Transmission Solenoids, Sensors, Switches & Control Units
- TRQ®Automatic Transmission Speed SensorAutomatic Transmission Speed Sensor by TRQ®. TRQ Genuine Series works with Tier 1 Original Equipment manufacturers to provide customers with the same parts supplied to dealerships at a more competitive price point.Intended to bring your vehicle back to its original gloryBudget-friendly alternative to the OEM part$24.91 - $87.95$25.95 - $87.95Save up to 4%
- TRQ®Neutral Safety SwitchNeutral Safety Switch by TRQ®. If you want to replace a faulty neutral safety switch, go with this high-grade TRQ part available at a fair price. Built to meet or exceed the highest customers’ expectations, it is made from...Intended to bring your vehicle back to its original gloryBudget-friendly alternative to the OEM part$17.81 - $76.95
- TRQ®Vehicle Speed SensorVehicle Speed Sensor by TRQ®. When it comes to quality replacement parts, TRQ is what you need to keep your vehicle running smoothly. As safe as the OEM part, this top speed sensor is made with superior materials to provide reliable...Intended to bring your vehicle back to its original gloryBudget-friendly alternative to the OEM part$19.90 - $49.87$20.95 - $51.95Save up to 5%
- ACDelco®Genuine GM Parts™ Transmission Clutch Pedal Position SwitchGenuine GM Parts™ Transmission Clutch Pedal Position Switch by ACDelco®. Designed utilizing the latest technology, this product by ACDelco features premium quality and will perform better than advertised. Perfect for your vehicle and...$14.60 - $45.69
- Walker Products®Vehicle Speed SensorVehicle Speed Sensor by Walker Products®. This product is made of high-quality materials to serve you for years to come. Designed using state-of-the-art technology and with customers in mind. It will meet your needs and deliver great...High quality at an affordable priceExpertly made from premium materials$6.97 - $161.20
- Mopar®Humidity SensorHumidity Sensor by Mopar®. This top-grade product is expertly made in compliance with stringent industry standards to offer a fusion of a well-balanced design and high level of craftsmanship. Manufactured from industry-leading materials...Carefully crafted from premium materialsExcellent corrosion and wear resistance$64.15 - $74.92
- ACDelco®GM Original Equipment™ Automatic Transmission Speed SensorGM Original Equipment™ Automatic Transmission Speed Sensor by ACDelco®. Designed utilizing the latest technology, this product by ACDelco features premium quality and will perform better than advertised. Perfect for your vehicle and...$9.56 - $178.15
- Dorman®Shift Interlock SolenoidShift Interlock Solenoid by Dorman®. Save time, money and labor with Dorman's Shift Interlock Solenoid. Now you can replace it without the expense and hassle of installing a complete shifter assembly.Restores ability to shift out of “park” when brake is depressedDirect fit for a trouble-free installation$19.82 - $148.46
- TRQ®Automatic Transmission Shift SolenoidAutomatic Transmission Shift Solenoid by TRQ®. Keep your automatic transmission working properly with this top-grade TRQ shift solenoid. Manufactured to restore the original performance of your vehicle, it is made using quality...Intended to bring your vehicle back to its original gloryBudget-friendly alternative to the OEM part$18.75 - $95.01
- WVE®Neutral Safety SwitchNeutral Safety Switch by WVE®. Replace your worn-out or faulty component with this quality replacement from WVE. This product is designed and tested to ensure the ultimate in durability and functionality. Made to meet or exceed the OEM...Excellent replacement for your worn-out factory partDesigned to keep your vehicle running reliably mile after mile$13.07 - $2,168.66
- ACDelco®GM Original Equipment™ Automatic Transmission Wire HarnessGM Original Equipment™ Automatic Transmission Wire Harness by ACDelco®. Designed utilizing the latest technology, this product by ACDelco features premium quality and will perform better than advertised. Perfect for your vehicle and...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$40.82 - $230.74
- Dorman®Auto Transmission Control SolenoidAuto Transmission Control Solenoid by Dorman®. Dorman's Auto Trans Control Solenoid is conveniently packaged with the installation gasket. It's designed for an exact fit on your vehicle-and easily plugs into the electrical harness for a...Hassle-free installation; no need to disassemble transmissionHeat-resistant materials$53.79 - $245.47
