E38 - L77 conversion - Won't start

They go by many names, P01, P59, VPW, '0411 etc. Also covering E38 and newer here.
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Tre-Cool
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Re: E38 - L77 conversion - No spark

Post by Tre-Cool »

i would of used efilive for the vats side of things. you shouldn't need a fpcm fitted as it'll trigger the ecu pin to gnd.

you will prob find that until you remove all the etc & pedal errors it wont start.

does the etc motor respond to pedal movement?
ben_att
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Re: E38 - L77 conversion - No spark

Post by ben_att »

Ah ok. I’ll have a look into EFI live and give that a go.

Yes it does. That’s what’s annoying me, pressing the pedal gets instant response from throttle body right through the whole travel to WOT and comparing all the APP and TB voltages matches very closely other running engines. It looks like it’s all working perfectly in that area.
I would like to clear those codes because I was thinking similar that maybe it won’t start because of them but I’m not sure where to go now that it all seems to be working correctly and definitely don’t have the conditions stated in the manual to cause the DTC’s in the first place.

Thanks
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Re: E38 - L77 conversion - No spark

Post by ironduke »

Just took a quick peek at the cranks no start diag on a 13 silverado with an e38 and first step is to check for a security light and/or codes when trying to start.. Then it checks for RPM reading and then spark or no spark.. Seeing this makes me wonder if a theft issue could disable spark but not fuel?? I have no idea how the patches work so?? Something to keep in mind..

One thing that I hope is simply an error on typing it out is you stated you have power on pins A and D? You shouldn't... A is a ground..
A is ground
B is low reference for the control circuit.
C is coil control
D is ign power..
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Re: E38 - L77 conversion - No spark

Post by ben_att »

Thanks for that.
When you say security light, how do I do that? On the VF there’s a light on the top of the dash but I’m tipping this comes from the BCM I don’t have as I don’t see anything on the X1 or X2 pin outs of the ECU for security status, is there a channel for this in HP Tuners I’m missing?

You are right that was bad typing on my end, I should have written I have power across A & D, A is ground and D has 12V on it when the ECU picks up the ignition control relay.

So if the VATS is disabled, does the ECU still want to be VIN matched to the BCM? I don’t have a BCM fitted to this car so that shouldn’t be a problem but I’m tempted to drop this ECU into a VF and see if starts to prove if it is the VATS not being disabled properly through HP Tuners.
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Re: E38 - L77 conversion - No spark

Post by ironduke »

With your swap you can't really look at the security light nor look for theft codes since you don't have any of that.. This is where I really can't help since I haven't done a swap or standalone and your using the vats disable to bypass the bcm and immobilizer system.

Something in my head want's me to have you try changing the vats settings and doing a write entire in between each attempt.. no valid reasoning behind that though.. try none, then 1, then 2.. See if you get spark back.. I remember efi live had 2 switches and you needed to use 1 or the other and then sometimes both depending on the OS?? not sure if hp is like that, I'll try to see where I found that information.
You also should probably change the P0615 from no mil to no error reported.. start check fault disable should probably be ignoring that but maybe not.


As far as ign feeds, are you using an ignition switch? toggle switches? Just want to make sure your not losing voltage to the coils during cranking by grabbing an accessory feed off an igntion switch.. That might even explain some of the throttle body codes if your losing 1 ign feed during cranking..
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Re: E38 - L77 conversion - No spark

Post by Cincinnatus »

Did you start a thread on hptuners forum? Some of those guys are excellent troubleshooters. They'll be more knowledgeable about your problem than anywhere else
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Re: E38 - L77 conversion - No spark

Post by antus »

Just a heads up not to mix no vats patches from efi live and hptuners if you do start looking at the other tool. The patches are aftermarket and likely not the same. One tool probably wont see the others patch, and patches from both tools would likely have unintended consequences.
Have you read the FAQ? For lots of information and links to significant threads see here: http://pcmhacking.net/forums/viewtopic.php?f=7&t=1396
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Re: E38 - L77 conversion - No spark

Post by ben_att »

Thanks for the info everyone.

At the moment, I’ve just got toggle switches straight off the battery feeding the ign input to the ecu then the relay is feeding a fused supply to all the circuits then just a button for starter. I’ve just done it like this to know it will run before trying to interface to the VZ.
So doubting it’s a VATS issue now, I just put the ECU into my LS3 VF and it started straight up with the wrong vin number and no linking procedure, just plugged it in and pressed start. It ran a little different to normal but that’s expected being from a L77 instead of LS3 but the point is my ECU must be good.
Put the original ECU back in the VF and started right up. I’m actually surprised that it started because I was expecting that the BCM wouldn’t send the start command over serial if it saw the ECU had the wrong vin in it, but it did.

