-
Welcome to Auto Parts Forum
Whether you are a veteran automotive parts guru or just someone looking for some quick auto parts advice, register today and start a new topic in our forum. Registration is free and you can even sign up with social network platforms such as Facebook, Twitter, Google, and LinkedIn.
How To Replace the Throttle Position Sensor on a Jeep Cherokee
-
Similar Content
-
- 0 replies
- 25 views
-
- 0 replies
- 53 views
-
- 0 replies
- 46 views
-
- 0 replies
- 40 views
-
- 0 replies
- 33 views
-
-
Similar Topics
-
By Counterman
Niterra North America Inc., formerly NGK Spark Plugs (U.S.A.) Inc., announced that the company is introducing 20 new part numbers for its O2-sensor line.
The new part numbers, sold under the company’s NTK brand, represent an increase in coverage for more than 4 million domestic, European and Asian vehicles in operation, according to Niterra North America.
“These 20 new part numbers fit a variety of late-model domestic and import vehicles and range from entry-level economy cars to luxury cars to cargo-vans to sport-utilities,” said Matthew Bickford, NTK product manager, aftermarket. “NTK is committed to application coverage leadership and providing service providers the latest OEM technology and we are excited to be able to extend our latest sensor technology into the aftermarket with these applications.”
For more information about Niterra and the NGK Spark Plug and NTK product brands, visit
link hidden, please login to view. The post
link hidden, please login to view appeared first on link hidden, please login to view.
link hidden, please login to view -
By Counterman
As modern cars and light trucks continue to grow in complexity, their maintenance needs are changing. Component failures that were commonplace just a decade or two ago are becoming much less common today.
An example of this is the throttle-position sensor (TPS). This small plastic sensor would be mounted on the throttle body, usually on the opposite of the throttle cable. The TPS was used to tell the engine control unit (ECU) what angle the throttle body was being opened to by the driver, and the ECU would adjust the fuel as needed based on this data as well as other inputs.
A faulty TPS reading can cause a number of drivability concerns, including:
• Unexplained bucking or jerking of the engine
• Surging engine idle
• Engine stalling, stumbling or hesitation
These sensors were rather inexpensive and usually pretty easy to replace. They didn’t fail too often, but I can remember having to replace them on a few of my own vehicles, as well as some customer vehicles. So what happened to throttle-position sensors, and why don’t we see them as often today?
Throttle-By-Wire
Throttle-by-wire technology has been called by many names, but it operates on a simple principle – an electronic throttle body is used to meter the air entering the engine. This electronic throttle body is controlled by the ECU based on a number of inputs including accelerator-pedal position, mass airflow, manifold air pressure, wheel speed and more. But the important thing to understand is that there is no longer a mechanical link between the accelerator pedal under the dashboard and the throttle body on the engine. So why is this important?
By decoupling the accelerator pedal from the throttle body, automakers are able to precisely control the throttle angle in all operating conditions to maximize throttle response and traction, reduce emissions and improve fuel economy. Throttle-by-wire systems are able to maximize the benefits of variable-valve timing and direct fuel injection by precisely controlling how much air is introduced to the engine.
With the advent of throttle-by-wire systems, we’ve seen a change in how the ECU measures the throttle position. The TPS still is being used today, but it’s now incorporated into the electronic throttle body. In fact, some electronic throttle bodies may contain more than one TPS. By using multiple sensors, the ECU can monitor and compare both sensor inputs. Redundancy in electronic systems can be a very good thing.
We’ll talk more about the pros and cons of throttle-by-wire a little bit later, but the fact that the TPS is now incorporated into the electronic throttle body can be a big drawback down the road. You see, it means that the system is now less serviceable than it was in the past. If a TPS failed on a cable-driven throttle body, you could replace the sensor for around $30 to $40 and be back on the road. If a TPS fails inside an electronic throttle body, now you have to replace the entire unit, and that could cost hundreds of dollars.
Then, after the electronic throttle body has been replaced, you’ll need to perform a “relearn procedure” so the ECU can learn how the new throttle body reacts to input, and where the internal mechanical stops are located. Failing to perform this critical step can cause a number of drivability concerns, and a costly customer comeback.
