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Home >> Chevrolet >> 2003 >> Tracker 2D Utility, 4WD, Automatic >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 1 (Engine Control System Self-Diagnostics - 2.5L) >> Diagnostic Tests >> DTC P0505: Idle Control System >> Diagnostic Procedures
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Diagnostic Procedures

WARNING: This page is about a different variant/trim than selected.
  1. Perform diagnostic system check - engine controls. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM. After performing diagnostic system check - engine controls, go to next step.
  2. Warm engine to normal operating temperature. Turn engine off. Turn ignition on, with engine off. Perform the scan tool Clear DTC Information function. Do not start the engine. Check for DTCs. Is there a current or pending DTC P0505 set? If yes, go to step  4 . If no, go to next step.
  3. Start and operate engine for 1 minute. Check for DTCs. Is there a current or pending DTC P0505 set? If yes,  5 . If no, see DIAGNOSTIC AIDS  .
  4. Turn ignition off. Disconnect the IAC valve electrical connector. Turn ignition on, with engine off. Probe the harness side of both IAC valve ignition positive voltage circuits with a test light connected to ground. Does the test light illuminate for both circuits? If yes, go to next step. If no, go to step  8 .
  5. Using a DVOM, measure resistance between IAC valve coil winding terminals No. 1 and 2, terminals No. 2 and 3, terminals No. 5 and 6, and terminals No. 4 and 5. Are resistances within 21-23 ohms at 68°F (20°C)? If yes, go to next step. If no, go to step  9 .
  6. Inspect the IAC coil control circuit for short to ground, open circuit, or high resistance. Repair faulty circuit. Did you find and correct condition? If yes, go to step  11 . If no, go to next step.
  7. Inspect the PCM and the IAC valve electrical connectors for faulty terminal contact. Repair as necessary. Did you find and correct condition? If yes, go to step  11 . If no, go to step  10 .
  8. Repair high resistance or open in ignition positive voltage circuit. After repairs, go to step  11 .
  9. Replace IAC valve. After repairs, go to step  11 .
  10. Turn ignition off. Replace PCM. Perform PCM relearn procedure. See POWERTRAIN CONTROL MODULE  under PROGRAMMING. After replacing PCM, go to next step.
  11. Turn ignition off. Remove DOME fuse for 30 seconds. Install DOME fuse. Reset radio clock time. Start engine. Operate vehicle within the Conditions for Running the DTC or until the DTC P0506 diagnostic test has run. See CONDITIONS FOR RUNNING DTC  . Does the DTC run and pass? If yes, go to next step. If no, go to step  2 .
  12. Using scan tool, observe stored information and Capture Info. If scan tool displays any undiagnosed DTCs, diagnose affected DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS  . If no other DTCs are displayed, system is okay.
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