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Old 10-10-2010, 07:04 PM   #1
mab
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Crankshaft Position Sensor Reset

Replaced CPS, now it idles rough, rpm's bounce around. Original problem, engines shuts down while driving.
Need to reset and have no instructions on How To Reset. Any help would be greatly appreciated.

Thanks in advance,

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Old 10-10-2010, 08:27 PM   #2
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Reset what? The computer? Disconnect the battery and let it sit over night or pull the negative cable and hold it on the positive and count to 15.

What year is your jeep? Motor?

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Old 10-10-2010, 08:47 PM   #3
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Quote:
Originally Posted by distortedtj View Post
Reset what? The computer? Disconnect the battery and let it sit over night or pull the negative cable and hold it on the positive and count to 15.

What year is your jeep? Motor?
Why would you wait over night if it can be done in 15 seconds?
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Old 10-10-2010, 08:51 PM   #4
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Quote:
Originally Posted by coyote_94yj View Post
Why would you wait over night if it can be done in 15 seconds?
Because for some odd reason some ppl are afraid that they will get shocked or fry the comp....truth be told...not true....well you could get zapped if your a moron but I try to give ppl the benefit of not being.



Also....OP...If this is all happening with the idle bouncing and dieing while you are driving...just a few suggestions. Check your plugs...wires.....and if all is good...change the cam sensor. Depending on your year of jeep....97 to 99..the cam sensor is in the distributor under the cap and the disk looking item under your rotor...and the cam sensor for the "distributorless" 2000 to 06 is in about the same location on the passenger side of the block beside the oil pressure switch...will be a flat round sensor with a connector going to it.

Also get a fuel pressure gauge and check the pressure...older TJ's are famous for wanting new fuel pumps.
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Old 10-10-2010, 08:54 PM   #5
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Quote:
Originally Posted by distortedtj View Post
Because for some odd reason some ppl are afraid that they will get shocked or fry the comp....truth be told...not true....well you could get zapped if your a moron but I try to give ppl the benefit of not being.



Also....OP...If this is all happening with the idle bouncing and dieing while you are driving...just a few suggestions. Check your plugs...wires.....and if all is good...change the cam sensor.
I know, I was just busting your chops.


Mab, you could also go down to Vatozone and get them to scan your ECU for DTCs(trouble codes).
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Old 10-10-2010, 08:58 PM   #6
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Quote:
Originally Posted by distortedtj View Post
Because for some odd reason some ppl are afraid that they will get shocked or fry the comp....truth be told...not true....well you could get zapped if your a moron but I try to give ppl the benefit of not being.



Also....OP...If this is all happening with the idle bouncing and dieing while you are driving...just a few suggestions. Check your plugs...wires.....and if all is good...change the cam sensor. Depending on your year of jeep....97 to 99..the cam sensor is in the distributor under the cap and the disk looking item under your rotor...and the cam sensor for the "distributorless" 2000 to 06 is in about the same location on the passenger side of the block beside the oil pressure switch...will be a flat round sensor with a connector going to it.

Also get a fuel pressure gauge and check the pressure...older TJ's are famous for wanting new fuel pumps.

It looks like this. (on an '00-'06)

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Old 10-10-2010, 09:05 PM   #7
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Quote:
Originally Posted by coyote_94yj View Post
Mab, you could also go down to Vatozone and get them to scan your ECU for DTCs(trouble codes).
Alway do this first.^^^^


I was putting out several of the causing issues..start with the know basic's first...get the codes pulled...then... Clean the IAC, check plugs and wires. Then go from there.
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Old 10-10-2010, 10:23 PM   #8
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Ooops,

1999, Wrangler Sport, 4.0L, Auto, OK so you don't reset the CPS, What will cause the rough idle after installation of new Crankshaft Position Sensor, rpm's jumping around. I pulled the gnd. cable off for approx. 15 sec, will redo with more time disconnected. maybe try the replacing the cam sensor. New Plugs (E3) New Wires, New Battery as of now. If all else fails then try to get a code check as mention above.

