Go Back   Jeep Garage - Jeep Forum > Jeep Technical Discussion > Troubleshooting/Problems Discussion

Join Jeep Garage Today
Reply
 
Thread Tools Display Modes
 
  #1  
Old 11-29-2010, 02:03 PM
Member
My Jeep: 2006 5.7L WK
 
Join Date: Jun 2010
Location: Calgary
Posts: 74
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 1656
kyle.jg is on a distinguished road
P0128 Error Code

Hey guys,

My 5.7 HEMI gave me the error P0128 the other day as I stepped on the gas to pass someone. It was a cold day (about -20C) and I hadn't really warmed up the Jeep too much and the engine temperature gauge was just above the lowest marker. I drove with it for the day and then later that night I cleared the code using my DiabloSport Trinity. Since clearing it on Thursday night, I've driven at least 300 KM and it has not come back and it is now Monday afternoon.


Should I be taking this in to have it looked at, or don't worry about it unless it comes back again?
__________________

__________________
Reply With Quote
  #2  
Old 11-29-2010, 02:36 PM
Long Live the Graphite Ghost

 
Join Date: May 2009
Posts: 13,418
Thanks: 55
Thanked 132 Times in 114 Posts
Rep Power: 542645
robpp has disabled reputation
Re: P0128 Error Code

since it was sooo cold you might want to wait until it pops up again.

here is what the manual says about it:

Theory of Operation


The PCM predicts what the engine coolant temperature should be, based on the engine coolant temperature at start-up, ambient temperature and how the vehicle is subsequently driven. The predicted engine coolant temperature is compared to the Engine Coolant Temperature Sensor reading. The error between the two is calculated and integrated with respect to time. When the Thermostat diagnostic runs, the integrated error is compared to a calibrated threshold and pass/fail is determined. Separate pass and fail thresholds are used in order to improve accuracy of the diagnostic.

When Monitored:
Engine running.

Set Condition:
This diagnostic will fail when the model temperature reaches 91 C (196 F) before the ECT. reaches 80 C (176 F). This monitor only runs after a cold start condition ECT, ACT, AMB are all within 10 C (50 F) of one another. Two Trip Fault. Three good trips to turn off the MIL.


Possible Causes

LOW COOLANT LEVEL

THERMOSTAT OPERATION

SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE

TEMPERATURE SENSOR

SIGNAL CIRCUIT OPEN

SENSOR GROUND CIRCUIT OPEN

SIGNAL CIRCUIT SHORTED TO GROUND

SIGNAL CIRCUIT SHORTED TO THE (K900), (G931) SENSOR GROUND CIRCUIT

OTHER POSSIBLE CAUSES

PCM
__________________

__________________
Reply With Quote
  #3  
Old 12-10-2010, 09:33 PM
Member
My Jeep: 2005 5.7L WK
 
Join Date: Apr 2010
Posts: 13
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 1644
n8jay is on a distinguished road
Re: P0128 Error Code

I just got this error code as well, and same situation cold as all get out and probably 10 minutes into my drive. I am going to get a rad flush as I put in a bit of non HOAX coolant in. I spoke with the dealer and they suggest that a flush is in order, what do you guys think??? The coolant looks fine but their trying to put the fear in me, saying that the NON HOAX can cause corrision, metal and seal break down within the coolant system. Again I don't know. I haven't cleared the code or done anything, yet. I am getting plenty of heat inside the vehicle and the temp gauge sits just under half, is this normal? I'm not even sure were it sat before. Any help would be greatly appreciated.

Thanks
n8j
__________________
1988 YJ
2005 Jeep Grand Cherokee Limited 5.7 Hemi
Reply With Quote
  #4  
Old 12-10-2010, 09:43 PM
Scottina06's Avatar
JeepGarage Founder
My Jeep: 2014 6.4L SRT8 WK2
 
Join Date: May 2009
Location: Berea, Kentucky
Posts: 49,274
Thanks: 869
Thanked 985 Times in 695 Posts
Rep Power: 7717920
Scottina06 has a reputation beyond reputeScottina06 has a reputation beyond reputeScottina06 has a reputation beyond reputeScottina06 has a reputation beyond reputeScottina06 has a reputation beyond reputeScottina06 has a reputation beyond reputeScottina06 has a reputation beyond reputeScottina06 has a reputation beyond reputeScottina06 has a reputation beyond reputeScottina06 has a reputation beyond reputeScottina06 has a reputation beyond repute
Garage
Re: P0128 Error Code

sounds like the tstat to me not opening/closing properly. get a new tsta when you have new coolant put in.
__________________
SCOTT
The HARDER you work...the LUCKIER you are!
2014 REDLINE red Jeep SRT "BLOODIED\BlackOps CFR Edition" 1 of 1
2013 JKU Wrangler 10A-stormtrooper'ed, JW Speaker and more!
Previous JEEP rides-
2013 Jeep Grand Cherokee SRT-deep cherry
2006 Jeep Grand Cherokee Laredo-inferno red



Twitter-The_Jeep_Guy
Instagram-thejeep_guy

Reply With Quote
  #5  
Old 11-05-2012, 04:16 PM
Member
My Jeep: 2005 5.7L
 
Join Date: Jan 2012
Location: Chicago
Posts: 20
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 997
Siner)8 is on a distinguished road
Re: P0128 Error Code

I'm also having the same problem. I've changed the tstat today and cleared the code but still getting code. also getting a p0004 for the trans
__________________
Reply With Quote
  #6  
Old 11-07-2012, 09:49 PM
ALPINEST4RS's Avatar
Member
My Jeep: 2007 4.7L WK
 
Join Date: Mar 2010
Location: Brighton, MI
Posts: 340
Thanks: 8
Thanked 1 Time in 1 Post
Rep Power: 1992
ALPINEST4RS is on a distinguished road
Re: P0128 Error Code

either a skewed ect or a tstat (as scott said)
__________________

__________________
2006 Jeep Grand Cherokee WK 3.7L - SOLD (lil bro's)
2007 Jeep Grand Cherokee WK 4.7L -SOLD
2011 - Mazdaspeed3 COBB AP/CS TIP-SRI/ CPE Axle Back/ Stage 1 RMM/ Internals/ Wiseco Pistons/ Forged Rods
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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 Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
P 0325 error Tim2 Troubleshooting/Problems 1 07-12-2012 12:21 PM
AZC error code 52? bjm9818 Troubleshooting/Problems 1 05-10-2012 12:24 AM
Navigation error???? snewt22 Audio, Video, Navigation & Electronic Modifications 14 05-02-2010 09:01 AM
CD Error on REC Navigation Unit 06HemiLtd Troubleshooting/Problems Discussion 9 03-01-2010 11:19 AM

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 06:27 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community