Another 2006 LJ With O2 heater codes and rebuild PCM - JeepForum.com
 2Likes
Reply
 
LinkBack Thread Tools
post #1 of 18 Old 12-10-2019, 01:48 AM Thread Starter
ApproachMedium
Registered User
1998 TJ Wrangler 
 
Join Date: Aug 2016
Location: Brick NJ
Posts: 107
Garage
Another 2006 LJ With O2 heater codes and rebuild PCM

So heres a sorta long one. I have a buddys 06 LJ Sahara 4.0L that he dropped off to swap PCMs because all 4 O2 sensors keep throwing the same code for low circuit voltage I believe P0051, 57, etc. I bought a PCM off somebody in facebook group that said it was tested good by something, idk what and should work. He had bought a replacement motor that came with this 05 PCM and couldnt use it in his 04. When i put the replacement PCM in, the jeep runs and then dies after 2 seconds. Im assuming that is because the replacement PCM has SKIM and the other one, does not because we do not have a SKIM key.

The PCM that was in the jeep already has a sticker on it that it was re-manufactured. Is it possible that it could have failed again? it doesnt look that old, dirty or damaged. The jeep also has what appears to be 4 new O2 sensors but i do not know who makes them or where they came from. I checked the ground on the engine block and i get good continuity from the sensor plugs to the engine block for ground, so it must be okay. I have tried many times now googling around on how to test the PCM and i cannot find anything specific to the 05/06 TJ/LJ for testing. Is there anything i can do to check to see if the PCM is in fact working right or not? I do not want to pay to get the SKIM taken out of the other PCM if its actually an electrical problem with the jeep that may be corrected, or maybe the wrong sensors?

Is there a way to bypass or disable skim in a PCM that has it??


No Good Deed goes Unpunished.
ApproachMedium is offline  
Sponsored Links
Advertisement
 
post #2 of 18 Old 12-10-2019, 02:38 AM
TJTurbo
Registered User
2006 TJ Wrangler 
 
Join Date: Nov 2015
Location: Hickory
Posts: 400
Quote:
Originally Posted by ApproachMedium View Post
So heres a sorta long one. I have a buddys 06 LJ Sahara 4.0L that he dropped off to swap PCMs because all 4 O2 sensors keep throwing the same code for low circuit voltage I believe P0051, 57, etc. I bought a PCM off somebody in facebook group that said it was tested good by something, idk what and should work. He had bought a replacement motor that came with this 05 PCM and couldnt use it in his 04. When i put the replacement PCM in, the jeep runs and then dies after 2 seconds. Im assuming that is because the replacement PCM has SKIM and the other one, does not because we do not have a SKIM key.



The PCM that was in the jeep already has a sticker on it that it was re-manufactured. Is it possible that it could have failed again? it doesnt look that old, dirty or damaged. The jeep also has what appears to be 4 new O2 sensors but i do not know who makes them or where they came from. I checked the ground on the engine block and i get good continuity from the sensor plugs to the engine block for ground, so it must be okay. I have tried many times now googling around on how to test the PCM and i cannot find anything specific to the 05/06 TJ/LJ for testing. Is there anything i can do to check to see if the PCM is in fact working right or not? I do not want to pay to get the SKIM taken out of the other PCM if its actually an electrical problem with the jeep that may be corrected, or maybe the wrong sensors?



Is there a way to bypass or disable skim in a PCM that has it??
I'll have to look but I'm thinking I saw an option to disable skim in HP Tuners. I know it has the ability to disable the lower O2s.

Sent from my LG-TP450 using Tapatalk
TJTurbo is offline  
post #3 of 18 Old 12-10-2019, 03:31 AM
TJTurbo
Registered User
2006 TJ Wrangler 
 
Join Date: Nov 2015
Location: Hickory
Posts: 400
Yep, it's possible with HP Tuners. Well worth the $ if you have an '05-'06 with an automatic transmission just to be able to change the shift points alone.

Sent from my LG-TP450 using Tapatalk
TJTurbo is offline  
 
post #4 of 18 Old 12-10-2019, 08:30 AM
jtec
Web Wheeler
 
jtec's Avatar
2014 JK Wrangler 
 
Join Date: Oct 2017
Posts: 6,955
swapatronics may not be helpful.
Install the PCM that was there when you started this work.

Hopefully the jeep starts and runs, ADVISE. yes No

check for codes with a scanner*.
Post ALL codes.

*will your scanner see live data? ECT, MAP etc?

When I see the price of OEM I think aftermarket.
When I see the quality of aftermarket I think OEM.
jtec is online now  
post #5 of 18 Old 12-11-2019, 01:51 AM Thread Starter
ApproachMedium
Registered User
1998 TJ Wrangler 
 
Join Date: Aug 2016
Location: Brick NJ
Posts: 107
Garage
Quote:
Originally Posted by jtec View Post
swapatronics may not be helpful.
Install the PCM that was there when you started this work.

Hopefully the jeep starts and runs, ADVISE. yes No

check for codes with a scanner*.
Post ALL codes.

