DTC P0440. GMC Truck GMC MD Steel Tilt (W Model) 2002

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 2002 🢒 GMC MD Steel Tilt (W Model) 🢒 Engine 🢒 Engine Controls - 5.0L and 5.7L 🢒 DTC P0440

Description

The EVAP LARGE LEAK TEST is based on applying vacuum to the EVAP system and monitoring the rate of vacuum decay. The Powertrain Control Module (PCM) uses the input from the fuel tank pressure (FTP) sensor in order to determine the rate of vacuum decay. At an appropriate time, the PCM turns the EVAP canister purge valve ON (open) and the EVAP canister vent valve ON (closed). This allows the engine to draw a vacuum on the system. At a calibrated time or vacuum level, the PCM turns the purge valve OFF (closed), and tests the system vacuum. If the system is unable to achieve the calibrated vacuum level, the PCM will set DTC P0440.

Conditions for Running the DTC

DTC P0107. P0108, P0110, P0112, P0113, P0115, P0117, P0118, P0121, P0122, P0123, P0125, P0443, P0449, P0452, P0453, P1106. P1107, P1111, P1112, P1114, P1115, P1121 and P1122 not active.
The system voltage is between 10-18 volts.
The startup (ECT) engine coolant temperature is between than 4-30°C (39-86°F), but the start up ECT is not more than 8°C (14°F) more than the startup IAT temperature.
The startup (IAT) intake air temperature is between than 4-30°C (39-86°F), but the start up IAT is not more than 3°C (7°F) more than the startup ECT temperature.
The fuel tank level is between 15-85 percent.
The barometric pressure (BARO) is more than 75 kPa.
The vehicle speed sensor (VSS) is less than 75 mph.

Conditions For Setting the DTC

The EVAP system is not able to achieve or maintain vacuum during the diagnostic test.

Action Taken When the DTC Sets

•	The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.

•	The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/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.

Diagnostic Aids

•	Use the EVAP pressure/purge diagnostic station in order to pressurize the EVAP system to aid in locating intermittent leaks.

•	Move all EVAP components while testing with the Ultrasonic Leak Detector.

•	A temporary blockage in the EVAP canister purge valve, purge pipe or EVAP canister could cause an intermittent condition. To repair a blockage in the EVAP system refer to Evaporative Emission System Cleaning .

Test Description

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

This step verifies that a failure condition is active.

This step is used to verify if a leak is present.

This step verifies proper operation of the fuel tank pressure (FTP) sensor.

This step tests the EVAP canister purge valve for a restriction or blockage.

This step verifies that repairs are complete and that no other condition is present.

Step

Action

Values

Yes

Schematic Reference:

EVAP System Overview

(1) EVAP Canister Purge Solenoid

(2) EVAP Canister

(3) Fuel Fill Neck/Fill Cap

(4) Rollover Valve/Fuel Tank Pressure (FTP) Sensor

(5) Fuel Tank

(6) EVAP Canister Vent Solenoid

(7) Vent Hose/Pipe

(8) EVAP Vapor Pipe

(9) EVAP Purge Pipe

(10) EVAP Service Port

Did you perform the Diagnostic System Check-Engine Controls?

Go to Step 2

Go to Diagnostic System Check - Engine Controls

Does the scan tool indicate DTC P0443 or DTC P0449 are also set?

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

Inspect the EVAP system for the following conditions:

•	Loose, missing, or damaged service port dust cap and/or schrader valve.

•	Loose, incorrect, missing, or damaged fuel fill cap.

•	A damaged EVAP canister purge valve.

Raise the vehicle on a hoist. Refer to Lifting and Jacking the Vehicle in General Information.
Inspect the EVAP system for the following conditions:

•	Disconnected, improperly routed, kinked, or damaged EVAP pipes and hoses.

•	A damaged EVAP canister vent valve or EVAP canister

Did you find and correct the condition?

Go to Step 19

Go to Step 4

With a scan tool, capture and record the fail record data and clear the DTCs.
Perform the Service Bay Test. Refer to Service Bay Test .

Does the scan tool indicate that the service bay test passed?

Go to Diagnostic Aids

Go to Step 5

Important: The following steps require the EVAP Pressure/Purge Diagnostic Station J 41413 and the Fuel Fill Cap Adaptor J 41415 .

Always zero the EVAP Pressure and vacuum (in. H2O) gauges on the EVAP Pressure Diagnostic Station before proceeding with diagnosis.

Install the fuel fill cap adaptor J 41415 .
Connect the pressure/purge diagnostic station to the fuel fill cap adaptor J 41413 .
Turn ON the ignition, with the engine OFF.
With the scan tool, seal the EVAP system.
With the EVAP pressure/purge diagnostic station, pressurize the system to the specified value.
Rotate the EVAP pressure/purge diagnostic station rotary switch to the OFF/HOLD position.

Did you obtain the specified value?

5 in H2O

Go to Step 6

Go to Step 8

Compare the EVAP pressure/purge diagnostic station value to the scan tool (FTP) fuel tank pressure sensor value.

Does EVAP pressure/purge diagnostic station value measure near the scan tool value?

Go to Step 7

Go to Step 14

With the pressure/purge diagnostic station, maintain EVAP system pressure at the specified value.
Monitor the pressure gauge on EVAP pressure/purge diagnostic station.
With a scan tool, command the EVAP canister purge valve to 50 percent.

Does the EVAP system pressure decrease?

5 in H2O

Go to Step 10

Go to Step 11

With the pressure/purge diagnostic station, continuously pressurize the EVAP system.

Important: It may be necessary to partially lower the fuel tank to inspect components located in the upper portion of the tank.

With the J 41416 ultrasonic leak detector inspect for leaks in the following locations:

•	The EVAP system purge pipe.

•	The EVAP vapor pipe. Refer to Fuel Tank Replacement .

•	The EVAP vent hose/pipe.

•	The fuel fill pipe/hose and fuel fill cap. Refer to Filler Tube Replacement .

•	The EVAP canister. Refer to Evaporative Emission Canister Replacement .

•	The EVAP canister vent valve. Refer to EVAP Canister Vent Valve Replacement .

•	The EVAP canister purge valve. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement .

•	The fuel sender assembly and/or seal. Refer to Fuel Sender Assembly Replacement .

•	The (FTP) fuel tank pressure sensor seal. Refer to Fuel Tank Pressure Sensor Replacement .

•	The fill limiter vent valve, pressure relief valve, rollover valves, permanent EVAP pipes and/or fuel tank. Refer to Fuel Tank Replacement .

Did you locate a leak?

Go to Step 9

Go to Diagnostic Aids

Repair the system as necessary.

Did you complete the repair?

Go to Step 19

Disconnect the EVAP purge pipe from the EVAP canister purge valve.
Install the EVAP pressure/purge diagnostic station vacuum hose on the EVAP canister purge valve port.
Start the engine.
Run the engine between 1200-1500 RPM.
With a scan tool command the EVAP canister purge valve to 50 percent.

Does the EVAP pressure/purge diagnostic station vacuum gauge measure above the specified value?

12 in Hg

Go to Diagnostic Aids

Go to Step 16