Throttle/Pedal Position Sensor B/C Voltage Correlation
Code P2137 indicates a correlation fault between the throttle position sensor (TPS) B and C circuits, or between the accelerator pedal position sensor (APP) B and C circuits. The PCM detects that the voltage signals from these two sensors do not match within a specified range, often due to a wiring issue, poor connection, or sensor failure. This can cause erratic throttle response, reduced power, or limp mode.
01. Most Common Causes
- Faulty throttle position sensor (TPS) or accelerator pedal position sensor (APP)
- Wiring or connector issues (corrosion, loose pins, shorts)
- Poor ground connection
- PCM software or hardware failure (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine power or limp mode
- Poor acceleration or hesitation
- Erratic idle or stalling
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect wiring and connectors for damage, corrosion, or loose connections.
Step 3: Use a multimeter to check voltage and resistance at the sensor connectors per manufacturer specs.
Step 4: Compare sensor B and C voltage readings while slowly pressing the accelerator pedal.
Step 5: If sensors are out of range, replace the faulty sensor (TPS or APP).
Step 6: Clear codes and test drive to verify repair.
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 (sensor) plus labor if done by a shop. DIY cost is lower.