Thankssss
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Old 10-10-2010, 10:36 PM   #9
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Quote:
Originally Posted by mab View Post
Ooops,

I pulled the gnd. cable off for approx. 15 sec, will redo with more time disconnected.

Thanks
Did you just disconnect it or did you disco it and hold it to the positive terminal for those 15 sec's? (that's what you need to do/will reset comp)

Next...The 99 don't like platinum or (E3) plugs...sorry...they work best with factory or Champion truck plug number 4412, They REALLY don't like platinum or split tip "cross-fire" plugs.

Next....check the firing order of the plug wires if you just changed them. I'll pull up a picture with the firing order in a minute and post it for you. A plug wire in the wrong spot = run like junk.

First I'd still get the codes pulled.
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Old 10-10-2010, 10:39 PM   #10
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Oh,,,and yes it is best to rest the comp after swapping the crank sensor.

Here is the fire order for your jeep....

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Old 10-10-2010, 11:18 PM   #11
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1st - just disconnected the gnd and did not touch it to pos. Battery, Plugs and Wires were changed a few weeks earlier when it was 1st happening (engine quits running traveling at speed limit)

Is PCM - Pulse Code Modulation or Powertrain Control Module

Here is a copy of info from a different post -

Ok Office 2010 won't let me make a picture out of it so here its long but it works I did it on my jeep 6 months ago after replacing the tps:

PCM Fast Learn Mode

The Jeep PCM performs several functions controlling Air Fuel ratios via Injector Bandwidth and Ignition Timing.

These outputs are controlled using the inputs received from all the sensors and then comparing these reading against a set of data tables burned into the PCM.

These memory tables are the brains that keep the engine running at low emissions and peak economy across the RPM band during closed loop mode.

These memory tables can and do change. They are adaptive, based on sensor readings, driving habits, engine performance and sensor tolerances.

Over time, the PCM Memory Tables become tuned to your engine.

This procedure first came to me from the folks at Avenger. I then verified it with a phone call to a Chrysler Engineer who had called me a year or so ago to ask about my experiences with a certain part on my TJ. I figured he owned me a favor. He had to check up on this for me. He called me back a week later and did indeed verify this procedure and what it does.

To the best of my knowledge it isn't documented in any of the FSM.


Forced Flash

This very simple procedure will Erase the Adaptive Memory stored inside the TJ PCM and allow a new Adaptive Memory to be developed.

After performing this procedure the PCM will re-learn and store into Adaptive Memory your engines performance characteristics.

Please perform these steps exactly as they are written, in the order they are written. This will cause the adaptive memory in the PCM to be erased and cause the PCM to go into Fast Learn Mode adaptive mode.


Disconnect the POSITIVE battery Terminal and touch it to ground for 30 seconds. (This is to discharge the PCM capacitors, which maintain the Adaptive Memory.
Reconnect the Battery Cable
Turn Ignition Switch to the On position but DO NOT start the engine
Turn Headlights On
Turn Headlights Off
Turn Ignition Key Off


The PCM Adaptive memory has now been flashed, or erased from the PCM.

When you start the engine it will be running off a set of pre-programmed tables that come with the PCM from the factory.

When you get the engine up to operating temperature the PCM will start to collect data for the Adaptive Memory.

The PCM will collect data for Adaptive Memory for the first 50 Warm-up Cycles.


Warm-up Cycle

A warm-up cycle happens when all of the following conditions exist.

Engine is running
A raise of 40F in engine temperature must occur ABOVE the engine temperature at start-up
Engine Coolant Temp must reach at least 160 F.


Once your engine has gone through 50 warm-up cycles in at least a 500-mile distance the PCM adaptive memory is set. It WILL NOT Change unless you flash it out and start all over again.
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Old 10-10-2010, 11:42 PM   #12
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copy of info was referred as a reset

Quote:
Originally Posted by mab View Post
1st - just disconnected the gnd and did not touch it to pos. Battery, Plugs and Wires were changed a few weeks earlier when it was 1st happening (engine quits running traveling at speed limit)

Is PCM - Pulse Code Modulation or Powertrain Control Module

Here is a copy of info from a different post -

Ok Office 2010 won't let me make a picture out of it so here its long but it works I did it on my jeep 6 months ago after replacing the tps:

PCM Fast Learn Mode

The Jeep PCM performs several functions controlling Air Fuel ratios via Injector Bandwidth and Ignition Timing.

