The turbocharger bypass valve controls the flow of air into the engine. If this code shows up, there is a problem with the circuit that handles it.
This number (DTC) P0034 might show up on your scan tool if you have a turbocharged engine. This piece will talk about what this code means, how to fix it, and any signs it may give you.
What Does the P0034 Code Mean?
The P0034 code is a general OBD-II powertrain code that all cars with a turbocharged engine made after 1996 must use. This is what the code means:
P0034 Low Voltage in the Turbocharger or Supercharger Bypass Valve Control Circuit
The turbocharger bypass valve can be used to change the boost pressure, which is the pressure of the air coming into the engine. The turbocharger spins faster and makes more boost pressure when the engine needs more power. The turbocharger spins less quickly and makes less boost pressure when the engine needs less power. The turbocharger bypass valve helps keep the boost pressure at the right level for each engine situation.
An electric actuator and a monitor work together to control the turbocharger bypass valve. The actuator moves the valve when the powertrain control module (PCM) tells it to. It sends information to the PCM about where the valve is located. The PCM checks a number of engine sensors to figure out where the valve should be and tell it to move to that place.
The P0034 code is set by the PCM when it finds a low voltage signal in the circuit that handles the turbocharger bypass valve. A short to ground, a high resistance, or a low voltage could be what this means.
What are Some Other Codes Related to P0034?
- P0033 Turbocharger / Supercharger Bypass Valve Control Circuit
- P0035 Turbocharger / Supercharger Bypass Valve Control Circuit High
- P0234 Turbocharger Boost Sensor A Circuit Low
- P0235 Turbocharger Boost Sensor A Circuit High
- P0294 Turbocharger Underboost Condition
- P0299 Turbocharger Overboost Condition
What are Some Possible Causes of P0034?
- Turbocharger bypass valve that doesn’t work right: The valve might be stuck, broken, or leaky, which keeps it from moving or sealing properly.
- Faulty turbocharger bypass valve actuator: The actuator may be broken, so it won’t move or listen to commands from the PCM.
- There is a problem with the wiring or connector for the turbocharger bypass valve actuator. The wiring or connector could be broken, corroded, or loose, which would stop the circuit from communicating or supplying power.
- Problem with the PCM: The PCM might not be working right, which means it sends the actuator the wrong signal or no signal at all.
What are Some Common Symptoms of P0034?
The signs of P0034 may be different based on how bad the problem is and what caused it. These are some of the most common signs
- Check engine light on: When the PCM sets the code, it will turn on the check engine light.
- Less power and economy from the engine: If the bypass valve isn’t working right, it could change the engine’s boost pressure and air-fuel ratio. This could mean less speed, slower acceleration, and worse gas mileage.
- Too much or too little boost pressure: If the bypass valve isn’t working right, the engine may have too much or too little boost pressure. This could hurt the engine parts or make the engine work less well.
- Getting stuck: If the bypass valve isn’t working right, it could let too much or too little air into the engine, which could make the idle unstable or cause the engine to stop.
- Sounds like squealing or clanking coming from the turbocharger or turbo pipes: If the bypass valve is stuck, broken, or leaking, it could cause strange sounds to come from the turbocharger or turbo pipes because of too much or too little boost pressure.
- Heavy smoke coming out of the tailpipe: If the bypass valve isn’t working right, it could let too much or too little fuel into the engine, which would lead to incomplete burning and more pollution. This could cause a lot of smoke, mostly black smoke, to come out of the tailpipe.
It’s also possible to keep other codes, such as codes related to the turbocharger boost, engine misfire, or knock sensor. These codes show more detailed issues with the turbocharger system, the performance of the engine, or the detonation of the engine.
If it applies, the boost pressure gauge may also show that the boost pressure is too high. It’s possible that this means the bypass valve isn’t controlling the boost pressure properly.
Conclusion
The code P0034 means that there is a problem with the circuit that handles the turbocharger bypass valve. This code can make your car’s efficiency and emissions worse in a number of ways. It is recommended that you have a professional repair look at your car if you notice any of the above signs.