There has been a trend in the automotive space for quite some time now where components are becoming more and more “modular.” When I say “modular,” I really mean “pre-assembled.” After all, vehicles are engineered to go down the assembly line as fast as possible. They’re not engineered to be easy to work on. So it makes sense that automakers would get creative with incorporating certain components together into a modular assembly that can be installed more quickly. Of course, the major drawback with this idea is that the replacement costs are increased, and that cost will eventually fall onto the vehicle owner once the warranty period expires.
Advantages & Disadvantages of Throttle-By-Wire
Throttle-by-wire systems offer a number of advantages. They contain fewer moving parts, so that means less maintenance and lower overall vehicle weight. Their precision allows for improved fuel economy and reduced tailpipe emissions, as well as a better overall driving experience for the typical driver. Finally, the throttle body can be used to help the traction or stability control regain vehicle control.
These systems also have a few drawbacks. They’re more expensive to develop, manufacture and replace. They’re more complex due to the wiring and electronic control units that are used. Some drivers may complain about a time delay or “lag” in engine response after they change their accelerator-pedal input.
Finally, they’re harder to service for technicians. Sure, there aren’t any cables or linkage points to grease or maintain, but the real difficulty lies in the electronic controls. Complex wiring and communication systems are needed in order to control the electronic throttle body and related systems. There also are special procedures that must be followed whenever servicing the electronic throttle body. If an electronic throttle body is replaced, the relearn procedure must be performed. This has a profound effect on engine performance, drivability and idle quality.
If you find yourself selling a replacement electronic throttle body to a customer, there are a few questions you should be asking. Do they have a scan tool that’s capable of bi-directional control? A simple code reader won’t work here. They need the real thing in order to relearn the new electronic throttle body. Many electronic throttle bodies are installed in plastic intake manifolds, so it’s a good idea to sell them a new throttle-body seal as well. Finally, it’s a good idea to check with the customer to see if they’ve inspected the wiring harness and connections for any signs of rubbing, fraying or other issues. These sorts of problems can come back to bite them later on down the road.
The post
link hidden, please login to view appeared first on link hidden, please login to view.
link hidden, please login to view -
By Counterman
I love this topic. Unfortunately, many brake rotors end up unnecessarily in the scrap pile. But I also know the reasons why, and if I’m looking to place blame, well, we only can blame ourselves. But is it bad? I’ll get into that down the page, but let me set the stage first.
Types of Rotors
Up through the mid-‘70s, the majority of all brake rotors “on the road” were hubbed rotors. What this meant is that the hub was cast into the rotor. Most cars and trucks up through that time were rear-wheel drive, and if they had disc brakes as an option, 99% of the time it was on the front only. The front wheel bearings of these cars were housed in the hub of the rotor. The rotors were very heavy and expensive to produce, and the wheel bearings were the tapered style of roller bearing that required regular cleaning, greasing, adjustment and seal replacement.
As front-wheel-drive cars grew in popularity in the mid-‘70s, so did the hubless or “hat” style of brake rotor. Hubbed rotors remained in regular use up through the mid-‘90s, but their popularity steadily declined until the hat rotor became almost the sole design choice of auto manufacturers. Hat rotors were far easier to service, with the front wheel bearings being sealed units mounted into the front steering knuckle. Hat rotors simply slid into place, and they were lighter-weight, less expensive and easier to manufacture.
It’s All About the Metal
Brake rotors get hot during braking, and they need to dissipate heat quickly. Functionally, all a brake rotor really does is absorb and dissipate heat. If a rotor gets too hot, it will cause brake fade and may easily warp, diminishing braking performance and causing severe brake vibration. The heavier the vehicle or the faster you’re going, the larger the rotors need to be, because the harder the brakes work, the more heat they produce.
So, the size of a brake rotor is proportionate to the type of braking it will be required to do. What’s a larger rotor? It’s more metal. What’s a thicker rotor? It’s more metal. And what determines how much heat can be absorbed and dissipated? The physical amount of metal. When a rotor wears, the diameter stays the same, but they get thinner, and when you resurface them, you’re removing even more material. The less metal you have, the less heat the rotor is able to absorb and dissipate.
