DTC P0449 Evaporative Emission (EVAP) Vent Solenoid Control Circuit. Cadillac Seville 2000

For 1990-2009 cars only

Makes 🢒 Cadillac 🢒 2000 🢒 Seville 🢒 DTC 🢒 DTC P0449 Evaporative Emission (EVAP) Vent Solenoid Control Circuit

Engine Controls Component Views
EVAP and EGR Valve
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The PCM uses output driver modules (ODMs) to control many functions of the engine, and the transaxle. The ODMs supply the ground path for the PCM controlled device when the PCM commands the device ON. Each ODM is able to control several outputs. Unlike the quad driver modules (QDMs) used in earlier model years, the ODMs are able to diagnose each output circuit. The PCM monitors the ODMs for circuit conditions that are incorrect for the commanded state of the ODM. If the PCM detects an improper circuit condition in the ODM that controls the EVAP vent solenoid, DTC P0449 will set.

Conditions for Running the DTC

•	The engine is running.

•	System voltage is between 8 and 16 volts.

Conditions for Setting the DTC

The PCM detects a circuit conditions that is incorrect for the commanded state of the ODM that controls the EVAP vent solenoid.

The condition is present for at least 10 seconds.

Action Taken When the DTC Sets

•	The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test runs and fails.

•	The PCM stores the conditions present when the DTC set as Freeze Frame/Failure Records data.

Conditions for Clearing the MIL/DTC

•	The PCM will turn the MIL OFF after the third consecutive trip in which the diagnostic runs and passes.

•	The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.

•	The DTC can be cleared by using the scan tool Clear DTC Information function.

Diagnostic Aids

If the condition is intermittent, refer to Intermittent Conditions .

Test Description

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

Listen for an audible click when the solenoid operates. Be sure that both the ON and the OFF states are commanded. Repeat the commands as necessary.

This step tests for voltage at the coil side of the EVAP vent solenoid. The ENG IGN fuse supplies power to the coil side of the EVAP vent solenoid.

This step verifies that the PCM is providing ground to the EVAP vent solenoid.

This step tests if a ground is constantly being applied to the EVAP vent solenoid.

Step	Action	Values	Yes	No
1	Did you perform the Powertrain On Board Diagnostic (OBD) System Check ?	--	Go to Step 2	Go to Powertrain On Board Diagnostic (OBD) System Check
2	Start the engine and idle at the normal operating temperature. With the scan tool, command the solenoid ON and OFF. Does the solenoid turn ON and OFF when commanded?	--	Go to Step 3	Go to Step 4
3	Review the Freeze Frame and/or Failure records data for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for running the DTC as specified in the supporting text or as close to the Freeze Frame and/or Failure records data that you observe. Does this DTC reset?	--	Go to Step 4	Go to Intermittent Conditions
4	Turn OFF the ignition. Disconnect the solenoid electrical connector. Turn ON the ignition, with the engine OFF. Probe the coil side feed circuit of the EVAP vent solenoid with a test lamp that is connected to a good ground. Does the test lamp illuminate?	--	Go to Step 5	Go to Step 11
5	Connect a test lamp between the control circuit of the EVAP vent solenoid and the coil side feed circuit of the EVAP vent solenoid. Refer to Probing Electrical Connectors in Wiring Systems . With a scan tool, command the EVAP vent solenoid ON and OFF. Does the test lamp turn ON and OFF with each command?	--	Go to Step 9	Go to Step 6
6	Does the test lamp remain illuminated with each command?	--	Go to Step 8	Go to Step 7
7	Test the control circuit of the EVAP vent solenoid for a short to voltage or an open. Refer to Circuit Testing in Wiring Systems. If you find a condition, repair as necessary. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition?	--	Go to Step 14	Go to Step 10
8	Test the control circuit of the EVAP vent solenoid for a short to ground. Refer to Circuit Testing in Wiring Systems. If you find a condition, repair as necessary. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition?	--	Go to Step 14	Go to Step 13
9	Inspect for poor connections at the EVAP vent solenoid. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. If you find a condition, repair as necessary. Refer to Repairing Connector Terminals in Wiring Systems. Did you find and correct the condition?	--	Go to Step 14	Go to Step 12
10	Inspect for poor connections at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. If you find a condition, repair as necessary. Refer to Repairing Connector Terminals in Wiring Systems. Did you find and correct the condition?	--	Go to Step 14	Go to Step 13
11	Repair the coil side feed circuit of the EVAP vent solenoid. Refer to Wiring Repairs in Wiring Systems . Is the action complete?	--	Go to Step 14	--
12	Replace the EVAP vent solenoid. Refer to Evaporative Emission Vent Valve Replacement . Is the action complete?	--	Go to Step 14	--
13	Important: Program the replacement PCM. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Is the action complete?	--	Go to Step 14	--
14	Use a scan tool in order to clear the DTCs. Operate vehicle within the Conditions for Running the DTC as specified in the supporting text. Does the DTC reset?	--	Go to Step 2	Go to Step 15
15	With a scan tool, review 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