Crankshaft Sensors

In an internal combustion engine, a crankshaft sensor is a component used to monitor the rotational speed and position of the crankshaft. The information provided by the sensor is used by the engine control unit to manipulate ignition system timing.

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What does the crank shaft sensor do?

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The Crankshaft position sensor, or (CKP) monitors the Crankshaft position and No#1 cylinder piston position while the engine is running. this information is sent to the engine's ECM. ( Electronic Control Module) the ECM then uses this information to calculate several operating parameters for engine performance but mostly it is used to operate the engine's Ignition system ( coil (s) and spark plugs). back in the day' you could replace your "points style distributor" for an "Electroinic-Ignition system" very much like todays MSD distributors. many of those used a Cam-sensor which essentially performed the same function. some used a Crank-sensor instead. basically:these sensors tell the ECM when to fire the spark plugs. before that it was all done with a set of "points" inside the distributor. hope this helps

What happens if the crankshaft positioning sensor fails?

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If your car uses VVT(Variable Valve Timing) or adjusts its ignition timing it could cause poor fuel economy, misfires, keep the car from starting. If the car is fuel injected the timing of the injectors is tied in with that too. In short nothing could, if the car manages to keep running it could lead to a blown motor depending on how you drive.

Car will not start after replacing harmonic balance and crank sensor?

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Some cats can go on either way but some can't did you put it on the right way

What are the signs of a bad camshaft sensor for a 2002 Dodge Intrepid?

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symptoms of a bad sensor will be , engine cutting out then starting again as you drive. cutting out then being able to restart when vehicle is stopped. hard starting. if left long enuff before replacing, you will not be able to restart

Average price to replace crankshaft sensor on 2000 Jeep Cherokee?

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If you get it done from a shop around $250 total for the new part, labor, and the computer diagnosis fee that is required for the mechanic to figure out what the probem is.

How do you change a crank case sensor on a 96 S-10 2.2 liter?

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remove the plug unscrew the bolts and put back the way you remove it .

Depending on what car you have, the crank angle sensor is normally located behind your harmonic balancer, or somewhere close to the crank. To remove the harmonic balancer you'll first need to remove the drive belt then remove the bolts holding on the harmonic balancer. It won't usually come off easily so it'll need some persuasion with a few light taps from a hammer, or in severe cases a bearing puller. Once the balancer is removed access to the crank angle sensor is very easy. All you need to do is interchange the busted sensor for a new one.

Where is the upper crankshaft sensor on a 2000 Cadillac Deville?

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Everyone should have a manual for their vehicle, and the library should have a professional shop manual available, for FREE, in the reference section(make copies of the correct sections) read up and fix it like a PRO! :) good luck-Dave

On a 98 Jetta GLX VR6 where is the camshaft positioning sensor located?

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i just had that fixed on my 97 jetta trek ... it's located in the distributor, just buy a new distributor it's about $400 dollars tho.. unless u get a used 1 .. once u replace that it willl turn off your check engine light!

Where is the camshaft positioning sensor located on a 2002 2.7?

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hey Zim==I think it is in the dist on this engine. GoodluckJoe

If your standing in front of the car its on the front of the moter where the trany and moter meet behind the exaust its a pain really tight space, best to go from under the car i have a lift and i still had a tough time.

Where exactly is crankshaft sensor in a Renault clio?

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The AA showed me where mine was on a 2004 laguna - auto. lean over the radiator and look for the cable loom - just to the right of centre is a small spur which connects to the sensor, there is a 10mm bolt holding the sensor in place. All reasonably reachable From the bonnet remove the air housing and on the right hand side of the gear box near the top you will see a black component bolted to a yellow strip.

Maxima engine cranks but no start?

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Check the coil packs. And I know this sounds not normal, but check for fuel in the tank. Check the fuel line and filters. I am assuming that it sounds normal when it turns over. If not, check the timing belt.

Make sure that when you attempt to start, the security light doesn't come on; if it is it might be a nats problem, meaning you inserted a wrong key in the ignition causing the ecu to lock.

