P0300, P0315, P0335 codes - misfire issue - Page 2 - JeepForum.com
 1Likes
Reply
 
LinkBack Thread Tools
post #16 of 19 Old 10-21-2019, 01:00 PM Thread Starter
99sajeep
Registered User
 
99sajeep's Avatar
2005 WK 
 
Join Date: Jan 2009
Location: San Antonio
Posts: 705
The FSM doesn't mentioned anything about a relearn procedure.


'05 WK 4x4 Ltd 5.7L (mine) 200k+ club
'01 WJ 4x4 Laredo 4.7L (daughter)
99sajeep is offline  
Sponsored Links
Advertisement
 
post #17 of 19 Old 10-26-2019, 09:48 PM Thread Starter
99sajeep
Registered User
 
99sajeep's Avatar
2005 WK 
 
Join Date: Jan 2009
Location: San Antonio
Posts: 705
So, here's where everything has ended up:

I did a lot of searching for info on a "re-learn" procedure for the crankshaft position sensor install (just in case) to maybe get rid of the random misfire code.

I ran across a thread on DodgeTalk(dot)com called "Crankshaft Position Sensor Learning Curve". There was a list of three options that could perform a computer reset.

The following is the third option that I ended up using"

You can do what is often called a "hard dump".
We (techs) often do this when we need to totally reset the ECU and either don't have the proper tool close by (too lazy to walk to the toolbox and get it) or just are "in a hurry."

First, disconnect positive + battery cable at the battery and ground it to the chassis. Yes, the POSITIVE CABLE.

Wait a few seconds, 30 won't kill ya.

Now reconnect the positive cable. Careful, no sparks now.

Get in the vehicle, turn ignition key to ON (run) position, now depress fully and release the gas pedal 5 times to set the TPS to WOT. (Make sure the floor mats do not keep the pedal from going WFO0

Turn the key OFF, wait a min, and you should have cleared everything in the ECU except for the factory programming.

The hard dump does not effect the (factory) alarm, the only thing I noticed is my radio presets, as this method came from a working Chrysler tech, I doubt there are any negative effects.


I tried this after three days of trying to get the P0300 Random Misfire code to go away after changing the CKP sensor. I'm now two days into driving the WK and the code has yet to come back and there have been no other running issues.

As of now, I'm calling it fixed.

I did end up changing all 16 spark plugs and wires, but this was after the hard reset and the code was gone prior to changing the plugs.

'05 WK 4x4 Ltd 5.7L (mine) 200k+ club
'01 WJ 4x4 Laredo 4.7L (daughter)
99sajeep is offline  
post #18 of 19 Old 10-27-2019, 07:45 AM
Avs
Registered User
2006 WK 
 
Join Date: Sep 2019
Posts: 87
Quote:
Originally Posted by 99sajeep View Post
The FSM doesn't mentioned anything about a relearn procedure.
I found the FSM has a lot of missing informations and diagram is not clear. It always default to the StarScan or whatever the factory scanner is.

Quote:
Originally Posted by 99sajeep View Post
So, here's where everything has ended up:

I did a lot of searching for info on a "re-learn" procedure for the crankshaft position sensor install (just in case) to maybe get rid of the random misfire code.

I ran across a thread on DodgeTalk(dot)com called "Crankshaft Position Sensor Learning Curve". There was a list of three options that could perform a computer reset.

The following is the third option that I ended up using"

You can do what is often called a "hard dump".
We (techs) often do this when we need to totally reset the ECU and either don't have the proper tool close by (too lazy to walk to the toolbox and get it) or just are "in a hurry."

First, disconnect positive + battery cable at the battery and ground it to the chassis. Yes, the POSITIVE CABLE.

Wait a few seconds, 30 won't kill ya.

Now reconnect the positive cable. Careful, no sparks now.

Get in the vehicle, turn ignition key to ON (run) position, now depress fully and release the gas pedal 5 times to set the TPS to WOT. (Make sure the floor mats do not keep the pedal from going WFO0

Turn the key OFF, wait a min, and you should have cleared everything in the ECU except for the factory programming.

The hard dump does not effect the (factory) alarm, the only thing I noticed is my radio presets, as this method came from a working Chrysler tech, I doubt there are any negative effects.


I tried this after three days of trying to get the P0300 Random Misfire code to go away after changing the CKP sensor. I'm now two days into driving the WK and the code has yet to come back and there have been no other running issues.

As of now, I'm calling it fixed.

I did end up changing all 16 spark plugs and wires, but this was after the hard reset and the code was gone prior to changing the plugs.
I didn't know you can do a TPS relearn by crossing the positive and negative cable with battery disconnected of course. A lot of manufacture such as toyota allow you to do a TPS relearn by letting the car run idle for a few minutes. With chrysler it's kind of annoying every time you clean the throttle body you need to do a relearn with a scanner or used the workaround you mention aboved. Good luck. Let us know how it works out.
Avs is offline  
 
post #19 of 19 Old 10-27-2019, 02:09 PM
904block
Registered User
 
Join Date: May 2017
Posts: 49
i had the similar issue a few months ago i was at a dead stop and i went to press the gas and my jeep started going crazy and my check engine light came on so i pulled over did the key dance pulled the codes and noticed it was for the crank sensor so i made to the Autozone bought a new crank sensor installed it there in the parking lot and i went to start my jeep and it was worse multiple codes jeep started buckling it sounded like it wanted to die . so after switching out multiple crank sensors from Autozone i decided to go to the junk yard and pull one out of a different jeep which was the OEM sensor from the dealership installed it and everything went away instantly ! so when i returned the crank sensor back to Autozone a employee that worked there said the reason why it may have not worked is because the OEM sensors might have had a different output than the sensors Autozone sell .. but since then i had no more problems like that .. just sharing my experience .
904block is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.



Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 2 (1 members and 1 guests)
duker_255
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome