Transmission Solenoids, Sensors, Switches & Control Units
- ACDelco®GM Original Equipment™ Automatic Transmission Shift Solenoid Valve Fluid FilterGM Original Equipment™ Automatic Transmission Shift Solenoid Valve Fluid Filter by ACDelco®. Designed utilizing the latest technology, this product by ACDelco features premium quality and will perform better than advertised. Perfect...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$6.94 - $8.22
- ACDelco®GM Original Equipment™ Automatic Transmission Speed Sensor ConnectorGM Original Equipment™ Automatic Transmission 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...High quality at an affordable priceExpertly made from premium materials$20.83
- ACDelco®GM Original Equipment™ Automatic Transmission Torque Converter Clutch Pressure Switch ConnectorGM Original Equipment™ Automatic Transmission Torque Converter Clutch Pressure Switch Connector by ACDelco®. ACDelco GM Original Equipment Pigtail Connectors are connectors ready to be spliced into vehicle harnesses, and are...Protective outer coverings help provide long-lasting durabilityColor-coded wires allow for easy installation$20.72 - $73.24
- ACDelco®GM Original Equipment™ Automatic Transmission Torque Converter Clutch Pulse Width Modulation SolenoidGM Original Equipment™ Automatic Transmission Torque Converter Clutch Pulse Width Modulation Solenoid by ACDelco®. Designed utilizing the latest technology, this product by ACDelco features premium quality and will perform better than...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$52.05
- ACDelco®GM Original Equipment™ Automatic Transmission Torque Converter Clutch Valve Solenoid ConnectorGM Original Equipment™ Automatic Transmission Torque Converter Clutch Valve Solenoid Connector by ACDelco®. ACDelco GM Original Equipment Pigtail Connectors are connectors ready to be spliced into vehicle harnesses, and are...Protective outer coverings help provide long-lasting durabilityColor-coded wires allow for easy installation$20.72 - $73.24
- ACDelco®GM Original Equipment™ Automatic Transmission Torque Converter ConnectorGM Original Equipment™ Automatic Transmission Torque Converter Connector by ACDelco®. ACDelco GM Original Equipment Pigtail Connectors are connectors ready to be spliced into vehicle harnesses, and are GM-recommended replacements for...Protective outer coverings help provide long-lasting durabilityColor-coded wires allow for easy installation$20.72
- ACDelco®GM Original Equipment™ Automatic Transmission Wiring Harness ConnectorGM Original Equipment™ Automatic Transmission Wiring Harness Connector 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$66.18 - $75.57
- ACDelco®GM Original Equipment™ Manual Transmission Fluid Temperature SensorGM Original Equipment™ Manual Transmission Fluid Temperature 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$69.35 - $97.63
- ACDelco®GM Original Equipment™ Manual Transmission Gear Position SwitchGM Original Equipment™ Manual Transmission Gear 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...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$82.88
- ACDelco®GM Original Equipment™ Manual Transmission Output Shaft Speed SensorGM Original Equipment™ Manual 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$67.67
- ACDelco®GM Original Equipment™ Manual Transmission Speed SensorGM Original Equipment™ Manual 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...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$39.87 - $48.86
- ACDelco®GM Original Equipment™ Neutral Safety Switch ConnectorGM Original Equipment™ 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...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$14.77 - $49.48
- ACDelco®GM Original Equipment™ Park Neutral Position and Back-Up Light SwitchGM Original Equipment™ Park Neutral Position and Back-Up Light Switch 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...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$18.62 - $312.19
- ACDelco®GM Original Equipment™ Shift Interlock SolenoidGM Original Equipment™ 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,...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$38.04 - $69.90
- ACDelco®GM Original Equipment™ Speed Sensor ConnectorGM Original Equipment™ 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...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$13.43 - $26.47
- ACDelco®GM Original Equipment™ Starter Solenoid Wiring Harness ConnectorGM Original Equipment™ Starter Solenoid Wiring Harness Connector by ACDelco®. ACDelco GM Original Equipment Pigtail Connectors are connectors ready to be spliced into vehicle harnesses, and are GM-recommended replacements for your...Protective outer coverings help provide long-lasting durabilityColor-coded wires allow for easy installation$88.45