How Brake Pads and Rotors Interact
Under normal braking, the surface of the rotor will become grooved to varying degrees based upon the pad material. This doesn’t affect the braking; because it occurs as a result of the contact between the brake pads and rotors, the surface of the two remain contoured. However, this surface is not acceptable when installing new brake pads and prevents the correct break-in of new pads, and it causes uneven pad wear and noise. “Pad slapping” is the comical term we use to describe replacing brake pads without resurfacing or replacing the rotors.
New brake pads have a break-in or “bedding” process that consists of repeated moderate braking. The purpose of the process is to bring the pads up to high temperatures in a controlled manner. When this occurs, the pad and rotor will transfer a thin layer of friction material to each other, allowing them to properly seat together. This is a very important aspect of brake service, as it ensures maximum braking and prevents brake fade, and this process only will occur correctly when new pads are mated with new or resurfaced rotors.
Turning the Rotors
We call it “turning,” because that’s the name of the machining process in which a workpiece is rotated against a fixed cutting tool. Any surface irregularities, including any grooves formed from normal service and also any rust or pitting, can be removed by turning the rotor.
In addition to surface condition, rotors often suffer from different forms of distortion. Lateral runout is the side-to-side movement of a rotor, measured with a dial indicator while rotating it by hand. Parallelism is the thickness of a rotor measured at multiple spots around the circumference for comparison. When describing this to a customer, we generally use the basic term “warped” rotor. These conditions will cause a vibration during braking, and in some cases, just driving at higher speeds.
Either one can be caused by normal wear or by incorrect mounting or installation of the rotor and wheels. Customers know what it means to have a warped rotor, and few of them care about the more technical terminology. Turning a rotor will correct these problems as well.
Turning a rotor involves a number of steps, the first of which is measuring it to determine if it still will be above the minimum thickness afterward. In most cases, the minimum thickness is cast or stamped into the rotor, but often it’s rusty and difficult to find, so we generally have to look up the specification anyhow.
Typically, when you turn a rotor, you’re going to remove a total of about .015 inches to .020 inches (15 to 20 thousandths of an inch) of material. It may be less on a really clean rotor, or more on a rusty, pitted or warped one. After measuring the thickness of the rotor and assessing the condition, you’ll know whether you have plenty of material left to turn it, or whether it’ll be too thin when you’re done.
If you determine the rotor can be turned, the next step is to remove it from the vehicle and mount it on the brake lathe. Hat rotors require a thorough cleaning and rust removal from the mounting surface to ensure they seat properly on the brake lathe. The mounting surfaces for a hubbed rotor are the wheel-bearing races, from which you can just wipe away the excess grease.
When the turning is complete and you’ve taken a final measurement to ensure the rotor is still at or above minimum thickness, the next step is to put a non-directional finish on the brake rotor, which aids in proper break-in. The most popular method is to use an angle-grinder with a cleaning disc, and it literally only takes a few seconds per side.
The final step includes washing the rotor in a mild soap-and-water solution. Though not visible, small metal particles remain on the rotor after turning, and these particles will embed themselves in the pad and prevent an effective break-in. Washing the rotor removes these particles. Hubbed rotors will require removing all the old grease, since a wheel-bearing clean and repack is a normal part of this service.
Back in the Day
There was a time when the hum of a brake lathe was almost as constant as the ticking of the clock on the shop wall. Hubbed rotors were big, heavy and expensive, and they lasted a long time, because they could be turned and reused multiple times before they were too thin to put back in service. The expectation of customers during this era was that their rotors would be “turned” during brake service. Even with the additional cost of labor, it still was far more expensive to replace them.
As the hat rotor slowly became the predominant rotor in use, many other changes were taking place in the automotive industry. Auto parts stores were opening up to meet the demands of the increasing number of cars on the road, and parts were being manufactured overseas. Price competition was high, and the more parts that were produced (hot rotors included), the less expensive they became.
At the same time, technician salaries were increasing, and suddenly, the labor cost to turn rotors was increasing. Then there was the process of turning the rotors. My intent in describing the process was to provide an indication of the amount of work involved, but any machining process requires very specific knowledge and procedure as well.
Turning a rotor is a machining process that can be done wrong as easily as it can be done right. Traditional hubbed rotors were very heavy, and as a result easier to turn because the weight inherently reduced vibration, and mounting them on the lathe was easy and straightforward.
Two things kill a rotor when turning it. One, vibration; and two, incorrect mounting. Guess what? You probably figured this: Hat rotors are lightweight, so it’s much more difficult to prevent vibration, and they’re commonly mounted incorrectly on the lathe. Most of this happens because of incorrect training, or simply a shop not having the proper lathe adapters, or both. But that subject can be reserved for a whole different article.
The trouble involved with turning hat rotors was sort of a nail in the coffin for the whole process. In today’s shops, you rarely hear the sound of a brake lathe. A good majority of the rotors that are scrapped could be turned and returned to service. But a new set of rotors is less expensive than the labor to resurface an old set (hubbed rotors being the exception). Then when you factor in the reality that they quite possibly could be machined incorrectly – causing a comeback – it simply doesn’t make sense.
Replacing them is quicker, a shop makes money on the parts, technicians make more money on labor and they can get onto the next job quicker. It’s easy to think it’s wasteful when the old rotors could in reality be turned, but on the other hand, maybe it’s good for the economy. Shops make more money and parts stores make more money too. And the old rotors don’t end up polluting a landfill; they’re one of a scrapper’s favorite metals.
They provide a source of income for scrappers and metal-salvage yards. Some shops save them and haul them in for scrap themselves. It’s good pizza money for the shop … or perhaps a cold beverage of sorts.
When and Why
Technically speaking, any brake rotor only needs replaced when it can no longer be resurfaced and remain at or above the minimum thickness specification. In the real world, as you can see, this really only holds true for hubbed rotors, which for the most part we only see on older cars and trucks. Resurfacing these rotors are the only ones we can justify, when you compare the expense of replacement.
However, even if a rotor can be turned from the standpoint of thickness, there still are two other factors that can deem it scrap instead. One is cracks that occasionally result from the continuous heat-and-cooling cycle of a rotor. If a rotor is cracked, it should be replaced. The other is hot spots, which occur when rotors aren’t broken in properly. Pad material is deposited unevenly on the rotor, and these spots cannot dissipate heat properly, causing brake vibration.
Hot spots are easily identified by an obvious discoloration on the surface of the rotor. In some cases, these can be removed by resurfacing the rotor.
Selling Your Customer
Your customer probably just wants a quick answer about replacement. Here’s an easy approach: Due to the critical importance of breaking in new pads, which relies on the surface of the rotor, any time you’re replacing pads, the rotors should be replaced as well – unless it makes economic sense to turn them. And that’s the key. With any rotor problems, unless it makes economic sense to resurface, replace them. As with any brake work, don’t forget to make sure caliper and pad slides are clean and working properly, and always torque those wheels.
The post
link hidden, please login to view appeared first on link hidden, please login to view.
link hidden, please login to view -
By Counterman
MEMA, the leading trade association in North America representing motor vehicle component manufacturers, announced a new business structure to better position the organization and the vehicle supplier community for the future.
The 118-year-old organization will now operate under one umbrella – MEMA – and represent automotive and commercial vehicle suppliers with two groups: MEMA Aftermarket Suppliers Group and MEMA Original Equipment Suppliers Group.
Over recent decades, MEMA’s reach and influence expanded through four divisions as the industry evolved: Automotive Aftermarket Suppliers Associations (AASA); Heavy Duty Manufacturers Association (HDMA); MERA – The Association for Sustainable Manufacturing; and Original Equipment Suppliers Association (OESA).
“Today, rapid changes are impacting our industry and we must be more adaptive and agile to respond,” said Bill Long, president and CEO, MEMA. “These industry challenges are not unique to one market segment but affect the entire membership. We must position MEMA for the future in a way that supports our vision of a growing, profitable and influential supplier community.”
