GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2004 🢒 Tracker - 4WD 🢒 DTC 🢒 DTC P0453

Circuit Description

The DTC P0453 Fuel Tank Pressure (FTP) Sensor Circuit High Voltage diagnostic monitors the function of the FTP sensor circuit. Emission laws require that the powertrain control module (PCM) detect any leakage within the EVAP system. The PCM tests the EVAP system for leaks by monitoring the vapor pressures in the fuel tank with the FTP sensor. The FTP sensor contains a silicon based chip that changes electrical resistance when pressure is applied. The PCM supplies a 5-volt reference, an electrical ground, and a signal return circuit that has a 5-volt bias. The FTP sensor signal voltage varies from a minimum of about 0.2 volts with negative pressure in the fuel tank, to a maximum of more than 4 volts with positive pressure in the fuel tank.

Fuel Tank Vapor Space

FTP mm Hg

FTP Signal Voltage

Pressure

Positive Value

High

No Pressure

Near Zero

2.5-2.6 V

Vacuum

Negative Value

Low

Conditions for Running the DTC
    • The engine coolant temperature is -8 to +110°C (18-230°F).
    • The intake air temperature is -14 to +70°C (7-158°F).
    • The engine has been running at idle for at least 2 minutes.

Conditions for Setting the DTC

The fuel tank pressure is higher than 49.5 mm Hg (-26.5 in H2O).

OR

The fuel tank pressure sensor signal voltage is greater than 4.5 volts.

Action Taken When the DTC Sets
    • The PCM illuminates the malfunction indicator lamp (MIL) after 2 consecutive ignition cycles in which the diagnostic runs with the fault active.
    • The PCM records the operating conditions at the time the diagnostic fails. This information is stored in the Freeze Frame buffer.

Conditions for Clearing the MIL/DTC
    • The MIL turns OFF after 3 consecutively passing trips without a fault present.
    • A history DTC clears after 40 consecutive warm-up cycles without a fault.
    • Perform the scan tool Clear DTC Information function in order to clear the DTC.

Test Description

The numbers below refer to the step numbers in the diagnostic table.

  1. The Diagnostic System Check-Engine Controls prompts the technician to complete some basic checks and store the Freeze Frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.

    2.

  2. If a DTC P0123 is also set there is a fault in the sensor ground circuit or the PCM.

    3.

  3. If a DTC P2027 is also set there is a fault in the sensor ground circuit or the sensor.

    4.

  4. The FTP sensor reading indicated on the scan tool will vary with the surrounding barometric pressure.

    5.

  5. The voltage measured with the DMM will vary with the surrounding barometric pressure.

    6.

  6. Clearing the DTCs by removing the DOME fuse also clears the PCM long term memory. Using the scan tool to clear DTCs leaves the long term memory active. DTC emitting diagnostics may not run to completion as expected unless the long term memory is cleared. Removal of the DOME fuse also clears the time display of the radio. The DTC P0453 diagnostic can be monitored on the scan tool under the Not Ran Since Code Cleared selection in the DTC Information menu. If DTC P0453 appears in the Not Ran Since Code Cleared list, the P0453 diagnostic has not yet run. When DTC P0453 does not appear in the Not Ran Since Code Cleared list, the P0453 diagnostic has run. If the MIL is NOT illuminated and there is no Pending DTC Status in DTC Information, the P0453 diagnostic has passed. The DTCs MUST be cleared in order to view the Current Status of the Not Ran Since Code Cleared list. The DTC Information screen must be checked for Current or Pending status in order to determine the outcome of the diagnostic test involved.

Step

Action

Value(s)

Yes

No

Schematic Reference: Engine Controls Schematics

1

Did you perform the Diagnostic System Check-Engine Controls?

--

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2

Is a DTC P0123 also set?

--

Go to Step 8

Go to Step 3

3

Is a DTC P2027 also set?

--

Go to Step 9

Go to Step 4

4

  1. Turn OFF the ignition.
  2. Remove the fuel filler cap.
  3. Turn ON the ignition, with the engine OFF.
  4. Select the FTP sensor parameter on the scan tool.

Is the pressure within the specified range?

0.0-0.9 mm Hg (0.0-0.5 in. H2O)

Go to Step 5

Go to Step 6

5
  1. Turn OFF the ignition.
  2. Remove the DOME fuse for 30 seconds.
  3. Install the DOME fuse.
  4. Reset the radio clock time. Refer to Radio/Audio System Description and Operation in Entertainment.
  5. Start the engine.
  6. Operate the vehicle within the Freeze Frame conditions that set the DTC or until the P0453 diagnostic test has run. Refer to the test description.

Does the DTC run and pass?

--

Go to Intermittent Conditions

Go to Step 6

6

  1. Turn OFF the ignition.
  2. Remove the fuel filler cap.
  3. Backprobe the FTP sensor input circuit at the PCM with a DMM connected to ground.
  4. Turn ON the ignition, with the engine OFF.
  5. Measure the voltage with the DMM set to the DC scale.

Is the voltage within the specified range?

2.5-2.6 V

Go to Step 11

Go to Step 7

7
  1. Test the FTP sensor input circuit for a short to voltage.
  2. Repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct a condition?

--

Go to Step 13

Go to Step 12

8
  1. Test for an open or high resistance in the FTP sensor ground circuit from S106 to the PCM. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
  2. Repair as necessary. Wiring Repairs and Connector Repairs in Wiring Systems.

Did you find and correct a condition?

--

Go to Step 13

Go to Step 10

9
  1. Test the FTP sensor ground circuit from S106 to the sensor for the following conditions:
    2. • An open circuit
    • High resistance
    • A poor electrical connection at the sensor--Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
  2. Repair as necessary. Wiring Repairs and Connector Repairs in Wiring Systems.

Did you find and correct a condition?

--

Go to Step 13

Go to Step 12

10
  1. Inspect the PCM electrical connectors for faulty terminal contact. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
  2. Repair as necessary. Refer to Wiring Repairs and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 11

11

Important: The replacement PCM must be programmed.

Replace the PCM. Refer to Powertrain Control Module Replacement .

Did you complete the replacement?

--

Go to Step 13

--

12

Replace the FTP sensor. Refer to Fuel Tank Pressure Sensor Replacement .

Did you complete the replacement?

--

Go to Step 13

--

13

  1. Turn OFF the ignition.
  2. Remove the DOME fuse for 30 seconds.
  3. Install the DOME fuse.
  4. Reset the radio clock time. Refer to Radio/Audio System Description and Operation in Entertainment.
  5. Start the engine.
  6. Operate the vehicle within the Freeze Frame conditions that set the DTC or until the P0453 diagnostic test has run. Refer to the test description.

Does the DTC run and pass?

--

Go to Step 14

Go to Step 2

14

With a scan tool, observe the stored information, Capture Info.

Does the scan tool display any DTCs that you have not diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List

System OK