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99 Grand Cherokee Limited Camshaft Position Sensor Code Fix?

20K views 10 replies 3 participants last post by  99JeepGCLimited 
#1 ·
I have a 99 Jeep Grand Cherokee Limited With 4.7L. Yesterday morning when my wife was taking our son to school it died on her while she was driving, so I went and towed the car home and I just first decided to change the fuel filter. Which was 29$ and that didn't fix the problem, so then I decided to check the OBD II and I got an error code that said, " Camshaft Position Sensor Bank A - Circuit Malfunction " So I replaced the CPS ( Camshaft Position Sensor 27$ ) And still had the same problem after erasing the codes and cranking the motor. After it cranked for about 30 seconds the check engine light came back on. So I asked a mechanic via telephone and he told me to change the Crankshaft Position Sensor 28.49$. I changed it and im still having the same problem. I checked all fuses and I tryed everyway possible to check for faulty wiring and still everything seems fine except the fact that my Jeep still won't start and I still have the Camshaft Position Sensor Code showing on it. Please if anyone has had this problem before and knows how to fix it or what I can do to run down the true problem without having to have it towed somewhere I would greatly appreciate it!
 
#2 ·
Welcome to the garage.
Did you use an OEM camshaft sensor? Sometimes non OEM give problems.
I would disconnect the battery and remove/check/clean/install the connectors on the PCM. If that all ok, and you´re sure the wiring is ok and not damaged somewhere, i would say its or the PCM itself or the right camshaft is not turning. The last one is quite rare, but there is a small pin on the camshaft which should hold the sprocket, and if its broken or the sprocket bolt loose, the shaft will stand still and you get a camshaft sensor fault. This last one would be the ultimate thing to check when it was me.
 
#3 ·
Well I did a few more things today and come to realize that I'm not getting any fire to any of the coils so I did take out the PCM and looked around all day for one at a salvage yard and come up unlucky so I'm going to try to clean up the PCM and reinstall it see if that helps if not then I guess I'll be selling this jeep I'm not paying 600$ for a new PCM
 
#4 ·
But i think that when you, for whatever reason, don´t have the cam signal, that you also won´t get any spark.
Maybe that 2005 JGC can chime in and give his ideas.
 
#5 ·
with a failed cam sensor you wont get spark or fuel, thats why the vehicle dies, I would make sure your connector is securely connected... also as Frank suggested, aftermarket sensors SUCK on chrysler products, so I would get a mopar cam sensor.

I wouldnt waste your time with the pcm... its not going to fix it ;)

if you have a p0340 cam sensor fault your problem is very likely in either the circuit, or the sensor.
 
#7 · (Edited)
That there probably is an open wire in the camshaft wiring circuit. You probably have to measure the wires to see if there is continuity.
 
#10 · (Edited)
Disconnect the negative battery lead, then disconnect the respective connector on the PCM. You need the wiring manual to know on which points to measure. You just put one lead of the ohm meter on the respective camshaft sensor wire connector pin and the other on the same wire on the PCM connector. There should be 0 Ohm or very close to it. When the wire is open, there will be an infinite resistance. In that case, you should try to bend the wire a bit over the whole loom lenght, to see if the resistance will come back to 0 ohm, which could indicate a broken internal wire. There could also be a resistance of a few ohms, which could mean corrosion or dirt at a wire connection.
Attached the wiring schematic.
So you need to remove the connector C1 from the PCM. Then measure between points 17 from connector C1 and point 3 from the camshaft connector. Then between point 18 from connector C1 and point 1 from the camshaft connector. Then last between point 2 from the camshaft sensor connector to point 4 on connector C1. All should have a resistance of 0 ohm.
 
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