P2149 moderate

Throttle/Pedal Position Sensor/Switch B Circuit

The P2149 code means the vehicle's onboard diagnostic system has detected: Throttle/Pedal Position Sensor/Switch B Circuit. This is a moderate severity code.

My Garage →
Keep driving?
Short distances only
DIY difficulty
moderate
Estimated cost
$80 - $400 (parts and labor)
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Common Symptoms

  • Check Engine Light on
  • Reduced engine power warning
  • Erratic throttle response
  • Engine may enter limp mode
  • Poor acceleration

Probable Causes (Ranked by Likelihood)

  • Failed throttle position sensor B Very High
  • Damaged wiring to TPS B High
  • Corroded TPS B connector Moderate
  • ECM input circuit fault Low

Step-by-Step Diagnostic Procedure

  1. Read TPS B voltage on scan tool at closed and wide open throttle

  2. Inspect TPS B wiring and connector

  3. Measure TPS B reference voltage (should be approximately 5V)

  4. Compare TPS B to TPS A readings for correlation

Frequently Asked Questions

What does P2149 mean?

P2149 indicates: Throttle/Pedal Position Sensor/Switch B Circuit. The ECM detected an abnormal condition in this sensor circuit.

Is P2149 serious?

Moderate. The vehicle may enter limp mode. Repair promptly.

What should I check first?

Start with a visual inspection of the sensor wiring and connector. Use a scan tool to read sensor data and compare to expected values. Check reference voltage (typically 5V) at the sensor connector.

Sources

This page is built from documented references. Verify against your own service info before repair work.

P2149 on Diesel, EV & Equipment

The same code ID appears across other engines and platforms. The diagnostic flow varies by manufacturer — these are the platform-specific breakdowns:

Duramax serious Fuel Injector Group B Supply Voltage Circuit/Open

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