According to Long, MEMA’s mission, vision and dedication to its members and the automotive, commercial vehicle and remanufacturing industries have not changed. It remains focused on advancing business interests of vehicle suppliers and working to successfully navigate the future of transportation and sustainability.
“No other organization can compare with MEMA’s longevity, respect, depth of knowledge and commitment to the supplier industry,” said Long. “With these changes, we leverage one MEMA, providing more services to all members in each respective market segment, greater platforms for industry dialogue and one collective voice on behalf of our members.”
To learn more, representatives from every MEMA member organization have been invited to attend a members-only MEMA Town Hall on Dec. 8.
The association will formally kick off the new brand and organizational structure in January 2023.
The post
link hidden, please login to view appeared first on link hidden, please login to view.
link hidden, please login to view 
-
By NAPA
If you drive a vehicle with an internal combustion engine, you can think of the battery like your vehicle’s beating heart. The battery cables act like arteries running a current to the alternator, which powers electronic systems such as the ignition system, the ECM (Electronic Control Module) and the lighting system.
Bad Battery Cable Symptoms
Just like in other areas of your vehicle, the components of your battery system will wear out and fail over time. Symptoms of worn or frayed battery cables are like that of a dying battery:
Dimming or flickering of interior lights or headlights Engine hesitation when starting Clicking noises If you notice a buildup of flaky white or blue crust around the top or sides of your battery, that’s corrosion. It’s a common problem caused by small amounts of escaping hydrogen gas or leaking electrolytes on the top of your battery or the battery cable terminals. Corrosion can develop on older batteries that were overcharged, undercharged or exposed to certain environmental factors.
The NAPA Network can show you how to replace battery cables in your car, as well as
link hidden, please login to view, your link hidden, please login to view, your link hidden, please login to view and—depending on the extent of the damage—your battery tray and link hidden, please login to view. If you determine your battery has good voltage by using a link hidden, please login to view and doesn’t need replacing, then it’s time to check your link hidden, please login to view. Start at the cable terminals attached to the battery posts. Inspect both the positive and negative cables for fraying, knicks and splits. If you see anything that doesn’t look right, it’s time to replace the cables.
Replacing Battery Cables
Just like any good at-home automotive repair, you should start with all your tools ready to go, as well as safety equipment such as
link hidden, please login to view and link hidden, please login to view. Replacing battery cables is straightforward, and you’ll need the following: link hidden, please login to view A Socket Wrench link hidden, please login to view link hidden, please login to view Step 1 – Using the screwdriver or socket wrench, gently disconnect the battery terminals from the battery posts—starting with the negative cable—then disconnect the positive to avoid shorting and potential danger. Trace the path of the negative cable to the chassis, then trace the positive cable to the fuse box. Make sure to take a picture or otherwise note the course so you can route the new cables correctly.
Step 2 – Use the ratchet to loosen the negative ground nut, then remove the nut that holds the positive cable to the fuse block. Inspect these for corrosion and damage and replace them if the metal is soft or the threading is deteriorated. Inspect the terminal posts on top of the battery and use a
link hidden, please login to view to remove any corrosion. Step 3 – Install the new cables starting with the negative. Reattach the negative ground nut to the chassis and the nut that holds the positive cable to the fuse block. Make sure the nuts are tight and snug.
Step 4 – Route the cables the way you originally found them and connect the terminal ends to the clean battery posts starting with the positive cable, then the negative cable.
Step 5 – Start your vehicle and ensure the electrical systems work properly.
Removing corrosion, cleaning your battery terminals and replacing worn battery cables is a part of routine vehicle battery maintenance that most at-home mechanics can do. However, this job involves the electrical system of your vehicle, so if you don’t feel comfortable doing the replacement yourself or can’t find the time, we are here to help. Just find a friendly local
link hidden, please login to view near you, and one of our ASE-certified technicians will replace the battery cables in your vehicle for you. We can even help you with an link hidden, please login to view to help you budget for your repairs and get you back on the road in no time! Photo courtesy of
link hidden, please login to view The post
link hidden, please login to view appeared first on link hidden, please login to view.
link hidden, please login to view
-
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.