jigga009

I thought so too, hence my disbelief when i was seeing readings of -95 degrees C in my garage. It's cold here, but not that cold! I figured that the AIM oil temp sensor should at least be reading around 12 deg C, which is what my standalone ECU was reporting the engine coolant as the car sat cold in the garage.

Is it pretty common for the binder connectors used on these devices to experience contact issues?

ProCoach

No, not common. A simple check when you see the -95 C is to disconnect the sensor and see if it changes. That reading does sound like an "open" connection.

jigga009

Yes, I really should have done that check to see what effect it had.. :/

I went back to the car in the garage after driving it a few hours ago to check and see if the temp reading is displaying, and it still is.... at 22 degrees C.

I suspect that once cold the readings will be off again. I will confirm that later tonight when I check again.


I suspect that what is happening here is that the cold might be causing a loss of contact in the connection to the sensor that hangs underneath the sump of the car. As the oil heats up in the sump, it may be heating up the entire connection, causing a more positive connection. Just positing here....

That Stabilant seems like it might be the ticket, but it sure is expensive for what looks like a tiny bottle of fluid!

ProCoach

Agreed.

Yes, but it's the DADDY! It works...

Matt Romanowski

Not really. It happens everyone once in a while, but I wouldn't say common. Most of the ones I've seen problems with have had some other issue, like wire routing pulling the connector apart, constant water exposure, etc. I think once you find the problem it will be solved for good.

jigga009

I'll report back with my results... Now have to find time to jack the car up and apply the stuff.

jigga009

Ok, unfortunately the Stabilant wasn't the solution to the problem, but that is not to say that it didn't do something...

After adding Stabilant, and I think it might have actually have done something to the connection between the sensor and the extension from the dash, because after using it, I now see a string of dashes for oil temp regardless of whether the oil temp sensor is connected or disconnected. Before Stabilant, I was seeing -95 degrees C.

When I connect the sensor, the dash starts displaying temp as -95 deg C, then starts creeping to -99 deg C, and then dashes across the box. This was not something I saw before the Stabilant.

I'm suspecting that the oil temp sensor is pooched, which is odd, given that the thing has not been on the car for 3 months yet. Suffice to say, I'm not very impressed.

jigga009

Performed this check, and I got the same values whether it was connected or not.

The odd thing about all of this is that it seems to work only intermittently while I drive. At random times it will read -95 deg, at which time I get a "cold oil" warning, and then other times it swings the complete opposite direction, giving me my oil overtemp warning. I've had to disable the alarms relating to oil temp in RS3 in order to avoid getting distracted by the constant range of warnings while driving.

Matt Romanowski

Have you tried disconnecting the main harness from the patch cable? If so, did it behave the same? Do you have any other sensors you can put on that channel, connected to the patch cable to make sure the wiring is ok up to the sensor?

jigga009

Yes, I tried disconnecting the sensor itself under the car, as well as the patch connector at the connection to the main harness, and same thing.

I suppose I can try connecting my oil pressure sensor to that same channel to see what happens.

Edit - I spoke too soon - No, sadly I don't have any other sensors I can connect to that same patch cable to make sure the wiring is ok. I have most of the sensors on my car going to the standalone. The only other sensor going to the dash would be the fuel level and oil pressure, but switching either of those over would require some major surgery on the car, as the sensors and associated wires are hidden quite deep in the engine bay

jigga009

Slight update...

I happened to be doing some tweaking on my standalone ECU last night when I noticed the same oil temp reading on its live display of -50 Degrees C as was displayed on the dash. Thought this was very odd, given that my oil temp sensor is connected only to the dash, and not the standalone. There was no way the ECU itself could have known what the oil temp reading was. I quickly concluded that the value I was seeing on the dash had to be a default value sent from the standalone as part of its data stream. The question though, is why the dash was now displaying oil temp from the data stream, when I had always set it up to display oil temp directly from the oil temp sensor connected to the dash.

Looked in the RS3 software, and noticed that oil temperature is one of the readings that the ECU was streaming to the dash. With that said though, I did not set the dash to display this info, but instead set it up to display what it was receiving directly from the sender connected to one of the dash inputs.

Once I shut off the oil temp data part of the stream from the standalone, the dash now started displaying the correct oil temp for a few seconds after the reboot, only to start displaying negative versions of what should be the correct oil temp. So instead of an oil temp of 14 degrees C, which matches what my coolant temp is as the car sits in the garage, it displays ~ -14 degrees C. Whenever I reboot the system, it displays 14 degrees C for about 3 or 4 seconds, then quickly starts going to negative 14 C.

I tried the different calibrations for sensors, and ended up with even higher negative values, depending on which calibration was used.

The plot thickens!

Matt Romanowski

That is odd. I'm assuming you have an AiM PT-100 sensor? I've never had one do that. Just to make sure we're not running into some unit problems, do you have RS2, your logger, and RS3 all set to SI units?

jigga009

Yes, the PT-100 sensor.

Prior to this, whenever I would change the sensor calibration, there was no difference in what the dash would display, but I know why that's the case now, even though I never set up the dash to display "oil temp" from the standalone.

When this issue first cropped up, I noticed while driving that the readings would fluctuate, changing from what I was used to seeing to a negative 50, then back and forth. As if the dash was trying to decide which oil temp to display.

Checking on the last question right now....

In the settings of RS3, the temps are set to display in degrees C, as I prefer.
RS2 is set to display in km/h, degrees C and PSI. MXG is set up to display oil temp in Degrees C also.

jigga009

Spoke to Robbie at Aim's office in California, and he thinks it is either an open circuit or a major software bug. Any time there is a negative number for temperature, he says it is due to an open in the circuit.

He could not explain how it was that the dash would switch between data within a datastream and data from a sensor hooked up to the dash, as the software did not have that functionality at the moment.

His suggestions were to switch channels to one powered by a different voltage generator (channels 1 and 2 share the same voltage generator, and channels 3 and 4 share the same generator).

Next suggestion was to install a new oil temp sensor and patch cable.

And failing all of that, send everything in to them to look at and debug.

ProCoach

My money is on an open circuit...

I've had all kinds of unentered config changes with software/firmware updates... Not an issue, just need to go through it all each time.

Robbie is good people.