P2578 - OBD Trouble Code

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The trouble code P2578 can be elucidated as Turbocharger Speed Sensor Circuit. This code is a generic trouble code, meaning it applies to all vehicles equipped with the OBD-II system, especially those made from 1996 up to present. It’s also more common among Audi, Citroen, Chevrolet, Ford, Hyundai, Nissan, Peugeot, and Volkswagen vehicles. Specifications on the definition, troubleshooting, and repairs, of course, vary from one make and model, powertrain configuration type, to another.

Want to learn something more about the P2578 fault code? Sensor input voltage signals would be received by the PCM which would indicate a turbocharger speed or RPM level that would vary from that specified by the manufacturer will cause a code to be stored and at the same time would give rise to the check engine light. The PCM would recognize this data as an inability to effectively manufacture or control turbocharger speed levels.

What causes this problem with the Turbocharger Speed Sensor Circuit?

• There can be inoperative turbocharger speed sensor
• There can be opened or shorted turbocharger speed sensor harness
• Turbocharger speed sensor circuit inferior electrical connection

1. Turbocharger - If excessive amounts of oil are being burned, then it is a sign of a turbo failure. Locate the downpipe, at the front of the turbo, and then it should be disconnected. You can look inside the turbine by using an endoscope; if there is oil inside, that’s a sign of gradual failure. Make sure to resolve the issue as soon as possible; if left untreated, your turbo will eventually fail. Buy top notch turbocharger from us at economical prices.
2. Exhaust Gas Recirculation Valve - It is auto part commonly found on many road going automobiles. It is a part of the vehicle’s exhaust gas recirculation (EGR) system, an emissions system that is designed to recirculate exhaust gases back into the vehicle’s intake so that it can reduce cylinder temperatures and NOx emissions. Purchase top notch exhaust gas recirculation valve from us at economical prices.
3. Engine Control Module - Most of the time it is difficult to intercept the ECM faults and thus must be checked for thoroughly. There can be a problem with the circuit or the software might have malfunctioned. Thus repair, replace or reprogram the component as per requirement.
4. Exhaust System Parts - Your exhaust system begins at the engine with the purpose of removing toxic gases and fumes from your vehicle. The components are a series of pipes, catalytic converters, sensors, mufflers, and often a resonator, as well as other emission devices. Thus, replace damaged exhaust system now!
5. Powertrain Control Module - If the PCM is faulty, it can stores wrong OBD codes and can lead to misdiagnosis. This can happen due to misinterpretation of data received from the various sensors and components which also affects the vehicle’s performance. Thus replace it immediately.
6. Catalytic Converter - Catalytic converters at fault will lead to dropped fuel efficiency and performance along with increased emissions. Thus replace faulty parts now!
7. Oxygen Sensor - The O2 sensor can also be at fault leading to lean or rich engine conditions and thus affecting the engine performance and improper fuel consumption. Buy new sensor and replace the faulty one now!
8. Electronic Control Unit - If the ECU is at fault, it will not be able to read the boost converter temperatures correctly leading to underperformance. Thus, replace faulty ECU now!
9. Diagnostic Tool - Choose from our diagnostic tools collection that will come handy to detect and correct the OBD error code.

You might be thinking that how would you diagnose these problems? We at Parts Avatar Canada would help you diagnose the major symptoms easily.

Common Symptoms

• The service engine soon light can start lighting up
• The car engine might start stalling
• Decrease in engine performance
• The car might not start at all

The repairs which you will have to do to correct this fault code are simply straightforward; you can surely pinpoint the necessary repairs on the basis of your diagnosis. Have a look at some common fixes:

• Make sure to mend the faulty turbocharger speed sensor
• It is essential to restore the flawed turbocharger speed sensor harness
• Repair or replace the quirky turbocharger speed sensor circuit
• Rehabilitate the defaults in the PCM/ECM 

There is no need to get strained if your OBD Code is still flashing up as we are here at your service. Have a look at our superior variety of MAP sensor, crankshaft sensor, injection pump, spark plug boot, catalytic converter, pcm, ecm, torque converter, turbocharger, oxygen sensor, exhaust manifold, exhaust system parts and many more. Now all your problems would vanish within no time.

Here are some steps which you should follow in order to diagnose this fault code:

The mechanic or the technician will use a diagnostic scanner or code reader like DVOM to visually scan for the error codes in the vehicle. After performing a careful inspection, every of the stored codes and freeze frame data are retrieved as it can help down the way for further diagnosis process.

A proper diagnosis of this code should start with a basic overview of the turbocharger system. You must know that turbo charging is a form of forced air induction.

Forced air induction is a means of introducing excessive amounts of air into an engine so that gains in horsepower can be promoted. Where a naturally aspirated engine utilizes vacuum created by downward piston movement to draw a controlled fuel/air mixture into the engine's combustion chambers, the forced air induction engine has air as well as fuel forced into the combustion chambers by outlining an alternately driven device.

Turbochargers are simply engine driven air compressors, which are designed to fulfill this task. Turbochargers utilize the pressure from engine exhaust to propel impellers in a two chambered housing. The two chambers are totally separate one from another. Engine exhaust pressure turns the impeller in chamber "A", which in turn spins turbine in chamber "B".

