AutoCodes – Cadillac – P0451 Cadillac

P0451 Cadillac Code - Fuel Tank Pressure Sensor Performance

Quick Answer

The fuel tank pressure sensor measures vapor pressure or vacuum in the Evaporative Emission (EVAP) system. Common causes include Faulty Fuel Tank Pressure (FTP) Sensor, Fuel Tank Pressure Sensor harness is open or shorted, Fuel Tank Pressure Sensor circuit poor electrical connection. Severity is Low - monitor the vehicle and repair when practical. The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

What it means: P0451 Cadillac indicates Fuel Tank Pressure Sensor Performance.
Common causes: Common causes include Faulty Fuel Tank Pressure (FTP) Sensor, Fuel Tank Pressure Sensor harness is open or shorted, Fuel Tank Pressure Sensor circuit poor electrical connection.
Severity: Low - monitor the vehicle and repair when practical.
Can I drive?: The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

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Code Popularity 13,060

How popular is this code, among other codes? Low

Repair Importance Level

Low (Monitor) (1 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 28, 2022

Description
Possible Causes
How To Fix
Tech Notes ▶
Cost to Diagnose
Comments
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Code P0451 Cadillac Description

The fuel tank pressure sensor measures vapor pressure or vacuum in the Evaporative Emission (EVAP) system. The Engine Control Module (ECM) supplies a 5 V reference and a low reference circuit to the fuel tank pressure sensor. The fuel tank pressure sensor signal voltage varies depending on EVAP system pressure or vacuum. The control module also uses this fuel tank pressure 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. The Diagnostic Trouble Code (DTC) will be set if the controller is unable to re-zero the fuel tank pressure sensor voltage within a calibrated range during the engine-off small leak test.

OBDII Code P0451 Cadillac - Fuel Tank Pressure Sensor Performance - AutoCodes.com — P0451 Cadillac Code - Fuel Tank Pressure Sensor Performance

What does this mean?

What are the Possible Causes of the DTC P0451 Cadillac?

Faulty Fuel Tank Pressure (FTP) Sensor
Fuel Tank Pressure Sensor harness is open or shorted
Fuel Tank Pressure Sensor circuit poor electrical connection
Faulty Engine Control Module (ECM)

How to Fix the DTC P0451 Cadillac?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

User Submitted Video

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0451 Cadillac code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.