Now reconnect the diagnostic tool and delete any related fault codes. Finally, run the ignition and confirm that the check engine light is extinguished, then perform a road test. Engine Management. Related Resources. How it works. A diesel particulate filter DPF differential pressure sensor measures exhaust backpressure and signals when the power-train control module PCM should begin a regeneration Click here to learn more.
Typically found in fuel injected engines, the manifold absolute pressure MAP sensor is one of the sensors an engine control module ECM uses to calculate fuel injection for Whilst traditional braking components may not have changed much, the addition of electronic controls has made braking systems much safer and smarter than ever before The oxygen sensor, otherwise known as the O2 sensor, does what its name suggests — it measures the amount of oxygen in the exhaust.
Whilst this may sound like a fairly modest Engine Management Solutions for improved emissions control, fuel economy, and driveability. See Product Details. Delphi Capability Advanced Diesel Diagnostics. Common Rail Injector. Electronic Unit Injector. Main elements simply wear away such as the tip of a spark plug. A lag or Check Engine Light will be your first warning something may be wrong with your sensors.
Global Automotive experts are ready to diagnose and repair any issue your vehicle may have. Signs a Vehicle has a Bad O2 Sensor. Let's not get ahead of ourselves.
First, what are the signs an O2 sensor may have gone bad? The coolant sensor keeps the PCM informed about the temperature of the coolant inside the engine.
This is vital information for the PCM because many control functions vary with temperature. A faulty coolant sensor, therefore, may cause the engine to run richer than normal, resulting in increased fuel consumption and higher emissions.
Coolant sensors can be damaged by overheating, so if the engine has experienced an episode of severe overeating for any reason, replacing the coolant sensor is often recommended.
It should match the air inlet temperature IAT reading when the engine is cold, and gradually increase as the engine warms up. If the sensor is not reading correctly, it needs to be replaced.
The throttle position sensor TPS is mounted on the throttle body and monitors the position of the throttle opening. The TPS value is displayed on a scan tool as percentage of throttle opening.
The PCM uses this information to estimate air flow and engine load. Contact-style TPS sensors can develop a worn spot just above the idle position as the miles add up. If there are any drops in the output as the throttle opens, the sensor is bad and needs to be replaced. On some older vehicles, the idle voltage setting of the sensor must be adjusted to a specified voltage.
The Manifold Absolute Pressure MAP sensor monitors the pressure differential between intake vacuum and the outside atmosphere.
The PCM uses this information to determine how much load is on the engine. Problems with this sensor can cause hesitation, fuel mixture and spark timing problems. The MAF sensor uses a heated wire or filament to measure airflow into the engine. This is vital information for controlling the fuel mixture. The most common problem here is contamination of the sensor element with dirt or fuel varnish. A dirty MAF sensor will typically report less airflow than is actually occurring.
This can cause a lean fuel condition, hesitation, and reduced performance. A sluggish or unresponsive MAF sensor can often be restored to normal operation by cleaning the sensor element with aerosol electronics cleaner. Many engines also have a Camshaft Position CMP sensor that helps the computer figure out the correct firing order of the engine. A failure of either sensor may prevent the engine from starting or running. Two types of sensors are commonly used for these applications: magnetic sensors or Hall effect sensors.
Heated sensors should be inspected or replaced every 60, miles. While heated oxygen sensors can be placed in safer locations than unheated models, they are made up of multiple circuits that can in turn allow for electrical issues. If the heater circuit in a sensor goes bad, the sensor will not function properly.
In order to do their jobs, all oxygen sensors must be exposed to a constant stream of harmful exhaust gasses, extreme heat and high velocity particulates.
Because of this, their efficiency will inevitably decrease over time. Sometimes, oxygen sensors can become contaminated by elements from within the engine. Exhaust from an overly rich fuel mixture can foul an O2 sensor, as will leaded fuel. Antifreeze or silicone residue resulting from faulty gaskets can have the same effect.
The sensors pictured below have been poisoned and need to be replaced. Carbon buildup from a rich fuel mixture is a frequent occurrence and causes many sensors to go bad. There are many possible causes of this, including a clogged air filter or a leaking or defective fuel injector.
Antifreeze can be very harmful to a sensor if it is allowed into the combustion chamber. This can happen in the case of a cracked or warped cylinder head, a leaking cylinder head gasket, or a leaking intake manifold gasket. Silicone poisoning, as pictured to the left, can leave the head of an oxygen sensor appearing white in color. The most common cause of this condition is the use of an improper silicone gasket sealant on the engine. Using improper leaded gasoline will harm an oxygen sensor.
Although this is a rare occurrence, it is good to know what the effects of leaded gasoline look like on a sensor. Soak the sensor thread area with a powerful penetrating lubricant. Starting and revving the engine should further aid in loosening the sensor by heating up the bung. If you are using an open end wrench, try an O2 socket. If this fails, try a long ratchet or breaker bar in conjunction with your socket to generate more torque.
If you are still unsuccessful, heat the bung with a torch until cherry red and remove the sensor. After the sensor is removed, be sure to use a thread cleaner to clean up the bung threads.
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