P0222 – Throttle Position Sensor 2 Circuit Low

Introduction

The P0222 code is a diagnostic trouble code (DTC) that indicates a problem with the throttle/pedal position sensor or switch "B" circuit. Specifically, it means that the voltage input from the sensor to the engine control module (ECM) is too low. This code is considered a generic powertrain code, meaning it applies to all makes and models of vehicles manufactured after 1996.

When the P0222 code is triggered, it's important to address the issue promptly. While the severity can vary depending on the specific cause, it often leads to drivability issues such as reduced engine power, rough idle, and stalling. In some cases, it may be safe to drive short distances, but it's generally recommended to diagnose and repair the problem as soon as possible to avoid further damage and ensure safe operation of the vehicle.

Technical Details

The throttle/pedal position sensor (TPS) is a critical component of the electronic throttle control system. It consists of two sensors, TPS "A" and TPS "B", which are mounted on the throttle body and work together to provide accurate information about the throttle valve position to the ECM.

The TPS "B" is responsible for sending a voltage signal to the ECM that corresponds to the current position of the throttle valve. The acceptable voltage range is specified by the manufacturer, typically between 0.5V and 4.5V. When the ECM detects that the voltage from TPS "B" has fallen below the expected range, it sets the P0222 code.

The throttle body itself is located between the air intake manifold and the engine, and controls the amount of air flowing into the engine based on driver input from the accelerator pedal. The throttle valve is usually 50-75 mm (2-3 inches) in diameter.

Causes

There are several potential causes that can trigger a P0222 code, including:

1. Faulty throttle/pedal position sensor: The TPS "B" may fail due to wear, contamination, or electrical issues.

2. Damaged wiring or connectors: Corrosion, fraying, or loose connections in the TPS wiring harness can cause intermittent or low voltage signals.

3. Throttle body problems: A dirty or sticking throttle body can affect the TPS readings and cause incorrect voltage output.

4. ECM issues: In rare cases, a faulty ECM may incorrectly interpret the TPS signals or fail to provide proper reference voltage.

Diagnosis

To properly diagnose a P0222 code, follow these steps:

1. Connect an OBD-II scanner and retrieve the freeze frame data to identify the conditions when the code was set.

2. Perform a visual inspection of the throttle body, TPS, and related wiring. Check for any obvious damage, corrosion, or loose connections.

3. Test the TPS "B" voltage using a digital multimeter. With the ignition on and engine off, the voltage should change smoothly as you move the throttle from closed to wide open position.

4. If the TPS voltage is out of range or erratic, disconnect the sensor and test the reference voltage and ground signals from the ECM.

5. If the ECM signals are good, replace the TPS. If the problem persists, check for issues with the throttle body or ECM.

Repair

The specific repair for a P0222 code will depend on the underlying cause. Here are some common solutions:

1. Replace the throttle/pedal position sensor: If the TPS "B" is faulty, install a new sensor. The cost of a replacement TPS ranges from $50 to $200 USD (€45 to €180 EUR).

2. Repair or replace damaged wiring: If the TPS wiring is corroded or frayed, repair or replace the affected sections as needed. Wiring repairs can cost anywhere from $50 to $500 USD (€45 to €450 EUR) depending on the extent of the damage.

3. Clean or replace the throttle body: If the throttle body is dirty or sticking, clean it using a throttle body cleaner and soft brush. If the throttle body is damaged, replace it. A new throttle body can cost between $300 and $1,500 USD (€270 to €1,350 EUR).

4. Repair or replace the ECM: In rare cases, the ECM may need to be repaired or replaced. ECM repairs can be expensive, ranging from $500 to $2,000 USD (€450 to €1,800 EUR) or more.

Prevention

To help prevent issues that can cause a P0222 code, follow these tips:

1. Perform regular throttle body cleaning as part of routine maintenance. This can help prevent buildup of dirt and carbon deposits that can affect TPS operation.

2. Inspect the TPS wiring harness and connectors during regular service intervals. Look for signs of corrosion, fraying, or loose connections and repair as needed.

3. Avoid using aftermarket "performance" throttle bodies or other modifications that can affect the TPS calibration and cause incorrect readings.

Related Issues

Other common problems that may occur alongside a P0222 code include:

• Reduced engine power
• Rough idle or stalling
• Hesitation or surging during acceleration
• Check Engine Light illumination

Related fault codes that may be logged in addition to P0222 include:

• P0121: Throttle/Pedal Position Sensor/Switch "A" Circuit Range/Performance Problem
• P0123: Throttle/Pedal Position Sensor/Switch "A" Circuit High Input
• P0223: Throttle/Pedal Position Sensor/Switch "B" Circuit High Input

If any of these related issues or codes are present, they should be diagnosed and repaired along with the P0222 code to ensure proper operation of the electronic throttle control system.

Frequently Asked Questions About P0222 Code

What does the P0222 code mean?

The P0222 code indicates that the Engine Control Module (ECM) has detected a low voltage input from the throttle position sensor (TPS) "B" circuit. This means there is an issue with the TPS or its wiring causing the voltage signal to be below the expected range.

