GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2004 🢒 XLR 🢒 Engine 🢒 Engine Cooling 🢒 Cooling Fan Inoperative

Diagnostic Aids

Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. Verifies the operation of the cooling fan.

    2.

  2. Tests the battery positive voltage circuit for voltage.

    3.

  3. Tests the cooling fan speed control circuit for voltage.

Step

Action

Values

Yes

No

Schematic Reference: Engine Cooling Schematics

Connector End View Reference: Cooling System Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

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Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, command the cooling fan ON and OFF.

Does the cooling fan turn ON and OFF with each command?

--

Go to Diagnostic Aids

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the cooling fan.
  3. Probe the battery positive voltage circuit of the cooling fan assembly with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

--

Go to Step 4

Go to Step 7

4

Inspect the ground circuit of the cooling fan assembly for an open. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair

--

Go to Step 12

Go to Step 5

5

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Command the cooling fan ON to 90 %.
  4. Measure the voltage on the cooling fan speed control circuit.

Is the voltage near the specified value?

0.45 V

Go to Step 8

Go to Step 6

6

Inspect the cooling fan speed control circuit for an open short to ground or short to voltage. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 12

Go to Step 10

7

Repair the battery positive voltage circuit of the cooling fan assembly for an open or short to ground. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 12

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8

Inspect for poor connections at the cooling fan assembly. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 12

Go to Step 9

9

Replace the cooling fan assembly. Refer to Cooling Fan and Shroud Replacement .

Did you complete the replacement?

--

Go to Step 12

--

10

Inspect for poor connections at the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 12

Go to Step 11

11

Important: Perform the setup procedure for the ECM.

Replace the ECM. Refer to Engine Control Module Replacement in Engine Controls.

Did you complete the replacement?

--

Go to Step 12

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12

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2