Back to the drawing board. So I think what I’ll do next is start trying to simulate the APP and ETC errors to see if they prevent start on the VF. The 1682 error still worries me to be the cause because it’s the ECU saying that a supply is missing missing. Provided all the drawings I have are correct, I’m very confident every pin on the ECU that needs power (or even pins that are monitoring relay coils I’ve connected relays too).
When I put the ECU from the swap car I could clear the DTC’s and had no errors.
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Re: E38 - L77 conversion - No spark

Post by ironduke »

What do you have available for a scan tool to look at the engine data list and observe both the Ignition 1 Voltage signal and the EC Ignition Relay Feedback signal parameters??
Difference of more than 3 volts is what sets the P1682, Is the DTC just permanent or is it setting as current??
I did see this in the P1682 ckt diag as well: Important: A resistance of 5 ohms or greater in the circuit will cause the DTC to set.

You mentioned relay coils wired up, did you wire the starter relay up as well even though it's not being used?

You have battery feed to the ECM wired to be on ALL the time, and then an ign switch to turn on the ign feeds.. your not switching the battery feed and ign feed on at the same time, right?

I am assuming but have you triple checked the wiring on the ecm power pins? made sure the 18,19,20 aren't shifted over by 1 pin?

One other thing which I very much doubt is looking at the truck schematics and pin 18 is connected to accessory.. Meaning it loses power during crank.. Honestly did not expect to see that since it turns on the ECM and TCM.. possibly this is screwing up things?
08 silverado.ign switch accessory.jpg
08 silverado.ign switch accessory.jpg (125.49 KiB) Viewed 2277 times
ben_att
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Re: E38 - L77 conversion - No spark

Post by ben_att »

Well I've been using HP Tuners as the ol' Tech II doesn't work with the VF (as far as I can tell).
I may have to get something else that I can use to view those voltages, however I'm making an assumption here that it's only looking at ECU voltages, hopefully this has no relevance to BCM voltages through serial bus as I don't have a BCM connected currently.

Reading with a multimeter, this is definitely not the case, the voltages are identical. You are right, I did connect the starter motor relay only because I read somewhere else that people where having issues where if they forced it to crank like what I'm doing and it wouldn't start however those guys seem to all of been reporting no fuel, not no spark, but was worth a try. I've read a few people saying they just stick a 120 Ohm resistor across it so the ECU thinks there a coil there.

The 1682 is showing as Permanent on the main screen, but then in another area it shows as current, so not 100% sure.

I have the drawings that I'm working to which are vehicle specific in the first post, and according to those, I need to have pin 20 always hot, 18 on with the accessory feed, then pin 19 for ignition, (this is what I have done) when I do get power to pin 19 the ecu then picks up the ignition relay I have wired in, the throttle body moves a little bit and there is power to ignition coils, TB, APP, etc, basically seems like it's ready to start.

After reading your post, I did play with having the accessory off while cranking, a few different scenarios and no change, injectors are pulsing but no spark. The only difference I could see by not putting power on the accessory feed was the speedo was reading as 280km/h which drops down to zero when the accessory feed goes high as it's feeding the transmission as well, so assuming the TCM isn't telling the ECU anything speed related until it is 'woken up' by having this feed high.

I have verified this, however this loom has not been tampered with, there are only 3 plugs which is the fuse box plug, the X110 and the X111 which were disconnected and the engine, gearbox, loom, ECU, etc remained connected and all swapped from one car to another in tact. So I'm very doubtful there are any pinning errors on the ECU as the engine was running when removed in one piece from the donor car.

I did start playing with my VF SS to see if I could simulate the fault and no luck yet. Initially I tried with ignition on, then to manually short the starter relay but it wouldn't run (i was expecting this, but wanted to prove) Then I disabled the starter circuit monitor & VATS, then bridging the starter motor would start it. I tried disconnecting brake switch, ABS Module, fuel level signals, fan control modules, basically all the stuff I don't have in the other car and each time it started. I even used the ECU from the car I'm having the issues with and it still started. I might have to try and go further with this and disconnect the BCM and FPCM but that would require me making a lot of wiring modifications as the BCM fires off the relays in the fuse box for the ECU which I don't really want to do to this car (I'm happy to unplug things and change settings that I can change back but I don't want to go cutting or modifying wiring)

So I guess now I'm going to have to start reading voltages on each pin in the VF SS to see where the difference is. I might also try and put a switched supply straight onto the fuel pump and disconnect the FPCM to see if this gives me the same fault. I've been over the wiring so many times and it's all doing what it's meant to, so trying all different things now.

Thanks
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