E80a Stand Alone with no BCM. Crank no start without starting fluid

[Barrymaxx]

Howdy,

I built an offroad buggy with a 2018 LE2 1.4 turbo (chevy cruze) engine. Engine harness is mostly unmolested and original E80a ECM runs the engine just fine in standalone configuration. Well it at least will idle, rev (Limp mode, ill get to this later), etc.

Issue is, I have no injector pulsewidth while cranking. A tiny sniff of the cosby sauce and it starts right up and runs on gasoline as intended. I believe the root cause of this is the E80a is looking for a "start signal" communication from the BCM.

Wiring diagram and service manual indicate IGN switch gives discreet signal to BCM when start is requested. BCM passes signal over GM HS LAN to ECM. ECM checks clutch switch or NSS, then fires off the starter. My starter is wired to a relay and my own switch so that's not a problem. My thought is the ECM has a "cranking mode" that comes along with this signal. Because we never get this signal, crank mode is never enabled. The starting fluid brings the RPMS up and the ECM switches to "run mode", similar to if you bump started the car.


Does anyone have a solution for this? Maybe the genV V8 guys have similar problems? Id like to find a work around for this. 1. because the BCM from the donor car is long gone and I dont want to get into programming a JY unit, and 2, there not waterproof, not great for my offroad tube frame buggy.

Inject a can packet that says start? Software config option I'm not aware of? Any and all help greatly appreciated!


14AUG2023 Update. Just want to update everyone. I found a 2017 6-speed cruze (E80A also) and read the tune on it and flashed it to mine. After configuring VATS and starter diag it starts and runs great. Problem Solved.
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Spent too many hours trying to make this work on the automatic OS. There must be something happening in the background that we do not have access to.

[sbarisic]

Did you wire the injectors correctly? They should have +12V on one pin, and the ECU grounds the other pin to fire them.

[Barrymaxx]

Did you wire the injectors correctly? They should have +12V on one pin, and the ECU grounds the other pin to fire them.

The wiring harness is all stock on the engine. The engine runs great once its started, its just getting it started is the issue. The ECU never sees Crank/Start mode, presumably because it doesn't get that signal from the BCM. Once the starting fluid kicks off the ecu changes to engine run mode and all is fine.

[TheMechanic]

Post your tune so we can see if you disabled anti theft and starter correctly.

[Barrymaxx]

Post your tune so we can see if you disabled anti theft and starter correctly.

Attached! Thanks

[Barrymaxx]

Just want to update everyone. I found a 2017 6-speed cruze (E80A also) and read the tune on it and flashed it to mine. After configuring VATS and starter diag it starts and runs great. Problem Solved.
.
Spent too many hours trying to make this work on the automatic OS. There must be something happening in the background that we do not have access to.

[I_drive_4wd]

Hi, I have the exact same issue with the exact same engine setup in a Buggy as well. Any chance you could share that tune so I could flash and fix mine? Thanks!