Inaccurate outside temp reading
Thread Starter
Member
Joined: Jun 2012
Posts: 81
Likes: 2
2000 E320
Inaccurate outside temp reading
Hi, my outside temp reading is off by about 11 degrees. The car is a USA model 300D with a display from a 89 300E CDN car. Not sure if that would be the issue or not. I will assume that the probes are the same and the displays different but I don’t know for certain. The display itself works properly and is clear and steady just wrong numbers. It will fluctuate with temp but again wrong reading. Would it be the probe?
MBWorld Fanatic!
Joined: Mar 2016
Posts: 1,369
Likes: 195
From: SF Bay Area, CA
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
Most likely the probe. Mine went bad after about 28 years. Started reading high by 10-20 degrees F, then eventually it got progressively worse until the gauge maxed out at ~136F.
I think at 136F or so the gauge either goes blank or puts out "---". I could be wrong about the 136F and could be a bit lower.
After that I had nothing to loose so I spliced in a used sensor from a junk yard. Has been working great for the last 5 years.
Did not want to deal with replacing the whole harness as the routing is a bit tricky and a lot of work.
I believe the temp sensor is standard for all models in the period. Not only that as far as I know all the sensors (thermistors) for the model years have the same temp versus resistance spec.
This includes, coolant temp sensor, aux fan switch, intake air temp, outside air temp, etc, etc.
I think at 136F or so the gauge either goes blank or puts out "---". I could be wrong about the 136F and could be a bit lower.
After that I had nothing to loose so I spliced in a used sensor from a junk yard. Has been working great for the last 5 years.
Did not want to deal with replacing the whole harness as the routing is a bit tricky and a lot of work.
I believe the temp sensor is standard for all models in the period. Not only that as far as I know all the sensors (thermistors) for the model years have the same temp versus resistance spec.
This includes, coolant temp sensor, aux fan switch, intake air temp, outside air temp, etc, etc.