*will your scanner see live data? ECT, MAP etc?
Had to re install original rebuilt PCM that was in jeep when it arrived to me starts and runs fine, the "new" pcm has the skim problem. For 1/3 the cost of HP tuners i can pay somebody to disable SKIM it looks like. No auto trans on this 06, not my vehicle.

Scanner can see live data, what data would show if the PCM is working correct or not? When i put the battery back in just now without starting engine i get Confirmed and Pending P0031, 37, 51 57. All say HO2S heater control circuit low. If i clear the codes, they come right back as soon as i clear them, even with a key cycled. When the engine is running cold i get 0.31V on the O2 sensor 1 and 1.27 on o2 sensor 2. They seem to be reading fine, the jeep runs and drives without any engine issues.

Scanner is OBDLinkMX+

No Good Deed goes Unpunished.
ApproachMedium is offline  
post #6 of 18 Old 12-11-2019, 09:12 AM
TJTurbo
Registered User
2006 TJ Wrangler 
 
Join Date: Nov 2015
Location: Hickory
Posts: 400
Quote:
Originally Posted by ApproachMedium View Post
For 1/3 the cost of HP tuners i can pay somebody to disable SKIM it looks like. No auto trans on this 06, not my vehicle.
True, in your case it's not worth it. It is good to know however that if you do know somebody who has a HPT for the price of 2 credits($100) it can be disabled that way.

Sent from my LG-TP450 using Tapatalk
TJTurbo is offline  
post #7 of 18 Old 12-11-2019, 11:18 AM
Rubi4MyMrs
Web Wheeler
 
Rubi4MyMrs's Avatar
2005 LJ Wrangler 
 
Join Date: Mar 2011
Location: Trails of
Posts: 4,229
If it throws the codes immediately after turning the key on (no start) with the original PCM, clearing the codes, then if plugging in the other PCM, even with SKIM, & turning the key does not throw the same codes that would indicate to me that the PCM is the cause for getting the codes. It is not a perfect test but certainly a strong indicator.

Here is an older thread that has some good info on the P0031, etc. codes. No final fix though…

https://www.jeepforum.com/forum/f9/2...p0057-2499970/

TJTurbo likes this.
Rubi4MyMrs is offline  
post #8 of 18 Old 12-11-2019, 12:05 PM
jtec
Web Wheeler
 
jtec's Avatar
2014 JK Wrangler 
 
Join Date: Oct 2017
Posts: 6,955
A 2006 wrangler, manual trans ?

Before reprogramming or reinventing the wheel - what is the SKIM code or issue?

P0031-O2 SENSOR 1/1 HEATER CIRCUIT LOW
P0037-O2 SENSOR 1/2 HEATER CIRCUIT LOW
P0051-O2 SENSOR 2/1 HEATER CIRCUIT LOW
P0057-O2 SENSOR 2/2 HEATER CIRCUIT LOW

Are you SURE correct o2 sensors installed( NTK or jeep) brands?
Have you checked sensor heater circuit ground?

FYI NOTE: When replacing an O2 Sensor, the PCM RAM memory must be cleared,
either by disconnecting the PCM C-1 connector or momentarily disconnecting the
Battery negative terminal
Attached Files
File Type: pdf 2006 o2 heater.pdf (141.4 KB, 3 views)

When I see the price of OEM I think aftermarket.
When I see the quality of aftermarket I think OEM.
jtec is online now  
post #9 of 18 Old 12-11-2019, 08:12 PM
TJTurbo
Registered User
2006 TJ Wrangler 
 
Join Date: Nov 2015
Location: Hickory
Posts: 400
Quote:
Originally Posted by jtec View Post
A 2006 wrangler, manual trans ?



Before reprogramming or reinventing the wheel - what is the SKIM code or issue?
As our PCMs age and die we are eventually going to have to resort
to hack reprogramming of whatever PCMs are left to be found and we might be able to "tune" out a problem here or there. I absolutely agree with your diagnostic suggestions and did not intend on sharing "bad" advice, rather tribal knowledge.

Sent from my LG-TP450 using Tapatalk
TJTurbo is offline  
post #10 of 18 Old 12-11-2019, 10:10 PM
WatchThis
Registered User
1997 TJ Wrangler 
 
Join Date: Jul 2016
Location: Festus
Posts: 198
Garage
I recently purchased a 06 LJ and it had the shifting issues. I also tried to get another chip key made and it wouldn’t skim the key. Dealer said I very likely have a bad PCM. Then Some thread searches and I was confident I did. I bought a PCM from wranglerfix.com and all problems fixed. Had Shipped to my daughter at college and she installed it in dorm parking lot. Well worth the money and cheapest option available.

I figured since that most of the are bad or going bad I was gong to buying one eventually. Worth the cost of owning my dream jeep.


