The crankshaft is the backbone of the engine’s functioning, and it converts the linear motion to a rotational motor to supply power for wheel spinning. Crankshaft position sensors are mounted on the rear side of the engine, and they monitor the rotational speed or position of the crankshaft. They provide signals to the power control module to determine the timing of sparks in specific cylinders.
Mercedes Benz crankshaft position sensor problems include disrupted pulse patterns, magnetic problems, melting of sensor plastic coverings, electric issues, poor fuel economy, engine misfiring and stalling, check engine light warning, and erratic response from the accelerator.
Last Monday morning, I was moving towards my workplace and faced an issue with my Mercedes Benz 2007 model. The engine started stalling because of power loss, and I thought the issue came from the faulty ignition switch or spark plug. I called my friend, and he told me to check the crankshaft position sensor. I opened the hood and checked it, which was badly damaged. I removed the damaged sensors and replaced them with new ones.
| Problems | Solutions |
| Disrupted pulse pattern | Replace oil pump |
| Magnetic problems | Replace contaminated oil |
| Melting of sensor plastic covering | Check engine oil and coolant levels |
| Electric problems | Replace short-circuited electric cables |
| Poor fuel economy | Compare fuel consumption of your car |
| Engine misfiring and stalling | Replacement of crankshaft position sensor |
| Check engine light illumination | Turn off your vehicle |
| Erratic response from the accelerator | Check accelerator components |
Disrupted pulse pattern
Crankshaft position sensors measure the pulse from the crankshaft wheels and send the power to PCM via electric wires. The disrupted pulse patterns do not allow the engine to ignite because of insufficient information transformation.
They measure the magnetic pulses generated by the toothed wheels of the crankshaft. It cannot correctly measure the crankshaft speed because of the broken pins or wheels.
These pins break or snap off because of their extended use and mechanical load. In addition, these can also break because of poor lubrication.
Lubrication issues come because of the failure of the oil pump and pressure relief valve. Snapped-off wheels cannot provide the proper pulsation to these sensors to generate a spark for ignition and supply power to the rear and front axles.
Abnormal combustion also increases the risk of wheel and pins damage. My friend experienced the loss of engine power issue because of driving over water puddles.
He was moving his car over water puddles, and water got inside the cylinder and led to the blockage of the pistons. Blocked pistons disrupted the functioning of the crankshaft position sensor. He tried to start his vehicle several times but could not because of water hammers.
He told me he treated the water hammer issue by removing the engine parts and drying or cleaning them completely for reinstallation.
Moreover, you can also replace the toothed wheels with new ones for correct pulse generation. It is better to ensure the functioning of the oil pump for lubrication and decrease the risk of damage.
Magnetic part problems
This sensor is the crankshaft part that monitors the rotational speed. These parts are made up of magnetic material that attracts the metal shavings from engine parts.
Engine parts are made of metal that produces shaving because of their continuous rubbing and friction. However, the chances of metal shaving production increase because of insufficient lubrication and increased friction between metal parts.
These metal shavings bind with magnetic parts of the sensors and wheels and affect their normal functioning. These cause the bridge between the sensors and wheels, and they cannot detect the correct impulses.
Moreover, a specific gap between the crankshaft position sensor and the reluctor ring is necessary for their proper functioning. Accumulation of metal shavings fills this gap and decreases the working efficiency of this component.
You can remove the metal shavings from the engine parts by adequately lubricating their parts. In addition, replacing the contaminated oil with a new one is better for efficient functioning.
Melting of sensor plastic covering
Crankshaft sensors contain plastic coverings that are vulnerable to heat-related damage. High-temperature exposure increases the risk of wear and tear and leads to poor functioning.
The high temperature of the engine parts causes the plastic covering to melt and lead to their failure. Engine parts are vulnerable to overheating because of poor lubrication.
In addition, temperature also increases during long drives. Low coolant levels also affect the engine temperature and cause overheating.
You can also face problems because of damaged pistons, valves, and seals. Maintaining the engine temperature by scheduling maintenance for their components is necessary.
You should also take short breaks during long trips to allow the engine parts to cool. Checking the oil levels and pressure for their parts lubrication is better. Avoid driving when you hear the clunking noise and feel a burning smell from the hood of your Mercedes Benz car because it can completely damage engine parts.
Electric problems
These sensors are connected to the ECU and power control module with electric wires. These electric wires help in signal transformation to the ECU and PCM.
Crankshaft sensors become faulty because of the failure of electric circuitry and damaged electric wirings. Wires can get damaged because short circuits do not allow the sensors to transmit voltage-based signals to PCM.
These sensors are the electric units that receive power from the engine for their functioning. These cannot function because of power supply issues in your vehicle.
Inspecting the electric circuit issues is necessary to ensure the power supply from the electromagnetic unit to these sensors. You should replace the short-circuited wires with new ones.
Poor fuel economy
Crankshaft position sensor failure also affects the fuel economy of your vehicle. Faulty sensors affect the ignition timing and functioning of fuel injectors.
Fuel injectors pump more fuel into the combustion chamber for burning, which affects fuel efficiency. Your vehicle consumes more fuel at the same distance traveled by other cars. This is a common problem in the B-Class models.
You can check the fuel efficiency by comparing it with the same model and year of Mercedes Benz. In addition, you can also resolve the issue by replacing the damaged sensor with a new one.
Engine misfiring and stalling
Damaged crankshaft sensors also affect the engine functioning and lead to power loss. These can affect the ignition timing because of incorrect pulsation generation.
Incorrect pulsation generation does not allow the spark plug to ignite the ignition mixture at the correct time. You can face the issue of misfiring of the engine cylinder.
One of the engine cylinders cannot misfire because of poor ignition timing and incorrect spark plug functioning. Moreover, you can also face engine stalling problems after pressing the accelerator pedal.
I also faced the same issue while moving on the road. I pressed the accelerator pedal, but the engine only cranked instead of starting properly because of a loss of power.
I checked the ignition switch, but it was fine; my friend told me to check the crankshaft position sensor, and I saw the damaged plastic covering. I removed it and installed the new one to decrease hard starting issues.
Check engine light illumination
These sensors stop functioning efficiently because of the overheating in the engine compartment. High engine temperature affects their plastic outer cause and causes their melting.
Moreover, high temperature compromises their pulse generation ability and incorrect signaling to the power control module.
You should not ignore the engine light on the screen and inspect the engine parts. It is better to stop your vehicle for cooling and turn the engine to reset the check engine light.
Erratic response from the accelerator
Damaged crankshaft position sensor problems also affect the normal functioning of the accelerator pedal in Mercedes Benz. Many people complain that they cannot quickly increase the speed of their cars while pressing the accelerator pedal.
You cannot rapidly increase the speed because of delayed response from the sensors.
Their working efficiency decreases because metal shaving accumulation affects the pulse generation. You cannot accelerate smoothly to increase or decrease speed because of their failure.
They cannot quickly monitor the crankshaft rotation’s speed and position and transmit the information to the spark plugs for ignition.
You should inspect accelerator components because the delayed response issue can also come because of accelerator failure.
Related Articles: