P2136 — Throttle/Pedal Position Sensor/Switch “A”/”C” Voltage Correlation #

The wording of this code may vary depending on the vehicle manufacturer (OEM). Below are some known variations:

• Throttle/Pedal Position Sensor/Switch “A”/”C” Voltage Correlation (General)
• Accelerator Pedal Position Sensor A/C Voltage Mismatch (GM, Ford)
• Throttle Position Sensor A/C Voltage Inconsistency (Honda, Toyota)
• APS Sensor Voltage Correlation Error (Hyundai, Kia)

Summary of DTC P2136 #

Diagnostic Trouble Code (DTC) P2136 is stored when the Engine Control Module (ECM) detects a voltage mismatch or correlation issue between Throttle/Pedal Position Sensor “A” and “C”. These sensors are designed to provide redundant signals to the ECM, ensuring accurate monitoring of the driver’s throttle input and the actual throttle plate position. If the voltages from these sensors do not align within a specified range, the ECM suspects a fault for safety reasons. This code often triggers the Check Engine Light and may lead to restricted engine performance. P2136 is commonly associated with issues in the electronic throttle control system, which is integral to modern drive-by-wire vehicles.

Frequent Symptoms for Code P2136 #

Drivers and technicians may observe a range of symptoms when P2136 is present. These issues can appear abruptly, sometimes after routine maintenance or seemingly at random during normal driving. Common symptoms include:

• Illuminated Check Engine Light (CEL)
• Reduced engine power or “limp mode” activation
• Unresponsive or erratic throttle response
• Intermittent stalling or hesitation on acceleration
• Hard starting or rough idle
• In some cases, a warning message such as “Reduced Engine Power” may display on the dashboard

Probable Causes of P2136 (Ranked by Frequency) #

P2136 can be triggered by a variety of issues—some more common than others. The root cause is typically a problem with the way the throttle or accelerator pedal position sensors are sending voltage signals to the ECM. The most frequent causes include:

1. Faulty or worn Throttle Position Sensor (TPS)
2. Defective Accelerator Pedal Position (APP) Sensor
3. Corroded, damaged, or loose wiring/connectors in the throttle/APP sensor circuit
4. ECM (Engine Control Module) malfunction (rare)
5. Mechanical issues in the throttle body (excessive carbon, sticking plate)

Step-by-Step Diagnostic for P2136 #

Diagnosing P2136 requires a systematic approach to avoid unnecessary parts replacement. Here is a recommended step-by-step process:

• Confirm the code with a scan tool and record freeze frame data for context.
• Visually inspect the throttle body and accelerator pedal sensor wiring and connectors for damage, corrosion, or looseness.
• With the key ON (engine OFF), use a multimeter or scan tool to check voltage readings from both sensors (“A” and “C”). Compare values to OEM specifications.
• If voltages are out of range or not tracking together smoothly as you slowly press/release the pedal, isolate the faulty component (sensor or wiring).
• Test continuity and resistance in the wiring harness between sensors and the ECM; repair any faults found.
• If sensors and wiring test good, perform a throttle body inspection for mechanical binding or sticking.
• As a last resort, suspect ECM malfunction if all else checks out and no external faults are found.

Possible Repairs for P2136 #

The correct repair depends on the identified cause. Always recheck for codes and verify repairs after each step. Typical fixes include:

• Replacing the Throttle Position Sensor or Accelerator Pedal Position Sensor if faulty
• Repairing or replacing damaged, corroded, or loose wiring/connectors in the sensor circuits
• Cleaning or servicing the throttle body if mechanical sticking is found
• Replacing the ECM only if proven defective (rare)

Can You Drive with Code P2136? #

Driving with P2136 is generally NOT recommended. While the vehicle may still operate in a limited “limp mode,” you may experience severely reduced power, poor throttle response, or unexpected stalling. These conditions can create unsafe situations, especially in traffic or at highway speeds. Immediate diagnosis and repair are advised to prevent further issues and ensure safe vehicle operation.

Vehicles Most Commonly Affected by P2136 #

While P2136 can occur in many modern vehicles equipped with electronic throttle control, it is most often reported on:

• Chevrolet (Silverado, Malibu, Equinox)
• GMC (Sierra, Acadia)
• Ford (F-150, Fusion, Escape)
• Toyota (Camry, Corolla, RAV4)
• Honda (Civic, Accord, CR-V)
• Hyundai and Kia (Sonata, Santa Fe, Optima, Sorento)

Other makes and models can be affected, especially as electronic throttle systems become the standard.

Common Mistakes & Best Practices for P2136 #

Misdiagnosis and unnecessary parts replacement are common with P2136. To avoid wasted time and cost, consider these best practices:

• Don’t immediately replace the throttle body or pedal assembly without confirming the sensor or wiring is faulty.
• Always check for technical service bulletins (TSBs) related to throttle or pedal sensor issues for your specific vehicle.
• Verify power and ground circuits to the affected sensors before condemning the ECM.
• After any repair, clear codes and perform a drive cycle to confirm the fix.

Quick FAQ for DTC P2136 #

What is the difference between Throttle Position Sensor and Accelerator Pedal Position Sensor?
Both are position sensors, but the Throttle Position Sensor (TPS) monitors the actual movement of the throttle plate, while the Accelerator Pedal Position (APP) Sensor detects how far the driver is pressing the accelerator pedal. Both signals are used for accurate drive-by-wire control.

Can a simple cleaning of the throttle body fix P2136?
Sometimes, if the issue is caused by a sticking throttle plate or excessive carbon buildup. However, if the code is due to a true electrical fault or sensor issue, cleaning alone will not resolve it. Always diagnose before replacing or cleaning parts.