Mpulse Car Sensor, Solenoid and Resistor Replacements

The anti-lock braking system uses an ABS or wheel speed sensor to monitor the speed of the wheel, which then sends this information to the ABS computer. In the event of an emergency stop, the ABS computer will use this information to prevent the brakes from locking. If the wheel speeds are not equal, the computer will regulate the anti-lock feature until the speeds are the same.

The ABS sensor is usually located in each wheel hub or rotor on a four-channel ABS system. The ABS sensor may also be mounted in the rear differential in some rear-wheel-drive vehicles.

A failing sensor can illuminate the ABS light and may cause the failure of the anti-lock braking system during an emergency stop. An illuminated ABS sensor light should be evaluated by an automotive professional.

An ABS sensor and wiring harness can be visually inspected for exposed wires or broken connections. The sensor may also be tested for OE-specified resistance with an ohmmeter.

Vehicle Speed Sensors measure wheel speeds and provide this information to the vehicle’s ECU (Electronic Control Unit). The ECU calculates ignition timing, transmission shift points, and air/fuel ratios for the vehicle. Data from the Vehicle Speed Sensor is also used in cruise control systems to maintain a constant speed.

The Vehicle Speed Sensor location depends on the vehicle as some are located on or near the transmission while others are located on the transaxle or on the hub like an ABS Sensor.

A faulty Vehicle Speed Sensor can cause harsh or improper transmission shifting, malfunctioning speedometer, faulty cruise control and the Check Engine Light may become illuminated.

An automotive professional will use specialized tools to measure Ohms and other data to determine if the sensor is malfunctioning.

The Blower Motor Resistor regulates the amount of hot or cold air that comes from the vehicle’s interior vents. When the fan control on the dash is adjusted, it sends a current to the Blower Motor Resistor which adjusts the fan speed, increasing or decreasing the amount of air.

The Blower Motor Resistor is located under the dash, attached to or inside the blower motor fan housing.

In most cases no, but with newer vehicles having more elaborate systems that check and double-check the status of the vehicle’s systems it is possible that a faulty Blower Motor Resistor could cause a warning light or code on the vehicle’s information system display.

Often the Blower Motor Resistor will fail due to excessive wear on the Blower Motor itself or an incorrect current being sent to the resistor.

Signs of a failing Blower Motor Resistor may be weak or erratic airflow from the vents or the fan only blows at certain speeds or no airflow at all.

The Brake Pad Wear Sensor, or brake wear indicator, is an added safety feature on many vehicles used to warn a vehicle’s driver if their brake pad wears too thin.

The Brake Wear sensor is mounted on the brake pad and connected by wire to the dashboard of the vehicle. Vehicles may have sensors on one to four wheels.

When the Brake Wear Sensor is worn down to the predetermined level, it will usually trigger the brake light on the dashboard.

By “failing” the Brake Wear Sensor is fulfilling its proper function of alerting the driver when new brake pads are needed. When the brake wear sensor is worn down, both the pads and sensors should be changed.

Some Brake Wear Sensors are made with inferior plastics that may melt under high-temperature braking situations, rendering them ineffective. These sensors can be visually inspected to determine if their fit is intact enough to perform the necessary function.

The Camshaft Position Sensor monitors camshaft rotation and the opening and closing rates of the valves and pistons. Camshaft Sensors work with Crankshaft Position Sensors to evaluate how the engine is performing.

The Camshaft Position sensor is usually located in the cylinder head of the engine.

Yes. When the measurements of the Camshaft Position Sensor and the Crankshaft Positioning Sensor differ, it will trigger the Check Engine Light on the dashboard.

Often, these sensors fail due to high temperatures.

An Automotive professional will use specialized tools to measure RPM and other data to determine if the sensor is malfunctioning.

The Crankshaft Position Sensor monitors the position and/or rotation speed of the crankshaft. The sensor communicates with the vehicle’s computer to control ignition timing and fuel injection. It works with the Camshaft Position Sensor to monitor the position of the valves and pistons. The Crankshaft Position Sensor also measures engine speed in revolutions per minute.

The crankshaft position sensor is generally located behind the harmonic balancer on the crankshaft.

Yes. When the measurements of the Crankshaft Positioning Sensor and the Camshaft Position Sensor differ, it will trigger the Check Engine Light on the dashboard.

Often, these sensors fail due to high temperatures.

An Automotive professional will use specialized tools to measure RPM and other data to determine if the sensor is malfunctioning.

A coolant temperature sensor is used to measure the temperature of the coolant/antifreeze mix in the cooling system, giving an indication of how much heat the engine is giving off.

The coolant temperature sensor will be located directly behind the coolant pipe. In most modern cars and vehicles, this is present behind the right cylinder head that is located right underneath the air intake pipe.

You may see your Check Engine Light come on if your coolant temperature sensor is failing or has failed. If your car’s computer senses a problem with the signal your sensor is sending, it may trigger the Check Engine Light.

The sensor becoming corroded or poor electrical connection to the ECU.

Signs of a coolant temperature sensor failure could include poor fuel economy, irregular temperature readings, an overheating engine, and/or your Check Engine Light coming on.

The Knock Sensor creates a voltage signal based on vibrations caused by engine detonation. The car’s computer uses this signal to slow timing if a spark knock occurs. If the knock sensor is faulty, the engine may run hot and produce higher emissions. The computer will not receive information regarding the engine’s performance, and car performance will be altered, especially in flex-fuel or high-compression engines.

The Knock Sensor is usually located on the left side of the engine block, just below the intake manifold.

The Check Engine Light may illuminate because of a faulty knock sensor. However, the sensor may test fine and can fail intermittently while the vehicle is being driven.

The most common cause of Knock Sensor failure is an electrical connection failure. The only solution to this problem is to replace the faulty sensor.

If a knock sensor is faulty, you may notice slow acceleration, lowered fuel economy, or an alarm emitted from the vehicle signalling that the engine has detected an abnormal noise. An automotive professional should be able to determine further if a faulty knock sensor is to blame.

The Variable Valve Timing Solenoid (VVTS) controls the oil flow to control the action of the sprocket, which shifts the position of the camshaft. The position is varied based on the car’s computer commands to increase or decrease the engine’s valve timing.

The variable valve timing solenoid is located at the front of the engine, typically near the front of the valve cover.

Yes, a malfunctioning VVTS may cause the Check Engine Light to be illuminated and may trigger multiple codes.

VVTS can fail due to low engine oil levels, clogs due to oil sludge, and/or irregularly changed engine oil and filters.

Possible indications of a malfunctioning or failed VVTS include an illuminated Check Engine Light, engine noise and/or stalling, rough idling, and general poor performance.