P212C: Throttle Position Sensor/Switch D/E Circuit Low
The P212C code indicates that the Engine Control Module (ECM) has detected a low voltage signal from the throttle position sensor (TPS) circuit D or E. This sensor is part of the electronic throttle control system and provides input on throttle plate angle. A low voltage reading suggests a short to ground, open circuit, or faulty sensor, which can disrupt air-fuel mixture and throttle response.
1. Most Common Causes
- Faulty throttle position sensor
- Short to ground in sensor circuit
- Open circuit in wiring or connector
- Corroded or damaged connector pins
- Failed ECM (rare)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine power or limp mode
- Poor acceleration or hesitation
- Rough idle or stalling
- Unresponsive throttle pedal
3. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Inspect wiring and connectors for damage, corrosion, or loose connections.
Step 3: Test throttle position sensor voltage with a multimeter (reference 5V, signal 0.5-4.5V).
Step 4: Check for shorts to ground or open circuits in the signal wire.
Step 5: Replace sensor if voltage readings are out of spec and wiring is intact.
4. 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. Have it diagnosed promptly.
How much does it cost to fix?▼
Typically $50-$150 for parts and labor, depending on the sensor cost and labor rates. DIY replacement can be cheaper.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.