2006 Commander in Atlanta 4x4 4.7 QT2 120k - Jeep Commander Forums: Jeep Commander Forum
New Member Section Drop in, say Hi and meet the community

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 12 (permalink) Old 10-14-2018, 07:29 PM Thread Starter
Junior Member
Points: 247, Level: 4 Points: 247, Level: 4 Points: 247, Level: 4
Level up: 94% Level up: 94% Level up: 94%
Activity: 0% Activity: 0% Activity: 0%
 
Join Date: Jul 2018
Location: Atlanta
Own a Commander?: Yes
Model year: 2006
Trim Package: Limited
Power-Train: 4.7L V-8
4WD
If 4WD - system: QT-II
Current Mileage: 120k
Posts: 6
2006 Commander in Atlanta 4x4 4.7 QT2 120k

Hey y'all,

I'm a 34 yr-old environmental engineer in Atlanta and this is my first Jeep! I'm no mechanic, but I work on older trucks, boats, and bikes on the side in addition to renovating old house.

I picked up this Commander two months ago and have loved it... when I haven't been working on it. This forum has been a big help so far with the issues I've had though!

The truck is in good shape and looks great. I bought it mainly to tow my boats around and it pulls nicely. It stops surprising well, which I learned when a car pulled out in front of my while I was pulling my boat - I was amazed it stopped as fast as it did because I was sure I was about to plow right into them with my new (to me) Jeep and new (to me) boat!

So far, I've replaced a leaking water pump (good think because it had the wrong coolant in it!), repaired a broken quick connect on the fuel line (after taping it together on the side of the road to get home), and now I'm working on a crank, no start issue that is caused by fuel pump not pumping. I've searched the threads thoroughly and they have helped me in troubleshooting and ruling out a number of things. I'll make a separate post about this issue in hopes y'all can help me.

Really apprecaite that y'all have such a nice and well-organized forum with helpful and nice folks!
Cheers,
Jake
jcatl is offline  
Sponsored Links
Advertisement
 
post #2 of 12 (permalink) Old 10-14-2018, 07:34 PM Thread Starter
Junior Member
Points: 247, Level: 4 Points: 247, Level: 4 Points: 247, Level: 4
Level up: 94% Level up: 94% Level up: 94%
Activity: 0% Activity: 0% Activity: 0%
 
Join Date: Jul 2018
Location: Atlanta
Own a Commander?: Yes
Model year: 2006
Trim Package: Limited
Power-Train: 4.7L V-8
4WD
If 4WD - system: QT-II
Current Mileage: 120k
Posts: 6
Well, I just went to start a new thread about my fuel pump problem, and I wasn't allowed to start a new thread! Did I miss something in the rules? This is what was indicated:

Quote:
you do not have permission to access this page. This could be due to one of several reasons:

Your user account may not have sufficient privileges to access this page. Are you trying to edit someone else's post, access administrative features or some other privileged system?
If you are trying to post, the administrator may have disabled your account, or it may be awaiting activation.
jcatl is offline  
post #3 of 12 (permalink) Old 10-14-2018, 08:50 PM Thread Starter
Junior Member
Points: 247, Level: 4 Points: 247, Level: 4 Points: 247, Level: 4
Level up: 94% Level up: 94% Level up: 94%
Activity: 0% Activity: 0% Activity: 0%
 
Join Date: Jul 2018
Location: Atlanta
Own a Commander?: Yes
Model year: 2006
Trim Package: Limited
Power-Train: 4.7L V-8
4WD
If 4WD - system: QT-II
Current Mileage: 120k
Posts: 6
I guess I'll just describe the problem here, and we can move it to a new thread when I'm able to create one. I just needed to get all of this out for my own sake...

Background:
A few days ago, I went to start my truck and it cranked and cranked, but wouldn't even try to run. Seemed like a "no fuel" problem to me. I checked the fuel pump fuse and relay. I disconnected by new quick connect in the fuel line and turned the key to "ON" to see if it would squirt some fuel out at me. Nope. So I rightfully concluded the fuel pump wasn't pumping. Got it towed to my house.

I left my code reader at a friend's house 100 miles away last week, so I learned and did the "key dance" (thanks for the stickies!) to read my codes on my dash:
P0627 - Fuel Pump A Control Circuit /Open
P0522 - Engine Oil Pressure Sensor/Switch Low Voltage

Ok. I had read on this forum that the Oil Sensor switch is a common problem. It's $15 a the parts store, so I just replaced it. Still no start.

