The first step in any TPMS diagnostic strategy is to figure out whether or not your customer’s vehicle actually has a TPMS problem. Why? Simply put, there are a number of factors that can cause a TPMS warning light to illuminate or flash – and some are hard to uncover.
Automatic hubs are used on many 4×4 trucks to disengage the front wheels when four-wheel drive is not needed. Disconnecting the front wheels reduces friction and may improve fuel economy as much as one mile per gallon depending on the vehicle. A one mpg difference may not sound like much, but every little bit helps.
When engineers came up with the idea of putting the wheel speed sensor (WSS) and tone ring inside a sealed wheel bearing hub assembly, it seemed like a great idea. The sealed environment would help protect the sensor and make it less vulnerable to damage or contamination from the outside.
In 2005, Ford introduced a new Mustang with an all-new platform and clean-sheet design. While the formula of a live axle rear and MacPherson strut front end were the same from the previous SN95 and Fox body, Ford refined the design for larger rims by making the bushings larger. These changes made for a vehicle
Everybody who works on brakes knows what brake rotors do. They provide a friction surface for the disc brake pads to rub against when the brakes are applied. The friction created by the pads rubbing against the rotor generates heat and brings the vehicle to a stop.
Driveshaft problems can be spotted from the moment you put the vehicle in gear to pull it into a bay. As the power is transmitted from the transmission to the rear axle, the slack from worn or damaged components is taken up, resulting in a sudden crunch or pop.
Brake calipers are a key component in a disc brake system. The calipers use hydraulic muscle to squeeze the brake pads against the rotors. The clamping force creates friction between the pads and rotor that slows the vehicle and brings it to a halt. If a caliper is leaking or sticking, however, it may not apply the brakes properly.
There are no recommended replacement intervals for brake pads because pad life varies widely depending on how a vehicle is driven, the type of brake pads on the vehicle, the driver’s braking habits and even the design of the brake system.
The first step in any diagnostic strategy is to figure out whether or not your customer’s vehicle actually has a TPMS problem. Any number of things can cause the TPMS warning light to come on or flash. The light should illuminate when a tire is low, and should eventually go out after the low tire has been inflated to its recommended pressure. If the light remains on after checking/inflating the tires, or if it flashes and remains illuminated, it may signal a TPMS problem that will require further diagnosis.
If all of the wheel speed sensors are generating a speed signal, and they all agree, the wheel speed sensor (WSS) is not an issue, but something else might be, possibly an intermittent wiring fault in one of the WSS circuits. If one of the WSS PIDs reads zero mph, and the other three are
Indirect Tire Pressure Monitoring Systems (TPMS) began making a comeback in 2011 on all Audi models. The highly popular Honda Accord switched to indirect TPMS for the 2013 model year. The 2013 Mazda CX-5 is now also using an indirect TPMS. Some of the VW Golf platform vehicles have switched to an indirect TPMS. Most of these models have the optional ABS and stability control system.