- Mopar®Automatic Transmission Control Solenoid ModuleAutomatic Transmission Control Solenoid Module by Mopar®. Do you feel shaking or shuddering when you engage the clutch; hear grinding noise when you shift gears? Does your engine race without an increase in road speed? You're in need of...OE quality parts from top original equipment and aftermarket manufacturersThe finest quality at a great price$10.64 - $519.17
- ACDelco®GM Original Equipment™ Automatic Transmission Output Shaft Speed SensorGM Original Equipment™ Automatic Transmission Output Shaft Speed Sensor by ACDelco®. Designed utilizing the latest technology, this product by ACDelco features premium quality and will perform better than advertised. Perfect for your...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$25.44 - $120.55
- ACDelco®Genuine GM Parts™ Transmission Control ModuleGenuine GM Parts™ Transmission Control Module by ACDelco®. Designed utilizing the latest technology, this product by ACDelco features premium quality and will perform better than advertised. Perfect for your vehicle and lifestyle, it...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$136.71 - $706.70
- Dorman®Automatic Transmission Pressure Sensor TransducerAutomatic Transmission Pressure Sensor Transducer by Dorman®. Dorman has all the components needed for a complete repair. Quickly and easily installed, it eliminates the clunking noise that may result when this part fails, while...Easy to installDirect replacement for a proper fit$38.13 - $65.90
- Dorman®Automatic Transmission Torque Converter Clutch SolenoidAutomatic Transmission Torque Converter Clutch Solenoid by Dorman®. Designed utilizing the latest technology, this product by Dorman features premium quality and will perform better than advertised. Perfect for your vehicle and...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$36.56
- Dorman®Automatic Transmission Wiring Harness ConnectorAutomatic Transmission Wiring Harness Connector by Dorman®. Dorman’s Automatic Transmission Wiring Harness Connector is engineered for ease and convenience. It comes with everything necessary for a complete installation.Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$26.38
- Dorman®Transmission Range SensorTransmission Range Sensor by Dorman®. Designed from high-quality materials for sustained reliability, Dorman's Transmission Range Sensor ensures that the correct gear selection input is provided to the electronic control unit....Durable wire loom protects wiring from oil and heat damageConnector features weather-pack seal for effective corrosion prevention$31.27 - $121.61
- Motorcraft®Automatic Transmission Output Shaft Speed SensorAutomatic Transmission Output Shaft Speed Sensor by Motorcraft®. Motorcraft is the way to restore the performance of your vehicle. Designed specifically for your vehicle, Motorcraft products meet stringent Ford Motor Company standards...Direct OEM replacementMeets strict Ford Motor Company standards$12.27 - $262.47
- WVE®Clutch Pedal Position SwitchClutch Pedal Position Switch by WVE®. Replace your worn-out or faulty component with this quality replacement from WVE. This product is designed and tested to ensure the ultimate in durability and functionality. Made to meet or exceed...Excellent replacement for your worn-out factory partDesigned to keep your vehicle running reliably mile after mile$4.77 - $324.44
- Standard®Neutral Safety SwitchNeutral Safety Switch by Standard®. SMP's vision is to be the leading independent supplier to the automotive aftermarket, providing the highest quality products, competitive prices and the highest reputation for integrity to all...All switches are designed using copper alloy conductors to ensure superior electrical conductivity with low resistive lossesAll parts are 100% tested to verify both mechanical and electrical switching performance$11.86 - $372.07
- ACDelco®Genuine GM Parts™ Automatic Transmission Control SolenoidGenuine GM Parts™ Automatic Transmission Control Solenoid by ACDelco®. Designed utilizing the latest technology, this product by ACDelco features premium quality and will perform better than advertised. Perfect for your vehicle and...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$33.39 - $986.50
