There is a disturbing bias among the three major American television networks. They love to sensationalize problems with cars and trucks.

The general coverage may not be the most even-handed journalism, but it is basically legitimate. The real problem is the networks have a penchant for broadcasting fraudulent reports in which cars have been secretly tampered with to fail spectacularly. In 1986, the CBS television program “60 Minutes” featured a consultant who was paid by plaintiffs suing Audi to jerry-rig an Audi 5000. He drilled a hole in the transmission, attached a canister of compressed air and made it look like the car could accelerate all on its own.

That played in beautifully with the news program’s attack on the Audi 5000 for sudden unintended acceleration. The public bought it, hook, line and sinker, and it helped bring Audi’s U.S. sales to a screeching halt.

If it hadn’t been for the deep pockets of parent company VW, Audi would have been out of business in the U.S.

In 1992, producers of “Dateline NBC” paid a consultant to rig a Chevrolet pickup truck to burst into flames when a vehicle crashed into its side-mounted fuel tanks. The fiery footage was used to bolster “Dateline’s” show attacking General Motors for having unsafe gas tank designs.

But viewers never were told the fuel system had been compromised or that the vehicle was outfitted with pyrotechnics to ensure it would catch fire.

In an impressive piece of investigative work of its own, GM uncovered the fraud. The network had to settle a lawsuit with the auto maker and publicly admit the crash test was doctored.

Last year, “ABC World News” aired a report in which an auto electronics expert modified a Toyota Avalon to cause it to suddenly accelerate, seemingly all on its own, as part of a story on unintended acceleration involving Toyotas.

An investigation by Toyota later revealed the expert had introduced new parts and re-engineered Toyota’s circuitry to produce the result, something that couldn’t happen on its own in the real world. But viewers were never told.

These are the most egregious examples of how the major television networks misrepresent problems with cars. But they’re not the only ones.

Even more insidious is how the networks turn to “consumer advocates” as sources for their stories, but rarely disclose the advocates’ vested interest in seeing lawsuits filed against auto makers.

Organizations such as the Center for Automotive Safety and companies such as Safety Research and Strategies derive much of their income from plaintiff attorneys. They consult with and sell data to the attorneys, who use the information to sue auto makers.

They also publish information that helps steer the public to litigators. There is nothing wrong with that. But it is wrong for major TV networks to quote these sources without acknowledging their conflict of interest.

I don’t know why ABC, CBS and NBC use a different journalistic standard when reporting on automotive issues. The quest for ratings, alone, does not explain it. They simply are biased against the auto industry. What I can’t explain is why.

John McElroy is editorial director of Blue Sky Productions and producer of “Autoline” for WTVS-Channel 56, Detroit, and “Autoline Daily,” the online video newscast.