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Old 06-04-2019, 11:02 AM   #23
Steve Van Gent
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Join Date: Feb 2009
Location: Redding, Ca
Posts: 333
Re: SMOG LEGAL ENGINE SWAP TO LS yesterday passed!

Quote:
Originally Posted by mikentosh View Post
@stevevangent Which ref did you go to? I’m assuming one near Redding.

We are just starting a 5.3 swap from a clean 2003 Yukon into an ‘86 shortbox with California emissions. Trying to piece back together the 80s computer controlled carb setup looks to be a nightmare so swapping it is. On the ‘03+ trucks and SUVs it is DBW and California emissions models no longer have air injection.

Interesting to know about the VATS setup. We were unsure whether the ref would allow VATS to be disabled in the ECU, so was going to hack together something to keep it all intact anyway.
The firmware and tuning in ECU MUST be exactly as OEM rig- you may NOT turn off VATS with tuner! They will check! This adds complications; for example, the resistance value of the fuel level sender is easy to change in ECM with tuner, but NOT ALLOWED! the ECM checksum must be from written document from OEM. Any tuning changes will change checksum.

ALso, the VATS system resistor value in ignition key is read VIA the body control module and sent to the ECM over GMs proprietary com bus.

Never fear however, if the body control module came from donor car, actually just becomes wiring exercise. Once you find the ignition key resistor value, just hard-wire a fixed value resistor to body control module.
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