If you can give me a bit more info, I could hopefully be more specific.

What is a cam shaft?

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cam shaft that allows the downward thrust of one

Piston to cause another piston to move back up to be ready to be pushed down again. The

Ignition is timed in a manner that allows the sequential firing of the spark plugs to cause

The cam shaft to rotate smoothly.

by Evan

The cam shaft opens the valves as the piston comes up and down to let fuel in and let exhaust pass the crankshaft pushes the pistons up and down

How do you test a crankshaft position sensor?

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Idk about the 99 civic but on my 95 jdm d15 the crank shaft position sensor is in the distributor. If the sensor is bad then you must replace the whole distributor. A bad wire could also cause this problem. Hope that helps good luck. jdmd15crx

Where is the oxygen sensor on a Chrysler PT Cruiser?

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There are to oxygen sensors on a 2004 Chrysler Sebring. They are located on the right side of the engine, against the firewall. Sensor 1 is located in front of the catalytic converter, and sensor 2 is located behind it.

Where is the crank sensor and how much does it cost?

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you would have to look up your specific model on a website like autozone. on my 97 lumina, the sensor is 18.99. where it will cost you, unless you replace it yourself, is labor at the shop.

ive had mine estimated at 150$

I was just quoted $200 for a crankshaft sensor replacement in a 1998 Chev Lumina.

Where is the camshaft position sensor on 1999 dodge avenger?

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The camshaft position sensor is located in the distributor on all 3.9L V-6 and 5.2/5.9L V-8 engines Camshaft Position Sensor


Distributor removal is not necessary to remove camshaft position sensor

Remove air cleaner assembly.

Disconnect negative cable from battery.

Remove distributor cap from distributor (two screws)

Disconnect camshaft position sensor wiring harness from main engine wiring harness.

Remove distributor rotor from distributor shaft.

Lift the camshaft position sensor assembly from the distributor housing Camshaft Position Sensor


Install camshaft position sensor to distributor. Align sensor into notch on distributor housing.

Connect wiring harness.

Install rotor.

Install distributor cap. Tighten mounting screws.

Install air cleaner assembly.

Will a crank shaft sensor on a Jeep Cherokee cause it not to start?

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yes you will lose pulse to the fuel injectors and fuel pump activation. common part to fail. the wires fray and brake near transmission.

Where is the crank shaft sensor in a 1996 jeep Cherokee sport Straight 6. 4.0 liter?

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The crank sensor is located on the top of the bell housing on the drivers side.

Can a bad cam sensor effect starting?

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yes, a bad cam sensor cause car not to start.


Diagnosis: Engine Won't Start or Run


Every engine requires four basic ingredients to start: sufficient cranking speed, good compression, adequate ignition voltage (with correct timing) and fuel (a relatively rich air/fuel mixture initially). So any time an engine fails to start, you can assume it lacks one of these four essential ingredients. But which one?

To find you, you need to analyze the situation. If the engine won't crank, you are probably dealing with a starter or battery problem. Has the starter been acting up? (Unusual noises slow cranking, etc.). Is this the first time the engine has failed to crank or start, or has it happened before? Have the starter, battery or battery cables been replaced recently? Might be a defective part. Has the battery been running down? Might be a charging problem. Have there been any other electrical problems? The answers to these questions should shed some light on what might be causing the problem.

If an engine cranks but refuses to start, it lacks ignition, fuel or compression. Was it running fine but quit suddenly? The most likely causes here would be a failed fuel pump, ignition module or broken overhead cam timing belt. Has the engine been getting progressively harder to start? If yes, consider the engine's maintenance and repair history.


What happens when you attempt to start the engine? If nothing happens when you turn the key, check the battery to determine its state of charge. Many starters won't do a thing unless there is at least 10 volts available from the battery. A low battery does not necessarily mean the battery is the problem, though. The battery may have been run down by prolonged cranking while trying to start the engine. Or, the battery's low state of charge may be the result of a charging system problem. Either way, the battery needs to be recharged and tested.

If the battery is low, the next logical step might be to try starting the engine with another battery or a charger. If the engine cranks normally and roars to life, you can assume the problem was a dead battery, or a charging problem that allowed the battery to run down. If the battery accepts a charge and tests okay, checking the output of the charging system should help you identify any problems there.

A charging system that is working properly should produce a charging voltage of somewhere around 14 volts at idle with the lights and accessories off. When the engine is first started, the charging voltage should rise quickly to about two volts above base battery voltage, then taper off, leveling out at the specified voltage. The exact charging voltage will vary according to the battery's state of charge, the load on the electrical system, and temperature. The lower the temperature, the higher the charging voltage. The higher the temperature, the lower the charging voltage. The charging range for a typical alternator might be 13.9 to 14.4 volts at 80 degrees F, but increase to 14.9 to 15.8 volts at subzero temperatures.

If the charging system is not putting out the required voltage, is it the alternator or the regulator? Full fielding the alternator to bypass the regulator should tell you if it is working correctly. Or, take the alternator to a parts store and have it bench tested. If the charging voltage goes up when the regulator is bypassed, the problem is the regulator (or the engine computer in the case of computer-regulated systems). If there is no change in output voltage, the alternator is the culprit.

Many times one or more diodes in the alternator rectifier assembly will have failed, causing a drop in the unit's output. The alternator will still produce current, but not enough to keep the battery fully charged. This type of failure will show up on an oscilloscope as one or more missing humps in the alternator waveform. Most charging system analyzers can detect this type of problem.


If the engine won't crank or cranks slowly when you attempt to start or jump start the engine (and the battery is fully charged), you can focus your attention on the starter circuit. A quick way to diagnose cranking problems is to switch on the headlights and watch what happens when you attempt to start the engine. If the headlights go out, a poor battery cable connection may be strangling the flow of amps. All battery cable connections should be checked and cleaned along with the engine-to-chassis ground straps.

Measuring the voltage drop across connections is a good way to find excessive resistance. A voltmeter check of the cable connections should show no more than 0.1 volt drop at any point, and no more than 0.4 volts for the entire starter circuit. A higher voltage drop would indicate excessive resistance and a need for cleaning or tightening.

Slow cranking can also be caused by undersized battery cables. Some cheap replacement cables have small gauge wire encased in thick insulation. The cables look the same size as the originals on the outside, but inside there is not enough wire to handle the amps.

If the headlights continue to shine brightly when you attempt to start the engine and nothing happens (no cranking), voltage is not reaching the starter. The problem here is likely an open or misadjusted park/neutral safety switch, a bad ignition switch, or a faulty starter relay or solenoid. Fuses and fusible links should also be checked because overloads caused by continuous cranking or jump starting may have blown one of these protective devices.

If the starter or solenoid clicks but nothing else happens when you attempt to start the engine, there may not be enough amps to spin the starter. Or the starter may be bad. A poor battery cable, solenoid or ground connection, or high resistance in the solenoid itself may be the problem. A voltage check at the solenoid will reveal if battery voltage is passing through the ignition switch circuit. If the solenoid or relay is receiving battery voltage but is not closing or passing enough amps from the battery to spin the starter motor, the solenoid ground may be bad or the contacts in the solenoid may be worn, pitted or corroded. If the starter cranks when the solenoid is bypassed, a new solenoid is needed, not a starter.

Most engines need a cranking speed of 200 to 300 rpm to start, so if the starter is weak and can't crank the engine fast enough to build compression, the engine won't start. In some instances, a weak starter may crank the engine fast enough but prevent it from starting because it draws all the power from the battery and does not leave enough for the injectors or ignition system.

If the lights dim and there is little or no cranking when you attempt to start the engine, the starter may be locked up, dragging or suffering from high internal resistance, worn brushes, shorts or opens in the windings or armature. A starter current draw test will tell you if the starter is pulling too many amps.

