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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 P0498 >> 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 a condition exists.
  2. 4:  This step tests the battery positive voltage circuit to the EVAP canister vent valve.
DTC P0498 Evaporative Emission (EVAP) Vent Solenoid Control Circuit Low Voltage

Step Action 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. 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 vent valve harness connector.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the battery positive voltage circuit of the EVAP canister vent valve with a test lamp that is connected to a good ground.
Does the test lamp illuminate?		 Go to Step 5  Go to Step 7 
5 Test the control circuit between the EVAP canister vent valve and the engine control module (ECM) for a short to ground. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 Go to Step 9  Go to Step 6 
6 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 9  Go to Step 8 
7
  1. Repair the short to ground in the battery positive voltage circuit of the EVAP canister vent valve. Refer to Wiring Repairs .
  2. Replace the fuse.
Did you complete the repair?		 Go to Step 9  -
8 Replace the ECM. Refer to Control Module References for replacement, setup, and programming.
Did you complete the replacement?		 Go to Step 9  -
9
  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 10 
10 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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