How to Troubleshoot Allison Transmission Speed Sensor Problems

Allison transmission speed sensor problems are a common issue for those with an Allison-equipped vehicle. The speed sensor is responsible for sending information to the transmission control module (TCM) about the speed at which the wheels of the vehicle are rotating. When this information is not correctly communicated, abnormal shifts and other drivability issues can occur. Common symptoms of a malfunctioning speed sensor include delayed shifting, decreased fuel economy, and engine stalling. To diagnose and repair these problems, it is important to first locate the faulty component and then replace it with an OEM-specified replacement part. It is also important to check all related wiring harnesses, connections, and fuses to ensure that they are in proper working order. Finally, it is essential to reset the TCM and all associated controllers after any repairs have been made.

Automobile: Allison Transmission Speed Sensor Problems

What is a Speed Sensor?

A speed sensor is an electronic device used in modern automobiles to measure the rotational speed of the engine’s crankshaft, which helps determine the speed at which the vehicle is travelling. This information is used to regulate various aspects of the vehicle’s performance, such as fuel efficiency and emissions control. The speed sensor is usually located on or near the engine’s crankshaft and is connected to the vehicle’s onboard computer system.

Different Types of Speed Sensors

Speed sensors come in several different varieties, each designed for a specific purpose. The most common type is a Hall effect sensor, which measures rotational speed by detecting changes in magnetic fields generated by a rotating metal armature or wheel. Other types include optical sensors, inductive sensors, and variable reluctance sensors. Each type has its own advantages and disadvantages; for example, optical sensors are more accurate but require additional power to operate.

How Does a Speed Sensor Work?

Speed sensors work by detecting changes in either magnetic fields or electric currents generated by a spinning wheel or armature on the crankshaft. When these fields or currents change, they cause an electrical signal to be sent to the onboard computer system which then processes this information and uses it to adjust various aspects of the vehicle’s performance accordingly. For example, when the vehicle accelerates, data from the speed sensor can be used to adjust fuel delivery and ignition timing for optimal performance and fuel economy.

Symptoms of a Failing Allison Transmission Speed Sensor

A failing Allison transmission speed sensor can cause several symptoms that can indicate there is a problem with your vehicle’s performance. These can include engine performance issues such as rough idle or stalling; unusual noises or vibrations coming from under the hood; and/or an illuminated check engine light on your dashboard’s instrument cluster.

Causes of an Allison Transmission Speed Sensor Failure

There are several possible causes of an Allison transmission speed sensor failure including worn or loose connections between components; electrical shorts or interference caused by faulty wiring; and oil contamination due to leaking seals or gaskets around related parts of your vehicle’s drivetrain system.

Diagnosing an Allison Transmission Speed Sensor Problem

In order to properly diagnose an Allison transmission speed sensor problem it’s important that you first check all related components and systems for any signs of wear or damage. This includes inspecting wiring harnesses for signs of corrosion or damage as well as checking seals around related parts for leaks that could potentially contaminate oil systems causing further issues down the line. Once all related components have been inspected it’s important that you also perform any necessary diagnostic tests in order to ensure that all systems are functioning properly before attempting any repairs yourself.

Maintenance Tips for an Allison Transmission Speed Sensor

In order to ensure optimal performance from your Allison transmission speed sensor it’s important that you regularly inspect all related components for signs of wear and tear as well as keep connections clean and tightly secured at all times. It’s also important that you check wiring harnesses for corrosion or other damage that could potentially lead to electrical shorts or interference with other onboard systems – if any damage is found then these should be replaced immediately in order to prevent further issues down the line. Finally, if necessary replace your speed sensor with one specifically designed for use with your particular make/model/year of vehicle – this will help ensure optimal performance from your system over time without any unnecessary complications down the line due to compatibility issues between parts from different manufacturers/models/years etc..

Cost of Replacing an Allison Transmission Speed Sensor

Replacing an Allison Transmission Speed Sensor can be a costly endeavor. Depending on the type of sensor, the cost could range from around $100 to several hundred dollars. In addition, labor costs can add up quickly if you don’t have the proper tools or knowledge to replace the part yourself. It’s important to research the cost of the part and any associated labor before deciding if it is worth it to replace the speed sensor yourself.

