Temperature indicator failure
 

As I arrived home tonight, I managed to stall the car as I backed onto the drive. I restarted - and immediately got "temperature indicator failure". Temp gauge stays at the bottom mark and the temp red light at the top of the gauge flashes. The car had reached normal temp on the way home (just over the 80 degree mark) although it's about -0.5 degrees outside.

Turning the car off / removing the key / restarting did not solve the problem. However - strangely, reading and then clearing the code with durametric immediately cleared the problem - the temp gauge shot straight up to the correct value. I logged engine temp reading, and this also seemed correct (I wish I'd done it before clearing the code).

I did a search before plugging durametric in - found nothing on this site, but did find a couple of posts on 911UK and it seems it's a problem a few people have had but no solution was posted. Somebody had suggested it was related to the tiptronic system - but mine is manual. Somebody else has had engine temp sensor replaced and a few other bits, but with no luck - although they seem to be intermittent problems (hence I suspect I may see it again). The suspicion seems to be instrument cluster, but nobody is willing to pay for one to see if it really is the cure.

Any ideas? It almost seems like starting the car (lights were on) triggered it and then it stayed until I cleared it, so it may be that I'll never see it again - but I doubt I'm that lucky (and my battery is only a week old so the voltage shouldn't be dropping enough to cause fake faults!).

Had same incident in a 04 GT3 I am pretty sure it is from the low voltage. Mine was a onetime thing.
Cleared the code never saw it since.
If you see it again take it from there and maybe change temp sens. etc.
Also the fact that you deleted the fault and it didn't come back at once rules out that something was really malfunctioning.
Maybe your new battery doesn't crank appropriately or battery is fine but your ground wire is not making a good contact.

Thanks. Battery cranking power should be fine (and is defintely better than the one I took out!) - but I don't usually crank the car with the lights on.

I'll keep my fingers crossed I don't see it again.

Can't say for sure this is what happened but I have seen from logging various engine sensor data over a long period of time -- many many trips -- that occasionally the coolant sensor reading will spike. The spike value is 0xFF (hex) and this is 255 (decimal). Coolant temp is biased by -40C so a 255 reading is 215C (415F). (The speed value also spikes once in a great while and produces a speed spike of 157 to 158 mph.)

I've always seen these temp spikes in the middle of a trip but if the spike happened to occur when you were starting the engine this could account for the behavior.

Having the lights on while starting may have something to do with this too, I can't say for sure, though. I've started my cars many times with the lights on -- I don't make it a habit but it happens once in a while -- and never had occur what you reported.

Unless the behavior repeats itself and becomes a nuisance I'd just drive the car. 'course, if any other symptoms appear you need to get things looked into. The warning light on may have been giving you a very early warning of something amiss. I assume the coolant level is ok and the coolant is reasonably fresh and the anti-freeze/water ratio ok and so on?

Sincerely,

Macster.

Coolant level is correct (I checked), and entire system was flushed and refilled in the summer - so I don't think the cause is coolant related.

This just happened to me...cleared the codes and temp gauge it went back to normal.

Mine hasn't happened again (so far) so hopefully it was just a glitch.

Booster 987 "Engine Temperature Failure"
 

Hello...

I have a ten year old Boxster, and a few months ago, I got a message from the cars computer stating the engine temperature failed. There was a red exclamation mark and the engine temperature was sitting at zero, with a flashing red light, even though the car was warm.

Initially this problem would go away by itself, I'd park up, leave it and restart the car and the thermostat was working and I could see a reading after a few minutes after the car came up to temperature.

After some time, this stopped happening and the thermostat would not work after leaving the car to cool. I went to my local Porsche specialist and they instructed that the temperature sensor should be replaced. They went ahead and did the work.

Problem is, after about twenty miles after the new sensor was installed, the same problem has come back, but now I have a new sensor installed, it hasn't made any difference. The sensor worked to start with, I left the garage, drove the car and it warmed up.

Could this be a connection issue (wiring)?
Or anything else??

Can someone please advise?

It was most likely a glitch caused by momentary low static voltage from the battery as you restarted the car.

Check your battery and main electrical connections. Including the engine ground strap.

I have the same issue on a 2005 997.1. Does anyone have the definitive solution for this problem?

In the same boat guys warning came up about a month ago haven't driven the car much but yesterday swapped it sensor and was good for the first few miles then warning temp sensor failure came on again. I'm stumped if this could be a voltage thing where should I check volt meter inside the car stays around 14 volts could that be a false reading? Also where might the ground strap be located?

Ground strap on the right side of the engine, just behind/next to rear wheel arch.

Thanks going to check this out and also going to put a volt meter on the + terminal in the engine bay and a ground to measure voltage

Low charge voltage or battery voltage does strange things in these cars