Cooling Fan Inoperative. Chevrolet Cobalt 2005

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 2005 🢒 Cobalt 🢒 Engine 🢒 Engine Cooling 🢒 Cooling Fan Inoperative

Cooling Fan Inoperative 2.0L

Step	Action	Yes	No
Schematic Reference: Engine Cooling Schematics Connector End View Reference: Cooling System Connector End Views DEFINITION: One or both cooling fan motors are inoperative in either high, low, or both speeds.
1	Did you perform the Diagnostic System Check - Vehicle?	Go to Step 2	Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2	Install a scan tool. Turn ON the engine. With a scan tool, monitor the engine coolant temperature (ECT) in the Inputs/Outputs scan tool data. Bring the vehicle up to normal operating temperature. At 106°C (223°F) the low speed engine cooling fans should engage. Do the low speed engine cooling fans engage?	Go to Step 3	Go to Step 4
3	Important:: A 3 second delay occurs before the powertrain control module (PCM) changes the cooling fan speed. With a scan tool, monitor the ECT in the Inputs/Outputs scan tool data. At 110°C (230°F) the high speed engine cooling fans should engage. Do the high speed engine cooling fans engage?	Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems	Go to Step 6
4	Important: Do NOT remove the jumper wire that you will be connecting until your testing is completed. If the cool fan 1 fuse opens when you connect the jumper wire, repair the cooling fan motor supply voltage circuit of the left cooling fan motor for a short to ground. Disconnect the cool fan 1 relay. Connect a jumper wire between the battery positive voltage circuit and the cooling fan motor supply voltage circuit of the cool fan 1 relay. Do both cooling fans operate in low speed?	Go to Step 14	Go to Step 5
5	Disconnect the S/P fan relay. With a test lamp connected to a good ground, probe the cooling fan low reference circuit at the S/P fan relay. Does the test lamp illuminate?	Go to Step 9	Go to Step 8
6	Does the left cooling fan operate at high speed?	Go to Step 16	Go to Step 7
7	Inspect the ground circuit of the S/P fan relay for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 25	Go to Step 15
8	Install the S/P fan relay. Disconnect the left cooling fan electrical connector. With a test lamp connected to a good ground, probe the cooling fan motor supply voltage circuit at the left cooling fan motor connector. Does the test lamp illuminate?	Go to Step 12	Go to Step 13
9	Install the S/P fan relay. Disconnect the right cooling fan motor connector. With a test lamp connected to a good ground, probe the cooling fan motor supply voltage circuit at the right cooling fan connector. Does the test lamp illuminate?	Go to Step 11	Go to Step 10
10	Inspect the cooling fan motor supply voltage circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 25	Go to Step 15
11	Inspect the ground circuit of the right cooling fan for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 25	Go to Step 18
12	Inspect the cooling fan low reference circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 25	Go to Step 17
13	Inspect the cooling fan motor supply voltage circuit of the left cooling fan for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 25	Go to Step 19
14	Inspect for poor connections at the cool 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 25	Go to Step 20
15	Inspect for poor connections at the S/P fan 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 25	Go to Step 21
16	Inspect for poor connections at the cool 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 25	Go to Step 22
17	Inspect for poor connections at the harness connector of the left cooling fan. 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 25	Go to Step 23
18	Inspect for poor connections at the harness connector of the right cooling fan. 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 25	Go to Step 24
19	Repair the battery positive voltage circuit for an open or high resistance. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?	Go to Step 25	--
20	Replace the cool fan 1 relay. Did you complete the replacement?	Go to Step 25	--
21	Replace the S/P fan relay. Did you complete the replacement?	Go to Step 25	--
22	Replace the cool fan 2 relay. Did you complete the replacement?	Go to Step 25	--
23	Replace the left cooling fan. Refer to Cooling Fan and Shroud Replacement . Did you complete the replacement?	Go to Step 25	--
24	Replace the right cooling fan. Refer to Cooling Fan and Shroud Replacement . Did you complete the replacement?	Go to Step 25	--
25	Operate the system in order to verify the repair. Did you correct the condition?	System OK	Go to Step 3

Cooling Fan Inoperative 2.2L

Diagnostic Instructions

•	Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

•	Review Strategy Based Diagnosis for an overview of the diagnostic approach.

The engine control module (ECM) grounds the low speed relay, which is relay 1, and the high speed relay, which is relay 2, control circuits through an internal solid state device called a driver. The primary function of the driver is to supply the ground for the component being controlled. Each driver has a fault line that is monitored by the ECM. When the ECM is commanding a component ON, the voltage potential of the control circuit should be low, near 0 volts. When the ECM is commanding the control circuit to a component OFF, the voltage potential of the circuit should be high, near battery voltage. If the ECM detects that the actual state of the control circuit does not match the expected state, a DTC will set.

Reference Information

Schematic Reference

Engine Cooling Schematics

Connector End View Reference

•	Cooling System Component Views

•	Cooling System Connector End Views

•	Engine Control Module Connector End Views

Description and Operation

Cooling System Description and Operation

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

•	Electrical Center Identification Views

DTC Type Reference

Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

•	Scan Tool Data List

•	Scan Tool Data Definitions

•	Scan Tool Output Controls

Circuit/System Verification

If DTCs P0480 or P0481 are set, then perform those diagnostics first.
Ignition ON, command each relay ON and OFF with a scan tool. Observe to verify that the fan turns ON and OFF with each command.

Circuit/System Testing

Important: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

Ignition OFF, disconnect the affected relay.
Connect a 30A fused jumper wire between the positive voltage terminal at the battery and the fan voltage supply circuit terminal and verify fan activation.

⇒	If the fan does not activate, test the fan voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal, test the fan ground circuit for an open/high resistance. If the fan did not activate and the circuits test normal, replace the fan.

Ignition ON, connect a 30A fused jumper wire between the relay switch voltage supply circuit terminal and the fan voltage supply circuit terminal and verify fan activation.

⇒	If the fan does not activate, test the relay switch voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and it's fuse is open, test all connected components and replace as necessary.

If the fan and all circuits test normal, replace the relay.

Repair Instructions

•	Cooling Fan and Shroud Replacement

•	Fan Shroud Replacement

•	Engine Control Module Replacement for the 2.2L engine

Repair Verification

Ignition ON, command each relay ON and OFF with a scan tool. Observe to verify that each fan turns ON and OFF with each command.