Non-OEM Equipment

The following equipment has been found to sometimes cause RFI  :

• Video equipment has been found to cause RFI  especially when the video and power supply lines are near the TPMS  .
• Car alarms (even those installed by dealerships) have been found to create enough RFI  to cause the TPMS  to malfunction or lose considerable range. These car alarms can sometimes be difficult to locate, as they are usually hidden somewhere out of the way for reduced accessibility.
• Many different in-vehicle cell phone chargers have been found to cause considerable RFI  . The vehicles with the power point closest to the TPM  module are the most affected. It must be noted that most cell phone chargers do not produce high levels of RFI  all the time. This depends on the state of charge of the cell phone battery. The phone must be almost completely discharged in some cases.
• Power supplies and DC/AC inverters typically create a lot of RFI  . Most consumer grade equipment has very little filtering or shielding.