2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2077

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2077

Instructions) provides an overview of each diagnostic category.

DTC Descriptors

DTC P0451

- Fuel Tank Pressure (FTP) Sensor Performance

DTC P0452

- Fuel Tank Pressure (FTP) Sensor Circuit Low Voltage

DTC P0453

- Fuel Tank Pressure (FTP) Sensor Circuit High Voltage

DTC P0454

- Fuel Tank Pressure (FTP) Sensor Intermittent

Diagnostic Fault Information

Typical Scan Tool Data

Circuit/System Description

The fuel tank pressure (FTP) sensor measures air pressure or vacuum in the evaporative emission (EVAP) system. The engine control module

(ECM) 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

P0451

* DTC P0451 runs only when the engine-off natural vacuum small leak test, P0442, executes.

* The number of times this test runs can range from 0-2 per engine-off period. The length of the test can be up to 10 minutes.

P0452 and P0453

DTC P0452 and P0453 run continuously when the ignition is ON.

P0454

* DTC P0454 runs only when the engine-off natural vacuum small leak test, P0442, executes.

* This test can run once per engine-off period. The length of the test can be up to 10 minutes.

* A refueling event is not detected.

Conditions for Setting the DTC

P0451

This DTC will set if the controller is unable to re-zero the FTP sensor voltage within a calibrated range during the engine-off small leak test, P0442.

P0452

The FTP sensor voltage is less than 0.1 volt for more than 5 seconds.