Dear Jim,

The ABS indicator light has been coming on in my 1999 Chevy Silverado. It only happens when I get up to speeds of about 40-50 mph, and sometimes both the fuel and volt gauges drop lower at the same time. What's making this happen?

-- Pete Gladwell

The first thing you should check, bro, is the anti-lock braking system (ABS). When that warning light comes on in a Silverado like yours, it usually means the electronic braking control module (ECBM) isn't responding the way it should. Normally, wheel sensors detect differences in rotation speed and report to the ECBM, which triggers the ABS motor to kick in and start pulsing the brakes.

It's possible that those sensors are dirty and need to be cleaned, but most likely that ECBM unit has gone bad and now isn't able to understand what the sensors are telling it about the wheels.

It'll need to be replaced, but have those other gauges you mentioned checked too. Through the magic of modern vehicle electronics, all this stuff is interconnected. In fact, bro, the fuel and volt gauges are part of the instrument panel cluster, which works on the same data line as the ECBM, the body control module (BCM), the power control module (PCM) and the automatic transmission control (ATC).

There could be more general problems with this circuit that may or may not be caused by the bad EBCM.

Tip of the week:

Most of you probably have seen those flashing red arrows that some cars have on the driver- and passenger-side mirrors. Not only are these extra turn signals a great way to improve driving safety, but you probably can have them installed on your current vehicle.

A company called Muth Mirror Systems makes after-market versions for an assortment of car and truck models, and they're powered right off the turn signal circuit you already have.

These things work with high-intensity LED lights that are very visible to other vehicles on the road (particularly the ones in your blind spots), but not so bright that they annoy you or your passenger. With so many accidents resulting from unseen signals, this is just a good way to make your turning and lane-changing intentions more easily known. Our friends on motorcycles will especially thank you.

By the way, bikers, they make these units for you too.

Buffalo Jim, owner of Allstate Auto & Marine Repair in Las Vegas, writes a weekly column. Send your automotive questions to him at buffalojim@lasvegasniftynickel.com. If Jim picks your question to answer in Nuts & Bolts, you'll also be the proud recipient of a deck of official Buffalo Jim playing cards, presented in a classy, tin box bearing his hairy image.