Would you replace a drum without changing the shoes? Andrew Markel discusses what must be performed when servicing rear rotors that use a drum in the hat of the rotor. Sponsored by Auto Value and Bumper to Bumper.
Courtesy of Brake & Front End.
Author: Tomorrow's Technician Staff
Tomorrow’s Tech (TT) delivers technical information for servicing today’s vehicles to more than 40,000 automotive students enrolled in more than 1,100 technical and vocational schools across the country.
Access to secondary waveform testing is nearly impossible on some modern coil over plug ignition coils. But what if you need to check the secondary circuit function of the coil? The solution might be scoping the current ramp. Sponsored by Blue Streak.
Using a scope and a low-amperage current clamp to measure and display current flow through the coil’s primary circuit can give you an indication of the health of the secondary side of the coil.
Checking the resistance of the coil can show if it’s good, shorted or open. Modern e-core or coil-on-plug systems might require as much as 8 amps of current at 12 volts to provide 30-60 kV of high-intensity spark. The driver of the primary circuits can be a non-current-limiting design, which creates a pointed current ramp waveform.
But some primary circuits can be a current-limiting design that creates a “flat-top” waveform indicating that the primary current is being limited to predetermined values.
On some vehicles, access to the primary circuit can most often be obtained through the “ignition” fuse in the vehicle fuse box or directly at the primary ignition wiring harness leading to the ignition coils. In many cases, all of the system’s ignition coils are powered by a single wire, which simplifies attaching an inductive current probe. For ignition systems with no other access, a set of jumper wires can be used to attach an inductive current probe.
If the coil driver in the PCM is ruined, it’s always good procedure to check the current ramp on the ignition coil. Remember that most ignition coils shouldn’t draw more than eight amps. If in doubt, compare amperage draw with a similar known-good system. If a coil is drawing excessive amperage, the primary circuit might be shorted which, in turn, might ruin the new PCM or ICM.
Courtesy of Underhood Service.
Battery replacement is one of the most common repairs performed by a shop, but some late-model vehicles require more than just attaching the cables and hold-downs. Many require an extra procedure to be performed with a scan tool to reset the battery monitors for the power management system. This video will also cover how Ford vehicles determine the state of charge of the battery so it can alert the driver to a potential no-start situation. Sponsored by Auto Value and Bumper to Bumper.
Courtesy of Underhood Service.
The ignition process seems like it’s a process of turning a key or pushing button – but it’s a little more complicated than that. It has to do with the charge in the ignition coil. Sponsored by Blue Streak.
A coil takes a finite amount of time to build up this charge. This is the dwell time, normally defined as the camshaft’s degree of rotation, during which the voltage flows through and charges the primary side of the coil. It is measured in degrees on older distributor systems – on modern ignition systems it is measured in milliseconds.
Back in the day of points and condensers, checking the dwell was part of an all-around tune-up. Because of the constant electrical arc between the points contact area, they would wear down and change the dwell periodically, which led to readjusting the point gap or replacing them regularly.
Dwell is regulated by the engine management system to optimize the strength of the spark required, voltage and the design of the coil. With today’s cars and their computer-driven electronic ignition, dwell can no longer be adjusted with a screwdriver and thickness gauge.
Dwell can still be used as a diagnostic test to determine if the ignition system and components are functioning correctly. The dwell will change depending on conditions inside the coil and combustion chamber. However, to see this, it requires the use of a scan tool and not one of these old dwell meters.
Too little dwell time and the coil won’t have time to charge up fully and you’ll get a weak spark. Too much dwell time and the coil loses some of its charge and can also cause a weak spark. Too much dwell can also cause the coil to overheat and cause the coil to breakdown and fail internally.
Most importantly, the dwell for modern engines is calculated on the design and construction of the original ignition coil. If a replacement coil does not match the OEM’s design for the windings and internal componentry, it might cause drivability issues and have a much shorter life.
Courtesy of Underhood Service.
