Pinpoint Tests AC: The Tire Pressure Monitoring System (TPMS) Warning Indicator Is Never/Always On
Instrumentation, Message Center and Warning Chimes
Pinpoint Tests
Pinpoint Test AC: 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 limits, a message is sent to the IC to turn on the TPMS warning indicator. 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 or deemed invalid by the IC for more than 5 seconds, the IC sets DTC U0140 and flashes the TPMS indicator for 60 seconds then turns the indicator on.
NOTE: If DTC U0140 is set in the IC, 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 AC: THE TPMS WARNING INDICATOR IS NEVER/ALWAYS ON
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AC1 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 Identification Codes.
- Do all the tires meet the recommended tire pressures?
Yes
GO to AC2.
No
CORRECT the tire pressures. TEST the system for normal operation.
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AC2 CHECK FOR MESSAGE CENTER TPMS WARNING MESSAGES
- Ignition ON.
- Monitor the message center for TPMS related warning messages.
- Are any TPMS warning messages displayed in the message center?
Yes
REFER to Wheels and Tires.
No
GO to AC3.
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AC3 CARRY OUT THE IC INDICATOR LAMP CONTROL ACTIVE COMMAND USING THE SCAN TOOL
- Enter the following diagnostic mode on the scan tool: IC DataLogger.
- Select the IC TPMS warning indicator (TPM_IND) active command and 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 AC4.
No
INSTALL a new IC. REFER to Instrument Cluster (IC) Instrument Cluster (IC). TEST the system for normal operation.
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AC4 RETRIEVE THE RECORDED DTCs FROM THE IC SELF-TEST
- Check for recorded IC DTCs from the self-test.
- Is DTC U0140 recorded?
Yes
GO to Pinpoint Test AX. Pinpoint Tests AX: DTC U0140
No
GO to AC5.
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AC5 RETRIEVE THE RECORDED DTCs FROM THE SJB SELF-TEST
- Check for recorded SJB DTCs from the self-test.
- Are any SJB DTCs recorded?
Yes
REFER to Body Control Systems.
No
If the TPMS warning indicator is never on, the system is operating correctly at this time.
If the TPMS warning indicator is always on, INSTALL a new SJB. REFER to Body Control Systems. TEST the system for normal operation.
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