Throttle Position Sensor/Switch Circuit Malfunction (P212A)
The P212A code indicates a problem in the throttle position sensor (TPS) or its circuit. The TPS is a potentiometer that tells the engine control module (ECM) the position of the throttle plate. This code is set when the ECM detects an unexpected voltage or signal from the TPS, often due to a faulty sensor, wiring issues, or a malfunctioning throttle body. This can lead to poor engine performance, reduced power, and in some cases, a failsafe mode.
01. Most Common Causes
- Faulty throttle position sensor
- Damaged or corroded wiring/connectors in the TPS circuit
- Carbon buildup on throttle body affecting sensor operation
- ECM software or hardware issues (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine power or hesitation during acceleration
- Rough idle or stalling
- Poor fuel economy
03. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm code P212A and check for additional codes.
Step 2: Visually inspect the TPS wiring and connector for damage, corrosion, or loose connections.
Step 3: Test the TPS voltage signal with a multimeter while manually opening the throttle; compare to manufacturer specs.
Step 4: If sensor is faulty, replace the throttle position sensor or throttle body assembly as needed.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. The vehicle may enter limp mode, limiting speed and acceleration, which can be dangerous in traffic.
How much does it cost to fix?▼
Typically $50-$150 for parts and labor, but can be higher if the throttle body needs replacement.