P063B DTC Code

Introduction to P063B DTC Code

P063B is a diagnostic trouble code (DTC) that is related to the Powertrain Control Module (PCM) of a vehicle. It indicates an issue with the vehicle’s Electronic Throttle Control (ETC) system, specifically the internal control module calibration. This code is commonly found in vehicles equipped with drive-by-wire throttle control systems.

Understanding the DTC Code

What is a DTC Code?

A Diagnostic Trouble Code, or DTC, is a specific code that is generated by the vehicle’s On-Board Diagnostic (OBD) system. These codes are used to identify and diagnose faults within the vehicle’s various systems, such as the engine, transmission, or emissions control system. Each DTC has a specific code number, which helps technicians identify the nature of the problem.

What is the Powertrain Control Module (PCM)?

The Powertrain Control Module, commonly known as the PCM, is the main control unit of a vehicle’s engine and transmission systems. It is responsible for controlling various aspects of the engine’s operation, such as fuel injection, ignition timing, and transmission shifting. The PCM uses various sensors and input signals to make adjustments and ensure optimal performance and efficiency.

What is the Electronic Throttle Control (ETC) System?

The Electronic Throttle Control system, also known as ETC or drive-by-wire, is a technology that replaces the traditional mechanical linkage between the accelerator pedal and the throttle body with an electronic system. It uses sensors and actuators to transmit a signal from the accelerator pedal to the PCM, which then opens or closes the throttle body accordingly. This system provides more precise control over the engine’s power delivery and is commonly found in modern vehicles.

Causes of P063B DTC Code

There are several potential causes for the P063B DTC code, including:

  1. PCM Calibration Issue: In some cases, the PCM’s internal control module calibration may be out of range or not properly set. This can cause the DTC code to be triggered.
  2. Faulty Throttle Control Actuator: The throttle control actuator, which is responsible for opening and closing the throttle body, may be malfunctioning or not responding correctly to the signals from the PCM.
  3. Electrical Issues: Faulty wiring or connectors in the ETC system can disrupt the proper communication between the various components, leading to the P063B DTC code.
  4. Software or Firmware Issue: Occasionally, the vehicle’s PCM software or firmware may need to be updated or reprogrammed to resolve the DTC code.

Symptoms of P063B DTC Code

When the P063B DTC code is present, the vehicle may exhibit the following symptoms:

  • Reduced Engine Power: The engine may go into a reduced power mode to protect the drivability of the vehicle.
  • Stalling or Rough Idling: The engine may stall or idle roughly when the throttle is not being properly controlled.
  • Engine Light On: The Check Engine Light or MIL (Malfunction Indicator Lamp) may illuminate on the vehicle’s dashboard, indicating a problem that needs attention.
  • Unresponsive Accelerator Pedal: The accelerator pedal may become unresponsive or not provide the expected response.

Diagnostic and Repair Procedures

To properly diagnose and repair the P063B DTC code, it is recommended to follow these steps:

  1. Scan the vehicle for DTCs: Use an OBD scanner or diagnostic tool to retrieve the specific DTC codes stored in the vehicle’s PCM. This will help identify the cause of the problem.
  2. Inspect the ETC System: Thoroughly inspect the wiring, connectors, and components of the ETC system for any signs of damage, loose connections, or corrosion. Repair or replace any faulty components as necessary.
  3. Update PCM Software: Check for any available software or firmware updates for the vehicle’s PCM. Updating the software can sometimes resolve calibration issues and clear the DTC code.
  4. Test the Throttle Control Actuator: Test the throttle control actuator using a multimeter or other appropriate tools to ensure it is functioning within the manufacturer’s specified parameters. Replace if necessary.
  5. Clear DTC Codes: After repairing any underlying issues, clear the DTC codes from the vehicle’s PCM memory using the diagnostic tool. This will reset the Check Engine Light and ensure that the repairs were successful.


The P063B DTC code indicates a problem with the vehicle’s Electronic Throttle Control system, specifically relating to the internal control module calibration. By understanding the nature of the code, its causes, symptoms, and diagnostic procedures, technicians can effectively diagnose and repair the issue. It is crucial to follow the recommended steps and address any underlying problems to restore the proper functionality of the ETC system and ensure optimal performance of the vehicle.


Q: Can I continue driving my vehicle when the P063B DTC code is present?

A: It is not recommended to continue driving the vehicle when the P063B DTC code is present. The reduced power and unresponsiveness of the accelerator pedal can result in unsafe driving conditions. It is best to have the vehicle inspected and repaired by a qualified technician.

Q: Can I clear the P063B DTC code myself?

A: Yes, you can clear the DTC code yourself using an OBD scanner or diagnostic tool. However, it is important to note that clearing the code will not fix the underlying issue causing the code. If the problem persists, the code will likely return.

Q: How much does it cost to repair the P063B DTC code?

A: The cost of repairing the P063B DTC code can vary depending on the specific cause of the problem and the labor rates in your area. It is best to consult with a trusted mechanic or dealership for an accurate estimate based on your vehicle’s make and model.

About author


Meet Sam Mitchell, your experienced and reliable guide in the complex world of car fault codes. With a robust career spanning over 15 years as a professional car mechanic, John has the skills, knowledge, and practical experience to help you navigate car fault issues with confidence.


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