So, I wanted to just see if the fuel pump was getting power. Dropped the tank, voltage to fuel pump is 0.5v lower than battery. That's right at the threshold of a problem, from what I've read, but it is still over 12V with a fully charged battery.

Ran a jumper from the hot side of the fuel pump relay to the fuel pump, used on of the grounds from the fuel pump harness that plugs into the fuel pump. I opened the fuel qucik connect again and watched the gas dump out of it when I connected the jumper. So the fuel pump works. I reconnected my fuel line and connected the jumper again for a few seconds, to see if it would pressurize my fuel system enough to start. Then I plugged the harness back into the fuel pump and tried to crank it - and it started! Idled down. Ran and sounded completely normal for about 45 seconds, then promptly ran out of gas. So, the fuel pump works. (Which I knew was likely anyway...)

Now I figured I really need to look hard into the 7000 page service manual PDF I have. I searched P0627 and got a troubleshoot process for it. Step 1-3 were fine. Step 4 and I've already got an issue:

I plugged a 12v test light into the indicated (top) spot at the relay plug. No light with key turned to "ON". Note: I do get a light when I plug into the bottom of the 3 signal spots on the relay, but not in the top one that is indicated in Step 4.

Since I didn't get a 12v test light to come on in Step 4, the manual instruct me to
Quote:
"Repair the open or short to ground in the (F942) Fused Ignition Switch Output circuit. Inspect the related fuse and repair as necessary"
It took my a some searching to conclude (perhaps incorrectly) that F942 goes through the #10 fuse in the interior (under dash) fuse box. The owners manual indicates that this "Ignition Run Only Out (R/O)". Fuse was good. I used by 12v test light in the supply to the fuse. It was off with the key off, and ON with the key on. Assuming I found the right fuse, there seems to be an open circuit between the the Ignition Run Only R/O fuse under the dash and the fuel pump relay. So, I'm at a wall on the P0627 / fuel pump issue. Unless it's being caused by the P0522 Oil sensor issue:

I've read in this forum that the Oil Pressure Sensor can cause a no start situation, presumably by cutting the fuel pump. So I recognize that this could be the ultimate problem here...




EDIT: I was using the troubleshooting guide for the 5.7. Everything below this is not valid for the 4.7, so I will have to start this troubleshooting guide over over.



I started the troubleshooting process for P0522. One step is to check the voltage on at the harness going into the oil presure sensor. It's supposed to be 5V, but mine i 12V! It's getting battery voltage. I would like to take the next step in troubleshooting which is:

Quote:
Turn the ignition off.
Disconnect the C2 PCM harness connector.
CAUTION: Do not probe the PCM harness connectors. Probing the
PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #881 to perform diagnostics. Measure the resistance of the (F855) 5-volt Supply circuit from the Engine Oil Pressure Sensor harness connector to the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?
However, I do not know which PCM harness is C2 (there are five harnesses going into the PCM and they look identical). I also don't have the special tool.
Any ideas on where to go from here?

Last edited by jcatl; 10-14-2018 at 09:51 PM.
jcatl is offline  
 
post #4 of 12 (permalink) Old 10-15-2018, 10:33 PM
Super Moderator
Points: 23,207, Level: 93 Points: 23,207, Level: 93 Points: 23,207, Level: 93
Level up: 86% Level up: 86% Level up: 86%
Activity: 100% Activity: 100% Activity: 100%
 
Big Blue's Avatar
 
Join Date: Oct 2015
Location: East Coast of Florida
Own a Commander?: Yes
Model year: 2008
Trim Package: Sport
Power-Train: 4.7L V-8
4WD
If 4WD - system: QT-II
Current Mileage: 101,200
Posts: 5,312
Garage
Quote:
Originally Posted by jcatl View Post
Hey y'all,

I'm a 34 yr-old environmental engineer in Atlanta and this is my first Jeep! I'm no mechanic, but I work on older trucks, boats, and bikes on the side in addition to renovating old house.

I picked up this Commander two months ago and have loved it... when I haven't been working on it. This forum has been a big help so far with the issues I've had though!

The truck is in good shape and looks great. I bought it mainly to tow my boats around and it pulls nicely. It stops surprising well, which I learned when a car pulled out in front of my while I was pulling my boat - I was amazed it stopped as fast as it did because I was sure I was about to plow right into them with my new (to me) Jeep and new (to me) boat!

So far, I've replaced a leaking water pump (good think because it had the wrong coolant in it!), repaired a broken quick connect on the fuel line (after taping it together on the side of the road to get home), and now I'm working on a crank, no start issue that is caused by fuel pump not pumping. I've searched the threads thoroughly and they have helped me in troubleshooting and ruling out a number of things. I'll make a separate post about this issue in hopes y'all can help me.

