Pinpoint Test N: The Tire Pressure Monitoring System (TPMS) Warning Indicator Is Never/Always On
Instrumentation, Message Center and Warning Chimes
Pinpoint Tests
Pinpoint Test N: 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 IC to turn the TPMS warning indicator on. If a TPMS fault condition exists, the SJB sends a message to the IC to flash the TPMS warning indicator. If the TPMS status message is missing for less than 5 seconds, the 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 IC sets DTC U0140 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
- IC
PINPOINT TEST N: THE TPMS WARNING INDICATOR IS NEVER/ALWAYS ON
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N1 CHECK THE TIRE PRESSURE
- Verify that the tire pressure in all tires meets the recommended tire pressures on the vehicle certification label. Refer to Vehicle/Application and ID.
- Do all the tires meet the recommended tire pressures?
Yes
GO to N2.
No
CORRECT the tire pressures. TEST the system for normal operation.
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N2 CARRY OUT THE IC INDICATOR LAMP CONTROL ACTIVE COMMAND USING THE SCAN TOOL
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: IC DataLogger.
- Select the IC TPMS warning indicator (TPM_IND) active command. Command the TPMS warning indicator on and off. Observe the TPMS warning indicator.
- Does the TPMS warning indicator illuminate when commanded on and turn off when commanded off?
Yes
GO to N3.
No
INSTALL a new IC. REFER to Instrument Cluster (IC) Instrument Cluster (IC). TEST the system for normal operation.
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N3 RETRIEVE THE RECORDED DTCs FROM THE IC SELF-TEST
- Check for recorded continuous memory IC DTCs.
- Are any DTCs recorded?
Yes
For DTC U1901, REFER to Information Bus to diagnose communication with the SJB.
For all other DTCs, REFER to DTC Charts. [1][2]Diagnostic Trouble Code Descriptions
No
GO to N4.
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N4 RETRIEVE THE RECORDED DTCs FROM THE SJB SELF-TEST
- Check for recorded SJB DTCs from the self-test.
- Are any TPMS DTCs recorded?
Yes
REFER to Wheels and Tires. Testing and Inspection
No
INSTALL a new SJB. REFER to Body Control Systems. TEST the system for normal operation.
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