A good starter will normally draw 60 to 150 amps with no load on it, and up to 200 amps or more while cranking the engine. The no load amp draw depends on the rating of the starter while the cranking amp draw depends on the displacement and compression of the engine. Always refer to the OEM specs for the exact amp values. Some "high torque" GM starters, for example, may have a no load draw of up to 250 amps. Toyota starters on four-cylinder engines typically draw 130 to 150 amps, and up to 175 amps on six-cylinder engines.

An unusually high current draw and low free turning speed or cranking speed typically indicates a shorted armature, grounded armature or field coils, or excessive friction within the starter itself (dirty, worn or binding bearings or bushings, a bent armature shaft or contact between the armature and field coils). The magnets in permanent magnet starters can sometimes break or separate from the housing and drag against the armature.

A starter that does not turn at all and draws a high current may have a ground in the terminal or field coils, or a frozen armature. On the other hand, the start may be fine but can't crank the engine because the engine is seized or hydrolocked. So before you condemn the starter, try turning the engine over by hand. Won't budge? Then the engine is probably locked up.

A starter that won't spin at all and draws zero amps has an open field circuit, open armature coils, defective brushes or a defective solenoid. Low free turning speed combined with a low current draw indicates high internal resistance (bad connections, bad brushes, open field coils or armature windings).

If the starter motor spins but fails to engage the flywheel, the cause may be a weak solenoid, defective starter drive or broken teeth on the flywheel. A starter drive that is on the verge of failure may engage briefly but then slip. Pull the starter and inspect the drive. It should turn freely in one direction but not in the other. A bad drive will turn freely in both directions or not at all.


When the engine cranks normally but won't start, you need to check ignition, fuel and compression. Ignition is easy enough to check with a spark tester or by positioning a plug wire near a good ground. No spark? The most likely causes would be a failed ignition module, distributor pickup or crank position (CKP) sensors

A tool such as an Ignition System Simulator can speed the diagnosis by quickly telling you if the ignition module and coil are capable of producing a spark with a simulated timing input signal. If the simulated signal generates a spark, the problem is a bad distributor pickup or crankshaft position sensor. No spark would point to a bad module or coil. Measuring ignition coil primary and secondary resistance can rule out that component as the culprit.

Module problems as well as pickup problems are often caused by loose, broken or corroded wiring terminals and connectors. Older GM HEI ignition modules are notorious for this. If you are working on a distributorless ignition system with a Hall effect crankshaft position sensor, check the sensor's reference voltage (VRef) and ground. The sensor must have 5 volts or it will remain permanently off and not generate a crank signal (which should set a fault code). Measure VRef between the sensor power supply wire and ground (use the engine block for a ground, not the sensor ground circuit wire). Don't see 5 volts? Then check the sensor wiring harness for loose or corroded connectors. A poor ground connection will have the same effect on the sensor operation as a bad VRef supply. Measure the voltage drop between the sensor ground wire and the engine block. More than a 0.1 voltage drop indicates a bad ground connection. Check the sensor mounting and wiring harness.

If a Hall effect crank sensor has power and ground, the next thing to check would be its output. With nothing in the sensor window, the sensor should be "on" and read 5 volts (VRef). Measure the sensor D.C. output voltage between the sensor signal output wire and ground (use the engine block again, not the ground wire). When the engine is cranked, the sensor output should drop to zero every time the shutter blade, notch, magnetic button or gear tooth passes through the sensor. No change in voltage would indicate a bad sensor that needs to be replaced.

If the primary side of the ignition system seems to be producing a trigger signal for the coil but the voltage is not reaching the plugs, a visual inspection of the coil tower, distributor cap, rotor and plug wires should be made to identify any defects that might be preventing the spark from reaching its intended destination.


If you see a good hot spark when you crank the engine, but it won't start, check for fuel. The problem might be a bad fuel pump

On an older engine with a carburetor, pump the throttle linkage and look for fuel squirting into the carburetor throat. No fuel? Possible causes include a bad mechanical fuel pump, stuck needle valve in the carburetor, a plugged fuel line or fuel filter.