- ACDelco®Genuine GM Parts™ Shift Interlock SolenoidGenuine GM Parts™ Shift Interlock Solenoid by ACDelco®. Designed utilizing the latest technology, this product by ACDelco features premium quality and will perform better than advertised. Perfect for your vehicle and lifestyle, it is...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$31.85 - $96.33
- Dorman®OE Solutions™ Automatic Transmission Pressure Sensor TransducerOE Solutions™ Automatic Transmission Pressure Sensor Transducer by Dorman®. This automatic transmission pressure sensor transducer is designed to match the fit and function of the original transducer on specified applications, and is...Direct replacement for a proper fit every timeConstructed from high-quality materials for long-lasting durability$45.48 - $46.34
- Mopar®Vehicle Speed SensorVehicle Speed Sensor by Mopar®. Do you feel shaking or shuddering when you engage the clutch; hear grinding noise when you shift gears? Does your engine race without an increase in road speed? You're in need of clutch/transmission...OE quality parts from top original equipment and aftermarket manufacturersThe finest quality at a great price$6.13 - $1,366.51
- Genuine®Automatic Transmission Control SolenoidAutomatic Transmission Control Solenoid by Genuine®. If your transmission is in need of repair, don't compromise the performance and safety of your car with suspect, off-brand replacement parts from the local auto parts chain store. On...Designed to restore your vehicle’s transmissionGenuine OE replacement parts from the OE manufacturer$37.58 - $1,048.98
- AISIN®Automatic Transmission Speed SensorAutomatic Transmission Speed Sensor by AISIN®. Do you feel shaking or shuddering when you engage the clutch; hear grinding noise when you shift gears? Does your engine race without an increase in road speed? You're in need of...OE quality parts from top original equipment and aftermarket manufacturersThe finest quality at a great price$53.66 - $153.88
- WVE®Automatic Transmission Speed Sensor ConnectorAutomatic Transmission Speed Sensor Connector by WVE®. Replace your worn-out or faulty component with this quality replacement from WVE. This product is designed and tested to ensure the ultimate in durability and functionality. Made to...Excellent replacement for your worn-out factory partDesigned to keep your vehicle running reliably mile after mile$4.00 - $742.72
- WVE®Automatic Transmission Torque Converter Clutch SolenoidAutomatic Transmission Torque Converter Clutch Solenoid by WVE®. Replace your worn-out or faulty component with this quality replacement from WVE. This product is designed and tested to ensure the ultimate in durability and...Excellent replacement for your worn-out factory partDesigned to keep your vehicle running reliably mile after mile$20.08 - $600.36
All modern automatic transmissions are electronically controlled by a computer. Depending on the vehicle, model year and system, the transmission may be controlled by a PCM (Powertrain Control Module), which controls both the engine and transmission, or by a dedicated TCM (Transmission Control Module). A network of engine and transmission sensors and switches provides input to the computer about operating conditions including engine load, temperature, and vehicle speed. The computer uses this input, along with internal programming, to regulate transmission pressure, shift timing, shift feel, and TCC (Torque Converter Clutch) engagement. The computer activates various solenoids to achieve this, including shift, TCC, and pressure control solenoids.
The engine associated sensors include the TP (Throttle Position) sensor, ECT (Engine Coolant Temperature) sensor, MAP (Manifold Absolute Pressure) sensor, and MAF (Mass Air Flow) sensor. Transmission related sensors include the TFT (Transmission Fluid Temperature) sensor, TSS (Turbine Shaft Speed) sensor, also called an input shaft speed sensor, TR (Transmission Range) switch, sometimes called a neutral safety switch or MLP (Manual Lever Position) switch, VSS (Vehicle Speed Sensor), also called an output shaft speed sensor, and BOO (Brake On/Off) switch. In addition to the above, some transmissions have various pressure switches, a line pressure sensor, and a clutch pressure sensor, and some vehicles have an APP (Accelerator Pedal Position) sensor, an overdrive switch, and buttons or a shift lever that allows manual shifting.
