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For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2006 🢒 STS 🢒 Vehicle Control Systems 🢒 Vehicle DTC Information 🢒 DTC P0453

DTC Descriptor

DTC P0453: Fuel Tank Pressure (FTP) Sensor Circuit High Voltage

Diagnostic Fault Information

Important: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Circuit

Short to Ground

High Resistance

Open

Short to Voltage

Signal Performance

FTP Sensor Low Reference

--

P0446, P0451

P0446, P0463, P2068

--

P0451

FTP Sensor Signal

P0452

--

P0452

P0453

P0451, P0454

FTP Sensor 5-Volt Reference

P0452, P0522, P0532, P0641, P1183, P2228

P0451

P0446, P0452

P0453, P0530, P0641

--

Typical Scan Tool Data

FTP Sensor Voltage

Circuit¹

Normal Range

Short to Ground

Open

Short to Voltage

FTP Sensor Low Reference

0 V

--

4.5 V

--

FTP Sensor Signal

0 V

0 V

0-1.5 V

5 V

FTP Sensor 5-Volt Reference

0 V

0-1.5 V

5 V

¹ With EVAP system vented to atmosphere

Circuit/System Description

The fuel tank pressure (FTP) sensor measures air pressure or vacuum in the evaporative emission (EVAP) system. The control module supplies a 5-volt reference and a low reference circuit to the FTP sensor. The FTP sensor signal voltage varies depending on EVAP system pressure or vacuum. The controller also uses this FTP signal to determine atmospheric pressure for use in the engine-off small leak test, DTC P0442. Before using this signal as an atmospheric reference it must first be re-zeroed.

Conditions for Running the DTC

DTC  P0453 runs continuously when the ignition is ON.

Conditions for Setting the DTC

The FTP sensor voltage is more than 4.9 volts for more than 5 seconds.

Action Taken When the DTC Sets
    • The control module illuminates the MIL on the second consecutive ignition cycle that the diagnostic runs and fails.
    • The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC
    • The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
    • A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
    • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
    • Clear the MIL and the DTC with a scan tool.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

    •  Engine Control Module Connector End Views
    •  Engine Controls Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Troubleshooting with a Test Lamp
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

    •  Scan Tool Data List
    •  Scan Tool Output Controls

Special Tools Required

J 41413-200 Evaporative Emission System Tester (EEST)

Circuit/System Verification

Ignition ON, observe the scan tool fuel tank pressure (FTP) sensor parameter. The reading should be between 1.3-1.7 volts with the fuel cap removed, and change with fuel tank pressure.

Circuit/System Testing
  1. Ignition OFF, disconnect the harness connector at the FTP sensor.
  2. Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit terminal A and ground.
    3. ⇒If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the control module.
  3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal C and ground.
    4. ⇒If less than the specified range, test the 5-volt reference circuit for a short to round or an open/high resistance. If the circuit tests normal, replace the control module.
    ⇒If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the control module.
  4. Verify the scan tool FTP sensor parameter is less than 0.1 volt.
    5. ⇒If greater than the specified range, test the signal circuit terminal B for a short to voltage. If the circuit tests normal, replace the control module.
  5. Install a 3-amp fused jumper wire between the signal circuit terminal B and the 5-volt reference circuit terminal C. Verify the scan tool FTP sensor parameter is greater than 4.7 volts.
    6. ⇒If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the control module.
  6. If all circuits test normal, test or replace the FTP sensor.

Repair Instructions

Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Fuel Tank Pressure Sensor Replacement
    •  Control Module References for ECM replacement, setup, and programming