Starts and dies before hitting 1500 rpm consistently

Hey everyone, first time poster but have been following threads routinely during my rebuild.

In the last stage of my rebuild, frame was getting bad as well as cab so I got an 05 double cab and frame. I've swapped everything I could from the 09 to the 05 , i mmobiliser, steering shaft, ecu, fuse box and every sensor behind the dash, motor and harness, box lights you name it. All of a sudden I have codes P2121(throttle circuit d performance) p2123 (throttle circuit d voltage high) b2977 (immobiliser)

Now what happens is the truck will fire and get to about 1500 rpm then die and it dies it everytime I try starting it. Sometimes I have to cycle the key or tap it and it will fire otherwise it will just crank over.

I've done the obd 2 pin 4 and 13 trick(on both immobilisers and ecus, went back and forth), swapped ecus, swapped immobiliser and chip in the key, verfified all my fuses, traced wires from the immobiliser, throttle pedal, throttle body (all are good), unhooked the MAF sensor as well as swapped and cleaned it, swapped interior fuse box, swapped relays, chased and cleaned every ground I could, checked ground voltages replaced the throttle body with a new one, tried resetting the throttle position by pushing slowly in and out a few times(watched on a video) and even hooked my fuel pump up to run constantly at full power.

None of that has gotten me anywhere and I'm curious if anyone has any leads or reccomendations for me as I can't think of anything else to even try?

Any feedback is greatly appreciated

 

Did you swap the interior harnesses over as well?

The immobilizer code doesn't seem to exist, are you sure you typed it right?

 

Maybe B2799?

But I can't see how the TB codes are related?

 

Well if it's a B2799 it ain't gona run, need to figure out why the registration isn't completing.
The other codes have to do with the Accelerator Pedal Position Sensor not the Throttle Body, they will cause limp mode but not a start/stall.

 

Yeah, the others are circuitry codes.
I referred to them as TB, I knew you’d know what I meant.

I didn’t look into the codes too much.
Not even the B2799…

It should even have started at all.

 

I didn't swap any of the harness in the cab for doors or harness to the rear

 

Yeah I'm completely stumped on it right now

 

Think it could possibly be the amplifier near the key is going bad?

 

I'll try but I kinda need to know exactly what parts are 05 and what is 09.
This is why I try to discourage such swaps because they rarely go as planned and are a nightmare to troubleshoot, unless you swap every harness, module, and electronic part over you just have a mess to sort through.
Even though the trucks may be identical on paper, alot of things changed electrically in 09.

If B2799 is the code you have it means the PCM can't communicate properly with the Transponder Key ECU, so either the secret key isn't learned correctly or there is an actual issue with communication between the 2 modules.
This is what we need to solve first as the truck will never run if the PCM and Immobilzer aren't communicating.

 

FWIW here's the Immobilizer wiring diagrams for 05 and 09, ECM definitely has a different pinout.

 

Yeah unfortunately I didnt realize that they switched up electrical components for 09 from 05 to 08, just figured all 2nd gens were the same. And those are going to be a great help thanks!
I'm going to dig through the wiring again and trace everything just to be certain a wire didn't get nicked when reinstalling causing this issue because I have already checked every pin to make sure it was inserted fully into the connector.

 

Oh yea while mechanically the 2nd gens are nearly identical 05-15 electrically alot of things changed during the 10 year run, the major year ranges were 05-08, 09-11, and 12-15.

Here's the engine wiring diagrams and pinouts as well.

 

OK so, aside from the front end changes the 09-11 would be the same? Just thinking if it is something in the wiring harness behind the dash and I swap it out, just want to look for the correct one.
But you've been a great help already! Very appreciated!

 

There are probably minor differences but without going over every single wiring diagram and connector pinout we can't be 100% certain they are the same, it only takes 1 pin on 1 wire to be different to cause big headaches.

Typically wiring harnesses you want to match part number to part number because of the differences in configurations but that can be quite difficult to do with used harnesses.

 

Started digging into it a bit more. One of the immobiliser wires go to my airbag control module. (Large difference between the 2 harnesses) Now I'm thinking if I can just use all airbag harness off my access cab and make that work. I can't for the life of me find anything else or understand a reason why it isn't running more than a second.

 

That explains the lack of communication with the Immobilizer.

The start/stall is classic Immobilizer behavior, the ECM allows the truck to start but it shuts off the fuel injectors when it can't complete the handshake with the Immobilizer.

You have an active Immobilizer code and a start/stall, no need to diagnose anything on the engine side until you get the Immobilizer and ECM talking and happy.

 

Well swapped the engine harness, ecu and dash harness from an 05 because one of the wires from the immobiliser goes to the airbag module and thought it may kill the motor because of the differences from 05 to 09, then did the pin 4 and 13 handshake in the obd plug and ended up with the same issue but only the immobiliser code came up. Swapped them and redid the handshake but more of the same. So either I have 2 screwed immobiliser cpus or I'm missing something.

 

Are we using the correct keys that are paired with the immobilizer ECUs (keys are stored in the Transponder Key ECU).

Do you have a scan tool that can talk to the Immobilizer so we can see if it communicates and if so what it's not happy about?

 

Yeah I made that mistake early in the build I have them matched up now.
Currently using my buddies matco scanner that can calibrate the immobiliser.
Currently re evaluating even using the 4.0. I've been reading into a 1.9l tdi swap the passed year or so and feeling like I'm done screwing around with the current set up. Not taking the truck to a dealer for a diagnosis as I'd be looking at a minimum $500 bill and they'd probably try to sell me the amplifier for the immobiliser ($500cad) or a new immobiliser and key ($750 cad) and I'll pass...

 

Can you see what codes the Immobilizer module has?