanks!

For reference:

What about B134 #8 for ignition?
The only power an ground I use is from the page of power supply connections in the MIL troubleshooting section.

I am afraid you failed to find correct Ignition pin.

Trace Ignition pin wire on the car.
Otherwise measure power current, try to apply +battery voltage (!) thru 1 kOhm resistor (!) to each pin suspected.

When battery voltage is applied to an appropriate pin power consumption current will be 300-500 mA and k-line becomes responsible.

I saw B134 pin13 as Ignition wire in a completely similar ecu pinout.

Just to make sure I had a mil light, I connected a 12v led to b137 #15 to 12v and it lit up. Yay! However when disconnecting power and grounding pin #14 of b134 (test mode pin) and then reintroducing power it does not go into check mode- the light just stays on instead of flashing at 3hz like it should.

B134 #8 is the ignition pin for an AT ecu- this one is out of a MT WRX- this pin is the power source for the neutral switch. B134 #13 goes to the fuel pump controller- I don't have a car/wiring harness to check for sure, but thank you both for the suggestions.

According to the diagnostic flow chart, need a new ecu. I don't think an "unbrick" procedure would help. I may have zapped something on the inside. And there's even less info about unbricking a 16bit ecu than there is for the 32bit ones, or my google skills are lacking today.

On the chip inside: D151851 3830

May be a motorola chip? MC68HC916?

I dont think I have seen an unbrick procedure posted yet for a 16 bits ecu.

Time to make one

Mart

It's MC68HC916(Y5 version ?) with a common Motorola BDM programming interface.
You may see the same chip on 32 bit ecu PCB. It controls DBW throttle.
Applicable for BDM pins should be located and marked at the PCB solder side.

You mean with something like a P&E Micro BDM interface and software? I think I may have found a few opensource interface options, not sure if the opensource cables/software support this particular ECU yet.

There is 16bit BDM ( you need ) and 32bit BDM options.
The majority of free BDM software relies upon obsolete LPT based interface.