U0146 - lost communication with Gateway - SOLVED(broke wire)

dunl · **Joined:** Mon Jul 27, 2009 6:18 pm **Posts:** 53

Hi all,

Slowly picking away at the issues with my CRD that has been sitting. I am getting the code U0146 - Lost communication with Gateway.

Is this for the wiring harness that runs along the firewall? Because if so, I see no evidence of a short, and I have no clue how else to check it. I am simply not up to the task of trying to hunt down every single wire in the harness to test, or should I say, my skills are not up to the task.

Is there some way to find this issue?

Thanks.

papaindigo · **Posted:** Thu May 30, 2019 8:00 pm

05 or 06?

dunl · **Joined:** Mon Jul 27, 2009 6:18 pm **Posts:** 53

Sorry, 2006.

Billybob · **Posted:** Fri May 31, 2019 7:17 am

The 2006 LHD CRD has a known problem with the Fuel Filter Head Assembly Mounting Bracket pressing down on the main harness going behind it and causing wire breaks or shorts to the Firewall or shorts from random wires to each other.

So I would start by removing this Mounting Bracket and carefully inspecting the condition of the wire harness in that vicinity!

dunl · **Joined:** Mon Jul 27, 2009 6:18 pm **Posts:** 53

I did check it, but I don’t see anything.

How else can I check this?

Billybob · **Posted:** Sat Jun 01, 2019 4:23 am

Very difficult to diagnose a BUS problem.
The 2006 CRD uses mainly a CAN bus but also some SCSI and PCI.
these Busses run all over the vehicle between the Cluster, BCM, Front Control Module (FCM) and probably the ECM and TCM...I will have to look.

Each Bus is a Serial Bus ie it streams data all over the place with the address of which module it wants to talk to usually at the beginning of the stream. The addressed module recognises its own address and connects to the Bus.

Without the proper instruments to trace the data you are generally speaking at the mercy of the Dealers who should have the correct equipment.

Use the Wiring diagrams to see what connector goes to the Gateway and try trace the various colored wires back out to the Cluster and BCM and then out into the engine bay.

I will look through the Theory of OPs and the Wiring Diagrams to become a bit more familiar with these Busses....never had to work in that area before thankfully! :wink:

Edit to add: This code is shown on Page 5-198 ie. page 435 of the total of 6059 pages!

WWDiesel · **Posted:** Sat Jun 01, 2019 12:39 pm

U0146 Lost Communication With Gateway A
The most common failure is a loss of power or ground to a module! :banghead:

Start with the basics first!

geordi · **Posted:** Sun Jun 02, 2019 12:46 am

Just fixed one with this on the Facebook group. Check the grounds, specifically the one under and just behind the driver's headlight housing.

Billybob · **Posted:** Sun Jun 02, 2019 5:35 am

I did eventually find the code in the 2006 documentation but the page it directs you to is for a totally different error. Not unexpected to find problems with the documentation!

Edit to add: This code is on Page 5-198.

geordi · **Posted:** Mon Jun 03, 2019 12:02 am

Billybob wrote:

I did eventually find the code in the 2006 documentation but the page it directs you to is for a totally different error. Not unexpected to find problems with the documentation but this time I cannot even find where the Front Control Module...as they call it...actually is located and cannot find it in the wiring diagrams! :shock:

So I think I will sit this topic out as without wiring diagrams I am pretty helpless here! :oops:

Do you have a 2005 or 2006? In 2005, the gateway module is located under the engine fuse box and forward of the battery. On the 2006, the gateway module is part of the interior fuse panel behind the dashboard.

If you don't have the module under the engine fuse panel, then I don't have any specific suggestions OTHER than chasing all the ground points you can, starting with the unmarked one that is behind the driver's headlamp on all models. Ground points are EXTREMELY important to this computer and all the electronics.

connolcj · **Posted:** Mon Jun 03, 2019 10:23 am

I had a similar fault and I was missing a ground wire underneath the coolant reservoir/ vacuum solenoid.

dunl · **Joined:** Mon Jul 27, 2009 6:18 pm **Posts:** 53

Back at it.....the "gateway module" - does someone have a picture of this? I tried googling a pic and couldn't find one.

Thanks.

Billybob · **Posted:** Sun Nov 24, 2019 4:26 am

dunl wrote:

Back at it.....the "gateway module" - does someone have a picture of this? I tried googling a pic and couldn't find one.

Thanks.

OK after tearing out what little hair I have left due to the 2006 CRD Service manual mistakes I advise you try the following:

Download the 2006 KJ Service Manual here if you do not already have it:

http://www.colorado4wheel.com/manuals/Jeep/KJ/

At the bottom of the Index page is the DTC index...look for DTC U0146 Gateway.....it tells you to go to Page 5-219. Page up to Page 5-219 and you will see that a different code is on that page...usual error!

