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1945GPW · **Joined:** Mon May 05, 2014 8:37 pm **Posts:** 27

ECM may have failed. Search on google did not turn one up. Any ideas? 2005 KJ diesel, GDE eco tune.

Thanks

casm · **Joined:** Sun Jan 29, 2006 5:05 pm **Posts:** 694

There're a few on eBay right now:

https://www.ebay.com/sch/i.html?_from=R ... u&_sacat=0

WWDiesel · **Posted:** Thu May 23, 2019 11:37 pm

1945GPW wrote:

ECM may have failed. Search on google did not turn one up. Any ideas? 2005 KJ diesel, GDE eco tune.
Thanks

Just curious, what makes you think it has failed?
Very uncommon and extremely rare on these vehicles. :shock:

I believe there has only be a couple of them reported failed on this forum and one of them was when a owner accidently let a 12v+ cable short out to the ECM housing and fried some internal components...

Billybob · **Posted:** Fri May 24, 2019 3:13 am

Yes the ECMs are pretty robust.

What exactly is the problem?

Could be a sensor error or wiring issues.

A few days ago a I fixed my 8th wiring problem on my 2002 Export 2.5 CRD.
The repair section in the manuals for this CEL code told me to first replace the MAP sensor and then to replace the ECM! :shock:

1945GPW · **Joined:** Mon May 05, 2014 8:37 pm **Posts:** 27

The story. Do not know if any of this matters or not. Going down the highway the brake light came on. Got home and check a few things, brake fluid etc. Check to see if any codes show up. Did not work as normal. So, start it up and the ABS light is now on. Well, drove through some muddy water earlier in the day. Figured that may have messed up the sensors. Next day, 70mph the engine quit. Starter did not work. Had it towed to a shop that has worked on the vehicle in the past. Computer did not respond, could not be read? Wiring was checked, connections seem fine. So, here we are. I have 2 KJ diesels. I come to this site when I have problems. Search did not turn up much concerning the ECM.

Thanks for the help.

GordnadoCRD · **Posted:** Fri May 24, 2019 10:12 am

Before investing in a new ECM, try replacing the Brake pedal switch. They are a really odd duck design, and a one-time use only, and a PITA to get set right. I went through 2 before I got it right. At least they aren't expensive.
That one proceeded to fail 6 months later, and ran the battery dead by keeping the brake lights on constantly even though the car was parked and not used. The 4th one is still going nearly 20 months later.
Forgive me if you've already checked this, but test your alternator output and get your battery load-tested as well, since the engine will crank pretty well at voltages lower than the ECM can function. (can crank but not start).

Also, avoid trying to start it if you have a battery charger hooked up and hot. Many ECM/ECUs can fry circuits under those conditions, not necessarily because of over-voltage, but due to the dirty power (not clean DC but weird rectifier oscillation.) I do not know if ours has this weakness, but I just avoid cranking with a charger connected as a precautionary practice.

Billybob · **Posted:** Fri May 24, 2019 10:51 am

If starter is not working, check that the battery is in good shape....
12.5 volts at rest...not less than 10 volts while cranking, about 13.4 v while running...if you get it to run!
Check battery contacts are clean and tight.
Check Negative battery lead going to chassis is clean and tight.
Check strap grounding engine to chassis is clean and tight both ends.

Check connections to solenoid/starter are good.
Try start in Neutral instead of Park

Check Fuse #8 40 Amps under the hood is good.

Swap over the Starter Relay under the hood with an identical one nearby.

Remove the Starter relay and identify female pin 30 and 87 inside the empty socket
With ignition On and in Park or Neutral briefly jumper female pins 30 and 87 together...engine should turn over and run if Fuse #8 is OK.

This above procedure overrides the Ignition Switch and the Park and Neutral interlocks.

If the engine turns over OK then the Actuator Pin Assembly is probably broken....lots of hits here on how to replace it or get back to this post to get more info.

Check under your floor carpets for any major water entrance.
The ECM connectors could have gotten wet....dry them off with a hairdryer.

Bet you it is not the ECM...if I lose the bet then your check is in the mail...trust me! :wink:

The brake switch could be a problem...as stated it cannot be removed and put back...new one needs to be fitted. Rather check this out via the Wiring Diagrams rather than throwing money at it. This has no connection to the Starter not turning over. :wink:

WWDiesel · **Posted:** Fri May 24, 2019 2:19 pm

Along with all the other great suggestions, a couple of thoughts.
The ECM must have a good ground and be provided with good proper 12v power supply. Make sure the battery is good, fully charged, and all connections are good, clean, and tight.
If the ECM were to lose either one of these above, the engine will shut down and will not start.
Start with the basics and make sure it has both of these before branching out.
A good 12v test light and a voltmeter can be your best friend in a situation like this.

Best of luck and keep us posted as to what you find.

1945GPW · **Joined:** Mon May 05, 2014 8:37 pm **Posts:** 27

Update my post. Ended up having a computer tech look at the Liberty. He narrowed the problem to the Gateway Module. A quick search, seems the parts is discontinued. Anyone have any ideas?

Thanks

1945GPW · **Joined:** Mon May 05, 2014 8:37 pm **Posts:** 27

Reading more post concerning this. May have more checking to do.

WWDiesel · **Posted:** Tue Jun 11, 2019 11:41 pm

1945GPW wrote:

Reading more post concerning this. May have more checking to do.

Have you checked all the grounds?

Billybob · **Posted:** Wed Jun 12, 2019 3:06 am

The Gateway module in the engine bay is prone to have a bad connector connection as it is exposed to snow, salt, mud, water etc.

Usually a good cleanup of the male and female connector pins resolves the issue.

According to the FSM there are no active components inside the Gateway Module ie. no transistors or chips that can get fried....just straight-through connections.

I you want to replace it you should visit some Breaker yards for 2005 CRDs. :wink:

Sir Sam · **Posted:** Fri Jun 14, 2019 9:12 pm

Nothing critical comes into the gateway, if it failed it should not cause a no start.

The ECU does control the starter, with the ECU the engine wont crank.

Turn the key to on, then jumper the starter relay so it cranks, does it start?

You said you have two jeeps, swap the ECU between them and see if the jeeps cranks or starts and runs for 3 seconds.

1945GPW · **Joined:** Mon May 05, 2014 8:37 pm **Posts:** 27

Thanks for the help so far. A tech with a scanner narrowed it down to the Gateway module. Could not find a used one, so sent mine off to be rebuilt. Just got it back as unrepairable. From what I gather the Gateway module is a fancy name for a junction block. Going to take the cover off and have a look inside. Nothing to lose at this point. Where are all of the grounds located? Want to make sure to check them all. I did check the one behind the left headlight. I have not tried to jump the starter solenoid. I am having problems with a 2005. My other liberty is a 2006. The computers are different. Will that make a difference for a brief test swap?

Billybob · **Posted:** Tue Jun 25, 2019 11:17 pm

1945GPW wrote:

Thanks for the help so far. A tech with a scanner narrowed it down to the Gateway module. Could not find a used one, so sent mine off to be rebuilt. Just got it back as unrepairable. From what I gather the Gateway module is a fancy name for a junction block. Going to take the cover off and have a look inside. Nothing to lose at this point. Where are all of the grounds located? Want to make sure to check them all. I did check the one behind the left headlight. I have not tried to jump the starter solenoid. I am having problems with a 2005. My other liberty is a 2006. The computers are different. Will that make a difference for a brief test swap?

I doubt it is the Gateway module...that basically is a junction block for the PCI, CAN and SCSI Busses. A problem there normally gives you NO BUS error.

The ECM from a 2006 KJ will not work in the 2005.

Do the procedures in my post above to see if the engine turns over.

The Wiring Diagram Index Page has a Locations Section that shows where most of the grounds are located. Wiring diagram is Section 8W in the 2005 Jeep KJ Service Manual here:

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

TKB4 · **Posted:** Wed Jun 26, 2019 3:05 am

I could be wrong but I believe the ecm from 06 will work just to start it for 3 seconds then it will cut off wouldn't take but a few minutes to try. It cannot be used by reprogramming the VIN in an 05 to operate it otherwise. It should act the same as using a key that doesn't have skim code that is cut correctly . This however, would just help to determine if its the ecm or not.

First you should do as Sir Sam and Billybob suggested if you haven't and jump the starter relay to see if it starts. He made a video about it here:

https://www.youtube.com/watch?v=EauvjE5VUU0

This will tell you if the problem is in the ignition system such as ignition switch pin broken .
Please tell us if you did this and what results were then try swapping the ECM s and tell us what happens.

1945GPW · **Joined:** Mon May 05, 2014 8:37 pm **Posts:** 27

Thank you all. Will give them a try and get back.

1945GPW · **Joined:** Mon May 05, 2014 8:37 pm **Posts:** 27

Jumped the starter relay. Cranks, no start. Rereading everyones post, I have not tried to start in neutral. Cannot swap out the ECM until monday.

Billybob · **Posted:** Thu Jun 27, 2019 7:53 am

1945GPW wrote:

Jumped the starter relay. Cranks, no start. Rereading everyones post, I have not tried to start in neutral. Cannot swap out the ECM until monday.

OK I am assuming that the ignition was switched ON when you jumped pins 30 and 87 together inside the Starter Relay and all the normal cluster lights were ON?

Check if all the Cluster lamps are working..maybe there is some error that you are not seeing due to a blown LED or LED has been removed by previous owner!

While pressing in the Odometer Reset button...turn ignition ON.
The cluster should turn the LEDS ON and OFF and move the gauges around. Make sure all the LEDS are still operational.

Jumpering out the Starter relay bypasses the Ignition Switch...may be faulty, the Ignition Actuator Pin Assembly...may be so bad that Ignition is not turned ON properly.... and bypasses the Neutral and Park interlocks. Also bypasses the Starter Relay...try swapping it over with an identical one nearby.

Check fuses under the hood: Fuse #6 30A, #14 40A #16 15A, #28 15A

Check connector C111...right rear-side of engine compartment.

Check G202 Black connector left kick panel.

With battery disconnected re-plug the ECM connectors several times to clean any bad contacts.

Sir Sam · **Posted:** Thu Jun 27, 2019 11:40 pm

TKB4 wrote:

I could be wrong but I believe the ecm from 06 will work just to start it for 3 seconds then it will cut off wouldn't take but a few minutes to try. It cannot be used by reprogramming the VIN in an 05 to operate it otherwise. It should act the same as using a key that doesn't have skim code that is cut correctly . This however, would just help to determine if its the ecm or not.

First you should do as Sir Sam and Billybob suggested if you haven't and jump the starter relay to see if it starts. He made a video about it here:

https://www.youtube.com/watch?v=EauvjE5VUU0

This will tell you if the problem is in the ignition system such as ignition switch pin broken .
Please tell us if you did this and what results were then try swapping the ECM s and tell us what happens.

06 or 05 ECU if not programmed to the vehicle will allow it to start once for 3 seconds and then not again because of the mistmatch SKIM untill the CEL is cleared then it will repeat.

If the ECU is programmed to the vehicle but not the correct year (05 in 06 or 06 in 05) it will trigger a CEL for the ABS mismatch. the CEL code can be deleted from the ECU but the ABS computer will still set a code.

With the key to on and jumping the starter solenoid out if it didn't start then its some other issue, possibly a ECU, or one of a million other things.

ECM

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