Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Engine Cooling Schematics Connector End View Reference: Cooling System Connector End Views DEFINITION: The engine cooling fan motor is inoperative in either high, low, or both speeds. | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |
2 |
Does the cooling fan turn ON and OFF with each command? | Go to Step 3 | Go to Step 4 |
3 | With a scan tool, command the high speed fan relay ON and OFF. Does the cooling fan turn ON and OFF with each command? | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 7 |
4 |
Does the test lamp illuminate? | Go to Step 5 | Go to Step 11 |
5 |
Does the test lamp turn ON and OFF with each command? | Go to Step 6 | Go to Step 9 |
6 | Probe the ground circuit of the cooling fan with a test lamp connected to battery positive voltage. Does the test lamp illuminate? | Go to Step 13 | Go to Step 12 |
7 |
Does the test lamp illuminate? | Go to Step 8 | Go to Step 11 |
8 |
Does the test lamp turn ON and OFF with each command? | Go to Step 13 | Go to Step 10 |
9 | Test the low speed cooling fan supply voltage circuit for a high resistance and an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 21 | Go to Step 15 |
10 | Test the high speed cooling fan supply voltage circuit for a high resistance and an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 21 | Go to Step 16 |
11 | Repair the battery positive voltage circuit of the cooling fans. Refer to Wiring Repairs . Did you complete the repair? | Go to Step 21 | -- |
12 | Repair the ground circuit of the cooling fan. Refer to Wiring Repairs . Did you complete the repair? | Go to Step 21 | -- |
13 | Inspect for poor connections at the harness connector of the cooling fan. Refer to Wiring Repairs . Did you find and correct the condition? | Go to Step 21 | Go to Step 17 |
14 | Inspect for poor connections at the harness connector of the 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 18 |
15 | Inspect for poor connections at the harness connector of 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 19 |
16 | Inspect for poor connections at the harness connector of 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 20 |
17 | Replace the cooling fan. Refer to Cooling Fan and Shroud Replacement . Did you complete the replacement? | Go to Step 21 | -- |
18 | Replace the ECM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 21 | -- |
19 | Replace the cool fan 1 relay. Did you complete the replacement? | Go to Step 21 | -- |
20 | Replace the cool fan 2 relay. Did you complete the replacement? | Go to Step 21 | -- |
21 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 3 |