These outputs are controlled using the inputs received from all the sensors and then comparing these reading against a set of data tables burned into the PCM.

These memory tables are the brains that keep the engine running at low emissions and peak economy across the RPM band during closed loop mode.

These memory tables can and do change. They are adaptive, based on sensor readings, driving habits, engine performance and sensor tolerances.

Over time, the PCM Memory Tables become tuned to your engine.

This procedure first came to me from the folks at Avenger. I then verified it with a phone call to a Chrysler Engineer who had called me a year or so ago to ask about my experiences with a certain part on my TJ. I figured he owned me a favor. He had to check up on this for me. He called me back a week later and did indeed verify this procedure and what it does.

To the best of my knowledge it isn't documented in any of the FSM.


Forced Flash

This very simple procedure will Erase the Adaptive Memory stored inside the TJ PCM and allow a new Adaptive Memory to be developed.

After performing this procedure the PCM will re-learn and store into Adaptive Memory your engines performance characteristics.

Please perform these steps exactly as they are written, in the order they are written. This will cause the adaptive memory in the PCM to be erased and cause the PCM to go into Fast Learn Mode adaptive mode.


Disconnect the POSITIVE battery Terminal and touch it to ground for 30 seconds. (This is to discharge the PCM capacitors, which maintain the Adaptive Memory.
Reconnect the Battery Cable
Turn Ignition Switch to the On position but DO NOT start the engine
Turn Headlights On
Turn Headlights Off
Turn Ignition Key Off


The PCM Adaptive memory has now been flashed, or erased from the PCM.

When you start the engine it will be running off a set of pre-programmed tables that come with the PCM from the factory.

When you get the engine up to operating temperature the PCM will start to collect data for the Adaptive Memory.

The PCM will collect data for Adaptive Memory for the first 50 Warm-up Cycles.


Warm-up Cycle

A warm-up cycle happens when all of the following conditions exist.

Engine is running
A raise of 40F in engine temperature must occur ABOVE the engine temperature at start-up
Engine Coolant Temp must reach at least 160 F.


Once your engine has gone through 50 warm-up cycles in at least a 500-mile distance the PCM adaptive memory is set. It WILL NOT Change unless you flash it out and start all over again.
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Old 10-11-2010, 12:14 AM   #13
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If you had the equipment that can go into the computer and see what the memory is doing, you'd know that the 30 second "touch the cables together" does NOT CLEAR THE MEMORY. It will clear the codes, but will not clear the complete memory.

There's only 2 ways to clear it -
One is to "force clear" it by sending a code into the computer, forcing it back to default - the basic information that it came from the factory with. That takes the DRB unit the dealer should have. Other scanners that claim they can are full of it!

The other way - leave the battery disconnected for at least 8 hours.

Try it - do the 30 second trick - no change? Then try the overnight trick.
Of course neither will correct the problem unless the problem is the PCM is using the data from a defective sensor.

It's not magic, just common sense.

Whoever made up the 30 second "touch" had no clue - just wishful thinking. It may discharge a few capacitors, but not the ones that count.
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Old 10-11-2010, 02:37 AM   #14
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^^ Info you state is true....I hope you don't think I meant it would clear the PCM???

Just resets the comp. (ie clear his codes).

Everyone should always start with the basic's. Check things over and see if you have any codes first. Then dig into the bigger items.
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Old 10-11-2010, 03:02 PM   #15
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installed new crankshaft position sensor > engine idles rough, replaced with old crankshaft position sensor > engine idles smooth, checked camshaft position sensor in distributor, while cranking engine: output from 0-5 volts.
plugs, wires & battery replaced prior to changing CKP.
Still get p1309, can reset, but returns. PCM > Pulse Code Modulation or Powertrain Control Module? Is the PCM in the engine compartment on firewall? What are the chances that the new crankshaft sensor is bad or does the engine have to warm up to get new signals over a period of time?
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Old 10-11-2010, 03:52 PM   #16
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PCM = Powertrain Control Module.

