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

Answer 1

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.

Answer 2

CPS: You can check it's basic function but be aware that sometimes the darn things can be 'intermittant' but still read 'ok' when measured due to engine heat/temperature. Even so, these tests will show up a borderline CPS more often than not.

Check the connector first

If you've just stalled out with same symptoms... unplug the CPS & plug it back in. If your motor fires back up you might get off easy, but don't count on it lasting forever. I dunno what doing this accomplishes other than cleaning the connector contacts enough to let additional voltage through to the computer. If unplugging & replugging worked then unplug the connector again and clean those contacts off. Then apply some OX-GARD, or other electrical contact cleaner & protectant (dielectric grease).

There is a distinct possibility that you're not getting a signal due to a faulty connector itself as well. Some people have cured their CPS problems by simply cutting the connector out of the harness and SOLDERING the wires together (Use heat shrink or electrical tape around the wire, of course!) Other's have replaced the connector with a newer, waterproof version from an electrical or automotive supply store.

Test#1 - Get a volt/ohm meter and set it to read 0 - 500 ohms. Unplug the cps and measure across the CPS connector's A & B leads. Your meter should show a CPS resistance of between 125 - 275 ohms. If it's out of that range by much; replace it. (* - Note: HO engines are measured from the B & C connectors and should have near zero ohms.)

Test#2 - You'll need a friend to help ya with this one.

Set your volt/ohm meter to read 0 - 5 AC volts or the closest AC Volts scale your meter has to this range. Measure across the CPS leads for voltage generated as your friend cranks the engine. (The engine can't fire up without the CPS connected but watch for moving parts just the same!) The meter should show .5 - .8 VAC when cranking. (That's between 1/2 and 1 volt AC.) If it's below .5vac, replace it.

Desperate last ditch tip to get home or a few more miles from a failing CPS: - Other than the unplug/replug trick... MJR passed on a trick of using a flat bar and a hammer to 'adjust' the CPS by smacking the CPS bracket and forcing a weak CPS just a tad closer to the flywheel. This lets a weak CPS get a stronger pulse and hopefully generate enough voltage to feed a good signal to the computer again. WARNING! - If ya smack it too hard... it'll go in too far and the flywheel will eat the CPS! Start walking.

Either way, if it fails ANY of the tests... you should replace it and save your self some major pain later. If not, at least carry a spare CPS but be aware that it's a royal pain to change on a cold motor and ya really don't wanna do it at night, on the trail and with a hot motor if ya can help it!

Answer 3

For a 6 cyl, cut a hole in the floor of the car on the driver side up near the center console so you can see the cps then replace part and cover the hole in the floor. trust me that's the only way to do it i had to replace that part and there is no other way to get at it.

You do not need to cut a hole, you just need to remove the front driveshaft to have enough room to access the sensor.

Answer 4

LOCATION OF CRANK ANGLE SENSOR ON 2003 4.7 PETROL MOTOR

Answer 5

CPS is located on bell housing drivers side. Hard to get to! Common problem for 90's Cherokee not to start.