Is the P0222 code a generic code?

Yes, P0222 is considered a generic powertrain code, meaning it applies to all makes and models of vehicles manufactured after 1996 that use the OBD-II system. However, the specific repair steps may vary slightly between different vehicle makes.

What are the symptoms of a P0222 code?

Common symptoms of a P0222 code include:

• Check Engine Light illumination
• Reduced engine power
• Rough idle or stalling
• "Limp mode" with limited RPM and speed
• Hard starting
• Hesitation or surging during acceleration

How serious is a P0222 code?

A P0222 code is considered fairly serious because it can significantly impact drivability. The reduced engine power and rough running can make the vehicle difficult or unsafe to operate. It's best to diagnose and repair the issue promptly.

Can I still drive with a P0222 code?

It's not recommended to continue driving if your vehicle is displaying a P0222 code, especially if you are experiencing drivability issues like reduced power or stalling. These symptoms can compromise your safety. Have the vehicle diagnosed as soon as possible.

What causes a P0222 code?

Potential causes of a P0222 code include:

• Faulty throttle position sensor (TPS)
• Damaged or corroded wiring and connectors in the TPS circuit
• Throttle body issues like carbon buildup or binding
• Faulty ECM (rare)

How do you diagnose a P0222 code?

To diagnose a P0222 code:

1. Connect an OBD-II scanner and check for other codes.
2. Visually inspect the throttle body, TPS, and wiring for damage.
3. Test the TPS voltage with a multimeter per manufacturer specs.
4. If TPS checks out, use a scope to test the TPS signal and ECM operation.

What parts are involved with a P0222 code?

The main components involved with a P0222 code are:

• Throttle Position Sensor (TPS) – mounted on throttle body, sends voltage signal to ECM
• Throttle Body – controls airflow into engine, contains the throttle plate
• Wiring harness – connects the TPS to the ECM

How do you fix a P0222 code?

To fix a P0222 code, one of the following repairs is usually needed:

• Replace the throttle position sensor
• Repair damaged wiring or connectors in the TPS circuit
• Clean the throttle body if dirty or clogged
• Replace the throttle body if faulty
• Repair or replace the ECM if defective (rare)

What is the typical replacement cost for a throttle position sensor?

The average replacement cost for a throttle position sensor is around $100-250. The part itself usually costs $75-200, while labor costs are typically $50-130. Costs can vary based on vehicle make, model, and location.

Can a dirty throttle body cause a P0222 code?

Yes, a dirty or clogged throttle body can cause a P0222 code. Carbon buildup on the throttle plate and bore can cause the TPS voltage to read incorrectly. Cleaning the throttle body may resolve the issue in some cases.

How do you test a throttle position sensor?

To test a throttle position sensor:

1. Unplug the TPS and test the reference voltage from the ECM (usually 5V).
2. Reconnect the TPS and backprobe the signal wire with a multimeter.
3. Slowly open the throttle and check that the voltage increases smoothly.
4. Compare the voltage readings to manufacturer specifications.

Can a P0222 code clear itself?

In most cases, a P0222 code will not clear on its own, even if the underlying issue is repaired. The code will need to be cleared using an OBD-II scanner after repairs are complete. Disconnecting the battery may also clear the code but is not recommended.

How do I clear a P0222 code?

To clear a P0222 code, you will need an OBD-II scanner or code reader. Connect the scanner to the vehicle's diagnostic port, navigate to the clear codes menu, and select to erase the code. The code should clear if the underlying problem has been fixed.

Can low battery voltage cause a P0222 code?

Potentially, yes. The throttle position sensor requires a steady 5V reference voltage from the ECM to operate properly. If the battery voltage is low or there are charging system issues, it could cause an incorrect TPS reading and trigger a P0222.

Can a P0222 code be caused by a vacuum leak?

No, a vacuum leak would not directly cause a P0222 code as this code is specific to the throttle position sensor circuit. However, a vacuum leak could potentially cause drivability issues similar to a TPS problem.

What does a throttle position sensor do?

The throttle position sensor (TPS) is a potentiometer that provides a voltage signal to the ECM indicating the current position of the throttle valve angle. The ECM uses this information to control air-fuel ratio, ignition timing, variable valve timing, and other engine management functions.

Where is the throttle position sensor located?

The throttle position sensor is mounted on the throttle body, which is located between the air intake manifold and the engine. Its shaft is connected to the throttle plate so that it rotates in sync with the throttle.

What other codes may be present along with a P0222?

Other codes that may appear along with a P0222 include:

• P0121 – Throttle position sensor inconsistent with MAF sensor
• P0123 – Throttle position sensor circuit high input
• P0221 – Throttle position sensor inconsistent with idle switch
• P0223 – Throttle position sensor circuit high input

How can I prevent a P0222 code from reoccurring?

To help prevent a P0222 code from reoccurring:

• Have the throttle body cleaned every 30,000 miles to prevent carbon buildup
• Ensure the wiring harness is in good condition and not rubbing on anything
• Address any other codes that may be present
• Use an OEM or high-quality aftermarket TPS when replacing the sensor