On newer vehicles with electronic fuel injection, connect a pressure gauge to the fuel rail to see if there is any pressure in the line. No pressure when the key is on? Check for a failed fuel pump, pump relay, fuse or wiring problem. On Fords, don't forget to check the inertia safety switch which is usually hidden in the trunk or under a rear kick panel. The switch shuts off the fuel pump in an accident. So if the switch has been tripped, resetting it should restore the flow of fuel to the engine. Lack of fuel can also be caused by obstructions in the fuel line or pickup sock inside the tank. And don't forget to check the fuel gauge. It is amazing how many no starts are caused by an empty fuel tank.

There is also the possibility that the fuel in the tank may be heavily contaminated with water or overloaded with alcohol. If the tank was just filled, bad gas might be causing the problem.

On EFI-equipped engines, fuel pressure in the line does not necessarily mean the fuel is being injected into the engine. Listen for clicking or buzzing that would indicate the injectors are working. No noise? Check for voltage and ground at the injectors. A defective ECM may not be driving the injectors, or the EFI power supply relay may have called it quits. Some EFI-systems rely on input from the camshaft position sensor to generate the injector pulses. Loss of this signal could prevent the system from functioning.

Even if there is fuel and it is being delivered to the engine, a massive vacuum leak could be preventing the engine from starting. A large enough vacuum leak will lean out the air/fuel ratio to such an extent that the mixture won't ignite. An EGR valve that is stuck wide open, a disconnected PCV hose, loose vacuum hose for the power brake booster, or similar leak could be the culprit. Check all vacuum connections and listen for unusual sucking noises while cranking.


An engine that has fuel and spark, no serious vacuum leaks and cranks normally should start. The problem is compression. If it is an overhead cam engine with a rubber timing belt, a broken timing belt would be the most likely cause especially if the engine has a lot of miles on it. Most OEMs recommend replacing the OHC timing belt every 60,000 miles for preventative maintenance, but many belts are never changed. Eventually they break, and when they do the engine stops dead in its tracks. And in engines that lack sufficient valve-to-piston clearance as many import engines and some domestic engines do, it also causes extensive damage (bent valves and valvetrain components & sometimes cracked pistons).

Overhead cams can also bind and break if the head warps due to severe overheating, or the cam bearings are starved for lubrication. A cam seizure may occur during a subzero cold start if the oil in the crankcase is too thick and is slow to reach the cam (a good reason for using 5W-20 or 5W-30 for winter driving). High rpm cam failure can occur if the oil level is low or the oil is long overdue for a change.

With high mileage pushrod engines, the timing chain may have broken or slipped. Either type of problem can be diagnosed by doing a compression check and/or removing a valve cover and watching for valve movement when the engine is cranked.

A blown head gasket may prevent an engine from starting if the engine is a four cylinder with two dead cylinders. But most six or eight cylinder engines will sputter to life and run roughly even with a blown gasket. The gasket can, however, allow coolant to leak into the cylinder and hydrolock the engine.

Why won't my engine crankshaft turn all the way by hand?

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Try taking out the spark plugs first, because turning the crank shaft with the plugs in creates pressure. Or it could be that there is a bent rod and the piston head is in the head wall.

How do you check a crankshaft sensor on a 1994 Jeep Cherokee?

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I have found the best way to change this sensor on the 318cid model is from the top. I removed the transmission crossmember and jacked the transmission all the way up to gain more space behind the engine. You will find the sensor on the right side, follow the 3 wire harness and unplug it. Then using a couple of extentions and swivels you can reach behind to feel the bolts and guide the socket on to the bolts. I could not see the bolts at all it was done by feel. Remove the bolts and sensor, then reverse this procedure.

Where is the crank or cam shaft position sensor located on a 2003 Jeep Grand Cherokee?

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The camshaft position sensor is located just above the oil filter on the right side (sitting in the vehicle) of the engine.

Where is the camshaft postioning sensor located on a 2000 Daewoo Leganza?

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when you open your hood and you look on the valve cover you see on your left side of top of your cover a cable sticking out from a black piece that is the positioning sensor that cranksup the car.