If you keep getting the P1309 Code, then I'd be double and triple checking that Camshaft Position Sensor, not the Crankshaft Sensor.
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Old 10-12-2010, 05:12 PM   #17
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I'll replace the camshaft senor and go from there, rats!

Greatly thanks for the feed back...
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Old 10-12-2010, 10:42 PM   #18
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Not sure your problem was the same as mine but mine randonly shut off for no reason a few times and had trouble starting and staying running... Turned out tto be a dead battery , switched it out and goodbye problems... Dont know if thats it but ive seen stranger things happen so dont rule it out and its a simple thing to check
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Old 10-15-2010, 03:05 PM   #19
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After replacing the Crankshaft position sensor with an aftermarket part. The sensor failed because it was missing a very important piece of the puzzle and no instruction/pictures.
Bought new crankshaft position sensor from Chrysler Dealership...

Quote from Chrysler installation instructions:
"1. Be sure the paper/cardboard spacer has been installed to the bottom of the new sensor. If original sensor is being reinstalled (such as with transmission or flywheel removal), clean bottom of the sensor before installation. Obtain a new spacer and remove the paper backing. Install the self-adhesive side to bottom of sensor. This spacer MUST be installed. If spacer is not installed, sensor will be damaged when engine is started."

The aftermarket sensor did not come with a spacer and therefore it was damaged from the start!

After replacing with the sensor with spacer, it now runs good. Also had the dealership flash the settings and reset.
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Old 06-26-2012, 04:33 PM   #20
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Has anyone ever measured the thickness of the paper spacer?
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Old 08-28-2012, 02:15 PM   #21
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Question

I know this is an old thread but I purchased a new CPS from the Chrysler dealer that did not include any spacer (or instructions). Had I not read this thread it would not have mattered--but now I'm wondering...what do you guys recommend?

97 2.5 manual
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Old 08-28-2012, 05:43 PM   #22
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They sell the spacer separately but it's a rip off at $4 and some change. You just peel it off the backing and stick it on.
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Old 05-01-2013, 08:25 AM   #23
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Is this paper spacer required for the 4.0? And if I installed the new sensor without a spacer, is it too late to stick one on?

Jason
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Old 05-01-2013, 10:32 AM   #24
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Is this paper spacer required for the 4.0?

Jason
Depends on the particular version of the CPS in question.

"The 4.0" means different things, depending on year model, etc.
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Old 05-01-2013, 10:41 AM   #25
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Depends on the particular version of the CPS in question.

"The 4.0" means different things, depending on year model, etc.
I guess I should have included that information. Its a 2006 Rubicon LJ, 6 speed.

Jason
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Old 05-01-2013, 12:05 PM   #26
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Its a 2006 Rubicon LJ, 6 speed.
Spacer is n/a.
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Old 05-01-2013, 12:17 PM   #27
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I have been looking for this spacer too. The folks at the parts store had no idea what I was talking about.

I have a 98 TJ with the 4.0l, 5speed manual. Does anyone know if I need the paper spacer?
I'd like to know I have all the parts I need before I start taking apart my daily driver.
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Old 05-01-2013, 12:23 PM   #28
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I have a 98 TJ with the 4.0l, 5speed manual. Does anyone know if I need the paper spacer?
You should have the two-bolt CPS. No spacer.

The CPS that requires a spacer features one bolt, transverse to the sensor and an elongated bolt hole.
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Old 05-01-2013, 12:29 PM   #29
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My CPS has one bolt. Spacer needed?


Jason
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Old 05-01-2013, 02:46 PM   #30
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My CPS has one bolt. Spacer needed?


Jason
No.

Just as not a 4.0L engines are the same, all one-bolt CPS's are not the same. An '06 CPS should have a bolt that is parallel to the sensor barrel and a round bolt hole.

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