The impeller in chamber "B" would gather fresh air through the turbocharger intake system (and inter-coolers) and would then force the cooler, denser air into the car engine. The cooler that the air temperature can become prior to entering the forced air induction device, the denser it will be when it reaches the combustion chamber. Denser air allows fuel to atomize more efficiently and promotes increase horsepower. Obviously, as engine RPM levels rise, forced air induction devices spin faster as well.

The typical turbocharger doesn't even begin to "spool up" until the engine reaches 1,700 to 2,500 RPMs and can operate at speeds of 250,000 RPMs under full boost pressure. Turbocharger speed or RPM levels are monitored using one or more speed sensors placed in the turbocharger housing.

As the metal impeller and rotor spin which is inside the housing, specially designed notches pass across the electromagnetic turbo speed sensor. The notches will provide a relief pattern in system voltage and these patterns are seen by the powertrain control module as waveform patterns. The PCM would then recognize these waveform patterns as turbocharger speed or RPM. The turbocharger impeller and rotor speeds are typically inspected independently of one another. The independent readings are then utilized in comparison in order for the PCM to detect potential issues inside the turbo system. Extreme RPMs are needed in order for the device to produce air pressure that is greater than that of the atmosphere. These elevated air pressure levels are called as "boost pressure".

As the boost pressure would rise, then the engine stress would also be elevated. Every engine manufacturer would provide maximum recommended boost pressure specifications which are programmed into the PCM. These specifications are calculated with the purpose of avoiding catastrophic engine failure because of a lot of boost pressure or reduced engine performance due to insufficient boost pressure in engines that are equipped with factory forced air induction devices. When the limits of these specifications are breached (high or low) a code is stored in the PCM and there would be an illumination in the service engine soon lamp. When the code is set and the service engine illuminated, then the issue in the boost should be investigated immediately.

Some special tools would be required to effectively diagnose this error code. You will require an OBD-II scanner, a boost pressure gauge, a hand-held vacuum pump, a vacuum gauge, and a dial indicator set. Confirm that the engine is in proper working order with no misfires and no engine knocks.

After that you should check all turbo hose clamps for tightness and examine turbo intake and inter-cooler hoses for leaks or cracks. Just keep in mind that all air intake hoses are tight and in decent shape. If all hoses are tight and in good order and there are no disconnected, torn, or cracked vacuum lines, then firmly grasp the turbo and attempt to "rock" it back and forth on the intake flange.

If the housing moves at all; tighten the bolts/nuts as needed to manufacturer's torque specifications. Place a boost gauge so that it may be observed while actuating the throttle. With the engine running in park or neutral, quickly rev the engine to approximately 5,000 RPMs and release the throttle suddenly. Carefully observe the boost gauge as boost pressure elevates and see if it exceeds 19-pounds. If it does, then it would mean that you have a waste-gate malfunction.

If boost fails to rise sufficiently (typically 14-pounds), then you have an issue in the turbocharger or exhaust. A scanner or code reader, a digital volt ohmmeter, and access to a manufacturer's wiring schematic will be needed to successfully diagnose this code. Start your diagnosis with a visual inspection of all wiring and connectors. Repair or replace damaged, disconnected, shorted, or corroded wiring, connectors, and components as necessary Always retest the system after repairs are completed to ensure success. If all system wiring, connectors, and components appear to be in normal working order, connect the scanner to the diagnostic connector and record all stored codes as well as freeze frame data. This will help to decide whether or not the malfunction is intermittent. Once the codes have been cleared, tests drive the vehicle to see if the code returns. If the code has failed to return immediately, you may have an intermittent condition. Intermittent conditions can be quite challenging to diagnose and in extreme cases they should be allowed to worsen before a correct diagnosis can be made. Waste-gate Malfunction: Remove the actuator arm from the waste-gate assembly.

Using the vacuum pump, manually engage the actuator valve and observe the waste-gate to make sure that it opens and closes fully. Any fluctuation from fully closed would cause a dramatic drop in boost pressure. If the waste-gate door will not open fully, it could result in low boost pressure. Turbocharger Malfunction: After allowing the engine to cool down, remove the turbo outlet hose and look inside. Look for oil standing inside of the housing.

See if any fins are missing or defective on the impeller and check for signs that the impeller has been striking or rubbing the inside of the housing. Spin the blades by hand and feel for loose or roaring bearings. Any of these conditions would indicate a defective turbocharger. Install the dial indicator so that it contacts the nose of the turbine outlet shaft and measure end play. Readings that exceed .003 should be considered excessive. If the turbocharger and waste-gate are in good working order, find a constant supply of vacuum from the intake manifold and install a vacuum gauge (in-line).

With the key on and the engine running (KOER), between 16 and 22-inches of vacuum should be produced by an engine in proper working order. If vacuum is less than 16-inches a bad catalytic converter may be the culprit.

If you still haven't found an obvious problem, then check the electrical circuitry and connectors of the turbocharger boost sensor. Confirm voltage and resistance values by utilizing manufacturer's specifications and the faults should be repaired as per the requirement.

Common Mistakes When Diagnosing The P2578 Code

• There can be some faults in the turbocharger speed sensor
• Negligence in the powertrain control module
• Wiring problems