Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register
  • We just completed a significant update, but we still have some fixes and adjustments to make. Please see this thread for more details and to find out how to revert to the old design. Cheers!

Error codes: 104 1144 922 923

My roadster is down now. From the logs: yesterday I received a 104, followed by two 1144 errors.
I've been having random 1144 errors ever since the annual service last summer. Today, driving to
work, it threw the 104, followed by 1144 and then 922. It powered down and I left it for a couple of hours
to cool off. When I picked it up to bring it home, it threw the 104 followed by a 923 and shut down again.
I'll note that the PEM fan was running yesterday but did not come on this morning when the PEM
heated up.

From the VMS messages:
104 TCM: Lost DMC comms
1144 DMC PEM Fan Problem
922 DMC HW: PhaseB OverTemp fault
923 DMC HW: PhaseC OverTerm fault

Any ideas? I don't have much faith in the Utah SC as last summer when it started with the 1144
errors, they said to start with replacing the fan but they would have to order one. I told them they
were available off ebay but they said they would only install Tesla parts. If it wasn't the fan, then
their response was going to be replace the PEM.
 
Upvote 0

X.l.r.8

Active Member
Supporting Member
Feb 18, 2018
1,555
998
Toronto/Miami
I’m going to make a huge assumption that you pulled the PEM fan plug cleaned and checked it followed by a physical check of the fan rotation.
DCM coms as I try to remember is again a communication from or through the PEM, followed by a PEM fan warming followed by a over temp. The problem seems to be at the plugs for the PEM and should now always be a first place to look at especially after a service. Following that make sure the fan is actually working by using an external power supply.
 

gregd

Active Member
Dec 31, 2014
2,597
1,815
CM98
I've had a lot of alert 104s, and they never seem to amount to anything. Sifting through the logs, they appear to date all the way back to nearly the car's birth.

Also had some 9xx alerts, mostly 920 and 934, also without apparent consequence. Your overtemp faults, however, appear to be more serious, and ones that need to be addressed.
 
Thanks for the feedback. The overtemp errors were clearly because the fan wasn't blowing.
As to why it wasn't blowing, I agree with XLR8: probably due to the PEM/fan plug.
I'll test the fan on Friday when I have time to eliminate that.

Unfortunately, I don't think I can pull the PEM myself to get at the plugs … from the youtube
PEM removal video, it seems you have to lift the PEM some to get at the plugs.
When I took it to the SC last summer for the 1144 errors, they said they checked the
plugs and they were in good shape. I doubt they looked for deflection though.
 
We have a 2.5 and began getting some 1144 errors. We verified that the fans were operating properly but continued getting the same errors. At the last service the PEM connector had no corrosion and was seated properly. The only other connectors were the two molex connectors directly connected to the fans and the PEM harness. We have the new fans with one motor but it has two connectors. After examining the connectors it appeared that one of the blade female connectors inside the molex was not making a good connection. Almost every time I accelerated or hit a bump the connector would wiggle thus it would disconnect long enough to cause the 1144 debug error. Until I can get replacement molex plugs, I zip-tied the connectors together and anchored them to another wire so they wouldn’t wiggle.
So far, it’s worked pretty good.

PEM Fan Connectors.jpg
 

jfischer

Member
Feb 6, 2014
188
248
Houston
Fan works when plugged into external power. I'm guessing the PEM connectors but since I was planning on having the PEM rebuilt by Gruber, I'll let them fix it when they rebuild the PEM.

Just replace the harness side of the PEM fan connector... I did and it solved my 1144 issue.

Mine had corrosion/burn marks so I know the issue was the female receptacle side...

Its tight, but with patience, you can do it WITHOUT pulling the PEM. I however removed the PEM as I wanted to clean out any debris as well.

PEM - Plug.jpg
 

jfischer

Member
Feb 6, 2014
188
248
Houston
If your receptacle is showing burning like yours, you really should also replace/fix the connector too. The connector end in the PEM likely has a pin(s) pushed in. That recessed pin(s) will cause your newly installed receptacle to also burn up.

