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Home >> Chevrolet >> 2005 >> Aveo Base, 4D Hatchback >> Repair and Diagnosis >> External Pages >> Different car >> Section 51 (Engine Controls - 1.6L (L91) (DTC P0502 To DTC U0426)) >> Diagnostic Information & Procedures >> DTC P0506 or P0507 >> Diagnostic Aids

Diagnostic Aids

WARNING: This page is about a different car, the 2004 Suzuki Swift + and 2004 Chevrolet Aveo. However, it is still accessible from the selected car via links, so may be relevant.
DTC P0506 or P0507

Step Action Values Yes No
Schematic Reference:  Engine Controls Schematics 
Connector End View Reference:  Engine Control Module (ECM) Connector End Views  or  Engine Controls Connector End Views 
1 Did you perform the Diagnostic System Check - Engine Controls? - Go to Step 2  Go to Diagnostic System Check - Engine Controls
2
IMPORTANT: Ensure that engine speed stabilizes with each commanded RPM change in order to determine if engine speed stays within the specified value of the commanded RPM.
  1. Start the engine.
  2. Turn OFF all the accessories.
  3. Command the engine speed to 1800 RPM, then to 600 RPM, and then to 1800 RPM with a scan tool.
  4. Exit the RPM control function.
Is the engine speed within the specified value of each command of the RPM?		 100 RPM Go to Step 3  Go to Step 4 
3
  1. Observe the Freeze Frame and the 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. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Does the DTC fail this ignition cycle?		 - Go to Step 4  Go to Diagnostic Aids
4
  1. Turn OFF the ignition.
  2. Disconnect the IAC valve.
  3. Connect the J 37027-A Idle Air Control Motor Tester to the IAC valve.
  4. Start the engine.
  5. Command the IAC valve in until near 600 RPM is reached with the IAC motor driver, then command the IAC valve out until near 1,800 RPM is reached.
  6. Return the engine speed to the desired idle, as displayed on the scan tool.
Did the engine speed steadily decrease to near 600 RPM and steadily increase to near 1,800 RPM when the IAC valve was commanded in and out?		 - Go to Step 6  Go to Step 5 
5 Is the engine speed over 100 RPM less than the desired engine speed? - Go to Step 11  Go to Step 12 
6
  1. Turn OFF the ignition.
  2. Connect a test lamp between one of the IAC valve control circuits and a good ground.
  3. Start the engine.
  4. With the J 37027-A , command low RPM while observing a scan tool until the IAC Counts start to increment.
  5. With the J 37027-A , command high RPM while observing a scan tool until the IAC Counts start to increment.
  6. While the IAC Counts are incrementing, observe the test lamp.
  7. Return the engine idle speed to the desired idle, as displayed on the scan tool.
  8. Repeat the above procedure for the other 3 IAC valve control circuits.
IMPORTANT: If the test lamp illuminates dimly on one or more of the IAC circuits, repair the high resistance in the appropriate IAC circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did the test lamp remain ON and never flash while the IAC Counts were incrementing at any of the IAC valve control circuits?		 - Go to Step 10  Go to Step 7 
7 Did the test lamp remain OFF and never flash while the IAC Counts were incrementing at any of the IAC valve circuits during the above test? - Go to Step 9  Go to Step 8 
8
  1. Connect a test lamp between the IAC coil A low circuit and the IAC coil A high circuit at the IAC valve electrical connector.
  2. With the J 37027-A , command low RPM while observing a scan tool until the IAC counts start to increment.
  3. With the J 37027-A , command high RPM while observing a scan tool until the IAC Counts start to increment.
  4. While the IAC counts are incrementing, observe the test lamp.
  5. Return engine idle speed to the desired idle, as displayed on the scan tool.
  6. Repeat the above procedure with the test lamp connected between the IAC coil B low circuit and the IAC coil B high circuit at the IAC valve electrical connector.
  7. Return the engine speed to the desired idle, as displayed on the scan tool.
Did the test lamp stay illuminated and never flash while the IAC counts were incrementing during the above test?		 - Go to Diagnostic Aids Go to Step 16 
9
  1. Turn OFF the ignition.
  2. Disconnect the ECM. Refer to Engine Control Module (ECM) Replacement .
  3. Test the IAC valve circuits for an open or for a short to ground on the IAC valve circuit that the test lamp remained OFF. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 17  Go to Step 14 
10
  1. Turn ON the ignition.
  2. Test the IAC valve circuits for a short to voltage on the IAC valve circuit where the test lamp remained illuminated. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 17  Go to Step 14 
11
  1. Remove the IAC valve. Refer to Idle Air Control (IAC) Valve Replacement .
  2. Inspect for the following conditions:
    • The throttle body for damage and/or tampering
    • For a clogged IAC passage
    • For excessive deposits on the throttle plate
    • For excessive deposits in the throttle bore
    • For excessive deposits on IAC valve pintle
    • For a restricted air intake system
Did you find and correct the condition?		 - Go to Step 17  Go to Step 13 
12
  1. Remove the IAC valve. Refer to Idle Air Control (IAC) Valve Replacement .
  2. Inspect for the following conditions:
    • The throttle body for damage and/or tampering
    • For vacuum leaks
    • For an incorrectly installed PCV valve and hose
    • For a malfunctioning PCV valve
    • The throttle shaft for binding
    • The throttle linkage for binding
Did you find and correct the condition?		 - Go to Step 17  Go to Step 13 
13 Test for an intermittent and for a poor connection at the IAC Valve. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 17  Go to Step 15 
14 Test for an intermittent and for a poor connection at the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 17  Go to Step 16 
15
IMPORTANT: If the IAC valve is removed or replaced, perform the IDLE LEARN PROCEDURE .
Replace the IAC valve. Refer to Idle Air Control (IAC) Valve Replacement .Did you complete the replacement?		 - Go to Step 17  -
16
IMPORTANT: If the ECM power is removed or the ECM is replaced, perform the IDLE LEARN PROCEDURE .
Replace the ECM. Refer to Engine Control Module (ECM) Replacement .Did you complete the replacement?		 - Go to Step 17  -
17
  1. Clear the DTCs with a scan tool.
  2. Turn the ignition OFF 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.
Does the DTC fail this ignition?		 - Go to Step 2  Go to Step 18 
18 Observe the Capture Info with a scan tool.
Are there any DTCs that have not been diagnosed?		 - Go to Diagnostic Trouble Code (DTC) List System OK
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