Really apprecaite that y'all have such a nice and well-organized forum with helpful and nice folks!
Cheers,
Jake
@jcatl ;

Welcome to the forum; Post some pics of your Commander when you can; Here are some links to help you out with future repairs and/or upgrades to your XK;

Chrysler/Jeep Factory Parts: http://www.factorychryslerparts.com/...ukey_make=1064

Cheapest factory Parts: Find OEM BMW, Fiat, Ford, GM, Mopar, Nissan, Subaru & Toyota Parts & Accessories

JeepinByAl: JBAoffroad.com

JustforJeeps.com - http://www.justforjeeps.com/?gclid=C...9i0hoCSS7w_wcB

Rough County lift kits - Suspension Lift Kits, Body Lifts, Leveling Kit, 4x4, Jeep, Chevy, Dodge, Ford, Off-road Truck | Rough Country Suspension SystemsŪ

AFE: Advanced FLOW Engineering | Engineered Adrenaline

CARiD.com - http://www.carid.com/?gclid=CjwKEAjw...NrrxoCEBbw_wcB

Bilstein shocks & struts - Home

The Steel Armadillo - Jeep Commander (XK/HK) 2006-2010

WAM Custom Bumpers - https://wambumpers.com/

4WheelParts.com - Truck Parts & Jeep Parts - Lift Kits, Winches, Tonneau Covers, Tires, Wheels, Bumpers, Performance ? 4 Wheel Parts

RockAuto - http://www.rockauto.com/en/catalog/j...catalog%2Fjeep

Also, please read this if you haven't done so already - lots of good information in here;

REQUIRED READING!!! New Member Introduction post & other important new member info.

Thanks and again, welcome aboard.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Big Blue is offline  
post #5 of 12 (permalink) Old 10-15-2018, 10:37 PM
Super Moderator
Points: 23,207, Level: 93 Points: 23,207, Level: 93 Points: 23,207, Level: 93
Level up: 86% Level up: 86% Level up: 86%
Activity: 100% Activity: 100% Activity: 100%
 
Big Blue's Avatar
 
Join Date: Oct 2015
Location: East Coast of Florida
Own a Commander?: Yes
Model year: 2008
Trim Package: Sport
Power-Train: 4.7L V-8
4WD
If 4WD - system: QT-II
Current Mileage: 101,200
Posts: 5,312
Garage
Quote:
Originally Posted by jcatl View Post
I guess I'll just describe the problem here, and we can move it to a new thread when I'm able to create one. I just needed to get all of this out for my own sake...

Background:
A few days ago, I went to start my truck and it cranked and cranked, but wouldn't even try to run. Seemed like a "no fuel" problem to me. I checked the fuel pump fuse and relay. I disconnected by new quick connect in the fuel line and turned the key to "ON" to see if it would squirt some fuel out at me. Nope. So I rightfully concluded the fuel pump wasn't pumping. Got it towed to my house.

I left my code reader at a friend's house 100 miles away last week, so I learned and did the "key dance" (thanks for the stickies!) to read my codes on my dash:
P0627 - Fuel Pump A Control Circuit /Open
P0522 - Engine Oil Pressure Sensor/Switch Low Voltage

Ok. I had read on this forum that the Oil Sensor switch is a common problem. It's $15 a the parts store, so I just replaced it. Still no start.

So, I wanted to just see if the fuel pump was getting power. Dropped the tank, voltage to fuel pump is 0.5v lower than battery. That's right at the threshold of a problem, from what I've read, but it is still over 12V with a fully charged battery.

Ran a jumper from the hot side of the fuel pump relay to the fuel pump, used on of the grounds from the fuel pump harness that plugs into the fuel pump. I opened the fuel qucik connect again and watched the gas dump out of it when I connected the jumper. So the fuel pump works. I reconnected my fuel line and connected the jumper again for a few seconds, to see if it would pressurize my fuel system enough to start. Then I plugged the harness back into the fuel pump and tried to crank it - and it started! Idled down. Ran and sounded completely normal for about 45 seconds, then promptly ran out of gas. So, the fuel pump works. (Which I knew was likely anyway...)

Now I figured I really need to look hard into the 7000 page service manual PDF I have. I searched P0627 and got a troubleshoot process for it. Step 1-3 were fine. Step 4 and I've already got an issue:

I plugged a 12v test light into the indicated (top) spot at the relay plug. No light with key turned to "ON". Note: I do get a light when I plug into the bottom of the 3 signal spots on the relay, but not in the top one that is indicated in Step 4.

