Devolont

Hey guys. Started my LH6 swap and while I save up more money for holley motor mounts and converting my t56 for the LS engine I am working on getting the engine started. Engine is sitting in the car with the holley 302-2 oil pan. I have power and grounds where I believe I need everything but I may have missed a few. On the fuse panel, I tapped ignition switch 12v to the ignition coil wires and that energizes everything but I don't know where it normally gets it power from. Also, I have power to pin 20 on the J1 connector which is the red/white stripe, 12v.

Second issue I am having is that after I got my dlc all wired up, pin 4 and 5 are gounds, but I have them both running to chassis ground (I want to know if pin 4 needs to be a ground related to the ecm) pin 6 is CAN+, pin 14 is CAN - and pin 16 is 12v. Honestly cannot remember if it is battery or ignition switch now. So ohms between CAN + and - read 120 ohms, I know there needs to be a 120 ohm termination in there so my plan is to buy two 120 ohm resistors and put them in line between the ecm and dlc. I am not running a bcm as I did not get one with my engine.

Vats have not been deleted yet and I do have hptuner suite 3.4 so once I get this connected to the ecu I should be good there. Last issue that I can think of right now is that the ecm wants to see confirmed crank otherwise it may not let the engine run? The purple wire off the back of the under hood fuse panel from my understanding would need to be grounded with a 100 ohm resistor in line?

If anyone has a schematic of a helpful tip on placement of grounds or where the 2007 silverado places them that would be really helpful as well.

First real engine swap for me other than replacement like for like.

Devolont

Okay, so I finally figured out all my issues and got the engine running. The engine is the LH6 all aluminum 5.3L with active fuel management (displacement on demand). I'll be getting a few pictures and detailing what I did to get everything powered for anyone else who is doing the swap as well. Pin out info is available online for the j1 and j2 connectors for the E38 computer.

From my understanding the 07 E38 sometimes has issues with vats wanting to reactivate themselves so if I experience this issue I will try to report on that. Everyone with info is more than welcome to chime in as I would like to try and make this a gen 4 swap guide to a degree with some useful one stop search. I spent many hours tracing wires and reading to figure out what to do.

The software I used is HPtuners version 3.6 which was just released. With hptuners they offer a free custom OS for a speed density 2 bar. As I learn more I want to report on that more as well.

johnw999

I used a similar 5.3L engine for my swap. Mine is the LC9 which is an LH6 with variable timing cam. I bought a VVT and DOD delete kit to simplify things. I had a shop install the engine and connect the E38 and a wiring harness from Speartech. There was some difficulty getting the engine to fire. Speartech said the problem was my ECM tune, and they reprogrammed it. Strangely, my ECM worked when it was plugged into another car. Whatever the problem was, the ECM and harness worked when Speartech shipped it back.

While the install shop was troubleshooting the problem, I searched LS1tech for a solution. Seems like 'no start after E38 is connected' is common. VATS not being fully disabled is frequently the culprit. I don't have experience with tuning, but I did read that some of the tuning software won't fully disable VATS. Here are some other problems and solutions that I found:

1. Spark but no injector pulse
Solution - the starter enable wire needs to be grounded, or the starter check needs
to be disabled in the ECM

2. Spark but no injector pulse
Solution - ground the fuel pump relay ECU PIN and ground the starter
relay ECU PIN

3. No Spark, no injector pulse
Solution - cam sensor connector had come out of the terminal

4. No Spark. Author didn't mention injector pulse
Solution - Engine didn't have fuel pressure. The fuel pressure regulator was
backwards. Once installed correctly, engine started when fuel
pressure reached 55 psi

5. Injectors won't fire
Solution - VATS wasn't completely turned off. HP Tuners (2 different versions)
said it was off. Sent ECM to Speartech, and they found that VATS
wasn't completely turned off


You said that you tapped the ignition switch 12v from the fuse panel. I'm sure you tapped a fused source of 12v power. There is a pink wire from the C100 that provides 12v power when the key is turned on. I read that this wire is unfused. My install shop used it, and I made sure they connected an inline fuse.
One guy tapped the wrong power source for his ECM and fuel pump relay. Both lost power during cranking:
https://www.hptuners.com/forum/showt...-swap-no-spark

Devolont

I used the factory ignition coil power wire to supply my initial voltage so I can definitely change the fuse to protect the ecu. The factory fuse block in the picture with a wire on the pin is the pin that I used to power the computer. Theoretically the fuse in the truck fuse panel should already be protecting everything as is. I couldnt get my computer to turn on when I spliced into the wires for the coils so when I finally found this pin and put power to it everything worked like it was supposed to. Everything got power like it was supposed too, so I am a little confused on that part. Since Hptuners has all the deletes in it and I got the engine running with the started check bypassed I was thinking of using an after market fuse block to replace the truck factory fuse block.

johnw999

Sounds like you're on the right track. I got a P0174 code after I got the engine running. I think I fixed the problem, but time will tell. After reading LS1tech, I think E38 swaps tend to take more time than the 411. One guy titled his thread "LY6 Crank No Start(yes another)".

QwkTrip

iTrader: (22)

The coil wire is fused but not at the fuse panel. It goes all the way back to one of the primary fusible links for the car. If you blow that fusible link then you'll lose half the functions on the car.

Also, a fusible link is a high current, "slow blow" type fuse. It is not suitable protection for low current devices such as the ECM switched power. It is a good idea to add an inline fuse rated for small current level of the ECM. (This is a case where I did not follow my own advice)

Devolont

I currently am using the truck fuse block which has the appropriate fuse for the computer. Been a few weeks since I went out and worked on the car.