P2137 — Throttle/Pedal Position Sensor/Switch “B”/”C” Voltage Correlation #

Note: The code description may vary depending on manufacturer. Always refer to your OEM documentation for the most accurate information.

• Chevrolet/GMC: Throttle/Pedal Position Sensor B/C Voltage Correlation
• Ford: Throttle/Pedal Position Sensor/Switch B/C Voltage Correlation
• Hyundai/Kia: Accelerator Pedal Position Sensor B/C Correlation
• Toyota: Accelerator Pedal Position Sensor B/C Voltage Correlation

Summary of the P2137 Code #

The P2137 diagnostic trouble code (DTC) is triggered when your vehicle’s engine control module (ECM), sometimes called the Powertrain Control Module (PCM), detects a mismatch between the voltage signals from the “B” and “C” circuits of the throttle or accelerator pedal position sensors. These sensors are crucial for translating how much you press the accelerator pedal into engine power. When their signals do not correlate as expected, it indicates a potential fault in the sensor system, wiring, or even the ECM itself. This code is part of the OBD-II (On-Board Diagnostics II) system, standard across most vehicles since 1996. Addressing this issue promptly is important since it can affect your ability to accelerate or even maintain engine speed safely.

Common Symptoms for P2137 #

When the P2137 code is present, your vehicle may exhibit a range of performance issues, some subtle and others quite obvious. The most common symptoms are often related to engine response and throttle control, making driving unpredictable or unsafe. Watch out for the following:

• Reduced engine power (sometimes called “limp mode”)
• Check Engine Light illuminated
• Hesitation or surging during acceleration
• Unresponsive accelerator pedal
• Stalling or difficulty maintaining idle speed

Likely Causes for P2137 (By Frequency) #

The most common causes for a P2137 code tend to involve the throttle or accelerator pedal position sensors and their wiring. However, other related components can also be to blame. Here are the most likely culprits, in order of frequency:

1. Faulty accelerator pedal position sensor (APP sensor)
2. Corroded, damaged, or loose wiring/connectors in the sensor circuit
3. Malfunctioning throttle position sensor (TPS) or throttle body assembly
4. Shorts or opens in the B/C reference voltage or signal circuits
5. Faulty ECM/PCM (rare, but possible if other causes are ruled out)

Step-By-Step Diagnostic Process for P2137 #

Diagnosing a P2137 code requires a systematic approach. Rushing or skipping steps can lead to unnecessary parts replacement or repeat failures. Follow this logical sequence:

1. Verify the code with an OBD-II scanner and check for related codes (especially P2135–P2140 series).
2. Visually inspect the accelerator pedal and throttle body area for damaged wires, loose connectors, or corrosion.
3. Check for Technical Service Bulletins (TSBs) related to P2137 for your vehicle make and model.
4. Monitor live data from the APP and TPS sensors using a scan tool, looking for inconsistencies or erratic values between B and C circuits.
5. Test the sensors using a digital multimeter to verify correct voltage output and smooth response throughout the pedal or throttle range.
6. Check wiring continuity and resistance from the sensor connectors back to the ECM/PCM.
7. Test the ECM/PCM only if all sensors and wiring check out, as this is rarely the root cause but not impossible.

Possible Repairs for P2137 #

Depending on the root cause, repairs will target the faulty component or connection. Addressing the issue promptly will restore proper throttle response and prevent further complications. Common fixes include:

• Replacing the accelerator pedal position sensor (most frequent fix)
• Repairing or replacing damaged wiring or connectors in the APP/TPS circuits
• Replacing the throttle position sensor or entire throttle body assembly (if integrated)
• Cleaning corroded connector terminals and ensuring secure connections
• Reflashing or, in rare cases, replacing the ECM/PCM

Is It Safe to Drive With Code P2137? #

Generally, driving with a P2137 code is not recommended. While the vehicle may run, you risk sudden loss of power, hesitation, or even stalling—especially at critical moments like merging or crossing intersections. Some vehicles may enter “limp mode,” drastically limiting throttle response to protect the engine and ensure safety. If this occurs, have the vehicle inspected as soon as possible to avoid being stranded or causing a traffic hazard.

Vehicles Most Commonly Affected by P2137 #

While P2137 can occur on any OBD-II equipped vehicle, certain makes and models report it more frequently—often due to specific sensor or wiring vulnerabilities. These include:

• Chevrolet and GMC trucks/SUVs (especially Silverado, Sierra, Tahoe, and Yukon from 2007–2017)
• Ford F-Series trucks (F-150, F-250, etc., late 2000s–2010s)
• Hyundai and Kia vehicles (various models, mid-2010s)
• Toyota Camry, Corolla, and Tacoma (2010–present)
• Chrysler, Dodge, and Jeep (occasional occurrences)

Common Mistakes & Best Practices for P2137 Diagnosis #

Avoiding misdiagnosis or unnecessary part replacement is crucial with P2137. Here are common pitfalls and how to avoid them:

• Replacing the throttle body or ECM/PCM without testing the sensor and wiring first
• Overlooking intermittent wiring faults caused by vibration or moisture
• Ignoring Technical Service Bulletins (TSBs) that may provide updated diagnostic or repair procedures
• Failing to clear codes and retest after repairs to confirm a successful fix
• Not using live data or a scan tool to observe real-time sensor values and correlations

Quick FAQ for P2137 #

Here are answers to common questions about code P2137:

• Q: Can I just clean the sensor to fix P2137?
  A: Cleaning may help if corrosion is present at the connector, but most often, replacement or wiring repair is required.
• Q: Will disconnecting the battery clear the P2137 code?
  A: Disconnecting the battery may temporarily clear the code, but if the root cause is not repaired, the code and symptoms will return.