Principle: TPMS sensors typically use a piezoelectric or capacitive pressure sensor technology.
Operation: Each TPMS sensor is mounted inside a tire and constantly monitors the air pressure. When the pressure decreases, the sensor's internal diaphragm or structure deforms, causing a change in capacitance or generating a voltage.
Transmission: The sensor wirelessly transmits the pressure data to the vehicle's onboard computer, which processes the information and triggers a warning light on the dashboard if the pressure falls below a predefined threshold.

Manifold absolute pressure (MAP) sensor

Principle: MAP sensors often use a piezoresistive or capacitive element.
Operation: The MAP sensor measures the pressure in the engine's intake manifold. As the engine sucks in air, the pressure in the manifold changes. The sensor responds to these changes by altering its electrical properties, such as resistance or capacitance.
Signal Processing: The sensor's output is sent to the Engine Control Unit (ECU), which uses this data to optimize fuel injection and air-fuel mixture for engine performance and emissions control.

Oil pressure sensor

Principle: Oil pressure sensors typically use a piezoresistive sensing element.
Operation: The oil pressure sensor is mounted in the engine and monitors the pressure of engine oil. When the oil pressure changes, it causes a corresponding change in the sensor's electrical resistance.
Output: The sensor's output is sent to the ECU and may also be used to trigger a warning light on the dashboard if oil pressure drops too low.

Transmission fluid pressure sensor

Principle: These sensors often use piezoelectric or piezoresistive elements.
Operation: Transmission fluid pressure sensors monitor the hydraulic pressure in the transmission. Changes in pressure result in a change in the sensor's electrical properties.
Signal Processing: The sensor's output is used to control transmission functions, such as gear shifting and torque converter lockup.

Popular Years for Toyota Sequoia

Related Categories

Oxygen Sensor

Air Flow Sensor

Crankshaft Position Sensor

Temperature Sensor

Code Readers & Scanners

Ignition Coils & Spark Plugs Kits

Related Blogs

P0190 Code: Fuel Rail Pressure Sensor Circuit Diagnosis

Diagnose P0190 correctly: it signals a sensor circuit fault, not necessarily bad pressure. Start with connector/wiring checks and live data before replacing parts. Avoid high-pressure risks and use VIN-specific specs to prevent misdiagnosis.

Sep 20, 2026

P0521 Code: Oil Pressure Sensor Range/Performance — Causes, Fix & Cost

P0521 is an engine diagnostic code that indicates a problem with the engine oil pressure sensor. It is important to address this issue promptly to ensure proper engine performance and prevent potential damage.

Aug 06, 2026

New MAP Sensor but the Code Came Back: Sensor, Wiring, or Vacuum Leak?

This guide explains how to determine whether the problem is a stored code, incorrect sensor fitment, damaged wiring, a blocked pressure passage, or a vacuum leak—and how to verify the repair before replacing another part.

Aug 05, 2026

P0108 MAP Pressure Circuit High Input Symptoms and Fixes

By understanding and promptly addressing the P0108 fault code, vehicle owners can proactively protect their investment, optimize performance, and maintain compliance and safety - making it a valuable diagnostic tool for responsible car ownership.

Jul 29, 2026