crankshift position sensor

[faris_jason]

I have a p0335 code. I am changing my sensors tomorrow. Is one of the symptoms of a bad sensor engine stalls? Can you explain to why if so and what this sensor actually does. Thanks. I'm trying to learn about cars. I am an aircraft electrician. I can fix a plane but not my own car. This must change!

[faris_jason]

Well I just found the search function on this site. I see it does cause your vehicle to stall at any speed! Scary, stuff!!! Well the code I am getting is for sensor A. Do I really need to change both if it constantly fails for the A circuit? They have both sensors for $39.99 each at auto zone with a two year warranty. Do you think these parts are ok to put on my caddy even tough there not OEM? Cause my AC in my house needs to be replaced as of today and I need to pich some pennies if I can!

[TDK]

Jeezy,

Was the 0335 the only code returned? If this is referance to your other existing thread, (heavy idleing), you may want to continue it there to maintain continuity.

Many modern cars do not have distributers that are mechanically-linked to the crankshaft etc. The crankshaft position sensors work together to electronically-time the engine ignition via the ECM and coil packs or coil-over plugs- along with knock sensors, and a host of other electronic add-ons.

Crank sensors are simply electronic coils sensing gaps in a toothed wheel or holes in a plate, etc, and thus generating a DC square wave, perfect for a computer input. A failure of one does not cause an immediate failure, but can certainly result in intermittant stalls etc. These similar sensors are used throught the car, in the tranny, at the wheels, the steering rack - everywhere a position or speed is desired. Sometimes the gap can be adjusted or the element cleaned, but usually - just replace it.

Good luck,

[faris_jason]

Yes that and the stall code. Do I need to change both or just the one thats failing? Are autozone parts ok to use? My mechanic told me no but I think they would be ok with a 2yr warranty.

[lothos]

The ACDelco Crankshaft Position Sensor for your car is only $42 at rockauto.com. For a couple bucks difference I'd go with OEM. There's a 5% discount code you can use, click the link on my signature. That should make it about the same price plus shipping. I've ordered from them before, they have real good customer service.

EDIT: Looks like that's the price for the upper sensor, the lower is $48.

[adallak]

As far as I remember, that model year is known for crankshaft position sensors failure. Some people went through several sensors... Typically the engine stalls when car comes to stop say, at traffic light. There will be no problem to restart though. It is always a good idea to go with OEM parts, which is ACDelco. On the other hand, that same part was probably used in your car... Go figure!

[winterset]

But an important point - the brand is the same, but the part was redesigned. I believe the CPS for that car is even made in a different country now.

[Poobah]

The crankshaft position sensors used in early 2000's Northstars were prone to failure. Cadillac has redesigned them at least twice since then and the newest ones are quite reliable.

I understand the need to save money but the least expensive way to solve a problem is to do it right the first time.

I would shy away from aftermarket sensors. Think about it: if it took Cadillac three times to get it right, what makes you think an aftermarket manufacturer can do any better? Crankshaft position sensors are not expensive parts so any savings realized by using an aftermarket part can't be all that much.

When I bought my 2000 Deville, the dealer's service records showed one of the crankshaft sensors had been replaced 4 or 5 times under waranty! I was told that it is difficult for the computer to accurately distinguish between a failure of the upper and lower sensors. Often, if you replace just one, it's the wrong one and the problem just comes back.

If you are having crankshaft position sensor problems with your 2000 Northstar, I strongly recommend that you replace both of them with the newest OEM parts. That way, you will positively solve the problem without having to go back and do it over soon. That will save you money (and aggravation) in the long run.

[Cadillac Jim]

To answer one of your original questions, "What is a crankshaft sensor for?" I have some inputs.

Begin with a conventional mechanical engine. There is a crankshaft with attached connecting rods and pistons, which has a 2:1 gear or chain drive to a camshaft or two or four or whatever. The camshaft provides valve motion at half the crankshaft rate. At least one of these camshafts has an ignition system attached that provides spark for one or more cylinders also at half the crankshaft rate. Engine RPM and manifold vacuum are used to modify the spark timing for best performance and economy.

The carburetor has a complex set of pressure, flow and throttle position sensors, links, and valves such as needle jets and vaccum controlled power valves that provides the best possible mixture for whatever the engine is doing, and maintains something close to 14:1 air/fuel mass ratio for cruising with a fully warmed-up engine.

An automatic transmission will operate with a hydraulic computer using information from analog sensors of throttle position, engine vacuum, engine RPM and output RPM.

A modern electronically controlled engine has a computer model of crankshaft motion that is implemented in one of the computer chips in the PCM; GM calls it the ignition control module. The crankshaft and cam position are found from two crankshaft sensors and a cam sensor. The crankshaft sensors are to get a fine measurement of crankshaft angle (24 X crank speed) and another to get a handle on which pulse is DTC for cylinder 1. The cam sensor is to resolve the 180 degree crank angle ambiguity for the purposes of timing the fuel injectors.

The crank speed and position is used, along with a throttle position sensor and vacuum sensors in the intake manifold and other fuel injector sensors to set the spark timing. These, and the cam sensor, are used to turn on the fuel injectors just long enough to get exactly the right amount of gas to that cylinder for that crankshaft revolution.

The fuel injection sensors and some other sensors inside the crankshaft provide data to a digital computer that replaces the hydraulic computer of older automatic transmissions and operates the electronic transmission through only three solenoids. The computer chip that operates the transmission is in the PCM, as is the knock sensor; the PCM then provides control to the ignition control module that models crankshaft angle.

[Ranger]

The failure prone sensors where made in Mexico. The new supplier is Japanese. Stick with OEM and change them both.