Fan motor inoperative in both speeds

Fan motor inoperative in high speed only

Fan motor low speed operates at high speed

Fan motor inoperative in low speed only

Open or short to B+ in the fan resistor circuit.

Schematic Reference: Engine Cooling Schematics .

Connector End View Reference: Cooling System Connector End Views

DEFINITION: The cooling fan motor is inoperative in both fan speeds.

Did you review the Cooling System Description and Operation and perform the necessary inspections?

Go to Step  2

Go to Symptoms - Engine Cooling

Run the engine until operating temperature is reached and the thermostat opens.

Does the cooling fan operate?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step  3

1. Stop the engine.
2. Disconnect the fan motor connector.
3. Connect a test lamp across the fan motor connector.
4. Start the engine.

Does the test lamp illuminate?

Go to Step 11

Go to Step  4

1. Connect the fan motor.
2. Exchange the fan 1 relay with a known good relay (the horn relay). Refer to Cooling Fan Relay Replacement .

Does the cooling fan operate?

Go to Step 10

Go to Step 5

Test the fan 1 relay and the fan 2 relay supply voltage circuits for an open or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 6

Test the fan 1 relay coil control circuit for an open or a short to B+. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 7

Test the fan 2 relay coil control circuit for a short to B+. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step  8

Test the fan motor supply voltage circuit for an open or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 9

Test the fan motor ground circuit for an open or a short to B+. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 12

Inspect for a poor connection at the harness connector of the fan 1 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 16

Go to Step 13

Inspect for a poor connection at the harness connector of the fan motor. 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 16

Go to Step 14

Inspect for a poor connection at the harness connector of the powertrain control module (PCM). 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 16

Go to Step 15

Replace the fan 1 relay. Refer to Cooling Fan Relay Replacement .

Did you complete the replacement?

Go to Step 16

--

Replace the fan motor. Refer to Engine Cooling Fan Replacement .

Did you complete the replacement?

Go to Step 16

--

Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls LNK or Powertrain Control Module Replacement in Engine Controls LV6.

Did you complete the replacement?

Go to Step 16

--

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step  3

Fan motor inoperative in both speeds

Fan motor inoperative in high speed only

Fan motor low speed operates at high speed

Fan motor inoperative in low speed only

Open or short to B+ in the fan resistor circuit.

Schematic Reference: Engine Cooling Schematics

Connector End View Reference: Cooling System Connector End Views

DEFINITION: The cooling fan motor is inoperative in low speed.

Did you review the Cooling System Description and Operation and perform the necessary inspections?

Go to Step  2

Go to Symptoms - Engine Cooling

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

Go to Step 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

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 .

Did you find and correct the condition?

Go to Step 9

Go to Step 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 .

Did you find and correct the condition?

Go to Step 9

Go to Step 8

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 .

Did you find and correct the condition?

Go to Step 9

Go to Step  7

Replace the fan 2 relay. Refer to Cooling Fan Relay Replacement .

Did you complete the replacement?

Go to Step 9

--

Replace the fan resistor.

Did you complete the replacement?

Go to Step 9

--

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3

Fan motor inoperative in both speeds

Fan motor inoperative in high speed only

Fan motor low speed operates at high speed

Fan motor inoperative in low speed only

Open or short to B+ in the fan resistor circuit.

Schematic Reference: Engine Cooling Schematics

Connector End View Reference: Cooling System Connector End Views

DEFINITION: The engine cooling fan motor is inoperative in high speed.

Did you review the Cooling System Description and Operation and perform the necessary inspections?

Go to Step  2

Go to Symptoms - Engine Cooling

Run the engine until operating temperature is reached and the thermostat opens.

Does the cooling fan operate at high speed?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

Test the fan 2 relay coil supply voltage circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step  4

Test the fan 2 relay coil control circuits for an open or for a short to B+. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 5

1. Remove the fan 2 relay.
2. Install a 30 amp fused jumper between the fan motor control circuit and the high speed fan circuit (between cavities 3 and 5) of the fan 2 relay connector.

Does the cooling fan operate at high speed?

Go to Step  7

Go to Step 6

Test for an open in the fan 2 relay high speed ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 8

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 11

Go to Step 9

Inspect for a poor connection at the harness connector of the Powertrain Control Module (PCM). 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 11

Go to Step 10

Replace the fan 2 relay. Refer to Cooling Fan Relay Replacement .

Did you complete the replacement?

Go to Step 11

--

Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls LNK or Powertrain Control Module Replacement in Engine Controls LV6.

Did you complete the replacement?

Go to Step 11

--

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3

Fan motor inoperative in both speeds

Fan motor inoperative in high speed only

Fan motor low speed operates at high speed

Fan motor inoperative in low speed only

Open or short to B+ in the fan resistor circuit.

Schematic Reference: Engine Cooling Schematics .

Connector End View Reference: Cooling System Connector End Views

DEFINITION: The cooling fan motor low speed operates at high speed.

Did you review the Cooling System Description and Operation and perform the necessary inspections?

Go to Step  2

Go to Symptoms - Engine Cooling

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 high speed?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step  3

1. Remove the fan 2 relay.
2. Use the scan tool to command the cooling fan ON.

Does the cooling fan operate at high speed?

Go to Step  8

Go to Step  4

Test the fan 2 relay. The relay should be normally open between terminals 3 and 5 and normally closed between terminals 3 and 4.

Did the relay test OK?

Go to Step 5

Go to Step 9

Test the fan 2 relay coil control circuits for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 6

Test the refrigerant pressure switch for a closed condition. The switch should be normally open between terminals 2 and 3.

Did the switch test OK?

Go to Step 7

Go to Step 10

Inspect for a poor connection at the harness connector of the Powertrain Control Module (PCM). 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 12

Go to Step 11

Repair the short to ground in the fan motor ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 12

--

Replace the fan 2 relay. Refer to Cooling Fan Relay Replacement .

Did you complete the replacement?

Go to Step 12

--

Replace the refrigerant pressure switch. Refer to Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement in Heating,Ventilation and Air Conditioning.

Did you complete the replacement?

Go to Step 12

--

Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls LNK or Powertrain Control Module Replacement in Engine Controls LV6.

Did you complete the replacement?

Go to Step 12

--

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step  3