Most late-model vehicles use a computer module to control the exterior lights on a vehicle. These modules can detect errors or problems with the lighting circuits like light high resistance, shorted and open circuits. When a bulb burns out it can produce a message in the instrument cluster and even a code. Andrew Markel discusses the procedures required to troubleshoot the circuit and to get the message to go away. Sponsored by Auto Value and Bumper to Bumper.
Courtesy of Underhood Service.
One of the most forgotten or misdiagnosed components is the seal between the master cylinder and the brake booster. If the seal or O-ring is leaking, it can cause a driveability issues with poor idle quality and lean DTC codes. Also, it can cause a hard brake pedal complaint from the driver. Andrew Markel covers how to inspect, replace and condition this critical seal. Sponsored by Auto Value and Bumper to Bumper.
Courtesy of Underhood Service.
Is the misfire the fault of the ignition coil, spark plug or could it be the spark plug wires. We’re going to find out how to test and rule out the wires. Sponsored by Blue Streak.
Ignition wires may not be as popular as a decade ago, but there are a lot of wires out there connecting spark plugs to coils and distributor caps.
Since they have to live under the hood, ignition wires are subjected to heat, oil and vibration. They can fail and cause a misfire and code.
Be sure to first visually inspect the wires and engine.
One of the most damaging elements under the hood is vibration. Excessive vibration can loosen the connection at the coil, plug or distributor cap. This can increase the resistance and energy required to fire the spark plug and damage the spark plug. Look at the general condition of the engine and check for issues like vacuum leaks and even excessive carbon deposits. Also, look at how the coils and wires are mounted to the engine.
Heat can burn wire insulation and boots. If the wire or boot is crispy it is more likely to offer the spark an easier path to ground. Look for missing heat shields and spark plug wires that were not properly routed past exhaust manifolds.
Look at the wire to see if there is any damage due to rubbing against other engine parts. Abrasions to the outside of the wire insulation can cause sparks to jump and impacts can crush and damage the wire inside insulation. Make sure to inspect the motor and transmission mounts for excessive movement.
Last, use an ohmmeter with the leads attached to both connectors of the spark plug wire. The resistance for most resistor core wire is between 10,000 to 12,000 ohms-per-foot. However, consult the service information for the correct value.
By performing these easy checks, you can determine if the spark plug wires are the problem or it is another component in the ignition system or on the engine.
Courtesy of Underhood Service.
Alfred State College of Technology Instructor Jason Kellogg works with students in a recently rebranded ‘Race to 2026’ technical training facility at the school.
Icahn Automotive recently celebrated the opening of a rebranded “Race to 2026” technical training facility at Alfred State College of Technology. Alfred State is a State University of New York (SUNY) and a traditional residential college of technology.
“Alfred State graduates are in a unique position because they graduate with the technical skills to perform automotive service, plus the business acumen that’s needed to manage a shop,” said Brian Kaner, CEO-Service, Icahn Automotive. “As a national service network that can both put students to work part-time and put them on the path of owning their own franchise someday, we’re excited about the possibilities for Alfred State students.”
As one of the largest service network operators in North America, Icahn Automotive offers a broad range of industry-leading opportunities and career paths. Technicians can start by providing basic maintenance and move on to more complex repairs, or progress to running a company-owned store, owning and operating a franchised business, or serving in a corporate leadership role. Once a technician joins an Icahn Automotive business, they can take advantage of benefits such as an apprenticeship program, company-sponsored certifications and more.
“Our partners enable us to provide opportunities to the students that might otherwise not be possible,” said Eric Wilmot, Chair, Automotive Trades Department, Alfred State College. “The updated technical facility has given our students a better environment in which to apply what they’re learning, and we’re looking forward to working closely with the team at Icahn Automotive to provide the students with jobs when they graduate. The automotive program relies on industry support to meet our technical and equipment needs, and our relationship with Icahn is a perfect example of how education and industry can work together for mutual benefit.”
Alfred State’s automotive technology program is NATEF Master Certified and draws students from across the Northeast. Graduates take advantage of Alfred State’s reputation by accepting technician positions across the country. The investment at Alfred State is a critical part of the Company’s larger, national “Race to 2026” technician recruitment initiative, which has invested in and supported promising future automotive technicians through scholarship, partnerships with schools, and continuing education opportunities, in an effort to fill the projected automotive technician gap. Throughout the course of the initiative in 2019, Icahn Automotive has made investments in dozens of technical training schools across the nation and awarded $50,000 in scholarships to students studying at automotive trade schools.
Icahn Automotive is an Icahn Enterprises L.P. company, which owns and operates leading repair and maintenance providers Pep Boys, AAMCO and Precision Tune Auto Care.
Attention automotive students! Tomorrow’s Technician wants to know what factors influence your career choices.
Help us out and take our brief, anonymous survey. It should take you less than five minutes to complete.
Students who complete the survey will receive a FREE Redbox movie rental code!
Complete the survey at bit.ly/T2CareerChoices.
Categories
Maintenance Matters: A Tire In Winter
In much of the country, all-season tires are the go-to choice for drivers. They offer reliable, consistent performance in a variety of road conditions. However, increasingly, “all-weather” tires are becoming the popular choice.
According to Tire Review magazine, all-season tires are designed to perform in a wide variety of temperatures and conditions but may prioritize attributes such as wear and ride comfort over snow performance.
In contrast, the all-weather tire has more characteristics of a winter-type compound that’s able to provide a reasonable amount of mileage for consumers who want to run it year around.
All-weather tires are also designed for year-round performance but are “three-peak mountain snowflake certified, meaning they offer more advanced snow performance than all-season tires.
All-season or all-weather? Sometimes the choice is neither. If your customers decide their best option is to change from summer to winter tires each years, the changeover brings with it a need for consumers to make some decisions. Should they swap tires on the original wheels or should they have a second set of wheels with snow tires already mounted? Cost and convenience will be factors – but regardless, don’t forget safety.
The decision to purchase or not purchase a second set of wheels needs to be followed with questions about TPMS sensors.
Performing changeovers can decrease the time for your return on investment for the equipment you have purchased to service TPMS equipment. Selling a second set of TPMS sensors can be profitable and there are also several more options for sensor service today than were available just a few years ago.
Shop technicians need to pay attention to the TPMS components to ensure proper sensor operation and an air-tight seal. Exposure to road salt and other ice-melting chemicals can take its toll on TPMS components, according to the Tire Industry Association (TIA).
Changeover Challenges
There can be certain difficulties with some vehicles when using the same sensors on summer and winter wheel assemblies. A TPMS relearn procedure may be necessary if the same sensors are used for both tire sets, but their positions on the axles change.
According to Sean MacKinnon, TIA’s director of automotive training development, “Using a handheld TPMS scan and programming tool, test each tire for sensor activity. Test results will indicate if any changes are needed to the customer’s setup of the winter tires. The technician can then inform the consumer of the proper service steps that can ensure a successful changeover.”
MacKinnon reminds shops that a TPMS relearn fee is becoming more common, especially if the customer has not made a major purchase at the service location. At this time, it’s rare to find vehicles with on-board computers capable of tracking two different sets of tires’ TPMS information. This feature, however, is found on several Toyota and Lexus SUVs and minivans, according to MacKinnon.
Of course, this time of year brings more glowing TPMS warning lights as cold temperatures cause a drop in tire pressure. MacKinnon reminds technicians to check the spare tire since an increasing number of vehicles with full-size spares are equipped with a fifth TPMS sensor.
Back To Summer
Sooner or later, the threat of snow will end and the switch to summer tires will begin. The same changeover process will take place. The vehicle may require a system relearn, and the TPMS should be inspected depending on what type of services take place during the seasonal exchange.
If a consumer refuses the service, many locations are opting to decline the business. Should a consumer choose to buy winter wheel-and-tire assemblies and the vehicle is TPMS-equipped, the service location should require the customer to implement TPMS for the winter tire set.
Article courtesy ImportCar.