Well, is it or is it not your CPS sensor. Jeep Part number
56027280
List US$86.70 but the "best price" should be closer to US$72.00 Without going into the this sensors guts, let's just say it's a magnetic field sensor. It contains a fairly strong magnet and spends it's life watching the flywheel. The flywheel has several notches cut into it and as these pass the sensor it allows current to flow. |
Generally this type of sensor never goes bad but... It can suffer
from a buildup of metal fragments and the wires will eventually suffer
from engine heat. If you pull your old CPS sensor and it is covered
with metal fuzzies, wipe it off with a cloth and measure it again.
(Same goes for your ABS sensors)
On the 42RE transmission the CPS sensor connector looks like this and can be found back by the dipstick. |
Using a DMM (Digital MultMeter) your going to probe Pins
B and C.
Watch the polarity, your Ohmmeter will have a RED and a BLACK lead |
||||
BLACK LEAD to | RED LEAD to | New Sensor | Old Sensor | |
B | C | Infinite (OPEN) | Infinite (OPEN) | |
C | B | 4.48 Mega Ohms | 2.50 Mega Ohms |
How do you get that thing out? Well, this is where being a body builder isn't going to help. If your forearms are fairly large you might have to drop the front shaft. You get at the bolt that holds the sensor by using one swivel, and two 16" extensions. The nut is 11mm. Your going to run the shaft from just behind the cross member, up above the transmission linkage mounting bracket, add on the swivel, then run the second almost straight in on the nut.
Getting that sensor out isn't too hard but it helps if your a human pretzel. Reach up in front of the transmission bell housing and grab it from the top. You will need to take it out enough to turn the ear toward the engine bay, that allows the sensor to clear the firewall, and out it pops.
Sorta the reverse for installation. My only real problem was getting
the stupid bolt into the sensors hole. And speaking of hole, This
sensor has only one fixed hole setting the gap where the original might
have an adjustable hole and relied on a paper spacer to attain the proper
gap. If this is your old sensor, now is the time to transfer a reference
mark from the new one.