Transmission Solenoids, Sensors, Switches & Control Units
- ACDelco®Genuine GM Parts™ Automatic Transmission Valve RetainerGenuine GM Parts™ Automatic Transmission Valve Retainer 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$5.74 - $5.84
- ACDelco®Genuine GM Parts™ Manual Transmission Shifter SolenoidGenuine GM Parts™ Manual Transmission Shifter 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$134.34
- ACDelco®Genuine GM Parts™ Neutral Safety SwitchGenuine GM Parts™ Neutral Safety 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 lifestyle, it is...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$65.23 - $117.19
- ACDelco®Genuine GM Parts™ Park and Neutral Position SwitchGenuine GM Parts™ Park and Neutral 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...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$82.78 - $121.85
- ACDelco®Genuine GM Parts™ Stop Light and Torque Converter Clutch SwitchGenuine GM Parts™ Stop Light and Torque Converter Clutch 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...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$24.40
- ACDelco®Genuine GM Parts™ Transmission Clutch Pressure SwitchGenuine GM Parts™ Transmission Clutch Pressure 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...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$9.20
- ACDelco®Genuine GM Parts™ Transmission Torque Converter Clutch Solenoid RetainerGenuine GM Parts™ Transmission Torque Converter Clutch Solenoid Retainer 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$3.22
- ACDelco®Genuine GM Parts™ Vehicle Speed Sensor BoltGenuine GM Parts™ Vehicle Speed Sensor Bolt 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$6.96 - $8.46
- ACDelco®Genuine GM Parts™ Vehicle Speed Sensor ReluctorGenuine GM Parts™ Vehicle Speed Sensor Reluctor 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,...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$2.98 - $38.78
- ACDelco®Professional™ Automatic Transmission Control SolenoidProfessional™ 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$28.26 - $296.36
- ACDelco®Professional™ Clutch Pedal Position SwitchProfessional™ 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 lifestyle, it is...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$38.01
- ACDelco®Professional™ Multi Purpose Connector KitProfessional™ Multi Purpose Connector Kit by ACDelco®. Looking to maintain the top condition of your electrical system? We are ready to help you! Just choose from their immense selection of premium replacement electrical parts...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$7.91 - $35.70
- ACDelco®Professional™ Neutral Safety SwitchProfessional™ Neutral Safety 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 lifestyle, it is...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$27.86 - $283.60
- ACDelco®Professional™ Neutral Safety Switch ConnectorProfessional™ Neutral Safety Switch Connector 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$33.29 - $92.42
- ACDelco®Professional™ Speed Sensor ConnectorProfessional™ Speed Sensor Connector 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$12.53 - $31.27
- ACDelco®Professional™ Vehicle Speed SensorProfessional™ Vehicle 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 lifestyle, it is...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$33.92 - $206.62
- Dorman®Automatic Transmission Kick Down SolenoidAutomatic Transmission Kick Down Solenoid by Dorman®. Includes: Remanufactured Transmission Kick-Down Module. Finish: Black/Silver. Terminal Type: Blade. Dorman’s Auto Trans Control Solenoid is conveniently packaged with the...Hassle-free installation; no need to disassemble transmissionHeat-resistant materials$133.15 - $356.07
- Dorman®Automatic Transmission Speed SensorAutomatic Transmission Speed Sensor by Dorman®. Dorman’s quality-engineered Auto Transmission Speed Sensor restores peak transmission function. Plus, your speedometer, cruise control, power steering and other systems that rely on the...Durable construction ensures accurate readingsDirect replacement for a proper fit every time$12.71 - $90.35
- Dorman®Automatic Transmission Torque Converter ConnectorAutomatic Transmission Torque Converter Connector by Dorman®. Dorman® Connectors are wire harnesses used for a wide range of applications to connect various components on the vehicle. All their Connectors are constructed of...No special tools required for installationEasy to install$12.50
- Dorman®Neutral Safety Switch ConnectorNeutral Safety Switch Connector by Dorman®. Dorman offers a comprehensive line of Neutral Safety Switch Connectors for a wide range of applications. All Neutral Safety Switch Connectors are constructed of high-quality materials for...Direct replacement Neutral Safety Switch Connectors available (where applicable) to ensure a proper fitVehicle try-on testing has been conducted on this part to ensure a trouble-free performance$22.12 - $26.62
- Dorman®OE Solutions™ Automatic Transmission Output Shaft Speed SensorOE Solutions™ Automatic Transmission Output Shaft Speed Sensor by Dorman®. Dorman's quality-engineered Auto Trans Output Shaft Speed Sensor restores peak transmission function. Plus, your speedometer, cruise control, power steering...Durable construction ensures accurate readingsDirect replacement for a proper fit every time$27.04 - $27.85
- Dorman®Transmission Control ModuleTransmission Control Module 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 restoring original ride control.The TCM restores the ability to shift the vehicle in and out of gear without hesitation or rough shifting100% replacement of gaskets, grommets and seals$109.42 - $960.49
- Dorman®Transmission Range Sensor ConnectorTransmission Range Sensor Connector by Dorman®. Connector Type: Female. Dorman offers a comprehensive line of Transmission Range Sensor Connectors for a wide range of applications. All the connectors are constructed of high-quality...Direct replacement for a proper fitReplacement restores drivability$42.09
- Dorman®Transmission Temperature SensorsTransmission Temperature Sensors by Dorman®. Prevent costly transmission damage with Dorman’s Auto Trans Temperature Sensor. It is durably built to gauge the transmission fluid temperature, ensuring accurate temperature readings.Direct replacement and direct fit sensors available for ease of replacementEngineered from durable materials for long-lasting service$12.43
- Dorman®Vehicle Speed SensorVehicle Speed Sensor by Dorman®. Dorman’s quality-engineered Auto Transmission Speed Sensor restores peak transmission function. Plus, your speedometer, cruise control, power steering and other systems that rely on the TSS return to...Durable construction ensures accurate readingsDirect replacement for a proper fit every time$12.78 - $66.98
- Mopar®Automatic Transmission ConnectorAutomatic Transmission Connector by Mopar®. Designed utilizing the latest technology, this product by Mopar features premium quality and will perform better than advertised. Perfect for your vehicle and lifestyle, it is manufactured to...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$1.77 - $203.48
- Mopar®Automatic Transmission Gear Position SensorAutomatic Transmission Gear Position Sensor by Mopar®. Designed utilizing the latest technology, this product by Mopar 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$13.13 - $359.56
- Mopar®Automatic Transmission Oil Pressure SwitchAutomatic Transmission Oil Pressure Switch by Mopar®. Increase the life of your vehicle's transmission by keeping your cooling system in top condition. Replace your faulty transmission cooling component with this highly efficient...The finest quality at a great priceOEM fit and function at a reasonable price$8.04 - $345.05
- Mopar®Automatic Transmission Overdrive Kickdown SwitchAutomatic Transmission Overdrive Kickdown Switch by Mopar®. Designed utilizing the latest technology, this product by Mopar features premium quality and will perform better than advertised. Perfect for your vehicle and lifestyle, it is...High quality at an affordable priceExpertly made from premium materials$51.14 - $94.69
- Mopar®Automatic Transmission Pressure Sensor TransducerAutomatic Transmission Pressure Sensor Transducer by Mopar®. Designed utilizing the latest technology, this product by Mopar 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$36.05 - $122.35
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
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- Transmission Fluids, Oils & Additives