Using a second computer?

J persons

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I have a '14 SHO with PP. I may have to relocate to California, and was wondering if I could use a second engine computer when I have to submit to their smog checks. The original engine computer would be tuned, but when it's time for the check I could install the computer with the factory tune in it. California has a unique way of smog checks, They query the computer and get a check sum. If there is any difference between what is stock they will fail. I don't understand it completely, but if a tune was installed and then taken out, they would know about it and fail the car.
 
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I'd guess if their software can detect whether any "non-Ford" computer changes were once made regardless of it's current status - it could also tell if the "current installed computer" is the one that came with the car or not.
 

Bluezone

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The computer uses an identification system, sort of Friend or Foe. It checks whether or not the VIN matches. Non non-vin parts are not recognized. The track only computer would have to have a matching Vin programmed.
 

tgabtg

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I have a '14 SHO with PP. I may have to relocate to California, and was wondering if I could use a second engine computer when I have to submit to their smog checks. The original engine computer would be tuned, but when it's time for the check I could install the computer with the factory tune in it. California has a unique way of smog checks, They query the computer and get a check sum. If there is any difference between what is stock they will fail. I don't understand it completely, but if a tune was installed and then taken out, they would know about it and fail the car.

Interesting... Is this a relatively new process? I'm in California and have never had an issue with returning my chipped Audi or tuned Expedition back to stock and getting it smogged. ¯\_(ツ)_/¯
 

Rsalazar35SHO

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from what I learned working as a technician at ford, one other way we could tell if and how long ago Vehicles were flashed with tunes or reverted to stock was the ignition counter. if its stock it will have like 30,000+ ignition cycles but once you flash a tune to it, it resets and same with going back to stock.



a little bit of a red flag having a car with 100,000 plus miles on it to only have 6 ignition cycles in its life time. lol
 

SHOrod

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What Rsalazar35SHO said makes more sense. The checksum should be calculated based on the loaded code, and if it's original and not corrupt, the checksum should be the same everytime. If the checker is comparing the checksum of the stock file to their database of acceptable stock files, it will match and there shouldn't be any issue. But modified code will have a different checksum which will not be in their database - possible issue. But the number of ignition cycles since codes were last cleared would be something smog checkers might key in on. Of course you could maybe have a spare, clean, new looking MAP sensor that you install just prior to going in for your smog check, and when reverting back to the stock code. Then if they challenge you based on the ignition counter, you could say you had a check engine light, the issue was due to a faulty MAP sensor, you installed a new MAP, reset the codes, completed the drive cycle, then brought your car in for the smog check. Oh yeah, you'll most likely need to complete the drive cycle after reverting to stock and before going in for the smog check.

-Rod
 

luigisho

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Interesting... Is this a relatively new process? I'm in California and have never had an issue with returning my chipped Audi or tuned Expedition back to stock and getting it smogged. ¯\_(ツ)_/¯
Curious about this as well. It seems like reverting to stock has worked in several places. When going for smog do they dig that deep vs investigating warranty work or other things? Any other Cali owners have experience on this?? Is this brand new or just an unconfirmed concern?
 

Rsalazar35SHO

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TBH, I don't think it can. not even the ford PCM knows its had its memory changed by a NON-Ford device. nothing inside it stores the device manufacturer in it. at Ford we did Roush super chargers with Ford IDS software to calibrate and tune them with some Roush programs as well. nothing ever showed up on the ECU as being modified.

the one thing I think that may be different that they can see when hooked up to the car, s the engine and trans mission Strategy. they are VIN specific and if altered would give them an indication that there is aftermarket ECU software at play. this and the combination of the Ignition cycle counter give them a good idea its been tampered with.
 

SM105K

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TBH, I don't think it can. not even the ford PCM knows its had its memory changed by a NON-Ford device. nothing inside it stores the device manufacturer in it. at Ford we did Roush super chargers with Ford IDS software to calibrate and tune them with some Roush programs as well. nothing ever showed up on the ECU as being modified.

the one thing I think that may be different that they can see when hooked up to the car, s the engine and trans mission Strategy. they are VIN specific and if altered would give them an indication that there is aftermarket ECU software at play. this and the combination of the Ignition cycle counter give them a good idea its been tampered with.
If I am not mistaken the SCT device uses the engine and transmission strategy. Pretty sure that is why the tuner asks for it specifically.
 

Rsalazar35SHO

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If I am not mistaken the SCT device uses the engine and transmission strategy. Pretty sure that is why the tuner asks for it specifically.
you are correct, but if you go look at vehicle info after the car has a tune on it, the strategy is different from when the car is stock.
 

Ta2dResqr

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If I am not mistaken the SCT device uses the engine and transmission strategy. Pretty sure that is why the tuner asks for it specifically.
I think it needs the strategy to communicate with the PCM. Somehow, it changes it though. If you tune it with a SCT X4, then you try to use ForScan, it says it cannot communicate. You then have to enter the OE Strategy Code or the PCM part number.
 

yaycandy

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If I am not mistaken the SCT device uses the engine and transmission strategy. Pretty sure that is why the tuner asks for it specifically.
So Brad has my o2 sensors to not make the check engine light come on with no cats. So an emissions place when they plug it in will fail on obd because it never reaches “obd readiness”. 30k miles on the engine and it never reaches obd readiness on the obd plug in portion. Most states dont even put the sniffer over the muffler pipe. They just plug into the obd. I dont have emissions but my performance shop is in an emissions county and wouldnt pass it for inspection because of the obd readout. But i have a friend in my county who inspects my car yearly just visual and passes it.
Ford’s computer sees the same thing. It dont read the odb correctly with a tune. Thats how they can tell its either tuned if the car runs fine.
 

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