digest
Short Summary
Main recommendation: Don't panic over a check engine light; scan the codes, erase them, and drive the car to see whether the codes return, since a light that stays off or comes back only intermittently is often a minor issue that can wait. Serious problems are indicated by a code/light returning after an erase-and-drive test, or by a check engine light that flashes while driving. Scotty Kilmer uses this approach on a car with 11 codes that otherwise runs well.
Key Points
- A check engine light comes from the car's computer detecting a problem, and it can range from serious to almost meaningless.
- Codes that return after a clearing drive, or that come and go over months, are generally less serious if the car runs normally.
- A flashing check engine light while driving signals a serious problem that needs prompt attention.
- Ignoring minor codes for a while can save money, because people who chase minor codes often spend thousands on parts that were guesses and didn't fix the issue.
- Some codes are linked to specific systems, such as ABS wheel speed sensors and variable valve timing, and can be assessed one at a time.
Details Worth Noting
- Concrete instructions: Get a scan tool and plug it into the car's OBD port to read the codes. Note all codes present (the video's example car had 11). Go to the erase codes function, select it, and press enter to clear them. Then drive the car normally for a sustained drive, about an hour in the video's example, and check whether the codes and check engine light return. The ABS light did return after the test drive, confirming an ABS problem; Scotty says you can pull the ABS fuse to disconnect ABS and revert to normal (non-ABS) brakes if you don't care about ABS.
- Example codes discussed: a P0014 code for variable valve timing, which can be addressed by changing dirty engine oil, replacing the cam shift sensor assembly, or replacing the entire cam assembly if the car runs poorly; a P0013 cam timing code handled the same way; and an erratic right rear wheel speed sensor, which can be fixed by buying the whole hub assembly with the sensor.
- The ABS codes on the example car could be largely ignored if the owner doesn't care about ABS, since the brakes revert to normal operation.
- The video stresses that the car's computer is always checking, so a light that goes off and returns later usually signals a minor problem.
Bottom Line
Check the codes, clear them, and test-drive: if the light stays off or returns only occasionally on a car that runs fine, waiting is usually safer and cheaper than replacing parts, but a flashing light or worsening performance means act immediately.
