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A. Penland
A. Penland, Ford Senior Master Technician, ASE
Category: Mercury
Satisfied Customers: 6386
Experience:  ASE Master Certified. ASE Gasoline Engine Performance Certified,Ford Senior Master Technician
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how do i repair trouble code P0453 Evaporative Emission Control

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how do i repair trouble code P0453 Evaporative Emission Control System Pressure Sensor High input on my 1999 mercury grand marquis

HelloCustomer

Do you have access to a scan tool that can monitor PID DATA? The pinpoint test is a bit long.

P0453 - FTP Sensor Circuit High Voltage Detected The PCM monitors the EVAP control system FTP sensor input signal to the PCM. The test fails when the signal average jumps above a minimum allowable calibrated parameter.
  • FTP circuit open
  • VREF shorted to VPWR
  • Damaged PCM
  • FTP circuit shorted to VREF or VPWR
  • SIG RTN circuit open
  • Damaged FTP sensor
FTP V PID reading greater than 4.50 volts with key ON and engine OFF or during any engine operating mode indicates a hard fault.

Customer: replied 7 years ago.
yes..i have one..but im not sure about it monitoring pid data...if it helps any- the car runs fine at a stand still but soon as i start driving and accelerate, the car bogs down as if i blew a ignition coil

Yes, here is the pinpoint test to follow.\

HX33 DTC P0453: CHECK FOR HIGH FTP SENSOR VOLTAGE

    Note: FTP sensor input with no pressure/vacuum on the fuel tank (fuel filler cap open or not open to atmosphere) is 2.37 to 2.97 volts.

  • Connect scan tool.
  • Key on, engine off.
  • Access FTP V PID.
  • If FTP V PID is not present on the scan tool, measure voltage between FTP and SIG RTN circuits at the PCM harness connector with PCM connected.

Is measured voltage or FTP V PID reading greater than 4.50 volts?

Yes No
KEY OFF. GO to HX34 . The fault that produced DTC P0453 is intermittent. GO to Pinpoint Test Step Z1 .

HX34 CHECK FTP CIRCUIT FOR SHORT TO POWER

  • Disconnect FTP sensor.
  • Key on, engine off.
  • Measure voltage between FTP circuit at the FTP sensor harness connector and battery negative post.

Is the voltage greater than 10.5 volts?

Yes No
KEY OFF. The FTP is indicating a short to VPWR. GO to HX35 . KEY OFF. GO to HX36 .

HX35 CHECK FTP CIRCUIT FOR SHORT TO VPWR IN HARNESS

    Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.

  • Disconnect PCM.
  • Key on, engine off.
  • Measure the voltage between FTP circuit at the PCM harness connector and battery negative post.

Is voltage greater than 10.5 volts?

Yes No
REPAIR short circuit. REPLACE PCM. (Refer to Section 2 , Flash EEPROM.)

HX36 CHECK OPPOSITE INDUCED LOW FTP SIGNAL

  • Connect a jumper wire between SIG RTN and FTP circuits at the FTP sensor harness connector.
  • Key on, engine off.
  • If a scan tool communication concern exists, turn the key off, remove jumper immediately and go directly to HX41 .
  • Access FTP V PID.
  • If FTP V PID is not present on the scan tool, measure voltage between FTP and SIG RTN circuits at the PCM harness connector with PCM connected.

Is measured voltage or FTP V PID reading less than 0.10 volt?

Yes No
REMOVE jumper. GO to HX37 . Unable to induce opposite signal. KEY OFF. GO to HX39 .

HX37 CHECK FOR IN RANGE VOLTAGE BETWEEN VREF AND SIG RTN CIRCUITS AT FTP SENSOR

  • Key on, engine off.
  • Measure voltage between VREF and SIG RTN circuits at the FTP sensor vehicle harness connector.

Is voltage between 4.0 and 6.0 volts?

Yes No
KEY OFF. GO to HX38 . VREF voltage is out of range. GO to Pinpoint Test Step C1 .

HX38 CHECK FTP CIRCUIT FOR SHORT TO VREF IN SENSOR OR HARNESS

    Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.

  • Disconnect PCM.
  • Measure resistance between FTP and VREF circuits at the PCM harness connector. (For LS6/LS8 measure to both VREF pins.)

Is the resistance greater than 10,000 ohms?

Yes No
REPLACE FTP sensor. REFER to Evaporative Emissions, Section 303-13 in the Workshop Manual for component removal and installation. RESTORE vehicle. FOLLOW the Vehicle Preparation for Monitor Repair Verification Drive Cycle and COMPLETE an Evaporative Emission Running Loss Monitor Repair Verification Drive Cycle (refer to Section 2 , Drive Cycles). REPAIR short circuit.

HX39 CHECK FTP CIRCUIT FOR OPEN IN HARNESS

    Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.

  • Disconnect PCM.
  • Measure resistance of FTP circuit between PCM harness connector pin and FTP sensor harness connector.

Is resistance less than 5.0 ohms?

Yes No
GO to HX40 . REPAIR open circuit.

HX40 CHECK FOR OPEN SIG RTN CIRCUIT BETWEEN PCM AND FTP SENSOR

  • Measure resistance of SIG RTN circuit between PCM harness connector pin and FTP sensor harness connector.

Is resistance less than 5.0 ohms?

Yes No
GO to HX41 . REPAIR open circuit.

HX41 CHECK FTP CIRCUIT FOR SHORT TO VREF IN PCM

  • PCM disconnected.
  • Measure resistance between FTP and VREF circuits at the PCM harness connector. (For LS6/LS8 measure to both VREF pins.)

Is the resistance greater than 10,000?

Yes No
REPLACE PCM (refer to Section 2 , Flash EEPROM). REPAIR short circuit.

 

 

 

If you need anything more, just ask on this post.

Customer: replied 7 years ago.
is there any common sensors, connections..etc that can be defaulty

It may be just the sensor, but it helps to make sure. The sensor is on top of the tank and you will have to remove the tank. But your symptoms are pointing to more than just the sensor. You may have wiring problems. The pin point test will lead you to the right place of the problem.

 

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