Fact or Fiction? Debunking the Top 5 Tire Pressure Monitoring System Myths

Truth or dare...true or false...tire pressure monitoring system (TPMS) repair is now as commonplace and necessary to understand and deal with as a standard oil change. I remember my first GM Computer Command Control class back in 1980. Leaving class that day, I recall thinking that this was going to be a specialty type of system to repair. Not everyone would want to get involved. As time went on, it became evident that some shops chose to stay current on computerized engine controls and some didn't. Even today, there are areas of repair that a shop may elect to stay away from. "We only fix the simple things," is a common battle cry. But today, define simple. The truth is, even putting air in tires or replacing them is a technology-based event.

Every shop that does oil changes and checks tire pressure is facing the technology challenge just as much as the shop that deals with scan tool-level computer diagnostics for any system on the vehicle. The truth is, tire service has changed in a very short period of time. Currently, there is an abundance of misinformation regarding TPMS. Let's go for a ride and separate the facts from fiction.

MYTH NO. 1: TPMS repair is a long, laborious process that often times delays shop productivity while tying up valuable time and resources.

Reality: FALSE TPMS service can be both quick and profitable if you are prepared to deal with the technology. There currently are two types of systems on the market: direct and indirect. While their reset and service procedures are as varied as the vehicles they are on, if you have the tools and knowledge, you can fix it efficiently and quickly. It's up to you. No knowledge or tools,no easy fix. But that's true in many areas of auto repair today, isn't it?

MYTH NO. 2: A direct TPMS requires a TPMS tool, while indirect does not in order to reset the light or service the system.

Reality: FALSE You will need the tool for both types. You will find information contained within the tool that tells you how to reset either system. So if you are a smaller shop or a quick lube without an electronic information source, or you're on a limited information budget, consider the tool. A complete TPMS tool will provide the means, the methods and the information required to service each system. By the way, if you're wondering what the differences between the two systems are, it should be in the tool you buy. That's what helps make it complete.

MYTH NO. 3: When doing a tire replacement, repair or service of some kind on a vehicle equipped with TPMS, as long as you let all the air out and refill the tires to the manufacturer's specifications, you don't need a TPMS tool.

Reality: FALSE. Well, actually it depends. Did someone turn the key on while the air was out of the tires and the vehicle was in the bay? Were the tires low on pressure when the vehicle came in? Are they all at different readings that will be corrected when the tire service is complete? Many systems require sensor ID or sensor training in order for the vehicle's TPMS module to operate properly. Each time you replace or rotate tires/wheels (or if a defective sensor is replaced), the TPMS module or TPMS sensors may need to be retrained/reprogrammed. On many vehicles, "sensor ID" is needed to inform the driver of the correct tire location when the TPMS light or warning comes on. If the sensors are not reprogrammed, the system will report incorrect information: low tire pressure, but wrong position on the vehicle information console or instrument cluster.

And while we're on the subject of servicing a TPMS vehicle rim, are you aware that you will need some special tools to remove and install stems? Also, the valve core is unique on one of these; you should not use a standard core. But you already knew that, didn't you?

MYTH NO. 4: Having a scan tool is more important than having a TPMS tool.

Reality: FALSE Unless it's a factory scan tool for the particular vehicle line you're working on, an aftermarket scan tool will not let you reset a TPMS light or train the sensors. Fact is that you need both, period. Chances are you will use a TPMS tool more. Think about how many oil changes you do in a day. How many times does someone in your shop check or reset tire pressure? Probably a lot more times than they use a scan tool. And how long will it be before that someone, by accident or otherwise, sets off a TPMS dashboard light, which in turn will set off the customer if you can't reset it?

MYTH NO. 5: For vehicles that run on a separate set of wheels or tires during winter, sensors must be trained or installed when the summer/winter tire changeover is performed.

Reality: TRUE Depending on where your shop is, some vehicle owners have two sets of rims or tires. When you swap their tires over, you need to be able to service the TPMS. It may mean swapping sensors over or installing new ones, but without a tool and/or knowledge of the system, you will be limited in how you are able to perform this and other tire-related services. Without a complete tool, you are running the chance of creating more work and headaches. But then again, this business is so easy to run, you would enjoy the challenge, right?

The bottom line is

Tire pressure monitoring systems are here to stay, and the need to understand them is as self evident as to how many times we check and reset tire pressure. No tool or knowledge? "Houston, you have a problem!"

Beginning in model year 2008 (by September 2007), TPMS has been standard equipment on all vehicles sold in the United States. Depending on the vehicle, you may or may not get caught in the "Gee, my TPMS light has been on since you last worked on it" scenario. Unless you're planning to stop putting air in tires altogether, you will have to purchase a TPMS tool. Make sure it's a complete system, giving you both information and the capability to service a wide array of vehicles. Having a tool that only performs resets won't cut it for long — as you will need information along the way. Be sure that the tool has the ability for "in the bay updates" so there is virtually no downtime if you happen to get caught short in an "information vacuum" that can exist from time to time.

And lastly, complete tools will provide the correct special tools needed when servicing the hardware of these systems. What used to be a simple repair, such as core and stem removal, now requires an exact procedure and tool. Simple doesn't seem to exist anymore, but hey, that's why we came into this conversation, right?

Ron Ananian, aka The Car Doctor on WOR Radio Network's nationally syndicated show, draws on his media experiences, relationships with leading automotive industry companies and insights from his own repair facility (R/A Automotive) to share with Motor Age readers.