For 1990-2009 cars

Table 1: | DTC P1441

Refer to Emission Hose Routing Diagram,

#### EVAP Control System Overview

(1) | EVAP Vent Valve/Solenoid
(2) | EVAP Vent Valve/Solenoid Ignition Feed Circuit Terminal
(3) | EVAP Vent Valve/Solenoid Control Circuit Terminal
(4) | EVAP Vent Valve/Solenoid Filter
(5) | EVAP Vapor Lines
(6) | Fuel Tank Pressure Sensor
(7) | Fuel Tank Pressure Sensor Ground Circuit Terminal
(8) | Fuel Tank Pressure Sensor Signal Circuit Terminal
(9) | Fuel Tank Pressure Sensor Circuit 5 Volt Reference Circuit Terminal
(10) | Fuel Filler Pipe
(11) | Check Valve (Spitback)
(12) | Modular Fuel Sender Assembly
(13) | Fuel Limiter Vent Valve (FLVV)
(14) | Pressure/Vacuum Relief Valve (Optional)
(15) | EVAP Canister
(16) | EVAP Canister Purge Valve/Solenoid Ignition Feed Circuit Terminal
(17) | EVAP Canister Purge Valve/Solenoid Control Circuit Terminal
(18) | Intake Manifold Vacuum Source
(19) | EVAP Canister Purge Valve/Solenoid
(20) | EVAP Service Port

.

### System Description

This DTC tests for undesired intake manifold vacuum flow to the evaporative emission (EVAP) system. The control module seals the EVAP system by commanding the EVAP canister purge valve Closed and the EVAP canister vent valve Closed. The control module monitors the fuel tank pressure (FTP) sensor to determine if a vacuum is being drawn on the EVAP system. If vacuum in the EVAP system is more than a predetermined value within a predetermined time, this DTC sets.

The following table illustrates the relationship between the ON and OFF states, and the Open or Closed states of the EVAP canister purge and vent valves.

Control Module Command | EVAP Canister Purge Valve | EVAP Canister Vent Valve
--- | --- | ---
ON | Open | Closed
OFF | Closed | Open

### Conditions for Running the DTC

• | DTCs P0107, P0108, P0110, P0112, P0113, P0115, P0116, P0117, P0118, P0121, P0122, P0123, P0125, P0440, P0442, P0443, P0446, P0449, P0452, P0453, P1106, P1107, P1111, P1112, P1114, P1115, P1121, or P1122 are not set.

• | The system voltage is between 10-18 volts.

• | The startup engine coolant temperature (ECT) is between 4-30°C (39-86°F).

• | The startup intake air temperature (IAT) is between 4-30°C (39-86°F).

• | The startup ECT and IAT are within 9°C (16°F).

• | 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 121 km/h (75 mph).

### Conditions for Setting the DTC

The PCM detects vacuum during a non-purge condition.

### Action Taken When the DTC Sets

• | The control module illuminates the malfunction indicator lamp (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.

### Diagnostic Aids

The EVAP system tests run when the engine is first started, and meets the Conditions for Running the DTC. An intermittent condition could be caused by an improperly installed or damaged EVAP canister purge valve, or by a temporary blockage in the EVAP canister purge valve. In order to repair a blockage in the EVAP system, refer to Evaporative Emission System Cleaning .

### Test Description

The number below refers to the step number on the diagnostic table.

1. This test determines if the EVAP canister purge valve can seal.

#### DTC P1441

Step | Action | Values | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | Go to Powertrain On Board Diagnostic (OBD) System Check
2 | Are DTCs P0443, P0449, P0452 or P0453 also set? | -- | Go to Diagnostic Trouble Code (DTC) List/Type | Go to Step 3
3 |

1. Remove the fuel fill cap.
2. Turn ON the ignition, with the engine OFF.
3. Monitor the fuel tank pressure (FTP) sensor with a scan tool.

Does the scan tool indicate FTP within the specified range?

-0.5 to +0.5 in H2O

Go to Step 4

Go to DTC P0453 Fuel Tank Pressure Sensor Circuit High Voltage

4 |

1. Disconnect the purge pipe from the evaporative emission (EVAP) canister purge valve.
2. Install a hand held vacuum gage to the EVAP purge port.
3. Disconnect the EVAP canister purge valve harness connector.
4. Monitor vacuum on the vacuum gage.
5. Start the engine and allow the engine to idle.
6. Increase the idle to 1,200-1,500 RPM.

Does the vacuum gage indicate an increase in vacuum?

--

Go to Step 5

Go to Diagnostic Aids

5 | Replace the EVAP canister purge valve. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement . Did you complete the replacement? | -- | Go to Step 6 | --
6 |

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

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

--

Go to Step 7

Go to Step 3

7 | With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | Go to Diagnostic Trouble Code (DTC) List/Type | System OK