Explanation of Code P2137: “Throttle/Pedal Position Sensor/Switch ‘D’/’E’ Voltage Correlation”
Severity
- Level: 🔴 High (risk of complete loss of throttle control).
- Urgency:
- Engine may stall while driving (immediate danger).
- Limp mode activated (reduced power).
Common Symptoms
- 🚨 Check Engine Light on (MIL) with code P2137.
- 🛑 Stuck throttle (engine RPM frozen).
- 🐌 Sudden loss of power (even at cruising speed).
- 🔄 Unstable idle or stalling at stop.
Common symptoms of a faulty rail pressure sensor
A faulty rail pressure sensor can cause various symptoms, including engine misfires, loss of power, starting difficulties, jerking during acceleration, and even sudden engine shutdowns. These signs often indicate a disruption in the fuel injection system, requiring immediate attention.
Diagnostic methods to identify the problem
To diagnose a problem with the rail pressure sensor, several methods can be used. This includes using an OBD scanner to read fault codes, checking fuel pressure with a pressure gauge, as well as a visual inspection of the sensor itself and its electrical connections.
Step-by-step guide for replacing the rail pressure sensor
Replacing the rail pressure sensor can be done by following a few simple steps. First, it is essential to locate the sensor on the engine, then disconnect the battery for safety reasons. Next, simply remove the old sensor, replace it with the new one, and reconnect all electrical connections.
Troubleshooting tips for related issues
In case of related issues, such as fuel leaks or pressure regulator malfunctions, it is important to check the entire fuel injection system to ensure no other component is faulty. Additionally, regular system cleaning can help prevent future problems.
Preventive measures to avoid future rail pressure sensor problems
To avoid future problems related to the rail pressure sensor, it is recommended to follow regular vehicle maintenance, including replacing the fuel filter according to the manufacturer’s recommendations and using quality fuel. Additionally, careful and attentive driving can help prevent premature wear of fuel injection system components.
Main Causes
- Wiring problems:
- Corroded/deformed throttle body connector (“pigtail”).
- Wires shorted to ground or bare wires.
- Electronic throttle body failure:
- Seized gears (deformed cover).
- Failed throttle actuator motor.
- Faulty accelerator pedal position sensor:
- Incorrect or intermittent signal.
- PCM/ECM error:
- Reprogramming needed (e.g., after throttle body replacement).
Diagnostic Procedure (Detailed Steps)
Step 1: Check Technical Service Bulletins (TSB)
- Example: TSB NTB14-058 for Nissan (stalling issues related to code P2137).
Step 2: Inspect the “Pigtail” Connector
- Location: On the throttle body (common models: Nissan Altima, Renault Mégane IV).
- Action:
- Disconnect and inspect the female terminals (corrosion, bent pins).
- Clean with CRC contact cleaner spray and apply dielectric grease.
Step 3: Test the Accelerator Pedal Position Sensor
- Multimeter:
- Measure voltage on the signal wire (0.5V to 4.5V progressive).
- If voltage jumps or is absent → Replace the sensor.
Step 4: Check the Throttle Body
- Remove the cover: Check plastic/metal gears for wear or binding.
- Throttle actuator motor test:
- Direct 12V power supply → Throttle plate should open/close.
- If no movement → Throttle body is faulty.
Solutions & Costs
| Problem | Solution | Average Cost |
|---|---|---|
| Faulty throttle body | Replacement (new or used) | €200 – €800 |
| Failed pedal sensor | Replacement | €80 – €150 |
| Wiring repair | Replace the “pigtail” connector | €30 – €100 |
| PCM reprogramming | At dealership | €100 – €300 |
Mistakes to Avoid
- ❌ Forcing the gears: Risk of breaking plastic teeth.
- ❌ Forgetting the relearn procedure: Necessary after replacement (e.g., Nissan = 5 pedal presses).
Frequently Affected Models
- Nissan Altima (2013-2018): Recurring connector issues.
- Renault Mégane IV (1.2 TCe): Fragile throttle body.
- Toyota Camry (2015-2020): Accelerator pedal sensor failure.
Practical Case
- Problem: Code P2137 on a 2016 Nissan Altima with stuck throttle.
- Diagnosis: Corroded throttle body connector (oxidized terminals).
- Solution: Cleaning + connector replacement (€40).
Pro Tips
- Handle with care: The electronic throttle system is highly sensitive.
- Relearn procedure:
- Nissan: Ignition ON → 5 rapid pedal presses → Wait 7 seconds → Start engine.