Mechanics

CRANK SENSOR

2002 Saturn L300

Transmission problem
2002 Saturn L300 6 cyl Front Wheel Drive Automatic 90000 miles

My L300 died at an intersection. It restarted after 15 minutes, then stalled at low rpm/idle 3 additional times on the way back home after I turned around. Each time I was able to restart the engine after a 10-20 minute cool down period. I've had a parts store pull codes (control unit, crank sensor, no rpm reading, and one other not related to transmission).

I've been told it could be crank sensor, cam sensor, or the control unit, but that the crank sensor would be the most likely culprit and one of the least expensive places to start the repair process.

I'm an amateur mechanic who has more experience with older vehicles than those with computer controls.

I am looking for the crank sensor. I was told by the dealership it is near the starter and exhaust manifold. After 40 minutes with a drop light and mirror I still can't see where it is. I don't have the special tools required (star shaped bolt heads, when did those come out?) To remove components to get to the exhaust manifold to get it out of the way.

Could someone please help me locate the crank sensor and let me know what I may have to move/remove to gain access to it? I found the part at a good price at the dealership ($40!), I'm hoping it won't take hours of dealer labor to get to and replace the part.

Thank you,

mrchuck
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Mrchuck
July 18, 2010.




The crank sensor is right next to the oil filter housing it's held in by a reverse torxs bolt it has a wire that come's off it that you have to unplug it from the engine compartment. It also has a silver cover over the wire it's real easy to find. What was the code number you had and I can tell you if it is most likely the sensor.

Saturntech9
Jul 18, 2010.
I believe the notes I took which had all 4 codes was thrown away when the kitchen table was cleared. I've looked everywhere.

I remember 0700 (control unit?), And as stated in my original post that the crank sensor and a 'no signal from ( I think ) rpm sensor' were two of the others.

I've been told by two mechanics that it could be crank or cam sensor, or the control unit that caused the problem, and that the only way to diagnose is by replacing parts.

I own a multimeter. Are there resistance specs available to test sensors or is it true that part by part replacement is the only way to go?

I wish I could find a manual or at least an exploded view of my engine without having to pay out the nose for a book I can't preview. I stopped buying Haynes and other manuals when I purchased one only to find it didn't have near the detail I needed. They may be good for general information and maintenance, but the wiring diagram included was lacking as were the engine diagrams. It ended up on a shelf, unused.

Thank you for your quick response to my original question. Once I get this fixed so I have a car to find and get to a job I'll gladly 'donate' to the cause for the help I've received.

Tiny
Mrchuck
Jul 21, 2010.
Here's what I want you to do get the car hot let it stall and when it won't start unplug the crank sensor then check it's resistance it should be 800-1200 ohm's if it's bad you will probably read a open no value.I really think it's the crank sensor so let me know what you find.

Saturntech9
Jul 21, 2010.
Found it! It was right where you said, by the oil filter.

I also found the 4 codes: P0700 -Trans Control System
P0335 - Crank Position Sensor
P1810 - Trans Control Module
P0727 - Engine Speed Sensor

I pulled the sensor cold and found an open circuit. I'm hoping I placed the lead on the correct spot on the business end of the sensor (the 1/8" short protrusion at the end of the cylinder and I alternated between the 3 prongs not knowing if it was a particular one). IT WAS AN OPEN CIRCUIT. Should there be a reading when the sensor is cold?

When I reinstalled the sensor to warm up the engine so I could test it hot the car failed to start. So I wasn't able to test the sensor hot as directed in your previous post.

I'm convinced the crank sensor is the trouble, so long as the circuit can be tested cold. If it is supposed to be an open circuit cold then I'm back to square one. With an engine that won't start.

I did try to reset the codes by unhooking the battery then tried to start the engine. It didn't work.

I'm about to order the part I need online. I'll wait a few days to see what your response is first just in case you have additional thoughts.

Thank you for your continued assistance.

Tiny
Mrchuck
Jul 25, 2010.


http://www.2carpros.com/forum/automotive_pictures/416332_2002_L300_crank_shaft_sensor_1.jpg


I don't know which sensor you removed but the crank shaft sensor only has two terminals going to it.Its held in by a small reverse torx head bolt it's by the oil filter canister and the two oil cooler line's coming off the block.When there good or cold will read 800-1200 ohm's between the two terminal's.It also has a sliver cover over part of the wire.With the code's you have it look's like a bad crank shaft sensor except the p1810 but i would address the other code's first then clear it and see if the p1810 come's back.I posted a diagram of where the sensor is you can even follow it to where it plug's in.Let me know what you find.

Saturntech9
Jul 25, 2010.
I definitely had the crank sensor. I went to the dealership to see one for myself and held it in my hand to help me locate it on the engine block. I purchased an E8 reverse torx socket today to pull it.

What I was trying to describe was how I measured resistance. There are three prongs in the coupler up top (definitely not two), and the sensor cylinder had a small protrusion (magnetic pickup?) At it's end.

Should I have tested the resistance between two of the three prongs instead of from the magnetic pickup to one of the prongs?

Tiny
Mrchuck
Jul 25, 2010.


http://www.2carpros.com/forum/automotive_pictures/416332_2002_L300_crank_shaft_sensor_wires_1.jpg


The crank shaft sensor only has two wires going to it there's my proof look and the wire diagram.The cam shaft sensor has three though.What color are the wire's going the sensor you took out?

Saturntech9
Jul 25, 2010.
Hmmm
i wish i could zoom in on your diagram.
the sensor i pulled was located next to the oil filter, and the other end plugged in in the area between the battery and the intake manifold.
it looked exactly like the one i held in my hand at the dealership.
i thought the cam sensor plugged in above the pulleys on the 'passenger' side of the engine.?

here is a fuzzy picture of the three prongs. i hope it's visible


http://www.2carpros.com/forum/automotive_pictures/551767_crank_sensor_1.jpg

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Tiny
Mrchuck
Jul 26, 2010.
What color are the wires going to it?

Saturntech9
Jul 26, 2010.
You are correct there are three pin's on the connector for some reason I only remember 2 being on it sorry about that. The way your going to test it is the pin's that have the yellow wire and the purple going to them on the sensor that's where you should have 800-1200 ohms between those two pin's. Let me know what you find.

Saturntech9
Jul 26, 2010.

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