Test Description
The numbers below refer to the step numbers on the diagnostic table.
- 2: Listen for an audible click when the cool fan relay 1 operates. Command both the ON and OFF states. Repeat the commands, as necessary.
- 3: Listen for an audible click when the S/P and cool fan 2 relays operate. Command both the ON and OFF states. Repeat the commands, as necessary.
| Step | Action | 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? | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 | Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, command the Fans Low Speed ON and OFF. Does the cool fan 1 relay turn ON and OFF with each command? | Go to Step 3 | Go to Step 4 |
| 3 | With a scan tool, command the Fans High Speed ON and OFF. Do the S/P and the cool fan 2 relays turn ON and OFF with each command? | Go to Diagnostic Aids | Go to Step 6 |
| 4 | Turn OFF the ignition. Disconnect the cool fan 1 relay. Turn ON the ignition, with the engine OFF. Probe the battery voltage circuit of the cool fan 1 relay with a test lamp that is connected to a good ground. Does the test lamp illuminate? | Go to Step 5 | Go to Step 16 |
| 5 | Connect a test lamp between the control circuit of the cool fan 1 relay and the battery voltage circuit of the cool fan 1 relay. With a scan tool, command the Fans Low Speed ON and OFF. Does the test lamp turn ON and OFF with each command? | Go to Step 12 | Go to Step 9 |
| 6 | Turn OFF the ignition. Disconnect the cool fan 2 relay. Turn ON the ignition, with the engine OFF. Probe the battery voltage circuit of the cool fan 2 relay with a test lamp that is connected to a good ground. Does the test lamp illuminate? | Go to Step 7 | Go to Step 16 |
| 7 | Connect a test lamp between the control circuit of the cool fan 2 relay and the battery voltage circuit of the cool fan 2 relay. With a scan tool, command the Fans High Speed ON and OFF. Does the test lamp turn ON and OFF with each command? | Go to Step 14 | Go to Step 8 |
| 8 | Turn OFF the ignition. Disconnect the S/P fan relay. Turn ON the ignition, with the engine OFF. Connect a test lamp between the control circuit of the S/P fan relay and the battery voltage circuit of the S/P fan relay. With a scan tool, command the Fans High Speed ON and OFF. Does the test lamp turn ON and OFF with each command? | Go to Step 13 | Go to Step 9 |
| 9 | Does the test lamp remain illuminated with each command? | Go to Step 11 | Go to Step 10 |
| 10 | Test the control circuit of the appropriate relay for a short to voltage or an open. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs . Did you find and correct the condition? | Go to Step 21 | Go to Step 15 |
| 11 | Test the control circuit of the appropriate relay for a short to ground. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs . Did you find and correct the condition? | Go to Step 21 | Go to Step 15 |
| 12 | Inspect for poor connections at the cool fan 1 relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 21 | Go to Step 17 |
| 13 | Inspect for poor connections at the S/P fan relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 21 | Go to Step 18 |
| 14 | Inspect for poor connections at the cool 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 21 | Go to Step 19 |
| 15 | Inspect for poor connections at the harness connector of the powertrain control module (PCM) or engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 21 | Go to Step 20 |
| 16 | Repair the battery voltage circuit for an open or high resistance. Refer to Wiring Repairs . Did you complete the repair? | Go to Step 21 | |
| 17 | Replace the cool fan 1 relay. Did you complete the repair? | Go to Step 21 | |
| 18 | Replace the S/P fan relay. Did you complete the repair? | Go to Step 21 | |
| 19 | Replace the cool fan 2 relay. Did you complete the repair? | Go to Step 21 | |
| 20 | Replace the PCM or ECM. Refer to Control Module References for replacement, setup and programming. Did you complete the replacement? | Go to Step 21 | |
| 21 | Use the scan tool in order to clear the DTCs. Operate the vehicle within the Conditions for Running the DTC, as specified in the supporting text. Does the DTC reset? | Go to Step 2 | System OK |
DTC P0480 or P0481