Speed sensor

[Doctor T]

I've replaced the rear speed/ASC sensor on my '07. An easy job, once i tracked the wiring, but now my speed reading is way out. With the old sensor, it was only 2-3 mph low. Now it's 8 mph low. At 70 mph, my GPS states 62 mph. Is there any way to correct the reading?. The part fitted is a genuine BMW part.

[David.]

What is the RT's production date and speed sensor part number.

[Glenn]

Enter the last 7 of your VIN and select the rear brake section https://www.realoem.com/bmw/enUS/select ... d=20070500

[Doctor T]

I checked REM, and two other places gave me the same part numbers. (Normans and BMW) The part number on the old one is the same as the new one. Can it be calibrated with a GS 9-11?

[Doctor T]

I've found out the problem. Instead of using my normal airman to pump the tyre up, I used the local fuel station. My normal pressures are F36 and R42 psi. Checking my tyres yesterday before i rode out, i found the front to be 45 psi and the rear at 54 psi. This explains why the ride felt hard and choppy, and riding around corners was a nightmare. Now the tyres are back to normal, the speedo compared to the GPS is back to the 2/3 mph low reading.
I reported this to the petrol station that their air line is out. I also said this could be dangerous. All i got was a shug of shoulders.
Today i popping in to fill up the car, i noticed there is an out of use sign.