California to start checking OBDII cars for tunes

[JSH]

Just a heads up. If you have chipped or flashed a custom tune on your car that isn't CARB certified it will fail California smog checks soon. From CARB:

My vehicle failed a Smog Check for having modified software. What can I do?

Beginning July 19, 2021, vehicles with software not provided by the original equipment manufacturer (OEM) or approved through a California Air Resources Board (CARB) Executive Order (EO) will fail Smog Check.

Before your vehicle will pass a Smog Check, you must have the vehicle’s software restored to the OEM software version. Once the software is restored, have your vehicle reinspected by a licensed Smog Check station. Note that vehicles initially directed to a STAR or Referee station must return to the same station type to complete the inspection process.

If you believe the vehicle’s software is already OEM or CARB-approved and yet your vehicle failed Smog Check, schedule an inspection with the Smog Check Referee.

If you unknowingly purchased a vehicle with illegally-modified software, you may file a complaint with BAR.

[freebeard]

[QUOTE][My vehicle failed a Smog Check for having modified software. What can I do?/QUOTE]

Move state. South Dakota, Florida or Texas; not Oregon.

[redpoint5]

[QUOTE=freebeard;652566]

[My vehicle failed a Smog Check for having modified software. What can I do?/QUOTE]

Move state. South Dakota, Florida or Texas; not Oregon.

Register somewhere else. All registration systems are based on troglodyte technology. I started accepting credit card payments a decade before the Oregon DMV started...

I've got an appointment scheduled for Aug 31st to title and register a vehicle, which was the earliest available time. The police don't cite expired and unregistered vehicles, so now's the time to steal cars and drive 'em like you stole 'em, with impunity.

Never been a better time to be a scoundrel.

[oil pan 4]

Aha, bahaahahahh,hahaha hahaha.
The government has demonstrated catastrophic lack of understanding to obd2 tuning.
I can drop the ecm out of my firebird in about 15 minutes with out any practice, pry the hot eprom chip out, insert an OEM tune eprom, then in 5 minutes move the distributor base advance to the BS 8 degree setting with a timing light.
After smog is passed put the hot eprom back in and crank the base timing back up to about 20 degrees by eyeballing it. It's good for about 2 to 3 mpg and at least 25 more hp.

[JSH]

CARB knows exactly how OBDII tuning works. Depending on how they implement their check will determine if simply flashing back will work. They could look for modified file names, the checksum, the tamper bit or all of the above.

Flashing an ECM changes the checksum. Most manufacturers (maybe all by now) put a "tamper bit" in their ECM. If the checksum ever doesn't match the correct value it flips the tamper bit which is memory that is not rewritable. That flags the ECM as tampered permanently even if it is flashed back to the factory tune. Manufacturers do this to combat warranty fraud were someone tunes a car, damages it, and the puts it back to stock and tries to file a warranty claim.

If CARB is just checking for files names and the checksum then flashing back will work. If they are checking the tamper bit then tuned cars will need to have a stock ECM to swap back in for smog testing. From my reading on this Massachusetts already checks for tunes and checks the tamper bit.

Checking the ECM is also a way to check for internal modifications that aren't visible If you have done hidden modifications (cams, pistons, valve work, gutted cats or DPFs, etc) it may be hard to get the car to run right on a stock tune.


At the end of the day this is about making illegal modifications more expensive and a hassle. This should help move people to legitimate tuning companies that do legal tuning and performance upgrades.

[Piotrsko]

Don't forget the eprom memory that tracks how many times software has been installed and Cali currently looks at. You can fudge the checksum if you can read it, load the software twice to flip the tamper bit back to original. I can buy a non neutered cpu for my VW and like oilpan4 said take 15 minutes to swap it.

Why bother? I do miss the 50+ mpg and performance the Golf has pre neuter, and the not every other day regens, but the mods violate my old age requirements of keeping it stock simple until 2013 when the fix the check engine light up to including a whole new engine and gimme a free rental warranty expires.

