AutoCodes – Generic – P1494

P1494 Code - EVAP Leak Detection Pump Pressure Switch Condition

Quick Answer

The Evaporative emissions system is designed to prevent the escape of fuel vapors from the fuel system. Common causes include Faulty Leak Detection Pump (LDP), Leak Detection Pump (LDP) harness is open or shorted, Leak Detection Pump (LDP) poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P1494 indicates EVAP Leak Detection Pump Pressure Switch Condition.
Common causes: Common causes include Faulty Leak Detection Pump (LDP), Leak Detection Pump (LDP) harness is open or shorted, Leak Detection Pump (LDP) poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 23,587

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Aug 25, 2019

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P1494 Description

The Evaporative emissions system is designed to prevent the escape of fuel vapors from the fuel system. Leaks in the system ca allow vapors to escape into the atmosphere. The leak detection system tests for EVAP system leaks and blockage.
During the self-diagnostics, the Powertrain Control Module (PCM) first checks the Leak Detection Pump (LDP) for electrical and mechanical faults. If the first checks pass, the PCM then uses the LDP to seal the vent valve and pump air into the system to pressurize it. If a leak is present, the PCM will continue pumping the LDP to replace the air that leaks out. The PCM determines the size of the leak based on how fast/long it must pump the LDP as it tries to maintain pressure in the system.

OBDII Code P1494 - EVAP Leak Detection Pump Pressure Switch Condition - AutoCodes.com — P1494 Code - EVAP Leak Detection Pump Pressure Switch Condition

What does this mean?

What are the Possible Causes of the DTC P1494?

Faulty Leak Detection Pump (LDP)
Leak Detection Pump (LDP) harness is open or shorted
Leak Detection Pump (LDP) poor electrical connection

How to Fix the DTC P1494?

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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P1494 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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Information for Specific Makes

P1494 Chrysler — EVAP Leak Detection Pump Pressure Switch Condition
P1494 Dodge — EVAP Leak Detection Pump Pressure Switch Condition
P1494 Jeep — EVAP Leak Detection Pump Pressure Switch Condition
P1494 Mitsubishi — EVAP Ventilation Switch Or Mechanical Fault
P1494 RAM — EVAP Leak Detection Pump Pressure Switch Condition
P1494 Subaru — EGR Signal Line 2 Circuit Low

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.