Do a search backwards for U0146 and you will land up on Page 5-198...page 435 of the total pages of 6059.

This states: 5-198 U0146 Brakes -ABS Electrical Diagnostics

When Monitored With Ignition on, Battery voltage between 10 and 16 volts, IOD fuse installed.

Read up what they have to say on this page and the following page...most actions require their "scan tool" but you can check the Battery Voltage and IOD fuse...I have seen a few posts regarding this IOD fuse causing various problems! Check the battery straps are clean and tight both ends.

The IOD Fuse is fuse #34 inside the Junction Block which is the internal fuse panel at left of console.
This fuse is near the top inside a white plastic holder that enables you to pull the fuse out.
I would re-plug all fuses under the hood and on the internal fuse panel.

Also swap over the ASD relay under the hood with an identical one near it.
The VIN number could be missing/mismatch.

End result if not fixed they state replace the ECM or ABS Module.

I will see if I can find the relevant pages in the Wiring Diagrams to see where problems may be traced.

Have another good look behind the Fuel Filter mounting bracket for any wire damage there!

Check wiring going to the Anti-Lock Brakes Module including ground.

Stupid question maybe. Does the Jeep start and run OK with or with or without the CEL displayed?
Or is the Jeep totally dead...not turning over or not starting?

TKB4 · **Posted:** Sun Nov 24, 2019 5:45 pm

I'll do you one better here is a link to video posted by Sir Sam which demonstrates what happens when it is unplugged etc:
https://www.youtube.com/watch?v=-1mFYesTZDo

Hope this helps

dunl · **Joined:** Mon Jul 27, 2009 6:18 pm **Posts:** 53

Thank you for the information. I was away all day so I will chip at it tomorrow.

It does run, just as if the tranny is in 3rd the entire time, CEL on.

Billybob · **Posted:** Mon Nov 25, 2019 2:50 am

TKB4 wrote:

I'll do you one better here is a link to video posted by Sir Sam which demonstrates what happens when it is unplugged etc:
https://www.youtube.com/watch?v=-1mFYesTZDo

Hope this helps

This video is for 2005 CRD..we are dealing with a 2006 CRD here :wink:

The 2006 CRD does not seem to have an actual "Gateway Module" although the U0146 error description on page 5-198 states "Lost Communication with Central Gateway".

Set Condition: If the Anti-Lock Brakes Module either fails to receive bus messages from the ECM for 500 ms or it receives invalid messages from the ECM, or it receives messages from the ECM that are of improper data length".

Possible Causes:

DTCs Related to Battery Voltage, Ignition, or VIN Messages
CAN C Bus Circuits Open or Shorted
ECM Power and Ground.
ECM
Antilock Brakes Module.

I have read somewhere that the 2006 KJ has its Gateway Module on the top of the Junction Module ie. the interior fuse panel but I cannot find this shown on any pictures...for the 2006 CRD...will keep looking!

Billybob · **Posted:** Mon Nov 25, 2019 2:59 am

dunl wrote:

Thank you for the information. I was away all day so I will chip at it tomorrow.

It does run, just as if the tranny is in 3rd the entire time, CEL on.

Must be in Limp Mode!

TKB4 · **Posted:** Mon Nov 25, 2019 9:52 am

Sorry I assumed since he wanted a picture of FCM/gateway it was an05 because I don't know that you can actually take a pic of FCM in 06 since its part of interior fuse panel but maybe still a separate module I haven't looked.

geordi · **Posted:** Mon Nov 25, 2019 12:05 pm

dunl wrote:

Thank you for the information. I was away all day so I will chip at it tomorrow.

It does run, just as if the tranny is in 3rd the entire time, CEL on.

That's a different issue (usually) than the rest of this thread. Do you have the codes from the transmission and ECM? An ELM327 device and several free apps from your smartphone app store can pull the transmission codes. If you only have a generic scanner then it might only read a P0700 which is a generic transmission code stored in the ECM.

dunl · **Joined:** Mon Jul 27, 2009 6:18 pm **Posts:** 53

The only codes I have showing from my generic code reader is glow plug codes (need replaced, haven't done that yet), and the 0146 Lost Connection with Gateway code.

Only real tools I have available to me are a generic code reader, the MPPS usb cable and program, and a "FasLink M2" usb bluetooth scanner.

I was just assuming the possible "limp" mode would be related to the Gateway connection error, causing issues with the transmission shifting.

U0146 - lost communication with Gateway - SOLVED(broke wire)

Who is online