Best Practices for Replacing an Allison Transmission Speed Sensor

When replacing an Allison transmission speed sensor, it is important to use quality parts and tools. Poor quality parts can cause damage to other components in your vehicle, while poor quality tools can make installation difficult or even dangerous. It is also important to wear protective gear when working on your vehicle, such as gloves, eye protection, and a dust mask. This will help keep you safe from any potential hazards associated with working on your car’s electrical system.

Safety Precautions When Working on An Allison Transmission

When working on an Allison transmission, safety should always be a top priority. Before beginning any work, make sure to disconnect the battery in order to avoid electric shock or short circuits. Additionally, it is important to wear eye protection when making repairs as small parts could potentially cause eye injury if they are not handled properly.

Troubleshooting Tips for An Allison Transmission Speed Sensor Issue

If you’re having trouble with your Allison transmission speed sensor, there are a few things you can do before replacing the part. First, check all connections to ensure that there are no loose wires or other issues that could be causing problems with the sensor’s performance. If these checks do not reveal any problems then try clearing the memory from your vehicle’s computer system as this may help resolve any issues with incorrect data being sent from the speed sensor.

Alternatives to Replacing An Allison Transmission Speed Sensor

In some cases it may be possible to clean or repair an existing speed sensor rather than replacing it entirely. However, this should only be done if you have experience in automotive repairs and understand how your particular vehicle works. Additionally, upgrades may be available for certain sensors which could improve their performance and reliability over time but these should only be done by a professional mechanic who is familiar with your particular car model and its electronics systems.

FAQ & Answers

Q: What is a Speed Sensor?
A: A speed sensor is an electronic device that monitors and measures the speed of a rotating object such as a wheel or gear. It is usually used to measure the rotational speed of an engine or transmission, and it sends the corresponding signal to the vehicle’s computer system.

Q: What are the Symptoms of a Failing Allison Transmission Speed Sensor?
A: Common symptoms of a failing Allison Transmission speed sensor include engine performance issues, unusual noises or vibrations, and the check engine light coming on.

Q: What are Some Causes of an Allison Transmission Speed Sensor Failure?
A: Potential causes of an Allison Transmission speed sensor failure include worn or loose connections, electrical shorts or interference, and oil contamination.

Q: How Do I Diagnose an Allison Transmission Speed Sensor Problem?
A: To diagnose an Allison Transmission speed sensor problem, you should first check all related components and systems for any issues. Then you should perform visual inspections and diagnostic tests to identify any potential problems.

Q: What Should I Consider When Replacing an Allison Transmission Speed Sensor?
A: When replacing an Allison transmission speed sensor, you should make sure to use quality parts and tools, wear protective gear when working on your vehicle, disconnect the battery before working on your vehicle’s electrical system, check all connections before replacing the part, clear the memory from the computer’s system if needed, keep all connections clean and tightly secured in order to avoid future problems, and replace the part if necessary.

In conclusion, Allison Transmission Speed Sensor problems can be a major issue for any automobile. While it can be difficult to diagnose the issue, there are a few steps you can take to help pinpoint the problem. It’s important to check for corrosion as well as other wiring issues that could be causing a malfunction. Additionally, it’s important to make sure the transmission fluid levels are properly maintained and replace the speed sensor if necessary. Taking these steps will help ensure your vehicle runs smoothly and efficiently.

Author Profile

Carl Frisch
Carl Frisch
With more than 30 years in the bicycle industry, I have a strong background in bicycle retailing, sales, marketing and customer service. I have a passion for cycling and a dedication to excellence. As a manager, I worked diligently to increase my capabilities and responsibilities, managing up to eleven mechanics (at Palo Alto Bicycles) and later as a working partner in my own store.

As the shop owner of Spoke n’ Word Cycles in Socorro, NM, the success of the mission was my responsibility, which I pursued passionately since we opened in 2003 through the spring of 2011. I am adept at managing owned and loan inventory, preparing weekly & annual inventory statements, and managing staff. The role as managing partner also allowed me tremendous freedom. I used this personal freedom to become more deeply involved in my own advancement as a mechanic, to spearhead local trail building, and advocating for cycling both locally and regionally.

As a mechanic, I have several years doing neutral support, experience as a team mechanic, and experience supporting local rides, races, club events. I consistently strive to ensure that bicycles function flawlessly by foreseeing issues and working with the riders, soigners, coaches and other mechanics. Even with decades of experience as a shop mechanic and team mechanic, and continue to pursue greater involvement in this sport as a US Pro Mechanic, and UCI Pro Mechanic.

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