GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Oldsmobile 🢒 2001 🢒 Aurora 🢒 Engine 🢒 Engine Controls - 3.5L 🢒 DTC P0443

Circuit Description

The powertrain control module (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 purge solenoid valve, DTC P0443 will set.

Conditions for Running the DTC
    • The engine is running.
    • The system voltage is between 8-16 volts.

Conditions for Setting the DTC
    • The PCM detects an improper voltage level on the output circuit that controls the EVAP purge solenoid valve.
    • The condition exists for at least 10 seconds.

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.

Test Description

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

  1. Listen for a click when the solenoid operates. Be sure that both the ON and the OFF states are commanded. Repeat the commands as necessary. The Fuel Tank Pressure sensor parameter on the scan tool can also be used to determine if the EVAP purge solenoid is operating. You should be able to see the pressure and/or vacuum change when you command the solenoid on.

    2.

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

    3.

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

    4.

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

Step

Action

Yes

No

Schematic Reference: Engine Controls Schematics

1

Did you perform the Diagnostic System Check-Engine Controls?

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2

  1. Idle the engine at the normal operating temperature.
  2. With the scan tool, command the solenoid to 50 percent and then to 0 percent.

Do you hear or feel clicking from the EVAP purge valve when the purge solenoid is commanded to 50 percent?

Go to Step 3

Go to Step 4

3
  1. Review the Freeze Frame and/or Failure Records data for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. 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

  1. Turn OFF the ignition.
  2. Disconnect the EVAP purge solenoid.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the coil side feed circuit of the EVAP purge solenoid with a test lamp connected to a good ground.

Does the test lamp illuminate?

Go to Step 5

Go to Step 11

5

  1. Connect a test lamp between the control circuit of the EVAP purge solenoid and the coil side feed circuit of the EVAP purge solenoid.
  2. With a scan tool, command the EVAP purge solenoid to 0 percent.

Is the test lamp illuminated?

Go to Step 8

Go to Step 6

6

With a scan tool, command the EVAP purge valve to 50 percent.

Does the test lamp illuminate or pulse when the purge valve is commanded to 50 percent?

Go to Step 9

Go to Step 7

7
  1. Test the control circuit of the EVAP purge solenoid for a short to voltage or an open. Refer to Testing for a Short to Voltage in Wiring Systems.
  2. 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
  1. Test the control circuit of the EVAP purge solenoid for a short to ground. Refer to Testing for Short to Ground in Wiring Systems.
  2. 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
  1. Inspect for poor at the connections at the solenoid. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
  2. If you find a poor connection, repair the terminal 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
  1. Inspect for poor connections at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
  2. If you find a poor connection, repair the terminal 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 purge solenoid. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

Go to Step 14

--

12

Replace the EVAP purge solenoid. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement .

Is the action complete?

Go to Step 14

--

13

Replace the PCM. Refer to Powertrain Control Module Replacement .

Is the action complete?

Go to Step 14

--

14
  1. Use the scan tool in order to clear the DTCs.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC run and pass?

Go to Step 15

Go to Step 2

15

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

System OK