[oil pan 4]

Originally Posted by JSH

CARB knows exactly how OBDII tuning works. Depending on how they implement their check will determine if simply flashing back will work. They could look for modified file names, the checksum, the tamper bit or all of the above.

Flashing an ECM changes the checksum. Most manufacturers (maybe all by now) put a "tamper bit" in their ECM. If the checksum ever doesn't match the correct value it flips the tamper bit which is memory that is not rewritable. That flags the ECM as tampered permanently even if it is flashed back to the factory tune. Manufacturers do this to combat warranty fraud were someone tunes a car, damages it, and the puts it back to stock and tries to file a warranty claim.

If CARB is just checking for files names and the checksum then flashing back will work. If they are checking the tamper bit then tuned cars will need to have a stock ECM to swap back in for smog testing. From my reading on this Massachusetts already checks for tunes and checks the tamper bit.

Checking the ECM is also a way to check for internal modifications that aren't visible If you have done hidden modifications (cams, pistons, valve work, gutted cats or DPFs, etc) it may be hard to get the car to run right on a stock tune.


At the end of the day this is about making illegal modifications more expensive and a hassle. This should help move people to legitimate tuning companies that do legal tuning and performance upgrades.

No they dont.
Checking the program is laughable. The only people who are going to get caught are people who bought a used car that was "tuned" and had no way of knowing or dummies who just fragrantly disregard the law. I think they will find an overwhelming number of first one.
Bigger cam, different pistons to raise compression is not "just tuning the ECM".
If they understand obd2 tuning so well then why did it take them 25 years to think of this?

It's like having your own emissions standards and still taking all of the top spots for most air polluted cities in the United States.

[serialk11r]

Wait is it actually true that they can tell if an ECU has been reflashed back to stock? Dealers do that for factory recalls all the time, it can't possibly make you fail...

Thankfully, my car ain't registered in California, so I get to keep my mpg gains

[oil pan 4]

You could still keep your gains, you woud just have to go with out for a few days each year.

[JSH]

Originally Posted by serialk11r

Wait is it actually true that they can tell if an ECU has been reflashed back to stock? Dealers do that for factory recalls all the time, it can't possibly make you fail...

Thankfully, my car ain't registered in California, so I get to keep my mpg gains

Yes, manufacturers can tell when a ECM has been reflashed. When a dealer flashes the ECM it doesn't flip the tamper bit because it is an authorized flash that is accounted for in the new flash. The tamper bit isn't looking for the number of times an ECM is flashed - it is looking for deviations from the factory authorized flash.

Say you factory software version 1.00. The ECM will know that for version 1.00 the check sum should be A. You can flash version 1.00 as many times as you want and the checksum will be A so the tamper bit doesn't flip.

When the factory comes up with a new software version it also tells the ECM to look for a new checksum. So version 1.01 may have a check sum of B. Again, you can flash this as many time as you want.

You can also flash version 1.00 back onto the ECM without an issue.

The tamper bit get flipped when someone flashes unauthorized software, and the ECM runs a check sum and gets a result different from the expected result.


You might ask why someone making a new tune doesn't just change the checksum to so that the ECM sees what it expect to see. The answer is that it they do (you need the checksum to work or the car won't start) however the tamper bit part of the ECU that is also looking for checksums is encrypted. So the tuner will need to break that encryption.

Of course any software can be hacked but OEMs don't make it easy. In the past that encryption was model year based so if you could crack one ECM you were good and could create a tune for that specific engine and model year. Now they are VIN based so just because a tuner hacks one car doesn't mean that software will work on another car of that year. The idea is to make it not worth the effort. Of course there is an arms race between the OEMs writing the software and the tuners trying to hack it and OEMs have really stepped up their game now that the market is moving to over-the-air software updates.

Chevy claimed the C8 ECM couldn't be hacked when it was launched. I don't think anyone has been successful to date but I'm sure it is only a matter of time. The 2017 Duramax took 2 years to hack and that was with a rebuilt ECM so their is no danger to Chevy that someone will blow up their engine and then claim a warranty.