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Home >> Mercury >> 2009 >> Grand Marquis V8-4.6L Flex Fuel >> Repair and Diagnosis >> Instrument Panel, Gauges and Warning Indicators >> Tire Monitoring System >> Testing and Inspection >> Pinpoint Tests >> Pinpoint Test D: Tire Pressure Monitoring System (TPMS) Indicator On Solid When The Ignition Key Is Turned To The On Position A

Pinpoint Test D: Tire Pressure Monitoring System (TPMS) Indicator On Solid When The Ignition Key Is Turned To The On Position A




Tire Pressure Monitoring System

Pinpoint Tests

Pinpoint Test D: Tire Pressure Monitoring System (TPMS) Indicator ON Solid When the Ignition Key is Turned to the ON Position 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 Driver Door Module (DDM). TPMS functionality is integral to the DDM. These transmissions are sent approximately every 60 seconds when the vehicle speed exceeds 32 km/h (20 mph). The TPMS function (integral to the DDM) 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 DDM communicates this on the vehicle communication bus to the instrument cluster. The instrument cluster then illuminates the TPMS indicator and displays the appropriate message(s) in the message center (if equipped).

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



PINPOINT TEST D: TIRE PRESSURE MONITORING SYSTEM (TPMS) INDICATOR ON SOLID WHEN THE IGNITION KEY IS TURNED TO THE ON POSITION AND MESSAGE CENTER (IF EQUIPPED) DISPLAYS LOW TIRE PRESSURE

NOTE: Use only a 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.

NOTE: A full-sized, matching spare wheel and tire, that is identical to the road wheel and tire, is available as an optional accessory. This spare wheel and tire is equipped with a tire pressure sensor, but the sensor is not initially programmed to the DDM. If this spare wheel and tire is in use on the vehicle, the sensor must be trained to the DDM and the remaining 3 sensors must be retrained to the DDM as well. If all 4 sensors are not trained to the DDM, the TPMS warning indicator will illuminate. Make sure that all the wheels and tires installed on the vehicle are inflated to the correct pressure and trained to the DDM before attempting to diagnose a TPMS concern. Refer to Tire Pressure Monitoring System (TPMS) Sensor Training Programming and Relearning.

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D1 CHECK THE TIRE PRESSURE


- 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 the TPMS sensors. Refer to Tire Pressure Monitoring System (TPMS) Sensor Activation Programming and Relearning. TPMS sensors do 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 DDM.
- Read and record the following PIDs:
- Left front tire pressure (LF_PSI)
- Right front tire pressure (RF_PSI)
- Left rear tire pressure (LR_PSI)
- Right rear tire pressure (RR_PSI)
- Compare the air pressure readings recorded from the function test to those recorded in E1.
- Do the compared tire pressure values match within ±34.47 kPa (±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 special 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 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 Tire Pressure Monitoring System (TPMS) Sensor.

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