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Home >> Saturn >> 2000 >> SW2 Automatic >> Repair and Diagnosis (Single Page) >> Engine Mechanical >> Cooling Fan >> Engine Cooling Fan System - Troubleshooting >> Electric Cooling Fan Circuit Diagnosis >> 3.0L CATERA >> Cooling Fan System Check

Cooling Fan System Check

  1. Turn ignition on, engine off. If heater water auxiliary pump operates, go to next step. If heater water auxiliary pump does not operate, repair heater water auxiliary pump as necessary.
  2. Ensure engine temperature is less than 203°F (95°C). If auxiliary engine coolant fans and/or electric cooling fan operating with engine temperature less than 203°F (95°C), see AUXILIARY COOLING FAN RUNS CONTINUOUSLY . If auxiliary engine coolant fans and/or electric cooling fan are not operating with engine temperature less than 203°F (95°C), go to next step.
  3. Connect fused jumper (5 amp) between fan control relay K26 diagnostic enable circuit and a known ground. Grounding fan control relay K26 diagnostic enable circuit will simulate closing of primary coolant fan temperature switch stage 1 contacts, this will energize fan control relay K26. If auxiliary engine coolant fan 1 and auxiliary engine coolant fan 2 operate at low speed, go to next step. If auxiliary engine coolant fan 1 and auxiliary engine coolant fan 2 do not operate at low speed, see AUXILIARY COOLING FANS NO. 1 & 2 INOPERATIVE .
  4. Observe electric cooling fan. If electric cooling fan operating at low speed, go to next step. If electric cooling fan does not operate at low speed, see COOLING FAN LOW SPEED INOPERATIVE .
  5. Turn ignition off. Leave all previously connected jumpers connected. If water auxiliary pump operates, go to next step. If water auxiliary pump does not operate, repair water auxiliary pump as necessary.
  6. Turn ignition on, engine off. Leave all previously connected jumpers connected. Connect fused jumper (5 amp) between fan control relay K28 and fan control relay K52 diagnostic enable circuit and ground. Grounding fan control relay K28 and fan control relay K52 diagnostic enable circuit will simulate closing of secondary cooling fan temperature switch, this will energize fan control relay K28 and fan control relay K52. If auxiliary engine coolant fan 1 operates at high speed, go to next step. If auxiliary engine coolant fan 1 does not operate at high speed, see AUXILIARY ENGINE COOLING FAN NO. 1 INOPERATIVE .
  7. Observe auxiliary engine coolant fan 2. If auxiliary engine coolant fan 2 operates at high speed, go to next step. If auxiliary engine coolant fan 2 does not operate at high speed, see AUXILIARY ENGINE COOLING FAN NO. 2 INOPERATIVE .
  8. Leave all previously connected jumpers connected. Connect fused jumper (5 amp) between fan control relay K67 diagnostic enable circuit and ground. Grounding fan control relay K67 diagnostic enable circuit will simulate closing of primary cooling fan temperature switch stage 2 contacts. This will energize fan control relay K67. If electric cooling fan operates at high speed, go to next step. If electric cooling fan does not operate at high speed, see COOLING FAN HIGH SPEED INOPERATIVE .
  9. Remove all previously connected jumpers. Start engine. Turn A/C compressor clutch coil on. If auxiliary engine coolant fan 1 and auxiliary engine coolant fan 2 operate at low speed when compressor clutch coil is turned on, go to next step. If auxiliary engine coolant fan 1 and auxiliary engine coolant fan 2 do not operate at low speed when compressor clutch coil is turned on, see AUXILIARY COOLING FANS INOPERATIVE AT LOW SPEED .
  10. Install scan tool. Monitor engine coolant temperature using scan tool. Remove any previously connected jumpers. Turn A/C compressor clutch coil off. Allow engine to run until primary cooling fan temperature switch reaches 212°F (100°C). Stage 1 contacts should close and energize fan control relay K26. If auxiliary engine coolant fan 1 and auxiliary engine coolant fan 2 operate at low speed, go to next step. If auxiliary engine coolant fan 1 and auxiliary engine coolant fan 2 do not operate at low speed, go to step  12.
  11. Continue to allow engine to run until secondary cooling fan temperature switch reaches 221°F (105°C). Secondary cooling fan temperature switch should close and energize fan control relay K28 and fan control relay K52. If auxiliary engine coolant fan 1 and auxiliary engine coolant fan 2 operate at high speed, go to step  15. If auxiliary engine coolant fan 1 and auxiliary engine coolant fan 2 do not operate at high speed, go to step  16.
  12. Check control circuit (Brown/Blue wire) of fan control relay K26 for an open. If problem was found, repair as necessary. After repairs, go to step  21. If problem was not found, go to next step.
  13. Check ground circuit (Black wire) of primary cooling fan temperature switch for open. If problem was found, repair as necessary. After repairs, go to step  21. If problem was not found, go to next step.
  14. Replace primary cooling fan temperature switch. After repairs, go to step  21.
  15. Continue to allow engine to run until primary cooling fan temperature switch reaches 230°F (110°C). Stage 2 contacts should close and energize fan control relay K67. If electric cooling fan operates at high speed, go to step  20. If electric cooling fan does not operate at high speed, go to step  18.
  16. Check control circuit (Brown/White wire) of fan control relay K28 and fan control relay K52 for open. If problem was found, repair as necessary. After repairs, go to step  21. If problem was not found, go to next step.
  17. Replace secondary cooling fan temperature switch. After repairs, go to step  21.
  18. Check control circuit (Brown/White wire) of fan control relay K67 for open. If problem was found, repair as necessary. After repairs, go to step  21. If problem was not found, go to next step.
  19. Replace primary cooling fan temperature switch. After repairs, go to step  21.
  20. Install A/C manifold gauge set to monitor A/C refrigerant pressure. Turn A/C compressor clutch coil on. Continue to operate engine until A/C refrigerant pressure switch reaches 275 psi. If auxiliary engine coolant fan 1 and auxiliary engine coolant fan 2 operate at high speed, go to next step. If auxiliary engine coolant fan 1 and auxiliary engine coolant fan 2 do not operate at high speed, see AUXILIARY COOLING FANS INOPERATIVE AT HIGH SPEED .
  21. If engine cooling fans and auxiliary water pumps operate properly, system is okay.
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