For 1990-2009 cars

Step | Action | Yes | No
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Schematic Reference: Cooling Fan Schematics DEFINITION: The cooling fan or all Three fans ON with the ignition ON and or OFF.
1 | Did you perform the Engine Cooling Diagnostic System Check? | Go to Step 2 | Go to Cooling Fan Schematics
2 | Important: Make sure the engine temperature is below 95°C (203°F). With the ignition OFF. Is the cooling fan ON or all fans ON? | Go to Step 4 | Go to Step 3
3 | Turn ON the ignition with the engine OFF. Is the cooling fan ON high speed? | Go to Step 5 | Go to Testing for Intermittent Conditions and Poor Connections
4 | With the ignition still OFF. Is the cooling fan the only fan ON? | Go to Step 6 | Go to Step 7
5 | With the ignition still ON. Disconnect the primary cooling fan temperature switch. Does the cooling fan turn OFF? | Go to Step 18 | Go to Step 10
6 | Is the cooling fan operating at low speed? | Go to Step 12 | Go to Step 14
7 | Disconnect the primary cooling fan temperature switch? Does the cooling fan and auxiliary engine coolant fan 1 and auxiliary engine coolant fan 2 turn OFF? | Go to Step 18 | Go to Step 11
8 | Remove the K26 fan control relay. Does the cooling fan turn OFF? | Go to Step 14 | Go to Step 12
9 | Remove the K67 fan control relay. Does the cooling fan turn OFF? | Go to Step 16 | Go to Step 13
10 | Repair circuit XM5 or XM997 of the primary cooling fan temperature switch for a short to ground. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 20 | --
11 | Repair circuit XP3, XP30 or XP999 of the primary cooling fan temperature switch for a short to ground. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 20 | --
12 | Repair circuit AP1, AP2, AP3 or XU2 of the K26 relay for a short to voltage. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 20 | --
13 | Repair circuit AM6, AM16 or AM17 of the K67 relay for a short to voltage. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 20 | --
14 | Inspect for poor connections at the K26 relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find the problem? | Go to Step 20 | Go to Step 15
15 | Notice: Installation of the proper relay is critical. If an enhanced relay -- equipped with a diode -- is installed into a position requiring a standard relay -- equipped without a diode -- excessive current will damage any components associated with the relay or its associated circuits.

Replace the fan control relay K26.

Did you complete the repair?

Go to Step 20

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16 | Inspect for poor connections at the K67 relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find the problem? | Go to Step 20 | Go to Step 17
17 | Notice: Installation of the proper relay is critical. If an enhanced relay -- equipped with a diode -- is installed into a position requiring a standard relay -- equipped without a diode -- excessive current will damage any components associated with the relay or its associated circuits.

Replace the fan control relay K67.

Did you complete the repair?

Go to Step 20

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18 | Inspect for poor connections at the primary cooling fan temperature switch . Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find the problem? | Go to Step 20 | Go to Step 19
19 | Replace the primary cooling fan temperature switch. Refer to Engine Cooling Fan Control Switch Replacement . Did you complete the repair? | Go to Step 20 | --
20 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2