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Comment by spacecadet | Hacker News Reader

Engine computers can easily be reprogrammed to make the engine run at all sorts of different operating bands. You could easily detect state emissions equipment, since it must pull information from the ECU. To me- these devices are either pre-programmed operating modes that produce clean emissions but the vehicle would not operate under this tune (emissions testing is often not under load) and so once back on the road, returns to the original operating mode. OR, entirely fake modules created to trick emissions systems without altering the operating mode.

PS check out Megasquirt if you want to learn about DIY Fuel Injection. I ran a home brew Megasquirt/Megaspark system off an IBM laptop in my Volvo 740 Turbo back in the 90s, one of the things that got me into hardware.

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VW's detected emissions testing when the steering wheel was never turned.

Makes sense. As I said, emission testing is often not performed when the vehicle is being driven/under load. States could incorporate dyno testing, but its technical, complicated, and unsafe.

Is that what it was?

I though it was when the car is on a dyno only the drive wheels turn while the other 2 are stationary.

You are correct, the steering wheel approach is very smart... all I was suggesting was that dyno testing would limit the ability to defeat, but testing stations would also need to simulate more of the vehicles systems.

Manufacturers were doing this well before OBD2. They'd look for a condition where the car was started and then idle raised and held raised, for example.

Once things like CANBUS became popular, as well as ECUs getting integrated with ABS/traction control, they'd look for drive wheels spinning and but not undriven wheels. When stability control systems became a thing, they could monitor steering angle and look for the car moving but not being steered, ditto for the accelerometer not detecting acceleration and cornering.

Tuners knew all about this shit because they disassembled ECU code and looked at ROM formats. They could point you right to the table used for when the ECU thought it was undergoing emissions testing. The cheating was plain as day and no government regulators cared enough to look. They probably even knew it was going on.

Here's the billion dollar question: the ECUs aren't developed by the car manufacturers. They aren't even coded by thr manufacturers. The car manufacturer just puts in maps for various engine parameters. The ECUs are supplied by companies like Bosch, Hitachi, Nippon-Denso, Magneti-Marelli, and so on.

They almost certainly knew this was going on and were complicit. Why have none of them been held responsible?

> Tuners knew all about this shit because they disassembled ECU code and looked at ROM formats. They could point you right to the table used for when the ECU thought it was undergoing emissions testing.

I guess the EPAs awards aren’t that great.

I wonder if they also run cars sloppy when it detects something that resembles a drive-cycle for fuel economy testing. e.g. Stop charging battery. Limit A/C or turn on mild heat to reduce radfan load. Limit power steering force. Dim lights 10%. Limit acceleration (gotta be a big one).

Probably enough data out there to identify offenders by comparing real world fuel economy data to official fuel economy.

The fuel tests basically already do all that as protocol. Accesories off. Accelerations are specified and extremely low (I think it was something like 30 seconds to accelerate from 35 to 55).

Sone today you live a dangerous life.

They DID.

"A $327.5 million settlement has been reached with Bosch, the supplier of the emissions software that was installed in some 2.0-liter and 3.0-liter Volkswagen, Audi and Porsche diesel vehicles. The Bosch Settlement follows similar settlements with Volkswagen, Audi and Porsche (called the “2.0-liter Settlement” and the “3.0-liter Settlement”, or together, the “VW Settlements”)."

Yup, and I would argue most are not even doing the tuning, Bosch ECUs come pre-mapped to the FI system selected for the application. Maybe some performance models or chassis builders modify in house, but think of all the shared platforms used by all the big and now consolidated automakers...

I mean, I can tell you first hand how easy it is to trick an OBDII emissions test just by messing with the ground wires associated to the O2 sensors and bam, you have different values being report by O2...

Wouldn’t the state emissions system throw an error if a vehicle’s O2 sensor was reading 0/null?

I cant speak for very recent systems, but they are not binary, the ECU expects a range of voltage readings...

Early OBD2 downstream O2 defeats were a simple astable timer (and, for some cars, a power resistor to simulated the heater draw).

The state testing in most states now is ‘make sure the ECU is reporting “READY” and has no emissions-related codes set.’

Since the advent of OBD2, it’s become rare for a state inspection to run the vehicle live for the purpose of emissions testing. Plugging in the OBD2 scanner is way faster, cheaper, more convenient, safer, and easier (albeit slightly) on the car than using a dyno.

Notable, however, California, the largest vehicle market by some margin, still requires sniffer tests.

* for vehicles model year 1999 and older, not more modern ones.

Only on older cars, which do not have OBDII. OBDI and before that require a sniffer. OBDII has enough sensors that the sniffer isnt needed. Am in CA, and only my foxbody ever got a sniff test. All of my other (newer) cars, the sniffer wasnt used

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