- ACDelco®GM Original Equipment™ Stop Light and Torque Converter Clutch SwitchGM Original Equipment™ 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...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$29.80
- ACDelco®GM Original Equipment™ Telematics Input Controller Call SwitchGM Original Equipment™ Telematics Input Controller Call Switch by ACDelco®. ACDelco GM Original Equipment Telematics Input Controller Call Switch is a GM-recommended replacement component for one or more of the following vehicle...GM-recommended replacement part for your GM vehicle's original factory componentOffering the quality, reliability, and durability of GM OE$21.98 - $58.65
- ACDelco®GM Original Equipment™ Transmission Clutch Pedal Position SwitchGM Original Equipment™ 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...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$10.34 - $27.38
- ACDelco®GM Original Equipment™ Transmission ConnectorGM Original Equipment™ Transmission 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$17.28 - $37.36
- ACDelco®GM Original Equipment™ Vehicle Speed SensorGM Original Equipment™ 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$7.60 - $105.34
- ACDelco®GM Original Equipment™ Vehicle Speed Sensor ReluctorGM Original Equipment™ 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...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$7.10 - $103.04
- ACDelco®Genuine GM Parts™ Automatic Transmission Control ModuleGenuine GM Parts™ Automatic 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...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$233.98
- 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$36.62 - $1,181.40
- ACDelco®Genuine GM Parts™ Automatic Transmission Electrical Connector Passage SleeveGenuine GM Parts™ Automatic Transmission Electrical Connector Passage Sleeve by ACDelco®. Designed utilizing the latest technology, this product by ACDelco features premium quality and will perform better than advertised. Perfect for...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$8.94
- ACDelco®Genuine GM Parts™ Automatic Transmission Input Shaft Speed Sensor BoltGenuine GM Parts™ Automatic Transmission Input Shaft 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...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$6.17
- ACDelco®Genuine GM Parts™ Automatic Transmission Lock-Up Torque Converter SwitchGenuine GM Parts™ Automatic Transmission Lock-Up Torque Converter Switch 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$9.62 - $21.33
- ACDelco®Genuine GM Parts™ Automatic Transmission Manual Shift Shaft Position SwitchGenuine GM Parts™ Automatic Transmission Manual Shift Shaft Position Switch by ACDelco®. Designed utilizing the latest technology, this product by ACDelco features premium quality and will perform better than advertised. Perfect for...$57.39 - $73.13
- ACDelco®Genuine GM Parts™ Automatic Transmission Manual Shifter Auxiliary Position SwitchGenuine GM Parts™ Automatic Transmission Manual Shifter Auxiliary Position Switch by ACDelco®. Designed utilizing the latest technology, this product by ACDelco features premium quality and will perform better than advertised. Perfect...$32.08 - $108.95
- ACDelco®Genuine GM Parts™ Automatic Transmission Pressure Control Solenoid FilterGenuine GM Parts™ Automatic Transmission Pressure Control Solenoid Filter by ACDelco®. Designed utilizing the latest technology, this product by ACDelco features premium quality and will perform better than advertised. Perfect for...Designed to deliver trouble-free, consistent performanceRight for your vehicle and lifestyle$6.78 - $8.11
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.
Browse by Part Name
Featured Brands
Related Categories
- Clutch Kits
- Automatic Transmission Oil Coolers
- Transmission Mounts
- Transmission Filters
- Automatic Transmission Torque Converters
- Transmission Shifters
- Clutch Flywheels
- Transmission Pans, Drain Plugs, Filler Caps
- Clutch Hydraulics
- Transmission Seals & Gaskets
- Transmission Rebuild Kits
- Clutch Linkages
- Clutch Release Bearings
- Automatic Transmission Valve Bodies
- Transmission Bearings
- Automatic Transmission Flexplates
- Automatic Transmission Oil Pumps
- Transmission Shafts & Gears
- AT Bands & Clutches
- Automatic Transmission Governors, Modulators
- MT Assemblies
- Automatic Transmission Assemblies
- Clutch Pressure Plates
- Clutch Discs
- Transmission Fluids, Oils & Additives