Since I didn't get a 12v test light to come on in Step 4, the manual instruct me to It took my a some searching to conclude (perhaps incorrectly) that F942 goes through the #10 fuse in the interior (under dash) fuse box. The owners manual indicates that this "Ignition Run Only Out (R/O)". Fuse was good. I used by 12v test light in the supply to the fuse. It was off with the key off, and ON with the key on. Assuming I found the right fuse, there seems to be an open circuit between the the Ignition Run Only R/O fuse under the dash and the fuel pump relay. So, I'm at a wall on the P0627 / fuel pump issue. Unless it's being caused by the P0522 Oil sensor issue:

I've read in this forum that the Oil Pressure Sensor can cause a no start situation, presumably by cutting the fuel pump. So I recognize that this could be the ultimate problem here...




EDIT: I was using the troubleshooting guide for the 5.7. Everything below this is not valid for the 4.7, so I will have to start this troubleshooting guide over over.



I started the troubleshooting process for P0522. One step is to check the voltage on at the harness going into the oil presure sensor. It's supposed to be 5V, but mine i 12V! It's getting battery voltage. I would like to take the next step in troubleshooting which is:

However, I do not know which PCM harness is C2 (there are five harnesses going into the PCM and they look identical). I also don't have the special tool.
Any ideas on where to go from here?
I think you will find this thread very useful to possibly help you diagnose your issues;

https://www.jeepcommander.com/forums...explained.html


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Big Blue is offline  
post #6 of 12 (permalink) Old 10-16-2018, 09:41 AM Thread Starter
Junior Member
Points: 247, Level: 4 Points: 247, Level: 4 Points: 247, Level: 4
Level up: 94% Level up: 94% Level up: 94%
Activity: 0% Activity: 0% Activity: 0%
 
Join Date: Jul 2018
Location: Atlanta
Own a Commander?: Yes
Model year: 2006
Trim Package: Limited
Power-Train: 4.7L V-8
4WD
If 4WD - system: QT-II
Current Mileage: 120k
Posts: 6
Thanks for the replies, Big Blue!



I understand why I can't post in another subforum now. I will get my post count up!



Regarding the thread you linked me to - thanks!

I have noted the Junction Box and checked what I believe to be the relevant circuit for the fuel pump. Fuse is intact and I get 12V when the key is turned on. I have no reason to think the problem is in the junction box at this point.



I'm trying to figure out:


1. my oil sensor problem (P0522)
2. whether my oil sensor problem is causing my fuel pump problem; I've read in some threads here that an oil sensor problem can cause a no start


However, I'm getting ~11.5v at the fuel pump wiring harness when I turn the key on (with batter at 12v), which makes me think I might have too much of a voltage leak somewhere in the fuel pump circuit. I'm going back to troubleshoot more tomorrow and will update.


I'm supposed to have emissions done in 10 days, so need to get this fixed!
Thanks again!
jcatl is offline  
post #7 of 12 (permalink) Old 10-16-2018, 10:13 AM
Super Moderator
Points: 23,207, Level: 93 Points: 23,207, Level: 93 Points: 23,207, Level: 93
Level up: 86% Level up: 86% Level up: 86%
Activity: 100% Activity: 100% Activity: 100%
 
Big Blue's Avatar
 
Join Date: Oct 2015
Location: East Coast of Florida
Own a Commander?: Yes
Model year: 2008
Trim Package: Sport
Power-Train: 4.7L V-8
4WD
If 4WD - system: QT-II
Current Mileage: 101,200
Posts: 5,312
Garage
Quote:
Originally Posted by jcatl View Post
Thanks for the replies, Big Blue!

1. my oil sensor problem (P0522)
2. whether my oil sensor problem is causing my fuel pump problem; I've read in some threads here that an oil sensor problem can cause a no start

However, I'm getting ~11.5v at the fuel pump wiring harness when I turn the key on (with batter at 12v), which makes me think I might have too much of a voltage leak somewhere in the fuel pump circuit. I'm going back to troubleshoot more tomorrow and will update.

I'm supposed to have emissions done in 10 days, so need to get this fixed!
Thanks again!
P0522 - Oil Pressure Sensor Low; Oil pressure sensor input below acceptable voltage.

