Test Description
The numbers below refer to the step numbers on the diagnostic table.
- 2: Listen for an audible click when the low speed fan relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
- 3: Listen for an audible click when the S/P and high speed fan 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 low speed fan 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 high speed fan relays turn ON and OFF with each command? | Go to Diagnostic Aids | Go to Step 6 |
| 4 | Turn OFF the ignition. Disconnect the low speed fan relay. Turn ON the ignition, with the engine OFF. Probe the ignition 3 voltage circuit of the low speed fan 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 low speed fan relay and the ignition 3 voltage circuit of the low speed fan 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 high speed fan relay. Turn ON the ignition, with the engine OFF. Probe the ignition 3 voltage circuit of the high speed fan 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 high speed fan relay and the ignition 3 voltage circuit of the high speed 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 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 ignition 3 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 low speed 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 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 high speed 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 19 |
| 15 | Inspect for poor connections at the harness connector of the powertrain control module (PCM). 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 ignition 3 voltage circuit for an open or high resistance. Refer to Wiring Repairs . Did you complete the repair? | Go to Step 21 | |
| 17 | Replace the low speed fan 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 high speed fan relay. Did you complete the repair? | Go to Step 21 | |
| 20 | Replace the PCM. 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
Circuit/System Description
The low engine coolant level indicator lamp is controlled by the engine control module (ECM). The normal state of the engine coolant level switch is closed when in contact with coolant.
The optional coolant heater operates using 110 volt AC external power and is designed to warm the coolant in the engine block area for improved starting in very cold weather. The coolant heater helps reduce fuel consumption when a cold engine is warming up. The unit is equipped with a detachable AC power cord. A weather shield on the cord is provided to protect the plug when not in use.
The optional coolant heater operates using 110 volt AC external power and is designed to warm the coolant in the engine block area for improved starting in very cold weather. There is an internal thermal switch in the power cord that prevents operation above -18°C (0°F). The coolant heater helps reduce fuel consumption when a cold engine is warming up. The unit is equipped with a detachable AC power cord. A weather shield on the cord is provided to protect the plug when not in use.
Reference Information
Electrical Information Reference
- «Circuit Testing»(ref-277884-S17422072462008012100000)
- «Connector Repairs»(ref-277884-S12371167392008012100000)
- «Testing for Intermittent Conditions and Poor Connections»(ref-277884-S20700666652008012100000)
- «Wiring Repairs»(ref-277884-S08861102212008012100000)
The optional coolant heater operates using 110 volt AC external power and is designed to warm the coolant in the engine block area for improved starting in very cold weather. There are two heater cords available. One has an internal thermal switch in the power cord that prevents operation above -18°C (0°F) and the other operates at all temperatures. A weather shield on the cord is provided to protect the plug when not in use.