GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Isuzu 🢒 2000 🢒 S/T Isuzu - 4WD 🢒 Engine 🢒 Engine Controls - 2.2L 🢒 DTC P0453 Fuel Tank Pressure Sensor Circuit High Voltage

Refer to

Fuel Level and Fuel Tank Pressure Sensors


Object Number: 538537 Size: FS
Engine Controls Components
Information Sensors/Switches Description
Fuel Injectors and Fuel Pump
Ignition Controls
OBD II Symbol Description Notice
Powertrain Control Module Connector End Views
Handling ESD Sensitive Parts Notice
SP201 (2.2L)
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The fuel tank pressure (FTP) sensor is used in order to detect a vacuum decay or an excessive vacuum during the evaporative emission (EVAP) diagnostic routine. The fuel tank pressure sensor responds to the changes in the fuel tank pressure or vacuum. The signal voltage to the powertrain control module (PCM) varies from a minimum of about 0.2 volts with pressure in the fuel tank to above 4.0 volts with a high vacuum in the fuel tank.

The fuel tank pressure display on the scan tool has an auto zero feature which occurs at each ignition cycle and is corrected according to the barometric pressure. Because of this, the fuel tank pressure may not accurately reflect the actual output of the sensor or the conditions within the fuel tank.

Conditions for Running the DTC

The engine is running.

Conditions For Setting the DTC

The fuel tank pressure sensor voltage is more than 4.9 volts for more than 25 seconds.

Action Taken When the DTC Sets
    • The malfunction indicator lamp (MIL) will illuminate.
    • The PCM will record the operating conditions at the time that the diagnostic fails. The Freeze Frame and Failure Records buffers will store this information.
    • A history DTC stores.

Conditions for Clearing the MIL/DTC
    • The MIL will turn OFF after 3 consecutive ignition cycles in which the diagnostic runs without a fault.
    • A history DTC will clear after 40 consecutive warm up cycles without a fault.
    • Use a scan tool to clear the DTCs.

Diagnostic Aids

Inspect for the following conditions:

    • Inspect the control module harness connectors for the following conditions:
       - Improper mating
       - Broken locks
       - Improperly formed
       - Damaged terminals
    • Inspect the wiring harness for damage. If the harness appears to be OK, observe the fuel tank vacuum display on the scan tool while moving the connectors and the wiring harnesses related to the sensor. A change in the display will indicate the location of the fault.

Refer to Evaporative Emission System Cleaning before starting repairs.

Test Description

Numbers below refer to the step numbers on the diagnostic table:

  1. This step will determine if DTC P0453 is the result of a hard malfunction or an intermittent condition.

    2.

  2. This step simulates conditions for a DTC P0452. If the PCM recognizes the change, that indicates that the following items are OK:

    3. • PCM
    • Fuel tank pressure sensor 5.0 volt reference circuit
    • Fuel tank pressure sensor signal circuit

  3. This step tests for an open in the fuel tank pressure sensor ground circuit.

    4.

  4. When the fuel tank pressure sensor signal circuit is shorted to battery voltage, The vehicle will remain in Open Loop, the TP sensor value will read above 0 percent at all times and the A/C high side value will read high on the scan tool.

    5.

  5. Disconnect all the sensors that use the same 5.0 volt reference circuit one at a time while monitoring the 5.0 volt reference circuit on the scan tool. Test and repair any circuit, or replace any sensor, that changes the scan tool reading of the 5.0 volt reference circuit.

    6.

  6. The replacement PCM must be programmed and the Crankshaft Position System Variation Learn procedure must be performed.

Step

Action

Values

Yes

No

1

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2
  1. Disconnect the fuel tank vapor line from the EVAP canister.
  2. Turn ON the ignition, with the engine OFF.
  3. With the scan tool, observe the fuel tank pressure sensor voltage.

Does the fuel tank pressure sensor voltage read more than the specified value?

3.0 V

Go to Step 4

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Reconnect the fuel tank vapor line to the EVAP canister.
  3. Operate the vehicle within the Freeze Frame conditions and Conditions for Running the DTC as specified in the supporting text.
  4. With the scan tool, observe the fuel tank pressure sensor voltage.

Does the fuel tank pressure sensor voltage read equal to or more than the specified value?

3.0 V

Go to Step 4

Go to Diagnostic Aids

4

  1. Turn OFF the ignition.
  2. Disconnect the fuel tank pressure sensor connector.
  3. Turn ON the ignition, with the engine OFF.
  4. With the scan tool, observe the fuel tank pressure sensor voltage.

Does the fuel tank pressure sensor voltage read more than the specified value?

0.2 V

Go to Step 6

Go to Step 5

5

  1. Connect a test lamp to B+.
  2. Probe the fuel tank pressure sensor ground circuit at the connector.

Does the test lamp illuminate?

--

Go to Step 7

Go to Step 9

6

  1. Turn OFF the ignition.
  2. Disconnect the PCM connector.
  3. Test the fuel tank pressure sensor signal circuit for a short to voltage.
  4. If a problem is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 10

7
  1. Connect a DMM to ground.
  2. Probe the fuel tank pressure sensor 5.0 volt reference circuit.

Does the 5.0 volt reference circuit measure near the specified value?

5.0 V

Go to Step 11

Go to Step 8

8

Important:: The powertrain control module (PCM) uses a single 5.0 volt power supply to supply power to all the engine control components. If one component shorts its 5.0 volt reference circuit to ground or battery voltage, the other 5.0 volt reference circuits will also have a low or high voltage.

  1. Turn OFF the ignition.
  2. Disconnect the PCM connector.
  3. Test the fuel tank pressure sensor 5.0 volt reference circuit for a short to voltage.
  4. If a problem is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 10

9
  1. Turn OFF the ignition.
  2. Test/Inspect the fuel tank pressure sensor ground circuit for the following conditions:
    3. • Open
    • Poor connection
  3. If a problem is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 10

10
  1. Inspect the PCM connector for a poor connection. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
  2. If a problem is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 13

11
  1. Turn OFF the ignition.
  2. Inspect the fuel tank pressure sensor connector for a poor connection. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
  3. If a problem is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 12

12

Replace the fuel tank pressure sensor. Refer to the Fuel Tank Pressure Sensor Replacement .

Did you complete the replacement?

--

Go to Step 14

--

13

Important: : The replacement PCM must be programmed. Powertrain Control Module Replacement/Programming

Replace the PCM. Refer to the .

Did you complete the replacement?

--

Go to Step 14

--

14
  1. Reconnect the fuel tank vapor line to the EVAP canister if still removed.
  2. Use a scan tool to clear the DTCs.
  3. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK