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Pinpoint Test D: Tire Pressure System (TPMS) Indicator ON Solid and Message Center (If Equipped) Displays LOW TIRE PRESSURE




Tire Pressure Monitoring System

Pinpoint Tests

Pinpoint Test D: Tire Pressure Monitoring System (TPMS) Indicator ON Solid and Message Center (if equipped) Displays LOW TIRE PRESSURE

Normal Operation

The Tire Pressure Monitoring System (TPMS) monitors the air pressure of all 4 road tires. The wheel-mounted tire pressure sensors transmit via radio frequency signals, to the Smart Junction Box (SJB). TPMS functionality is integral to the SJB. These transmissions are sent approximately every 60 seconds when the vehicle speed exceeds 32 km/h (20 mph). The TPMS function (integral to the SJB) compares each tire pressure sensor transmission against a low-pressure limit. If it has been determined that the tire pressure has fallen below this limit, the SJB communicates this on the vehicle communication bus to the Instrument Cluster (IC). The IC then illuminates the TPMS indicator and displays the appropriate message(s) in the message center (if equipped).

This symptom can also be caused by a spare tire currently being used in place of a road tire. Make sure that the spare tire is not currently in use. On vehicles with different front and rear tire pressures, if the sensors are not trained following a tire rotation, this symptom will also be present. Advise the customer that on vehicles with different front and rear tire pressures, the sensors must be trained as directed in the Owner's Literature.

This pinpoint test is intended to diagnose the following:
- Low air pressure in tire(s)
- Tire pressure sensor(s)



PINPOINT TEST D: TPMS INDICATOR ON SOLID AND MESSAGE CENTER (IF EQUIPPED) DISPLAYS LOW TIRE PRESSURE

NOTE: Use only the Digital Tire Gauge any time tire pressures are measured to be sure that accurate values are obtained.

NOTE: If a warranty case is opened for an actual TPMS fault, document and include the actual tire pressure data in all warranty communications.

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D1 CHECK THE TIRE PRESSURE


- Using the Digital Tire Gauge, measure and record the air pressure in all 4 road tires.
- Adjust the air pressure for those found to be below the specification listed on the Vehicle Certification (VC) label.
- NOTE: If the vehicle has been stationary for more than 30 minutes, activate each TPMS sensor. Refer to Tire Pressure Monitoring System (TPMS) Sensor Activation Programming and Relearning. The TPMS sensor does not transmit when the vehicle is stationary.
- Verify system operation.
- Have the TPMS indicator and the message center (if equipped) warnings gone out?

Yes
The system is functioning normally, diagnosis is complete. INFORM the customer of correct tire pressure maintenance as instructed in the scheduled maintenance guide and the Owner's Literature.

No
GO to D2.

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D2 CHECK THE SYSTEM COMPONENTS


- Train all 4 tire pressure sensors. Refer to Tire Pressure Monitoring System (TPMS) Sensor Training Programming and Relearning.
- Connect the scan tool.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger SJB.
- Read and record the following PIDs:
- Left Front Tire Pressure (LF_PRES)
- Right Front Tire Pressure (RF_PRES)
- Left Rear Outer Tire Pressure (LRO_PRES)
- Right Rear Outer Tire Pressure (RRO_PRES)
- Compare the air pressure readings recorded from the function test to those recorded in D1.
- Do the compared tire pressure values match within ±5 psi, and have the TPMS indicator and the message center (if equipped) warnings gone out?

Yes
The system is functioning normally, diagnosis complete.

No
Before installing a new sensor(s): If a sensor(s) does not respond to the Tire Pressure Monitor Activation Tool, ATTEMPT to activate the same sensor(s) with the Tire Pressure Monitor Activation Tool. If the sensor(s) still does not respond, MOVE the vehicle to rotate the wheels at least one-fourth of a turn and ATTEMPT to activate the same sensor(s) again.

INSTALL new tire pressure sensors for those with discrepancies or those that fail to activate. REFER to Tire Pressure Monitoring System (TPMS) Sensor Service and Repair.

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