TPMS Tip of the Month

RELEARNS FOR MERCEDED VEHICLES WITH TPMS IN SPARE TIRE

Description:

  1. Are you trying to Relearn in NEW sensor IDS (using the Auto-learn process) and the TPMS Malfunction Indicator Lamp (MIL) will not go off?
  2. Does the vehicle have a TPMS sensor in the Spare Tire?
  3. If there is a sensor in the spare tire and the sensor shows signs of ware (corrosion, etc. - does not look new) then it is likely the spare was mounted as a drive tire.
  4. If this is the case, the ONLY way to complete the relearn is with a properly formatted scan tool as the Sensor IDS have to be hard coded to the vehicle using the Star C3 shown below.

Scenarios if not done properly:  
  • TPMS Malfunction Indicator Lamp (MIL) will not go off as the Spare Tire ID cannot be learned in using the Auto-Learn method - MIL will always be on.
  • Technician could replace perfectly working sensors assuming they are not working since the MIL is not going off.

Improper service will result in dissatisfied customers as well as the risk in leaving the vehicles TPMS system inoperative.

Proper system understanding and diagnostics are critical with these vehicles to prevent wasted time, sensors, and money.

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TPMS TIP OF THE MONTH ARCHIVES

Proper Assembly of a Schrader Sensor to the Rubber Valve Stem