On older vehicles with mechanical throttle linkage, the TP sensor measures throttle opening, which is controlled by the driver’s foot on the gas pedal. The TP sensor is a potentiometer connected to the throttle body shaft that sends a voltage signal to the computer according to the change in resistance that occurs when varying throttle opening. This signal directly affects the computer’s control of line pressure, shift scheduling, and TCC engagement. When the throttle is closed or moderately open, resistance is high and the voltage signal is low, so the computer will keep line pressure low and shifts will be early. Conversely, at WOT (Wide Open Throttle), resistance is low, and the voltage signal is high, so the computer raises line pressure and shifts are delayed and occur at higher rpm. The APP sensor signal serves a similar function on newer vehicles with electronic throttle “drive-by-wire” control.
The ECT sensor is a thermistor that varies the voltage output with engine temperature. When the engine is cold, the sensor’s resistance is high, and as engine temperature rises, the resistance falls. The computer uses the ECT voltage signal to delay shifts and prevent TCC engagement until the engine warms up. The MAP sensor sends a voltage signal to the computer that varies according to engine vacuum, which the computer uses to determine engine load. At idle and light engine load vacuum is high and the voltage signal is low, and at WOT and heavy engine load, vacuum drops and the voltage signal increases. The computer uses the MAP sensor signal to control line pressure, shift timing, and TCC engagement. The MAF sensor also detects engine load but does so by measuring the amount of air entering the engine.
The VSS measures transmission output shaft speed. It can be a permanent magnet or reed-style sensor that signals vehicle speed to the computer. The VSS signal affects shift timing and feel, and if the sensor is defective or there is a problem in the VSS circuit it can result in improper shift timing, abnormally firm shift feel, no upshifts and no TCC engagement. The TSS sensor is the same type of sensor but measures input shaft speed. It is used by the computer for line pressure control during shifts and TCC engagement. A problem with this sensor or its circuit can result in incorrect shift timing, hard shifts, and no cruise control or TCC operation. The TFT sensor functions like the ECT sensor, except instead of engine coolant temperature it is used to signal the transmission fluid temperature to the computer. The computer will delay shifts when the fluid temperature is cold and prevent overdrive or TCC engagement until the fluid reaches a specified temperature.
The BOO switch signals the computer to disengage the TCC when the driver steps on the brake pedal. The BOO switch may or may not be integrated with the stoplight switch. The TR switch signals transmission manual lever position to the computer, which in turn activates the desired transmission gear and prevents the engine from starting in gears other than Park or Neutral. Some vehicles, particularly trucks and SUVs that routinely tow trailers, have an overdrive switch. When the driver activates the switch, it signals the computer to disable overdrive, to prevent overloading the transmission when pulling a heavy load. Some vehicles allow the driver to select transmission gears manually, via a +/- switch located on the column shifter stalk or a floor-mounted shifter that is placed in the manual mode.
The actuators that are commanded by the computer to control transmission operation are electric solenoids. There are pressure control solenoids, shift solenoids that direct fluid pressure to the appropriate clutches or bands, and a solenoid that directs fluid pressure to engage the TCC. A solenoid contains a coil of wire with an iron plunger inside. When current is applied to the solenoid it becomes an electromagnet and the plunger changes position. When the plunger moves it opens or closes a valve, allowing or preventing fluid flow. In addition to the above, we have neutral safety switches for older, non-electronic transmissions and clutch switches for manual transmission vehicles, both used to keep the engine from starting with the transmission in forward or reverse gears.
Every vehicle will not necessarily be equipped with all the sensors, switches, and actuators mentioned here, and those detailed above do not represent all the solenoids, sensors, switches, control units and related components we have on offer. No matter what you’re working on, we have the necessary components to restore proper transmission performance and vehicle operation. We offer components that are manufactured according to original equipment specifications, so when repairs are completed you can count on the performance your vehicle was designed to deliver.
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- Clutch Kits
- Automatic Transmission Oil Coolers
- Transmission Mounts
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- Automatic Transmission Torque Converters
- Transmission Shifters
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- Clutch Hydraulics
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- Automatic Transmission Valve Bodies
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- Transmission Shafts & Gears
- AT Bands & Clutches
- Automatic Transmission Governors, Modulators
- MT Assemblies
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- Clutch Pressure Plates
- Clutch Discs
- Transmission Wiring Harnesses
- Transmission Fluids, Oils & Additives