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Unread 06-22-2013, 10:59 AM   #46
Kong1965
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I've swapped two different sensors, one a BWD and the other direct from the dealership ($140), and I'm still throwing a P0340. Checked the pins as directed above, and everything checks fine. Go to the socket and I get straight continuity from the ground plug to the main ground strap/bolt on the firewall, but I get 5v from both plug 1 and 3 when the key is in the on position. Is this what I'm supposed to receive?

If I had any hair, I'd be pulling it out by now.

Thanks for any help.

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Unread 06-22-2013, 11:31 AM   #47
CJ7-Tim
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All the OBD sensors run on 5 volts.

Crankshaft Sensor or Camshaft Sensor ?

P0340 JEEP - Camshaft Position Sensor

Possible causes

- Faulty Camshaft Position Sensor
- Camshaft Position Sensor harness is open or shorted
- Camshaft Position Sensor circuit poor electrical connection
- Faulty starter motor
- Starting system circuit
- Dead (Weak) battery

Tech notes:

- This code is triggered when the Camshaft Position Sensor signal is not detected by the Engine Control Module (ECM) during the first few seconds of engine cranking.
- Sometimes and in some models, low battery voltage or a weak starter may trigger a Camshaft Position Sensor code.
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Unread 06-22-2013, 12:13 PM   #48
Kong1965
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Doh!!!

Talk about reading what you want into something. Thanks CJ7-Tim!!

Holy crap. Well, hopefully I won't have to replace the Crank sensor for some time now.

Appreciate the fast response.

Kong
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Unread 06-22-2013, 12:22 PM   #49
CJ7-Tim
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Installing a new Cam sensor in the distributor should fix the problem. Some parts stores call it a Camshaft Pickup.

.
cmp.jpg  
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Unread 06-22-2013, 05:42 PM   #50
Kong1965
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Bingo

That was it. Fires up instantly now. Gas gauge works accurately too for a change. Maybe it was a combo of the two.

Guess I'll need to read the scanner a little more carefully next time.

Thanks again.
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Unread 03-31-2014, 08:43 AM   #51
motoxxxman
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I`m having an aggravating cps issue with my 95 XJ.
2 weeks ago my cps went out, it was the original sensor, with 234,000 miles on it. got a new one from carquest, fired right up, ran fine since.
yesterday I was idling from a cold start for about 2 minutes, then randomly died for an instant, then caught itself and came back to life. a minute later it flat out died and would crank but no start. 3 ignition toggles and sure enough got a code 11 again, cps. bought a new bwd sensor from AAP, installed it and cleared the codes, fired it up and it ran for 3 seconds and died again, again throwing code 11 for cps.
I exchanged the new sensor I'd just installed for another new BWD one, but I'm afraid to install it in fear it'll just fry right off the bat again forcing me to make a 45 minute hike to get yet another replacement.
all guages work fine, zero blown fuses, fuel pump primes fine when ignition cycles on.

what can be causing my cps to keep failing like this? I did pick up a new cam sensor (ignition pickup, inside the distributor) when I got the replacement cps yesterday after looking at wiring diagrams and seeing the 5v wires (org) for each sensor are tied together. I plan to clean all grounds, double check bellhousing bolts for tightness, and try closing the harness plug terminals down a hair with a pin. but is there anything else that might be contributing to my cps failing so frequently that I should check?
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Unread 03-31-2014, 11:21 AM   #52
CJ7-Tim
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Quote:
Originally Posted by motoxxxman View Post
...what can be causing my cps to keep failing like this?
Cheap parts are cheap for a reason. Cheap crappy "Lifetime Warranty" Jeep sensors are often out of specifications or even failed right out of the box.

Using genuine Jeep sensors is highly recommended.
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Unread 04-03-2014, 05:21 AM   #53
motoxxxman
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Quote:
Originally Posted by motoxxxman View Post
I did pick up a new cam sensor (ignition pickup, inside the distributor) when I got the replacement cps yesterday after looking at wiring diagrams and seeing the 5v wires (org) for each sensor are tied together.
^this^ was my issue. as it turns out, all the cps sensors I thought kept frying were actually still good. my cam sensor on the other hand had frayed wires at it's pigtail (sensor side) and the power supply wire (shared with the cps power supply) was randomly shorting out into the ground wire next to it, causing voltage to the cps to drop to zero, causing instant loss of cps signal. after replacing the cam sensor (aka sync sensor, ignition pickup) it fired right up and stayed running. and I must say, in the 60k miles I have owned this XJ it has never run better than it does now. smooth as glass and picked up a good amount of lower rpm torque. it also warms up much faster now.

I also no longer have my rare/random issue with the tranny not unlocking the torque converter in 3rd and 4th gears. probably because the ground for all the sensors is sourced from the tcu.
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Unread 09-16-2014, 10:55 PM   #54
Brown_dog
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"Unplugging and reconnecting the CPS sensor where it connect to the main harness near the back of the intake manifold usually resets the ECU and if the jeep fires right up after doing this you can bet that the CPS is faulty and needs to be replaced."

Best piece of advise I have found! I had what I thought was a TQ converter lockup issue and still think there is something to that problem. But I exchange my transmission fluid, removed the check valve from the cooler line. My issue change to a bad miss at operating temp. Had to leave the jeep on the side of the road one night. After it completely cooled I drove it half way home and parked it to let it cool. Mid day I read this testing procedure went over and tried it before everything cooled. Bam it worked enough to get me home. The ZJ started missing a couple blocks from the house. When i got home, unplug and plug... Worked, Damn, dude (CJ7T) is on to something. Next I measured resistance between B&C about 16K Ohms.

I called the dealer, no CPS, second try NAPA, they had both styles, I bought both as I hadn't crawled under to see which I needed. Drive up on the ramps, determine I need the one bolter. think to myself. Measure B to C, crap 6k ohms, measure the other (two bolter), it shows open. Call NAPA, they have 2 more, I ask the guy to check resistance and it's open. Next drive 20 miles to NAPA to get the CPS that works.

Use about all the long extensions I have, little cursing and the CPS is out. Now the challenge, after 1/2 hr come to realization my hands are just too big. Rock star wife got helped got it in the hole in about 2 mins. Snugged it up, strung the loom around the back of the engine.


Started right up, I drove about 15miles w/o anything.

Thanks again.
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Unread 01-28-2015, 07:23 AM   #55
MrMcClellen
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Same issues except...

My 2001 xj has all of the symptoms of a cps issue. Driving down the road and gauges quit working with a "no bus". Drove it home and parked it. Would not start after that. Cranks bit no spark and no fuel. The fuel pump does not run or prime for 3 seconds. When i pull my fuel pump relay and bypass it, it will pump fuel. I replaced my cps and my relays and still no fix. Is there anything else i should try or something i missed?
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Unread 02-09-2015, 07:13 PM   #56
GFunk1
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I think I need to replace my CPS on my 2000 XJ. IS the sensor plug under the vehicle or up where it is on a 1999? I can't seem to find mine under the hood.
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Unread 02-10-2015, 04:55 AM   #57
peelman
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Haven't checked mine myself but apparently if you follow the harness it maybe on the passenger side of the trans bell housing. The harness is not quite a foot long so you wont see it in the engine bay.
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Unread 02-11-2015, 10:17 AM   #58
MDchanic
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Quote:
Originally Posted by GFunk1 View Post
IS the sensor plug under the vehicle or up where it is on a 1999? I can't seem to find mine under the hood.
If I recall from last year, it is clipped into a bracket with a few other plugs (like O2 sensor) up high, sort of above and the the left of the bellhousing.

It's a bit hard to really get your fingers around it.

- Eric
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cps , cranking not starting , crankshsft position , No bus , no start , no-bus

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