The PEM connector didnt look too bad. Had some corrosion but I cleaned it off. Looks like most of the damage was from a bad fan and connector... but yes agree, next time ill replace molex connector on the CIC PEM board.

PEM - JACK.jpg
 
We have a 2.5 and began getting some 1144 errors. We verified that the fans were operating properly but continued getting the same errors. At the last service the PEM connector had no corrosion and was seated properly. The only other connectors were the two molex connectors directly connected to the fans and the PEM harness. We have the new fans with one motor but it has two connectors. After examining the connectors it appeared that one of the blade female connectors inside the molex was not making a good connection. Almost every time I accelerated or hit a bump the connector would wiggle thus it would disconnect long enough to cause the 1144 debug error. Until I can get replacement molex plugs, I zip-tied the connectors together and anchored them to another wire so they wouldn’t wiggle.
So far, it’s worked pretty good.

View attachment 428488

Hi Nvbob,

I have a roadster 2.5. I am getting the same issue (#1144) and I would like to tighten the molex plugs like what you did. Could you show me some light on how to locate the molex plugs? I don’t think I have the skill and strength to move the PEM out myself. How can I locate the molex plugs without moving the PEM out?

hope you can give me some feedback

thanks in advance!
 
Hi Nvbob,

I have a roadster 2.5. I am getting the same issue (#1144) and I would like to tighten the molex plugs like what you did. Could you show me some light on how to locate the molex plugs? I don’t think I have the skill and strength to move the PEM out myself. How can I locate the molex plugs without moving the PEM out?

hope you can give me some feedback

thanks in advance!

@nicky _cwt,

I continued to have issues with the fan side connectors so I just rebuilt the entire harness from the PEM to the fan connector. Luckily, I have skinny arms and was able to reach the PEM side connector without removing the PEM.

I would suggest reading the thread (the entire thing) posted by @gregd "Think I need a new PEM fan anything else to check". It provides some really good insight on his process. Also, What exactly is the 1146 Alert?. It describes the difference between the 1144 and 1146 alerts.

Also, look at this thread entry - Molex Connector Numbers

As you mentioned, you do not possess the skills or strength - Please do not open the PEM without inhibiting APS and unplugging the battery disconnect. There is quite a bit of power going through the system and you could become injured. Your best friend is searching and reading the posts. You will find more assistance than I could ever offer.

I am not that technically competent so I tread very carefully when working on my Roadster.

Also, if you are not very comfortable with what you are doing, don't do it.
 
Last edited:
@nicky _cwt are there any other Roadster owners in Hong Kong that can assist you with replacing the connectors or the harness?

The last time you had your car serviced for it's annual PEM cleaning, did the tech check the connectors for issues? If there was no evidence of burnt pins then you might be able to just replace the connectors on the fan end. That would be the simplest solution. Once you get the parts the rest is easy.
 

gregd

Active Member
Dec 31, 2014
2,597
1,815
CM98
I would change the connectors for the gold plate ones if you are unplugging the plug for the fans. It’s pretty simple and worth the small investment.
I would think that one should use the same metal on both sides of the connector, otherwise you may be inducing (galvanic action) a failure yourself. Does anyone know if this is true? There's not a statement about it on the Molex website that I can find.

If so, swapping the PEM-side connector is not trivial. You therefore may be forced to continue to use the tin-plated pins on the wiring harness side.
 

X.l.r.8

Active Member
Supporting Member
Feb 18, 2018
1,555
998
Toronto/Miami
coming from audio amplifiers that use tin and gold plate connectors I have never come across this. However even the car amplifiers are generally placed inside the vehicle away from the elements so who knows. Swapping the PEM side is on my list to do.
 

Products we're discussing on TMC...

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


SUPPORT TMC
Top