Test U: The Tire Pressure Monitoring System (TPMS) Warning Indicator Is Never/Always On

PINPOINT TEST U: THE TIRE PRESSURE MONITORING SYSTEM (TPMS) WARNING INDICATOR IS NEVER/ALWAYS ON

Normal Operation
Each road tire is equipped with a tire pressure sensor fastened to the inside rim of the wheel. The pressure sensor is covered by the tire and is not visible unless the tire is removed. The pressure sensor is located opposite (180 degrees) from the valve stem. The tire-mounted pressure sensors transmit signals to the SJB by using the valve stem as an antenna. These signals are sent approximately every 60 seconds when the vehicle speed exceeds 32 km/h (20 mph). The SJB compares each tire pressure sensor signal against low and high pressure limits. If the SJB determines that the tire pressure has exceeded the limit, the SJB communicates over the medium speed controller area network (MS-CAN) to the instrument cluster (IC), which then illuminates the TPMS warning indicator. If the TPMS status message is missing for more than 5 seconds, the instrument cluster (IC) sets DTC U0140 and flashes the TPMS indicator for approximately 70 seconds then turns on the TPMS indicator.

This pinpoint test is intended to diagnose the following:
- TPMS concern
- SJB
- Instrument cluster (IC).

U1-U3:

U4-U5: