GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2003 🢒 Vibe - AWD 🢒 Engine 🢒 Engine Cooling 🢒 Cooling Fan Always On

Cooling Fan Always On Always On in Low Speed

Table 1: Reference Table

Reference Table

Symptom

Causes

Fan motor always on in high speed

Short to ground in the fan 2 relay coil control circuits.

Fan motor always on in low speed
    • Short to ground in the fan 1 relay coil control circuit.
    • Short to B+ in the fan motor supply voltage circuit.

Step

Action

Yes

No

Schematic Reference: Engine Cooling Schematics

Connector End View Reference: Cooling System Connector End Views

DEFINITION: The cooling fan motor is always on 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. Ensure that the ECT is below 93°C (199°F).
  2. Depress the A/C switch to the OFF position.
  3. Turn the blower switch to the OFF position.
  4. Turn the ignition switch to the RUN position.

Is the fan motor running continuously?

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections

3

Remove the fan 1 relay from the underhood fuse block.

Is the fan motor running continuously?

Go to Step 4

Go to Step 5

4

Repair the short to voltage in the fan motor supply voltage circuit. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 7

--

5

Test the fan 1 relay coil control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 7

Go to Step 6

6

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

Did you complete the replacement?

Go to Step 7

--

7

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3

Cooling Fan Always On Always On in High Speed

Table 1: Reference Table

Reference Table

Symptom

Causes

Fan motor always on in high speed

Short to ground in the fan 2 relay coil control circuits.

Fan motor always on in low speed
    • Short to ground in the fan 1 relay coil control circuit.
    • Short to B+ in the fan motor supply voltage circuit.

Step

Action

Yes

No

Schematic Reference: Engine Cooling Schematics

Connector End View Reference: Cooling System Connector End Views

DEFINITION: The cooling fan motor is always on in high 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. Ensure that the ECT is below 93°C (199°F).
  2. Depress the A/C switch to the OFF position.
  3. Turn the blower switch to the OFF position.
  4. Turn the ignition switch to the RUN position.

Is the fan motor running continuously?

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections

3

Remove the fan 2 relay from the underhood fuse block.

Is the fan motor running continuously?

Go to Step 4

Go to Step 5

4

Repair the short to ground in one of the two fan 2 relay coil control circuits. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 6

--

5

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

Did you complete the replacement?

Go to Step 6

--

6

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3