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Pinpoint Test D: The Tire Pressure Monitoring System (TPMS) Warning Indicator Is ON Continuously and The Message Center Display




Tire Pressure Monitoring System

Pinpoint Tests

Pinpoint Test D: The Tire Pressure Monitoring System (TPMS) Warning Indicator Is ON Continuously and The Message Center Displays LOW TIRE PRESSURE

Normal Operation

The Tire Pressure Monitor (TPM) module monitors the air pressure of all 4 road tires. The wheel-mounted tire pressure sensors transmit data via radio frequency signals to the TPM module. The TPM module is a radio receiver that collects the air pressure data from the Tire Pressure Monitoring System (TPMS) tire pressure sensors. The data is then sent to the Body Control Module (BCM) where a predetermined pass/fail criteria is applied. The TPMS sensor radio transmissions are sent approximately once every 60 seconds when the vehicle speed exceeds 32 km/h (20 mph). The BCM compares each TPMS sensor transmission against a low-pressure limit. If it has been determined that the tire pressure has fallen below this limit, the BCM communicates this on the vehicle communication bus to the Instrument Panel Cluster (IPC). The IPC then illuminates the TPMS warning indicator and displays the appropriate message(s) in the message center .

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 may result. 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:
- Spare tire currently in use
- Tire pressure not set to specifications listed on the Vehicle Certification (VC) label
- TPMS sensors not trained following tire rotation
- TPMS sensor(s)

PINPOINT TEST D: THE TPMS WARNING INDICATOR IS ON CONTINUOUSLY AND THE MESSAGE CENTER DISPLAYS LOW TIRE PRESSURE

NOTE: Use only the Digital Tire Pressure 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 FOR LOW TIRE PRESSURE

- Using the Digital Tire Pressure Gauge, measure and record the air pressure in all 4 tires.
- Adjust the pressure for those found to be below the specification listed on the VC label.
- Activate each sensor at least twice with the training tool or customer activation tool to make sure the TPM module gets the latest air pressure data. Refer to Tire Pressure Monitoring System (TPMS) Sensor Activation Tire Pressure Monitoring System (TPMS) Sensor Activation or drive the vehicle for at least 2 minutes above 32 km/h (20 mph) to clear the low pressure warning. Do not train the sensors at this time.
- Has the TPMS warning indicator gone out?

Yes
The system is operating correctly at this time. The concern was caused by low tire pressure.

No
GO to D2.

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D2 CHECK FOR SPARE TIRE IN USE

NOTE: The spare tire is not programmable even if it is equipped with a TPMS sensor. If a damaged road wheel is located in the trunk, the sensor may still be recognized by the TPMS as low. Make sure the spare tire is not currently in use. To restore TPMS functionality, repair the damaged road wheel and re-mount it to the vehicle.

- Check spare tire location.
- Is the spare tire in use?

Yes
REPAIR and REMOUNT the wheel to the vehicle. REFER to Wheel and Tire Overhaul. ADJUST tire pressures to the required pressure as defined on the VC label located in the driver door jam.

No
GO to D3.

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D3 CHECK IF THE TIRES WERE ROTATED WITHOUT TPMS SENSOR TRAINING

NOTE: If the TPMS sensors at the front of the vehicle are still trained in the rear positions but inflated to the front air pressures, the TPMS warning indicator illuminates continuously.

- Ignition ON.
- Enter the following diagnostic mode on the scan tool: BCM DataLogger.
- Monitor and record the following BCM PIDs:
- Left Front Tire Pressure (TPM_PRES_LF)
- Right Front Tire Pressure (TPM_PRES_RF)
- Left Rear Tire Pressure (TPM_PRES_LRO)
- Right Rear Tire Pressure (TPM_PRES_RRO)
- Do the rear PIDs show front air pressures and the front PIDs show rear air pressures?

Yes
The tires have been rotated without training the sensors. TRAIN the sensors. REFER to Tire Pressure Monitoring System (TPMS) Sensor Training Tire Pressure Monitoring System (TPMS) Sensor Training.

No
GO to D4.

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D4 CHECK FOR STUCK TPMS SENSOR

- Monitor and record the following BCM PIDs:
- Left Front Tire Pressure (TPM_PRES_LF)
- Right Front Tire Pressure (TPM_PRES_RF)
- Left Rear Tire Pressure (TPM_PRES_LRO)
- Right Rear Tire Pressure (TPM_PRES_RRO)
- Using the Digital Tire Pressure Gauge, measure the actual tire pressures.
- Compare the air pressure PIDs with the actual air pressures.
- Do the compared tire pressure values match within ± 5 psi?

Yes
REFER to Instrumentation, Message Center, and Warning Chimes Testing and Inspection to diagnose the TPMS warning indicator is always on.

No
INSTALL a new TPMS sensor(s) for the sensor(s) in question. REFER to Tire Pressure Monitoring System (TPMS) Sensor Service and Repair.

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