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:

- TPMS concern
- SJB
- IC
- Tire pressure



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/Application and ID.
- 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 Tire Monitoring System. Tire Monitoring System

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 AV. Pinpoint Tests AV: DTC U0121

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
INSTALL a new SJB. TEST the system for normal operation.

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