Ls3 crank sensor p0315 code

[Zedn]

Hi All,

When I first wired up my car (ls3 with factory ecu vats removed) it started first go. It ran a bit rough, but I had no cooling system connected so couldn't warm it up. Motor was a crate motor.

After not running it for 12 months, i tried to start and it wouldn't. It has no spark.

I finally hooked up a scanner today and got p0315 code crankshaft position system variation not learned. From my research this is not a code that would stop it running and the engine needs to run to run the learning procedure. Given its a crate motor with second hand ecu, it's probably no suprise. Anyone know much about this code and if it could cause a no start situation?

I also had a code for clutch position connected to ground but didn't write down the code. My harness has no clutch sensor.

[Modena]

Sounds like a normal relearn is needed, thats what that code usually means. Ive also seen that code after the engine has been misfiring as it can sometimes then detect pulses out of tolerance and get confused.

Any other codes apart from clutch one?

What ecu is it and who did the loom?

[Zedn]

Factory ecu (E38). The loom is a PSI performance loom.

Everything worked fine until i tried to start it again after 12 months. I didn't work on the car much through out that time, but i did do some work so its possible i disconnected something or bumped something and don't remember. I have checked all the connections though and can't see anything.

I am going to test the wiring and sensor for crank and cam sensors. I don't have spark, but haven't been able to test injectors without a noid light.

Do you know what type of noid light is needed for the LS3 or are they universal?

There were some other codes related do fuel but they didn't come back once cleared. I think they were from cranking it without fuel connected to get the oil spread around. I have fuel pressure.

[RICK LAKE]

Zedn Guy you have no thief system signal to the ECM to let the motor run. You need a stand alone ECU. As for the p0315, once the motor is running and warns up you need to do this test with a MDI or tech 2 and candi depending on the year of the ECU. IF you keep trying to start the motor. The system will totally default and you will need another ECU.
Only other way around this is to get a ECM, BCM, and ignition cylinder assembly and install them in the car. Will need to wire them up for power, grounds, data lines, and ign switch signal.
The only one that has a stand alone ECU I think is MSD. I could be wrong.
You would be better to go after market. Try F.A.S.T or Big Stuff. Good luck Rick L.

[Zedn]

Vats are removed from the ecu already.

[Gav]

Like Modena said, I would start again from scratch.
I have an LS1 ECU in mine which I sourced from a wrecker, after discovering the original ECU had an intermittent fault which killed the spark, I learned that many second hand ECU's on the market are actually repaired units that have been removed under warranty.
Yours, like my first one may unfortunately be a dud.

Rick, Zedn stated in the first post that the VATs (vehicle anti theft) had been removed.

[renovationinnov]

zedn
thought of giving sideshow a pm as he's the only one that maybe able to find your problem I feel
or reprogramme your 's to run as he's always doing this up this way
a call can't hurt

[RICK LAKE]

Zedn If the ecu was programmed with a Vats system in it, YOU can't remove the software without a whole new programming. Just because you removed the wires from the connector doesn't mean the thief system is dead. it is hard programmed into the ecu. No signal or wrong signal, No start. The thief system kills fuel pump, or spark to the plugs or injector pulse. You will get a 1 shot of fuel into the motor and that's it. Motor will start and stall within 3 seconds. 3 times of this and the system shuts down for 10 minutes. Keep doing this and then 30 minutes. thief system relearn will need to be relearned or a 12 minute tech 2 with candi in the thief system of the bcm or thief module, depending on which system. It's all in the software, Hey where's Bernie??? Rick L. PS 98% of all ECM, BCM, IPC, are repaired and sold as remanufactured. The programming needs to come through GM TAC system at a GM dealership. You may be able to get an aftermarket program to get the car running but will need to do a total programming of the motor from start to WOT. Good luck. Rick

[Zedn]

Hi Rick,

Not sure about the programming side of it, but it has no security.
This was the first start in December 2013. I ran it a couple of times after this video also, but last start was in Jan 2014. Then i left the car for a year and tried to start it Jan 2015 and it wouldn't start. I didnt have time to look at it then and now just getting back into it.

https://youtu.be/wDGTyJUR-70

[Gav]

Rick, the LS ecu software has a box that you can select or cancel the vehicle anti theft function. This allows the ECU to operate without needing a BCM.
Perhaps you should stick to making comments about something you have a clue about rather than needlessly confusing people.

[deano59]

hundreds if not thousands of people use ls engines with the e38 ecu and the vats "ie security " removed from the software no one is just pulling the wires from the plug rick .i think you need too find a new tuner . how do you think there is so many cars cobras /hotrods drag cars ect running on the factory ecu ?.
you dont need a fast set up or perhaps your a dealer for them lol.
i would talk to side show he has just done my engine loom and ecu so it will run stand alone .

[Tenrocca]

My E38 ECU ran my L76 with just VATs removed and little else. Since been modded to remove a few more things that were throwing up codes. I suspect your P0315 code has nothing to do with the engine not running. It ran once and something changed, does the fuel pump run when you turn on ignition? If you crank it can you here a tick from the coils like its getting spark? Havent clogged a fuel filter or something simple? The clutch switch would only be used for Cruise control and "clutch to start which Im not even sure if the commonwhores had enabled, but if its cranking that would be a non issue.

[kyleb]

Have you checked all the Earth leads are grounded properly?
Both for the battery and the ECU etc..
I had an issue with mine early on that caused all sorts of weird stuff to happen.

[Zedn]

Thanks guys.

I've now got the gear to test it properly so will start with testing injectors and spark, then look at power and earth and crank and cam wiring.

I have read a few posts on forums with similar issues traced to voltage drop.

Only problem is I have to wait to the weekend as the garage is under the kids bedrooms so cranking will be too noisy at night.

[Zedn]

Had another look at this today.

It's got me stumped. No spark or fuel. Power feeds are all ok. Ecu is seeing rpm because it shows up on the scanner when cranking.

I think it's time now to pull off and re plug every connector.

When I tested the injector harness with ignition on I got 12v when probing both wires. This doesn't seem right as I expected to have only power with no earth. I thought the ecu pulses the earth to spray the injectors. Will have to investigate further.

[Modena]

That's right it switches the earth to the injectors, not the power. You should be able to hear the injectors clicking when cranking. Got any fuel pressure?

[Zedn]

I havnt actually measured fuel pressure, but it sprays when I press the Schroder valve (spelling?)

I have a ls fuel filter/regulator combined so pressure should be right.

What I was trying to say in my last post is that the injector harness seems to have earth connected when ignition is on. I have to measure again tomorrow because it can't be right or fuel would be pouring into the cylinders. The spark plugs are dry though.

At least I now know the crank sensor is working so maybe cam could be causing it. Strange there are no other codes than p0315 and p0807.

[RICK LAKE]

Zedn Pull the crank sensor and check the pin wheel for movement and being tight on the crank shaft. They had some wheel come loose. What year is the motor and ECU? P0315 is a relearn of crankshaft position. Motor ran you said. Power to injectors all. ECu uses drivers to pull the ground and pulse them. How lng was this car without battery power? It could have lost the programming. Have you tryed to reload it? If you clear the code, does it come right back on? Hey GAV you seam to be the GM answer man, help the guy fix it. Rick L. Ps are you still running a MAF sesnor? Did you have p807 before this started? Clutch position sensor would need to see wiring and to who the signal goes to. With seeing the wiring would think that is would control the starter from cranking or fuel and igniton from firing up the motor no spark or fuel. if you have above 20 psi of fuel pressure the motor will try and start. The plugs should be wet.

[Zedn]

Hi Rick.
Ecu sees about 170rpm when cranking so I think that rules out the crank sensor.

As far as I know, the computer can't lose the program from not having a battery.

[Modena]

Dont LS motors (ecu) get the rpm from the cam sensor, hence they ouput a 4-cyl style pulse ?