Sent from my iPhone using Tapatalk Pro
TJTurbo likes this.
WatchThis is offline  
post #11 of 18 Old 12-11-2019, 11:49 PM
TJTurbo
Registered User
2006 TJ Wrangler 
 
Join Date: Nov 2015
Location: Hickory
Posts: 400
Quote:
Originally Posted by WatchThis View Post
I recently purchased a 06 LJ and it had the shifting issues. I also tried to get another chip key made and it wouldn’t skim the key. Dealer said I very likely have a bad PCM. Then Some thread searches and I was confident I did. I bought a PCM from wranglerfix.com and all problems fixed. Had Shipped to my daughter at college and she installed it in dorm parking lot. Well worth the money and cheapest option available.

I figured since that most of the are bad or going bad I was gong to buying one eventually. Worth the cost of owning my dream jeep.


Sent from my iPhone using Tapatalk Pro
Sorry, but that's not going to help anyone who needs to modify the stock parameters of the PCM as their ad states: Not compatible with aftermarket programmers or whatever. Try to find a usable '05-'06 PCM for sale these days. Sure, every website claims they are in stock or can refurbish yours but they always are either out of stock or come back with problems. I'd like to keep mine boosted with the transmission shifting correctly. Unless someone starts manufacturing new PCMs for our Jeeps this TJ forum will become irrelevant within the next 20 years other than LS swap how to threads...not that I'm totally opposed to that idea as having owned a LS vehicle I can say it is a fairly stout engine.

Sent from my LG-TP450 using Tapatalk
TJTurbo is offline  
post #12 of 18 Old 12-12-2019, 12:59 AM Thread Starter
ApproachMedium
Registered User
1998 TJ Wrangler 
 
Join Date: Aug 2016
Location: Brick NJ
Posts: 107
Garage
Okay so tonight's troubleshooting reveals the following after following this procedure:
Recheck PCM for codes, clear codes, cycle key, codes still there. Disconnect battery, remove supposed bad PCM, replace with OEM PCM with SKIM problem. Reconnect battery. NO codes set. Attempting to start gives start, run for 2 seconds shut down. If you do this enough it will eventually refuse to even crank. NO codes set, so other than behavior, i have no "skim codes" set. There is no SKIM light on the gauge cluster of an 06 LJ. I did the cluster start up self test and there is no light for it. All indications and gauges work correctly.
Disconnect battery, disconnect SKIM problem PCM, reconnect bad PCM and 02 codes still set in PCM. I do not know the brand of o2 sensors installed. They appear new, installed by previous owner. I disconnected them and checked the pins on the vehicle harness side for ground to engine continuity with a DMM. I get a ground ring out on one of the pins at each connector of the vehicle side harness.

I will note that the previous night the jeep spent 24hrs with the battery and no PCMs connected to it before i tried running it again. If there is some kind of reset that the sensors needed after being installed, im sure at this point its been long since met.

No Good Deed goes Unpunished.
ApproachMedium is offline  
post #13 of 18 Old 12-12-2019, 08:06 AM
jtec
Web Wheeler
 
jtec's Avatar
2014 JK Wrangler 
 
Join Date: Oct 2017
Posts: 6,955
I do not know what wires you checked IDK hope the attachment helps.

There is ALSO a ohm test for the sensor - but is very broad in its span - I am not on line to jeep info and will post later.

you cannot swap PCM without programming some info and SKIM codes is one, the replacement unit may NOT have the keys programmed into it.

GTG

When I see the price of OEM I think aftermarket.
When I see the quality of aftermarket I think OEM.
jtec is online now  
post #14 of 18 Old 12-12-2019, 08:18 AM
jtec
Web Wheeler
 
jtec's Avatar
2014 JK Wrangler 
 
Join Date: Oct 2017
Posts: 6,955
OK some info

o2 heater - @ 70°F, heating element approximately 4.5 ohms. This is where aftermarket often FAIL to meet specs - check it.

getting complicated and details here matter -
You said NO SKIM light ? check attachment advise.. neither PCM's illuminate the bulb?
Attached Images
 
Attached Files
File Type: pdf TJ 06 o2's.pdf (141.4 KB, 3 views)

When I see the price of OEM I think aftermarket.
When I see the quality of aftermarket I think OEM.
jtec is online now  
post #15 of 18 Old 12-12-2019, 01:04 PM
Rubi4MyMrs
Web Wheeler
 
Rubi4MyMrs's Avatar
2005 LJ Wrangler 
 
Join Date: Mar 2011
Location: Trails of
Posts: 4,229
The fact that you get immediate CEL with original PCM but not with the other (possible SKIM) PCM is probably the best test other than removing SKIM from that PCM to say the original PCM is bad.

Also, getting those 4 codes the way you are also points to bad PCM. Searching those codes will confirm most need a replacement PCM to fix. I would not consider all sensors are bad & the fact that all look new tells me they were all replaced after getting the codes, hoping all sensors had gone bad & all at the same time(?).

As for my thoughts on no SKIM light or codes, there may not be bulbs installed in non SKIM builds (but the place for the light in the cluster is certainly there) & no codes is probably because with no SKIM module in non SKIM builds there is nothing to send the code to the PCM.
Rubi4MyMrs 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: 1 (0 members and 1 guests)
 
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