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Test A: Excessive Fan Noise: Test

WARNING: This page is about a different car, the 2002 Oldsmobile Bravada, 2002 GMC Envoy XL, 2002 GMC Envoy, and 2002 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
  1. If the Engine Cooling Diagnostic System Check was performed, go to next step. If the Engine Cooling Diagnostic System Check was not performed, go to DIAGNOSTIC SYSTEM CHECK - ENGINE COOLING  under SELF-DIAGNOSTIC SYSTEM.
  2. Rotate the cooling fan 3 complete revolutions. Is the resistance of the cooling fan clutch even through out each rotation? If so, go to step  4 . If not, go to next step.
  3. Inspect the cooling fan clutch for proper installation. Did you find and correct the condition? If so, go to step  9 . If not, go to step  7 .
    4. NOTE: DTC P1482 (on 4.2L), or P0480, (on 5.3L) will set when the cooling fan relay is disconnected.
  4. Turn OFF the ignition. Disconnect the coolant fan relay. Connect a 10-amp fused jumper wire between the cooling fan clutch supply voltage circuit of the cooling fan and the ignition 3 voltage circuit of the cooling fan relay. Start the engine. Raise engine speed to 2000 RPM for 2 minutes. Does the cooling fan clutch engage? If so, go to next step. If not, go to step  7 .
    5. NOTE: Continuous excessive fan noise is due to a mechanical failure. If the fan noise decreases during this step, then there is an electrical malfunction. Replacing the cooling fan clutch will not correct the condition.
  5. Turn OFF the ignition. Remove the 10-amp fused jumper wire. Install cooling fan relay. Disconnect the cooling fan clutch connector. Start the engine. Raise engine speed to 2000 RPM for 2 minutes. Does the cooling fan disengage? If yes, system is OK. If not, go to next step.
  6. Turn OFF the ignition. Connect the cooling fan clutch connector. Turn ON the ignition, with the engine OFF. With a scan tool, clear all DTCs. Start the engine. Test drive vehicle. With a scan tool, observe the DTC list. Does the scan tool display any cooling system DTCs? If so, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS  . If not, system is OK.
  7. Inspect for poor connections at the harness connector of the cooling fan clutch. See INTERMITTENT OR POOR CONNECTIONS  under TROUBLE SHOOTING. Did you find and correct the condition? If so, go to step  9 . If not, go to next step.
  8. Replace the cooling fan clutch. See FAN CLUTCH  under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to next step.
  9. Operate the system in order to verify the repair. Did you correct the condition? If yes, system is OK. If not, go to step  3 .
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