Alignment and Scan Tools – UnderhoodService

Alignment and Scan Tools

How can centering a steering wheel during an alignment cause a vehicle to turn a blind eye?

In the past two years we have seen more vehicles on the market with stability management and adaptive cruise control. If a vehicle with one of these systems comes into your shop for alignment, be aware that any changes in the steering position sensor’s “zero” position may have drastic consequences for the safety of the vehicle. These systems use multiple inputs from different sensors to set the distance from the cars in front. If the data from one of these sensors is false, it could cause the system to go blind.

Adaptive cruise control builds on the functionalities of the cruise control system and, within certain system limits, maintains the correct distance from the vehicle in front – automatically. The system uses a special radar sensor to measure the distance from the vehicle ahead. If the distance is too small, the system reduces speed moderately by easing the throttle or it automatically activates the brakes, up to approximately 25 percent of maximum vehicle deceleration. Once the road ahead is clear again, adaptive cruise control accelerates the car back up to the speed previously set.

If the braking process activated by the adaptive cruise control does not decelerate the vehicle sufficiently, an acoustic signal is triggered immediately to warn the driver to intervene manually. An outstanding feature of adaptive cruise control is its driving dynamics. The program maintains a short distance from the vehicle in front and accelerates swiftly back up to the journey speed set if the road ahead becomes clear.

Even if adaptive cruise control is activated, the driver is still responsible for monitoring his vehicle’s speed and the distance from the vehicle in front. Adaptive cruise control does not react to stationary objects or approaching vehicles.

The radar systems on these vehicles are designed to look at what it thinks is in the lane ahead while monitoring the cars in the lanes next to it. Since the radar sensor does not move, to interpret the radar signals it looks at the input from the steering position sensor. If a technician centers the steering wheel during an alignment without “zeroing out” the steering position sensor with a scan tool, it could cause some problems.

If the steering position sensor is giving a false reading, the information from the radar sensor is interpreted differently. Since the car now thinks that it is turning, the computer might think that that car in front might just be a car in the next lane over. The vehicle probably will not hit the approaching vehicle, but the driver will notice abnormal operation like rapid deceleration or brake engagement.

On these systems, the radar unit may need to be aligned. If the rear suspension is adjusted and the thrust angle is altered by damage or adjustment, the radar sensor on some Audi models may need to be adjusted with specialty tools.

It is critical that the technician look for these systems on 2004 and newer vehicles that come in for alignment. Typically, these systems are only found on high-end models from Audi, BMW and Cadillac. But, these systems are being offered on many mundane models for 2006, like the Toyota Sienna Minivan. Some aftermarket scan tools can reset the steering position sensor to zero, or at least let you read the input from the sensor to determine if there is a problem.

You May Also Like

HVAC Sensors: More Than Just Temperature

When a driver sets a temperature in the control head of an HVAC system, what does it mean to the vehicle? Seventy-two degrees could mean many different settings depending on the outside temperature, humidity and even the position of the sun.

When a driver sets a temperature in the control head of an HVAC system, what does it mean to the vehicle? Seventy-two degrees could mean many different settings depending on the outside temperature, humidity and even the position of the sun.

When a passenger decides that 70 degrees is a better temperature for their zone, things get even more complicated. Automatic Temperature Control (ATC) systems require a complex array of internal and external sensors that include ambient air temperature sensors, interior temperature sensors, outlet duct and evaporator temperature sensors, pressure sensors, humidity sensors, blend door position sensors and sunload sensors.

Nearly 5,000 To Participate In Auto Value, Bumper To Bumper ‘Festive Walk’ To AAPEX 2018

On Thursday, Nov. 1, nearly 5,000 Auto Value and Bumper to Bumper automotive professionals wearing matching yellow shirts will begin their “festive walk” from the Mirage hotel to AAPEX 2018 at the Sands Expo, temporarily shutting down the busy Las Vegas Boulevard along the way.

Drive Belt Checklist: What Are You Missing?

You might have only one chance to sell a customer a new serpentine belt. With belts lasting roughly 90,000 miles, proper inspection at the time of failure is critical not only for selling the belt, but also for ensuring add-on sales and better customer satisfaction.

VIDEO: Using Airflow To Sell Cabin Air Filters

Andrew Markel introduces an inexpensive tool that can assist in selling cabin air filter replacements. Sponsored by Auto Value and Bumper to Bumper.

Air Conditioning Odor Causes

Air conditioning odors typically result from the uncontrolled growth of bacteria and other microorganisms in the evaporator. Research by independent laboratories has found fungi such as Aspergillus, Cladesporium, Penicillium and others growing on cooling coils and other A/C system areas.

ac air conditioning smells featured

Other Posts

Bolster Your Steering and Suspension with Delphi!

A vehicle’s steering and suspension system is integral to its ride, handling, safety, and must always be up to the job–that’s where Delphi comes in. All Delphi chassis parts undergo rigorous dimension, material, durability, temperature, and performance tests to ensure they meet or exceed OE specifications at every turn. Because Delphi’s debut in steering and

Climate Control Modules

HVAC control modules may fail when the contacts and switches become inoperable. Sponsored by The Group Training Academy.

Dorman Launches 300+ New Products In November

Among the new products is an OE FIX climate control module designed to fit 1.7M Chevrolet Express & GMC Savana vehicles.

Curing Springtime Air Conditioning Smells

Air conditioning scents can come from a host of things.