LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 549 (Electric Cooling Fans) >> Diagnostic Tests >> DTC P1482 >> Test

DTC P1482: 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. Did you perform the Engine Cooling Diagnostic System Check? If so, go to next step. If not, go to DIAGNOSTIC SYSTEM CHECK - ENGINE COOLING  under SELF-DIAGNOSTIC SYSTEM.
  2. With a scan tool, observe the Powertrain DTC list. Start the engine. Operate the vehicle within the CONDITIONS FOR RUNNING THE DTC  . Does the scan tool indicate the DTC Failed this ignition cycle? If so, go to step  5 . If not, go to next step.
    3. NOTE: DTC P1482 (with 4.2L) will set when the cooling fan relay is disconnected.
  3. 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 engage? If so, go to next step. If not, go to step  5 .
    4. NOTE: Continuously excessive fan noise is due to the PCM commanding the cooling fan to 100 percent engaged or a mechanical failure. If the fan noise decreases during this step, then this DTC is due to an electrical malfunction. Replacing the cooling fan will not correct the condition.
  4. 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 clutch disengage? If so, go to next step. If not, go to step  17 .
  5. Install a scan tool. Start the engine. Observe the Fan Speed parameter in the powertrain control module Output Controls. With a scan tool, command the fan speed to increase. Does the Fan Speed increase? If so, go to DIAGNOSTIC AIDS  . If not, go to next step.
  6. Turn OFF the ignition. Disconnect the cooling fan relay. Turn ON the ignition, with the engine OFF. Probe the ignition 1 voltage circuit of the cooling fan relay with a test lamp connected a good ground. Does the test lamp illuminate? If so, go to next step. If not, go to step  11 .
  7. Test the cooling fan clutch control circuit of the cooling fan relay for a short to voltage or an open. Did you find and correct the condition? If so, go to step  19 . If not, go to next step.
  8. Test the cooling fan clutch control circuit of the cooling fan relay for a short to ground. Did you find and correct the condition? If so, go to step  19 . If not, go to next step.
  9. Connect a test lamp to the cooling fan clutch control circuit of the cooling fan relay and ground. Connect a digital multimeter (DMM) to the test lamp probe and ground. Set the DMM to A/C range and select frequency. Start the engine. Verify that the Fan Control is commanded to zero percent. Is the frequency less than out of limits? If so, go to step  14 . If not, go to next step.
  10. Command the Fan Control to 100 percent. Does the frequency fluctuate? If so, go to step  13 . If not, go to step  14 .
  11. Inspect the Eng Fan fuse. Is the fuse open? If so, go to next step. If not, go to step  15 .
  12. Test the cooling fan clutch control circuit of the cooling fan relay for a short to ground. Did you find and correct the condition? If so, go to step  19 . If not, go to step  15 .
  13. Inspect for poor connections at the cooling fan relay. See INTERMITTENT OR POOR CONNECTIONS  under TROUBLE SHOOTING. Did you find and correct the condition? If so, go to step  19 . If not, go to step  16 .
  14. Inspect for poor connections at the harness connector of the PCM. See INTERMITTENT OR POOR CONNECTIONS  under TROUBLE SHOOTING. Did you find and correct the condition? If so, go to step  19 . If not, go to step  18 .
  15. Repair the ignition 1 voltage circuit of the cooling fan relay. Did you complete the repair? If so, go to step  19 .
  16. Replace the cooling fan relay. See COOLING FAN RELAY  under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step  19 .
  17. Replace the cooling fan clutch. See FAN CLUTCH  under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step  19 .
  18. Replace and program the PCM. See appropriate REMOVAL & INSTALLATION article in ENGINE PERFORMANCE. Did you complete the replacement? If so, go to next step.
  19. Use the scan tool in order to clear the DTCs. Operate the vehicle within the CONDITIONS FOR RUNNING THE DTC  . Does the DTC reset? If so, go to step  2 . If not, system is OK.
scientia non olet · About LEMON Manuals