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

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

Normal Operation
The instrument cluster (IC) receives the tire pressure monitoring system (TPMS) messages from the smart junction box (SJB) over the medium speed controller area network (MS-CAN) communication bus. If the SJB determines that the tire pressure has exceeded the low tire pressure limits, a message is sent to the instrument cluster (IC) to turn the TPMS warning indicator on. If a TPMS fault condition exists or if the TPMS is in the tire training mode, the SJB sends a message to the instrument cluster (IC) to flash the TPMS warning indicator. If the TPMS status message is missing or invalid for less than 5 seconds, the instrument cluster (IC) defaults the TPMS warning indicator to the last setting (on or off), based upon the last known good message received. 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 75 seconds then turns on the indicator steady. If the TPMS status message is invalid for more than 5 seconds, the instrument cluster (IC) sets DTC U2023 and flashes the TPMS indicator for approximately 75 seconds then turns on the indicator steady.

NOTE: If DTC U0140 is set in the SJB, other symptoms may also be present such as high beam indicator, RH/LH turn indicators, instrument panel backlighting, and door ajar indication.

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

Z1-Z2:

Z2-Z6: