Can you check your battery voltage?
And you know the obd scanner works!
Does sound like the immobilizer is part of the issue, check grounds especially since you swapped an ecu.

 

the obd scanner does NOT work

voltage was good until I killed it trying misc things. Waiting on a tow before I can do more
Grounds I can see are fine. Is there a list of them? Additionally I put the old ecu back in since neither appear to work

 

prior to it dying , were there any indicators?
rough idle?

trusty starting fluid
pump fuse
llisten for pump to come on
check those coils and plugs

not sure if anyone has tried but try a live stream and post here

 

prior to it dying , were there any indicators?
rough idle?

trusty starting fluid
pump fuse
llisten for pump to come on
check those coils and plugs

not sure if anyone has tried but try a live stream and post here

very minor miss at idle but not enough to pick up on a CEL. Always attributed to valve adjustment being needed

 

Are the battery terminals oem style? Some universal battery terminals don’t grip the battery posts very well. Or the clamps don’t hold the wire very tight. Had this issue on my corolla before.

Do you have the original battery tie down?

 

I’m thinking vacuum leak, but it mimics what I experienced in the past.

It goes like this. In 2018, had crank no start issues. Battery terminals destroyed by corrosion. Replaced both positive and negative terminals with a set from Walmart. In doing so, I cut my ignition switch wire to the starter by accident. At the time, had no idea what the wire controlled. But it wasn’t starting. Repaired wires and it ran. For a while, it was running fine. During the summers, the crank no start increased in frequency. Discovered that the issue was not environmental. Instead, it was the negative that kept sliding out of the terminal and causing the no start. Replaced the terminals from the junkyard and life was great again.

Double check the battery, ground points, starter, and the alternator. It’s very possible that your alternator is over charging the battery and causing the engine to not crank. Or your starter is stuck and isn’t engaging the flywheel.

 

Okay, everyone. It happened again car worked fine for a few weeks. Drove it last night and it was fine. Today it did it again.
This isn’t a vacuum leak, it’s not bad gas.
THE COMPUTER IS NOT COMMUNICATING WITH THE CAR. happens out of the blue for no reason.
This isn’t something that’s just as easy as air spark fuel. Etc. scanners won’t talk to the ecu nor will it talk to the car.

not a bad ecu, swapped another and relearned the immobilizer, same issue. Please suggest some constructive things here other than things that would prevent a functional vehicle from starting. I have an electrical paperweight.
Relays and fuses all appear fine and they all work in an 07 S, they’re not the issue.

 

Additionally EVERYTHING in the car gets power. Battery voltage is fine. Terminals are fine.

 

You’ll have to do a point to point voltage check at this point. Since it’s happenening randomly.

Describe for us what occurred when it died. This will help us understand what’s going on. It’s a incomplete picture at this point. Fragmented by a ecu swap. This basically says there’s a electrical wiring issue.

 

sits down
Starts car
Car runs several seconds
Car dies.
car cranks and won’t start. Sometimes the CEL comes on and it will sputter and die.
cel stays off most of the time
OBd won’t connect.
Voltage good.

 

What part number ecu did you use?

Have you ruled out the fuel pump yet?

 

offhand, I don’t know. But the one that is for 05-6 corolla/matrix xrs.
Fuel pump wouldn’t cause the ecu to shut down would it?

 

My former corolla xrs did something similar to your description. But most of it was due to mistakes made by me.

No crank, no start condition was cause because the corrosion on my battery terminals were beyond saving. I had to cut it off on both the positive and negative wires. Used universal battery terminals as a temp solution until I could locate a oem terminal in the junkyard. As this item could not be sourced by Toyota. The wires kept backing out of the terminals and caused the no crank, no start condition. This was due to no longer having my battery tie down. Corrosion destroyed it. When I replaced it, the disconnection was minimized but still happened.

For the communication error, I found that one of the pins in my obdii adapter were bent. When I straightened it out, I was able to connect with my ecu.

 

it’s not just communication issues with the obd port. The ecu is flat out not talking to anything

 

I had something similar happen to me a few years ago. It ended up being a bad ground under the driver's side kick panel. It also affected the DRL module somehow, but I'm still not 100% sure how that all works.

I believe the 9th gen had DRL's similar to the 8th gen, and they don't come on with the e brake applied. Try starting it with the e brake on so the DRL's stay off and the "brake" light on the gauge cluster comes on.

 

I had something similar happen to me a few years ago. It ended up being a bad ground under the driver's side kick panel. It also affected the DRL module somehow, but I'm still not 100% sure how that all works.

I believe the 9th gen had DRL's similar to the 8th gen, and they don't come on with the e brake applied. Try starting it with the e brake on so the DRL's stay off and the "brake" light on the gauge cluster comes on.

DRL still come on and get kicked off by the brake

 

"It’s not getting power."
See alldata.com for schematic wiring/voltage/resistance specs.
Verify that positive and negative supplies to ECU are good.

 

XRS

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here is what it did to me just now. It started but this was mostly with the key held forward.It shut itself off

 

Sounds like a bad fuel pump. Spray the starter fluid into the throttle body. If it starts and runs, then it’s your pump. This test bypasses the pump since you’re spraying igniter into the combustion.

Don’t know what else to tell you.

 

No idea, but you’re losing fuel pressure. It’s not starting nor is it staying running.

 

dude. It’s literally because the ecu is losing power and it’s cutting spark and fuel becuause the ecu lost power.
I’m so confused on how this keeps getting skipped over

 

Did the key programming get accepted? You mentioned earlier you have the security light. Does the security light go out when the key is inserted into the ignition?

 

Dude. You keep thinking it’s ecu related. Test the damn thing already.

 

Oh my god.
It’s not the ecu. The ecu stops communicating. It is losing power somewhere between the ignition, battery, and itself. Something is causing this and I’m asking what will.
^^^^^^^^^^^^^^^^
The ecu loses power
vvvvvvvvvvvvvvvvvvvv

if you cannot contribute then don’t.

 

You’re not helping yourself. You want the answer, but nobody can give it to you. Get yourself a wiring diagram and start doing the point to point checks.

 

Electrical gremlins creeps beneath your feet. Looks like a fuel pump issue on video


Sent from my iPhone using Tapatalk

 

would that cause an ecu shutdown? Yeah it would cause issues with stalling however it ONLY does it when the ecu is shut down

 

Alright since the ECU is fine, have you checked that every wire on the ECU that should be getting 12V IS getting 12V? And regardless of how they look, clean all the grounds you can find with a brass or stainless bristle brush. Every connector that's attached to the grounds for the ECU gets cleaned. I had a random no start on my Jaguar XJR (shocking, I know). Cleaned the grounds and its never had a problem again. Pro tip, unhook the battery when you clean the grounds or you get sparks. The corrosion happens in between the little spade/ring connectors so you're never going to see it.

I agree its not a vacuum leak, it looked like it idled fine. And the ECU should be fine as well, again because it just wouldn't idle.

I guess it might be worth checking the idle air control valve voltages and such? Not sure if that would cause your symptoms.

Clogged fuel filter or slowly dying fuel pump seems like a possible culprit? But then I think it would also run poorly at high rpm/ wide open throttle because the pump would be too clogged to keep up.

Anyway I'm only a hobby mechanic so I'm just throwing ideas out there for you to think about. Good luck!

 

any update on the issue, did you get it fixed?!?