The P0222 code is a throttle position sensor check engine light code. In other words, your engine doesn’t exactly know what the throttle is doing or is having trouble communicating with this component. An issue with the throttle can often mean that your vehicle is now borderline undrivable. This sensor is extremely important, to say the least.
Like any sensor, it can fail, and when it does, you need to know how to fix it and the related P0222 trouble code. In this guide, we will discuss the symptoms, causes, diagnostic techniques, and potential fixes for this trouble code.
What is the P0222 Code, and What Does It Mean?
The P0222 code stands for “Throttle Position Sensor B Low Input.” This means that the ECU is detecting an abnormally low voltage from Circuit B of the Throttle Position Sensor. Circuit B refers to the signal circuit/wire in the wiring harness.
Why Does the Throttle Position Sensor Get Low Voltage?
Voltage is a sensor’s way of signaling to the ECU that input is happening. In this case, the input is you pressing the throttle pedal and the output would open the throttle body to let air in. Low voltage means that the input signal is not being transmitted properly.
What Causes the P0222 Code?
The causes of this trouble code mainly involve the throttle system, which comprises the throttle body, pedal, and wiring. Either of these can malfunction and cause the P0222 trouble code. Here are some of the common causes:
- A malfunctioning throttle position sensor
- Throttle body failure
- Damage to the wiring harness
- Faulty ECU
Malfunctioning Throttle Position Sensor
The type of sensor that your vehicle uses can determine its durability. A resistance-based potentiometer is more likely to fail than a hall effect sensor that uses magnetic fields. Both these sensors output within a specific voltage range when the throttle pedal is depressed and when the P0222 code is logged, it can mean that the sensor has failed. It can also malfunction when carbon builds up on the sensor.
Throttle Body Failure
Now, this would be a case where the throttle position sensor voltage is correct, and the reading is low because of a failed throttle body. This would cause the P0222 code and is easily identifiable, as the throttle body would not open properly when the pedal is depressed.
Damage to the Wiring Harness
This is another known cause of sensor trouble codes, including the P0222. Luckily, there are methods to inspect the harness both internally and externally, and fixes often don’t involve replacing the entire wiring harness.
With this trouble code, you also need to check your fuses and relays for damage.
Faulty ECU
Voltage spikes or a short circuit in the wiring harness can sometimes damage the ECU. When this happens, there will be a host of codes other than the P0222, so it shouldn’t be first on your checklist of causes, but if all else fails, you can check your ECU.
What Are the Common Symptoms of P0222 Fault Code?
As your throttle system’s main purpose is to control how much air flows into your engine and through that, how fast you travel, the symptoms are mostly performance related. Some of the common causes of the P0222 code are:
- Check engine light
- Jerky acceleration
- Unresponsive throttle pedal
- Poor starting behavior
Check Engine Light
The check engine light is your initial indicator that something is wrong with your vehicle. With the P0222 code, you will likely experience throttle issues at the same time the check engine light appears. Your vehicle may go into limp mode along with the light. This is to prevent further damage or a potential safety hazard.
Unresponsive Throttle Pedal
Although pedal issues are not always related to the throttle system, a TPS is often one of the first sensors you should test when you notice a change in how your car reacts to your pedal input. It’s one of the most conclusive symptoms of the P0222 code. A spongy pedal can be a sign that your TPS sensor is contaminated.
Jerky Acceleration
This symptom often occurs when the sensor is dirty or the throttle body is malfunctioning. When the body is failing, air can no longer enter the engine to match the amount of throttle applied, so you may notice that your car is having issues accelerating even at wide-open throttle. It may also work intermittently.
Poor Starting Behavior
Extended cranking, stalling, or high idle on start, are all signs of the P0222 code. That said, this particular symptom also occurs due to other engine issues, so it’s not guaranteed that you have throttle problems. Often, having to depress the pedal while cranking is a sign of throttle position sensor issues, so if you’re doing that to start your vehicle, you may have a P0222 code.
How to Diagnose and Fix the Cause of P0222 Code
Once you’ve identified the causes and symptoms, the next step is to diagnose which component has failed and fix it. Doing so can be tricky if you don’t know how to approach the job at hand. Let us walk you through a simple diagnostic procedure.
OBD-II Reader
Identifying the codes that your ECU has logged will help you narrow down the problem to one or a few systems. Of course, in this case, you will be looking for the P0222 code, but additional codes can be more than helpful in diagnosing your problem.
Plug your OBD scan tool into the connection port on the passenger side and scan for trouble codes. The live data option can also be useful, as this will tell you whether the TPS sensor is working correctly. Your car needs to be on for this.
On idle, the throttle percentage should be around 10%. As you depress the throttle pedal gradually, the percentage graph should also increase gradually.
Visual Inspection
This test will verify whether there is any external damage to the sensor. Look for any melting, dents, carbon build-up, and corrosion on the sensor and throttle body. Additionally, look out for any frayed or exposed wiring.
Wiring Harness Test
Testing your wiring harness is important with any trouble code, more so with the P0222 code because this code focuses specifically on the signal wire failure.
You need a multimeter to conduct this test. You must consult your owner’s manual for specific TPS voltages and wiring diagrams. However, this test is very similar between vehicles. Your vehicle needs to be in the KOEO (Key on, engine on) state.
Once you’re prepped and ready, take your red (positive) multimeter probe and contact the green wire and the black (ground) wire to the vehicle chassis. On idle, you should have around 0.8V and as the throttle increases, so should the voltage to around 5V.
Fuse and Relay Inspection
The first thing you should look for once you open the fuse box cover will be burnt or blown fuses. You need to consult the specific fuse diagram of your vehicle to check whether the throttle actuator relay or fuse has failed. A failed battery or a ground usually causes a failed fuse or relay short, so at this point, you should test whether you’re getting 12V from your battery terminal or look for corrosion on the terminals.
You should be able to access the throttle actuator relay through the OBD scan tool. When your vehicle is on, but the engine is off, the relay should be closed and once the vehicle is started, it should feed power to the sensor and read open.
How to Fix the P0222 Code
If the sensor has failed, it needs replacing. These often either work or not. Cleaning the throttle body might help in some cases, but don’t count on it delivering a guaranteed fix. A stuck throttle valve is a mechanical issue. A failed TPS is more of an electrical issue that can only be resolved with a new unit.
Does P0222 Clear Itself?
Once you’ve fixed the root cause, what you should look for is that the throttle percentage and pedal feel are back to normal. The P0222 code should clear itself within your vehicle’s drive cycle. You can also use the scan tool to clear the codes.
Is It OK to Drive with P0222?
Likely, you cannot drive as the throttle pedal will be unresponsive. If you manage to get your vehicle started and moving, avoid driving with this trouble code, as it is a safety hazard. Unintended acceleration is always a possibility when experiencing any throttle issues.
Fix Your P0222 Using Quality Parts
Any car issues can send your head into a tailspin. Often you need to solve the problem as soon as possible and in the most cost-effective manner. This guide is 75% of the solution to your car trouble.
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