DTC P0453 Fuel Tank Pressure Sensor Circuit High Voltage. Oldsmobile Shelby Series 1 1999

For 1990-2009 cars
Engine Controls Components
Fuel System
OBD II Symbol Description Notice
Powertrain Control Module Connector End Views
Handling ESD Sensitive Parts Notice

### Circuit Description

The fuel tank pressure sensor changes resistance based on the fuel tank pressure or vacuum. A vacuum is considered negative pressure.

The powertrain control module (PCM) provides a 5.0 volt reference and a ground. The fuel tank pressure sensor signal varies between ground and 5.0 volts as the fuel tank pressure varies. The fuel tank pressure sensor voltage increases as the fuel tank pressure decreases (negative pressure, or vacuum). The fuel tank pressure sensor voltage decreases (positive pressure, low voltage) as the fuel tank pressure increases. The PCM uses the fuel tank pressure sensor voltage for the evaporative emission (EVAP) system leak detection. This diagnostic trouble code (DTC) sets when the fuel tank pressure sensor signal goes above a predetermined value.

### Conditions for Running the DTC

The ignition switch is in the RUN position.

### Conditions for Setting the DTC

• | The fuel tank pressure sensor voltage is more than 4.90 volts.

• | All conditions are present for more than 5.0 seconds.

### Action Taken When the DTC Sets

• | The powertrain control module (PCM) stores the DTC information into memory when the diagnostic runs and fails.

• | The malfunction indicator lamp (MIL) will not illuminate.

• | The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Failure Records.

### Conditions for Clearing the DTC

• | A last test failed, or current DTC, clears when the diagnostic runs and does not fail.

• | A history DTC will clear after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.

• | Use a scan tool in order to clear the DTC.

### Diagnostic Aids

Important: Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing or replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent water intrusion into the PCM.

The fuel tank pressure sensor range is from +7.5 in. H2O of pressure to -17.5 in. H2O of pressure or vacuum.

Observe an open ground circuit does not set DTC P0453. A fuel tank pressure sensor that does not respond to pressure change may indicate a ground circuit problem.

For an intermittent, refer to Symptoms .

The vacuum and pressure in the EVAP system is measured in inches of water (H2O). Most gauges measure vacuum in inches of mercury (Hg) and pressure in pounds per square inch (psi). The following shows how the values compare:

in H2O | in Hg | psi
--- | --- | ---
1in H2O | 0.07 in Hg | 0.0361 psi
5 in H2O | 0.36 in Hg | 0.180 psi
10 in H2O | 0.73 in Hg | 0.361 psi
15 in H2O | 1.10 in Hg | 0.541 psi

### Test Description

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

1. This step determines if the 5 volt reference circuit is shorted to a voltage.

1. This step determines if a fault is present.

2. Using the Freeze Frame and/or Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can also help determine how many ignition cycles the diagnostic reported a pass and/or a fail. Operate the vehicle within the same Freeze Frame conditions, such as RPM, load, vehicle speed, temperature, that you observed. This will isolate when the DTC failed.

3. This step tests whether the signal circuit is shorted to a voltage.

4. This step tests whether a ground circuit is available at the fuel tank pressure sensor connector.

5. This step is testing the ground circuit for an open.

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 | Did DTC P1639 fail this ignition? | -- | Go to DTC P1639 5 Volt Reference 2 Circuit | Go to Step 3

3

Important: The ignition must be OFF for a minimum of 15 seconds when you are instructed to turn the ignition OFF. If the ignition switch is not in the OFF position for 15 seconds, mis-diagnosis occurs. This information applies to every step that instructs you to turn OFF the ignition.

1. Turn OFF the ignition for 15 seconds.
2. Turn ON the ignition leaving the engine OFF.
3. Monitor the fuel tank pressure sensor voltage on the scan tool.

Is the fuel tank pressure sensor voltage above the specified value?

4.3 V

Go to Step 5

Go to Step 4

4

1. Turn ON the ignition leaving the engine OFF.
2. Review the Freeze Frame and/or Failure Records data for this DTC and observe the parameters.
3. Turn OFF the ignition for 15 seconds.
4. Idle the engine.
5. Operate the vehicle within the conditions required for this diagnostic to run, and as close to the conditions recorded in the Freeze Frame and Failure Records as possible. Special operating conditions that you need to meet before the PCM will run this diagnostic, where applicable, are listed in Conditions for Running the DTC.
6. Select the Diagnostic Trouble Code (DTC) option, the Specific DTC option, then enter the DTC number using the scan tool.

Does the scan tool indicate that this diagnostic failed this ignition?

--

Go to Step 5

Go to Diagnostic Aids

5

1. Turn OFF the ignition for 15 seconds.
2. Disconnect the fuel tank pressure sensor electrical connector at the fuel tank.
3. Turn On the ignition leaving the engine OFF.
4. Observe the fuel tank pressure sensor voltage display on the scan tool.

Is the fuel tank pressure sensor voltage below the specified value?

1 V

Go to Step 6

Go to step 7

6 | Probe the sensor ground circuit with the test lamp connected to B+. Refer to Probing Electrical Connectors in Wiring Systems. Is the test lamp illuminated? | -- | Go to Step 11 | Go to step 8
7 | Measure the voltage from the fuel tank pressure sensor signal circuit at the harness connector to the battery ground using the DMM. Is the voltage near the specified value? | 0 V | Go to Step 14 | Go to Step 9

8

1. Disconnect the PCM connector C1 located on the same side as the manufacturers logo. Refer to Powertrain Control Module Replacement/Programming .
2. Test for continuity of the fuel tank pressure sensor ground circuit between the PCM and the fuel tank pressure sensor electrical connector. Refer to Testing for Continuity in Wiring Systems.

Does the DMM display continuity within the specified range?

0-5 ohms

Go to Step 12

Go to Step 10

9 | Repair the signal circuit for a short to voltage. Refer to Wiring Repairs in Wiring Systems. Is the action complete? | -- | Go to Step 15 | --
10 | Repair the open or high resistance in the ground circuit. Refer to Wiring Repairs in Wiring Systems. Is the action complete? | -- | Go to Step 15 | --

11

1. Inspect for a poor ground connection at the fuel tank pressure sensor connector. Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.
2. If you find a poor connection repair the terminal as necessary. Refer to Repairing Connector Terminals in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 13

12

1. Inspect for a poor connection at the PCM. Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.
2. If you find a poor connection repair the terminal as necessary. Refer to Repairing Connector Terminals in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 14

13 | Replace the fuel tank pressure sensor. Refer to Fuel Tank Pressure Sensor Replacement . Is the action complete? | -- | Go to Step 15 | --
14 | Important: The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Is the action complete? | -- | Go to Step 15 | --

15

1. Select the Diagnostic Trouble Code (DTC) option and the Clear DTC Information option using the scan tool.
2. Idle the engine at the normal operating temperature.
3. Select the Diagnostic Trouble Code (DTC) option and the Specific DTC option, then enter the DTC number using the scan tool.
4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text, if applicable.

Does the scan tool indicate that this test ran and passed?

--

Go to Step 16

Go to Step 2

16 | Select the Capture Info option and the Review Info option using the scan tool. Does the scan tool display any DTCs that you have not diagnosed? | -- | Go to the applicable DTC table | System OK