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Home >> Pontiac >> 2006 >> Vibe Base, AWD >> Repair and Diagnosis >> Engine Mechanical >> Cooling System (Mechanical) >> Engine Cooling System >> Diagnostic Information and Procedures >> Cooling Fan Inoperative (Inoperative in Low Speed)

Cooling Fan Inoperative (Inoperative in Low Speed)

Reference Table

Symptom Causes
Fan motor inoperative in both speeds
  • Open or short to ground in the fan 1 relay supply voltage circuits.
  • Open or short to B+ in the fan 1 relay coil control circuit.
  • Open or short to ground in the fan motor supply voltage circuit.
  • Short to ground in the fan 2 coil supply voltage circuit.
  • Open or short to B+ in the fan motor ground circuit.
  • Short to B+ in the fan 2 coil control circuit.
Fan motor inoperative in high speed only
  • Open in the fan 2 relay supply voltage circuit.
  • Open in the fan 2 relay coil control circuit.
  • Open in the fan 2 relay high speed ground circuit.
Fan motor low speed operates at high speed
  • Short to ground in the fan motor ground circuit.
  • Short to ground in the fan resistor circuit.
Fan motor inoperative in low speed only Open or short to B+ in the fan resistor circuit.
Cooling Fan Inoperative (Inoperative in Low Speed)

Step Action Yes No
Schematic Reference: Engine Cooling Schematics 
Connector End View Reference: Cooling System Connector End Views 
DEFINITION: The cooling fan motor is inoperative in low speed.
1 Did you review the Cooling System Description and Operation  and perform the necessary inspections? Go to Step 2  Go to Symptoms - Engine Cooling 
2
  1. Connect a scan tool. The engine must be below operating temperature.
  2. Use the scan tool to command the A/C compressor clutch relay ON. When the relay is energized the cooling fan will also run at low speed.
Does the cooling fan operate at low speed?		 Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems Go to Step 3 
3
  1. Remove the fan 2 relay.
  2. Install a 30 amp fused jumper between the fan motor control circuit and the low speed fan circuit (between cavities 3 and 4) of the cooling fan 2 relay connector.
  3. Use the scan tool to command the A/C compressor clutch relay ON. When the relay is energized the cooling fan will also run at low speed.
Does the cooling fan operate at low speed?		 Go to Step 6  Go to Step 4 
4 Test the low speed fan motor ground circuit for an open, or for a short to B+, between the fan 2 relay terminal 4 and S103. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Step 9  Go to Step 5 
5 Inspect for a poor connection at the harness connector of the fan resistor. 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 9  Go to Step 8 
6 Inspect for a poor connection at the harness connector of the fan 2 relay. 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 9  Go to Step 7 
7 Replace the fan 2 relay. Refer to Cooling Fan Relay Replacement .
Did you complete the replacement?		 Go to Step 9  -
8 Replace the fan resistor.
Did you complete the replacement?		 Go to Step 9  -
9 Operate the system in order to verify the repair.
Did you correct the condition?		 System OK Go to Step 3 
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