P0237 OBD Error Code: Problem & Solutions

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The error code P0237 can be defined as turbocharger/supercharger boost sensor A circuit low. This trouble code is generic, which would mean that it can apply to all the vehicles which are equipped with the OBD-II or the vehicles which are made since 1996 up to the present. The specifications on the definition, the troubleshooting steps as well as repairs can always vary from one vehicle make to another.

This fault code would start appearing when the powertrain control module which is also known as engine control module in some cases would detect the intake boost pressure sensor A input circuit below the specifications. This would indicate a case of short to ground.

What causes this problem with the Turbocharger Boost Sensor A Circuit Low?

• There can be some faults in the boost sensor "A"
• Defects in the turbocharger
• Some issues in the powertrain control module
• There can be some wiring problem

1. Turbocharger - Defective car Turbocharger can be a major reason why P0237 code depicts. So, make sure to replace it online so that you don’t have to face any further issues.
2. Turbocharger Boost Sensor - Everything is okay with the Turbocharger and still OBD code P0237 triggering? Then there must be some defects in Turbocharger Boost Sensor. Replace them as soon as possible.
3. Manifold Pressure Sensor - P0237 code flashing? Get your Manifold Pressure Sensor inspected from a mechanic.
4. Engine Control Module - If everything is alright with Pressure Sensor, then there is surely some defect in Engine Control Module. Get it replaced before the situation gets worse.
5. Powertrain Control Module - P0237 code can display due to some issues in the Powertrain Control Module. So, it is very important to replace the Powertrain Control Module with us at equitable prices.

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

• Check engine light can start appearing
• Engine might start pinging or knocking. This can see during acceleration
• Issue of engine hesitation or stalling
• There can be a lack of power in the engine/no turbo charger boost
• No unusual symptoms may be noticed

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:

The defective boost sensor should be replaced as it would help to fix this issue

The hoses and connections of the turbo boost sensor which have defects like blockage and kinks should be repaired and replaced if needed

This error code can cause lack of power on acceleration. This is because vehicles with only one sensor have their turbo boost disabled by the PCM, as the turbo boost sensor stays out of range or experiencing performance problems

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

• It is very important to diagnose this fault code properly and for that you should begin with a basic overview of the turbocharger system. Turbo charging is a form of forced air induction. Forced air induction is a means of introducing excessive amounts of air into an engine in order to promote gains in horsepower. 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 and fuel forced into the combustion chambers using an alternately driven device
• Turbochargers are simply engine driven air compressors, which are designed to accomplish this task. The pressure from engine exhaust is used by the turbochargers 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 intercoolers and would force the cooler, denser air into the 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 increased horsepower. Obviously, as engine RPM levels would rise, forced air induction devices would spin faster as well
• The typical turbocharger would not 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. In order for the device to produce air pressure that is greater than that of the atmosphere, then extreme RPMs would be necessary. These elevated air pressure levels are known as “boost pressure”. As boost pressure rises, engine stress is also elevated. Each engine manufacturer provides maximum recommended boost pressure specifications which are programmed into the powertrain control module
• These specifications are calculated with the purpose of avoiding catastrophic engine failure due to excessive 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 powertrain control module and a service engine soon lamp would be illuminated. When the code is set and the service engine illuminated, the boost problem should be investigated immediately. Some special tools will be needed to effectively diagnose this code. These include 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. Next, inspect all turbo hose clamps for tightness and examine turbo intake and intercooler hoses for leaks or cracks. Make sure 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 required 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. Observe the boost gauge as boost pressure elevates and see if it exceeds 19-pounds. If it does, then you have a wastegate malfunction. If boost fails to rise sufficiently (typically 14-pounds), then you have a turbocharger or exhaust problem. If you want to successfully diagnose this code, then you will need a scanner or code reader, a digital volt ohmmeter, and access to a manufacturer’s wiring schematic
• Begin 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 (Including fuses) appear to be in normal working order, connect the scanner (or code reader) to the diagnostic connector and record all stored codes and freeze frame data. This information can be extremely helpful in diagnosing intermittent conditions that may have contributed to this code being stored
• Once the codes are cleared, operate the vehicle to see if the code returns. If the code fails to immediately return, you may have an intermittent condition. Intermittent conditions can prove to be quite a challenge to diagnose and in extreme cases may have to be allowed to worsen before a correct diagnosis can be made. Wastegate Malfunction: Remove the actuator arm from the wastegate assembly. Using the vacuum pump, manually engage the actuator valve and observe the wastegate to make sure that it opens and closes fully. Any fluctuation from fully closed will cause a dramatic drop in boost pressure. If the wastegate 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 damaged 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 indicate a defective turbocharger. Install the dial indicator so that it contacts the nose of the turbine outlet shaft and measure endplay. Readings that exceed .003 should be considered excessive. If the turbocharger and wastegate are functioning properly, find a constant supply of vacuum from the intake manifold and install a vacuum gauge. With the key on and the engine running (KOER), between 16 and 22-inches of vacuum should be produced by an engine in good working order. If you find out that the vacuum is less than 16-inches a bad catalytic converter may be the culprit. If you still haven’t found an obvious problem, test the electrical circuitry and connectors of the turbocharger boost sensor. You can always confirm the voltage and resistance values using manufacturer’s specifications and the faults should be repaired

Common Mistakes When Diagnosing The P0237 Code

Follow these simple guidelines to prevent misdiagnosis:

• There can be some obstructions or kinks in the boost pressure sensor hose. So you must check it properly
• Carefully verify that connections to the sensor are secure and not leaking, kinked or cracked