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Home >> Cadillac >> 2006 >> STS Base, 3.6 7, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - 3.6L - DTC P0342 To P0690 >> DTC P0443 >> Test Description
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Test Description

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

  1. 2:  This step determines if the condition exists.
  2. 4:  This step tests the control modules ability to supply a ground to the EVAP canister purge valve.
  3. 5:  This step tests the feedback voltage from the ECM. If a voltage is not available, this indicates an internal ECM condition.
  4. 6:  This step tests the ignition 1 voltage circuit to the EVAP canister purge valve.
DTC P0443 Evaporative Emission (EVAP) Purge Solenoid Control Circuit

Step Action Values Yes No
Schematic Reference:  Engine Controls Schematics 
Connector End View Reference:  Engine Control Module Connector End Views  or  Engine Controls Connector End Views 
1 Did you perform the Diagnostic System Check - Vehicle? - Go to Step 2  Go to Diagnostic System Check - Vehicle
2 
  1. Start the engine.
  2. Allow the engine to reach operating temperature.
  3. Observe the DTC Info with a scan tool.
Did the DTC fail this ignition?		 - Go to Step 4  Go to Step 3 
3
  1. Observe the Freeze Frame/Failure Records 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. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition?		 - Go to Step 4  Go to Diagnostic Aids
4 
  1. Turn OFF the ignition.
  2. Disconnect the evaporative emission (EVAP) canister purge valve.
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a test lamp between the ignition 1 voltage circuit of the EVAP canister purge valve and the control circuit of the EVAP canister purge valve.
    5. IMPORTANT:
    • The EVAP Purge Solenoid Command parameter may not change states when using the EVAP Purge Solenoid output control.
    • The DTCs may need to be cleared if the output control does not operate.
  5. Command the EVAP canister purge valve to 50 percent and then to 0 percent with a scan tool.
  6. Exit the output control with a scan tool.
Does the test lamp illuminate or flash?		 - Go to Step 5  Go to Step 6 
5  Measure the voltage from the control circuit of the EVAP canister purge valve to the engine control module (ECM) housing with a DMM.
Is the voltage within the specified range?		 2.6-4.6 V Go to Step 8  Go to Step 9 
6  Connect a test lamp between the ignition 1 voltage circuit of the EVAP canister purge valve and the ECM housing.
Does the test lamp illuminate?		 - Go to Step 7  Go to Step 10 
7
  1. Turn OFF the ignition.
  2. Disconnect the ECM.
  3. Test for an open in the control circuit of the EVAP canister purge valve. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 13  Go to Step 9 
8 Test for an intermittent and for a poor connection at the EVAP canister purge valve. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 - Go to Step 13  Go to Step 11 
9 Test for an intermittent and for a poor connection at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 - Go to Step 13  Go to Step 12 
10
  1. Repair the ignition 1 voltage supply circuit of the EVAP canister purge valve for an open or for an intermittent short to ground. Refer to Wiring Repairs .
  2. Replace the fuse as necessary.
Did you complete the repair?		 - Go to Step 13  -
11 Replace the EVAP canister purge valve. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement .
Did you complete the replacement?		 - Go to Step 13  -
12 Replace the ECM. Refer to Control Module References for replacement, setup, and programming.
Did you complete the replacement?		 - Go to Step 13  -
13
  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition?		 - Go to Step 2  Go to Step 14 
14 Observe the Capture Info with a scan tool.
Are there any DTCs that have not been diagnosed?		 - Go to Diagnostic Trouble Code (DTC) List - Vehicle System OK
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