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 Engine Cooling Diagnostic System Check? | Go to Step 2 | |
2 |
Do the low speed engine cooling fans turn ON and OFF with each command? | Go to Step 3 | Go to Step 4 |
3 |
Important:: A 3-second delay occurs before the PCM changes the cooling fan speed. With a scan tool, command the Fans High Speed ON and OFF. Do the high speed engine cooling fans turn ON and OFF with each command? | 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 untill your testing is completed. If the low speed fan fuse opens when you connect the jumper wire, repair the cooling fan motor supply voltage circuit of the right cooling fan motor for a short to ground. Do both cooling fans operate in low speed? | Go to Step 14 | Go to Step 5 |
5 |
Does the test lamp illuminate? | Go to Step 9 | Go to Step 8 |
6 | Does the right 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 Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 25 | Go to Step 15 |
8 |
Does the test lamp illuminate? | Go to Step 12 | Go to Step 13 |
9 |
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 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 left cooling fan for an open or high resistance. Refer to Circuit Testing 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 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 right cooling fan for an open or high resistance. Refer to Circuit Testing 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 low speed 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 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 high speed 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 22 |
17 | 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 23 |
18 | 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 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 low speed fan 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 high speed fan relay. Did you complete the replacement? | Go to Step 25 | -- |
23 | Replace the right cooling fan. Refer to Engine Coolant Fan Motor Replacement . Did you complete the replacement? | Go to Step 25 | -- |
24 | Replace the left cooling fan. Refer to Engine Coolant Fan Motor 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 |
