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 Engine Cooling Diagnostic System Check? | 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 in Wiring Systems | 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 in Wiring Systems. 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 in Wiring Systems. 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 in Wiring Systems. Did you complete the repair? | Go to Step 21 | -- |
12 | Repair the ground circuit of the cooling fan. Refer to Wiring Repairs in Wiring Systems. 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 in Wiring Systems. 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 powertrain control module (PCM). 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 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 in Wiring Systems. 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 in Wiring Systems. Did you find and correct the condition? | Go to Step 21 | Go to Step 20 |
17 | Replace the cooling fan. Refer to Engine Cooling Fan Replacement . Did you complete the replacement? | Go to Step 21 | -- |
18 |
Important: Program the PCM. Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls - 4.8L, 5.3L, and 6.0L. | Go to Step 21 | -- |
19 | Replace the cool fan 1 relay. Refer to Cooling Fan Relay Replacement . Did you complete the replacement? | Go to Step 21 | -- |
20 | Replace the cool fan 2 relay. Refer to Cooling Fan Relay Replacement . 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 |
