DMC fan failed, car stopped, flatbed to service...

[Adrian Cockcroft]

I'd just left home and was driving down the hill when a series of alerts shut down drive. I ended up with just enough to get to a safe location at the bottom of the hill near the highway for a AAA truck to (eventually) take me to Tesla service. Here's the collection of interesting messages courtesy of OVMS. I'll update this thread when Palo Alto let me know what actually happened. First time the car has let me down and not got to my destination, luckily I was close to home and had some flexibility in my schedule today...

Adrian

 

[markwj]

I feel bad for you, but thanks for sharing. Those messages tell an interesting story. First the fan failed, then things started to heat up, then torque limited, and finally the car shutdown.

The scary thing is that all those messages, apart from the last one, are DMC debug-only. They wouldn't be shown on the VMS (not in debug mode). So, all you would normally see would be 'powertrain problem service required' and a dead car.

 

[gregd]

First thing to check is the PEM fan connector. Have there been 1144/6 errors previously?

Yeah, really poor judgment on the part of the firmware team to not let you know about really important "debug" messages.

 

[Adrian Cockcroft]

The car showed an error and torque limited a few minutes before it shut down completely, so there would have been some warning. At a recent service (I guess less than 1000 miles ago), they cleaned out the fans etc. and some warning messages stopped at that time. I also guess it's the connector, but I'll update when I find out what they say.

 

[Adrian Cockcroft]

I feel bad for you, but thanks for sharing. Those messages tell an interesting story. First the fan failed, then things started to heat up, then torque limited, and finally the car shutdown.

The scary thing is that all those messages, apart from the last one, are DMC debug-only. They wouldn't be shown on the VMS (not in debug mode). So, all you would normally see would be 'powertrain problem service required' and a dead car.

It would be better if the OVMS app had a screen that listed the messages, they get lost in the popup backlog.

 

[Adrian Cockcroft]

They are replacing the PEM fan.

 

[Adrian Cockcroft]

And have now found that the PEM fan connector had burnt, so now we're looking at reconditioning the PEM, which will take several weeks and potentially cost a lot, depending on how much work it needs.

 

[X.l.r.8]

Why does that not surprise me. I wonder how many PEMs were replaced because of that faulty plug. i wonder if its a problem with the fan upgrades only and how soon after the 'upgrade' this would occur.

 

[utch]

interesting, I was getting 1144 errors when it was hot (above 95F). When I took it into the SC (July), they said they needed to replace the PEM fan but had to order one. They said they couldn't order one from a different supplier or ebay although the 2.0 fan is certainly available. They never have called back saying they had one ready to install. I talked with the tech who worked on it and he claimed they pulled the PEM and checked the fan connectors but they were fine. I tested the fan and it ran at different speeds when fed different amps (not very robust testing). However, now that the weather has cooled down, I haven't had any 1144 errors. I suspect I'll have to have the connectors replaced at some point in the future … like next summer.

 

[smorgasbord]

And have now found that the PEM fan connector had burnt, so now we're looking at reconditioning the PEM, which will take several weeks and potentially cost a lot, depending on how much work it needs.

I had a similar problem exactly 3 years ago:

First, I got a "DMC #1152: Motor Fan Problem."
Then got failures while charging:
DMC FW: PhaseA OverTemp fault ID:946
DMC Motor Fan Problem ID: 1146
DMC PEM Fan Problem ID: 1144

The car still worked and had good power as I attempted to drive it down what I believe is the same hill as Adrian (we're practically neighbors) to Tesla service. But the PEM overheated even coasting down the hill, so I pulled over and got a tow. Car was under the extended warranty at the time (not something I usually purchase), so I don't know what the cost would have been. It's been fine since then.

 

[dpeilow]

It's such a well known problem Gruber offers a fix for it Tesla Roadster PEM Engineering Flaw Resolution

The connectors can be bought from Mouser for a few dollars. If you are handy with a soldering iron...

 

[backmost]

The 1.5s aren't as prone to these failures right? Seeing these errors gets me worried at night...

 

[Adrian Cockcroft]

It's such a well known problem Gruber offers a fix for it Tesla Roadster PEM Engineering Flaw Resolution

The connectors can be bought from Mouser for a few dollars. If you are handy with a soldering iron...

The PEM was sent our for re-work, so maybe Tesla send it to Gruber? I don't know. However the description above matches, my car was fine until soon after a service where they cleaned out the dust, and that probably was when the connector was messed with.

 

[dpeilow]

and that probably was when the connector was messed with.

The connectors have a fairly limited number of connect/disconnect cycles. It was discussed recently in another thread about the same type of failure.

 

[Adrian Cockcroft]

Got the car back with a reconditioned PEM last week. Almost three months and not a cheap fix. Hopefully it will be good for another 8 years or more.