Communication problems with Immobilizer
 

Hey guys. After i worked on the car i have some new issues. It looks like the communication between Body ECU/ ECM... and the key ECU is not working. But the keyless functions are working :iono: I can open the car with the key and also with the door handle (keyless). Also the green Key lamp is on and the car starts. the it runs a bit rough but quiet steady (think the P0171 is the reason for that). But i cant drive well when i put it in D and start driving it stalls as soon as i break.

To the Car: 2013 Gt86 AT
I rebuilded it after a fire in the enginebay. I swapped both wireharnesses in the front the ECM & Direct injector ECU.

U0100
U0164
U0140
U0155

P0171 (think this is because the other problems)

Sorry for my english i hope you understood everything :)

i believe all the ecu's are married to each other in tech stream programming, so swapping just 1 will cause some issues.

I followed the Step By step guide for the Communication Mode. Isn‘t that all i Need to do?

Was it this guide you followed?

https://www.ft86club.com/forums/showthread.php?t=102810

Yes this was the guide i followed. Is there anything wrong With That?

I was under the assumption that was the correct procedure. I haven't done it myself.

Ok. I think so too. It already solved many problems so I asume it is working, also the comments pretty positiv. I think about a damaged Itelligent key ECU. But how could I check it and what do I need to do when changing it?

First I believe you made a mistake about U0164… There isn’t any such dtc on this model at least.
Second your immobiliser works fine as it starts the car… you would have had dtc B1402 if there was an issue I believe.

I’d suggest you fix the P0171 which can be related to the wire harness where you have the body ecu, ecm and cluster connected to each other.

Thanks for your answer! Where should i start to look? I have the Interieur ripped out so everything is open. But i can´t find any problems till now. Tell me if i am wrong but i think that the U0164 = Communication Problem with the heating/AC ECU.

The heating system doesn’t have an ecu… are you sure you’re getting U0164?
You had a fire in the engine bay so you changed the wires, did you also have a look at the hoses for leaks? What about the air intake it’s in plastic so a fire could have damaged it easily! Without proper DTC it would be hard to find the problem but if you can maybe record the air fuel ratio and fuel trims once you start the car until it stalls it could help pinpoint the issue.

"U" codes are communication issues, "P" codes are emissions issues:

U0100 - Engine data not received / Lost Communication With ECM/PCM "A" / Missing data for engine
U0164 - Missing data for air conditioner
U0140 - Lost Communication With Body Control Module / Missing data for body integrated unit
U0155 - Lost Communication With Instrument Panel Cluster (IPC) Control Module

P0171 - System too Lean (Bank 1)

For the U codes;
Have you tried to clear all the codes and see which ones return?
Are you sure all the harness connectors are plugged in securly and seated properly?
Were the ECM & Direct injector ECU you replaced new, or used?
If the ECM was brand new, it will need to be set up for the vehicle, available settings are shown in graph below. You will need to specify what market the car is in (Japan,North America,CAN,EU,etc). Once you do that it will ask for other regional settings including A/C type (Auto or Manual), Headlight type (HID or Halogen), Brand (Subaru or Toyota), Transmission type (MT or AT), and more. If these are not set properly for how the car is equipped, you will get odd codes.
To set these up using the Subaru Select Monitor (SSM3):
(a) Connect the SSM3 to the DLC3 and turn the ignition to IG ON.
(b) On the [Main Menu] screen, select [Each System Check].
(c) On the [System Selection Menu] screen, select [Integ. unit mode].
(d) Click the [OK] button after the control name (integrated unit) is displayed.
(e) On the [Integ. unit mode failure diag.] screen, select [Unit customizing].
(f) Use the up and down keys to select each item and apply customization settings.
Pretty sure these setting instructions are similar and can be changed in Techstream as well.

For the P code, check the following components;
• Intake system
• Fuel injector ASSY (port injection)
• Fuel injector ASSY (cylinder injection)
• Intake air flow meter ASSY
• E.F.I. water temperature sensor
• Fuel pressure
• Gas leakage from exhaust system
• Open/short circuits in the air/fuel ratio sensor
• Air/fuel ratio sensor
• PCV valve and hose
• PCV hose connection
• ECM
• Wiring harness or connector

I have done a log run a few weeks ago this are the results(in the .txt below). The fire was near the battery and I extinguished it in a min. The hoses are ok or new. The air intake is an aftermarket and is also good. Yesterday I worked on the car and used a other code reader. (From a Mechanic shop) the I saw that the ECM, transmission ecu and the cluster got the fault code U0140 so I checked the wires and they were good. Now I am searching a used Body ECU.

https://www.ft86club.com/forums/atta...8&d=1649620578

(The txt is an attachment in a other Thread)

Tbh I never heard of that. I think that the ECM is preloaded because as I bought it it was important to buy the right one. For AT and more.

How I wrote in the post before I think I found the issue with the communication.

I tried nearly everything. The intake is closed The sensors are working probably. Also the fuel pressure is fine. I have some exhaust leaks but I also had them before the fire. The ECM and wiring harness are new. I am a but confused. Do you think the P0171 could come from a bad body ECU?

Thanks for your help!

The list of potential causes is in order of likelyhood. ECM is pretty close to the bottom.
• Intake system are there any intake leaks? Intake manifold gasket? Hoses melted by the fire? Airbox & tubing?
• Fuel injector ASSY (port injection), check the compontent, melted or damaged?
• Fuel injector ASSY (cylinder injection), check the compontent, melted or damaged?
• Intake air flow meter ASSY, check the compontent, covered with soot, melted or damaged?
• E.F.I. water temperature sensor, check the compontent, melted or damaged?
• Fuel pressure
• Gas leakage from exhaust system, fix your exhaust leaks!!!
• Open/short circuits in the air/fuel ratio sensor, check the compontent, melted or damaged?
• Air/fuel ratio sensor, check the compontent, melted or damaged?
• PCV valve and hose, check the compontent, melted or damaged?
• PCV hose connection, check the compontent, melted or damaged?
• ECM - maybe, if you have rulled out everything else...
• Wiring harness or connector