Jeep Grand Cherokee WJ - Diagnostic Trouble Codes


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Big Blue is offline  
post #8 of 12 (permalink) Old 10-16-2018, 01:49 PM
Member
Points: 562, Level: 11 Points: 562, Level: 11 Points: 562, Level: 11
Level up: 24% Level up: 24% Level up: 24%
Activity: 0% Activity: 0% Activity: 0%
 
Carbuff's Avatar
 
Join Date: Aug 2018
Location: NY
Own a Commander?: Yes
Model year: 2007
Trim Package: Sport
Power-Train: 4.7L V-8
4WD
If 4WD - system: QT-II
Current Mileage: 170k
Posts: 84
<<2. whether my oil sensor problem is causing my fuel pump problem>>


I dont know about our jeeps but I have heard of other cars that shut down the fuel supply if there is no oil pressure. In order to save the engine from damage. Also, do out jeeps have the roll over switch that shuts down the fuel pump in care of roll over? i know from experience that a 2005 ford explorer sport trac does not have this feature. I could have sworn that my old xj did though. Might be another thing to look into.
Carbuff is offline  
post #9 of 12 (permalink) Old 10-16-2018, 04:21 PM
Senior Member
Points: 32,015, Level: 100 Points: 32,015, Level: 100 Points: 32,015, Level: 100
Level up: 0% Level up: 0% Level up: 0%
Activity: 8% Activity: 8% Activity: 8%
 
rblapham's Avatar
 
Join Date: May 2009
Location: Cleveland TN
Own a Commander?: Yes
Model year: 2006
Trim Package: Limited
Power-Train: 5.7L V-8 Hemi
4WD
If 4WD - system: QD-II
Current Mileage: 103,000
Posts: 616
Garage
Quote:
Originally Posted by jcatl View Post

However, I do not know which PCM harness is C2 (there are five harnesses going into the PCM and they look identical). I also don't have the special tool.
Any ideas on where to go from here?
See this on the harness locations - PS it is in the service manual also
See figure 6 on the first PDF - has the C2 connector

https://www.jeepcommander.com/forums...locations.html

06 Commander Limited Hemi - QDII,
Past -89 Comanche, 98 Grand Cherokee (2WD), 2000 Cherokee, 05 Grand Cherokee Limited 4.7
Had to replace the brakes - they opened more gas stations in town
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Last edited by rblapham; 10-16-2018 at 04:28 PM.
rblapham is offline  
post #10 of 12 (permalink) Old 10-16-2018, 07:46 PM Thread Starter
Junior Member
Points: 247, Level: 4 Points: 247, Level: 4 Points: 247, Level: 4
Level up: 94% Level up: 94% Level up: 94%
Activity: 0% Activity: 0% Activity: 0%
 
Join Date: Jul 2018
Location: Atlanta
Own a Commander?: Yes
Model year: 2006
Trim Package: Limited
Power-Train: 4.7L V-8
4WD
If 4WD - system: QT-II
Current Mileage: 120k
Posts: 6
I haven't found any reference to a roll-over sensor.

Thanks, rblapham!
I've located them in the Service Manual now. That 7000 page beast isn't the most user friendly!

I disconnected the battery for an hour tonight and my P0522 code is now gone, so the new oil pressure sensor seems to have addressed that.

However, the truck still won't crank and I've still got the P0627 - fuel pump relay circuit

Going through the troubleshooting guide:
The manual says that the resistance of the fuel pump relay should be between 70 and 90 ohms. I'm reading 40 ohms, so SM say I should replace relay (which I'm going to). However, I tested the 3 other identical relays adjacent to the fuel pump relay (Started, A/C clutch, EATX) and they all show the same resistance 40ohm ... seems odd.

Also, as I mentioned above. Step 3 in the guide is ok. Step 4 is no good. The bottom signal circuit for the relay shows 12V when key is on, top shows 0v though.
Steps 3 and 4 can be seen at www . imgur . com /a/SINEBea (without the spaces of course. I still can't post photos or links until I get mt post count up, apparently) I typically wouldn't be so impatient, but I have to pass emissions by Oct 26...

All of this is complicated by the fact that I dropped the tank and found 11.5v at the fuel pump harness. Do I simply have a 0.5V voltage leak somewhere and the fuel pump just won't run on <12v??

Thanks for any help!!!
jcatl is offline  
Sponsored Links
Advertisement
 
Reply

  Jeep Commander Forums: Jeep Commander Forum > Jeep Commander Discussion > New Member Section

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Jeep Commander Forums: Jeep Commander Forum 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 email 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
Display Modes
Linear Mode Linear Mode



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 On
Pingbacks are On
Refbacks are On

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