For 1990-2009 cars

Step | Action | Yes | No
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Schematic Reference: Cooling Fan Schematics DEFINITION: Auxiliary coolant fan 1 and or 2 are ON with the ignition ON and or OFF.
1 | Did you perform the Engine Cooling Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Engine Cooling
2 | Important: Make sure the engine temperature is below 95°C (203°F). With the ignition OFF. Is one or both auxiliary engine coolant fans ON? | Go to Step 4 | Go to Step 3
3 | Turn ON the ignition with the engine OFF. Is one or both auxiliary engine coolant fans ON? | Go to Step 5 | Go to Testing for Intermittent Conditions and Poor Connections
4 | With the ignition still OFF. Is the auxiliary engine coolant fan 2 the only fan ON? | Go to Step 6 | Go to Step 7
5 | With the ignition still ON. Is the auxiliary engine coolant fan 2 the only fan ON? | Go to Step 11 | Go to Step 15
6 | Remove the K52 fan control relay. Does the auxiliary engine coolant fan 2 turn OFF? | Go to Step 16 | Go to Step 8
7 | Remove the K60 a/c compressor relay. Does the auxiliary engine coolant fan 1 and auxiliary engine coolant fan 2 turn OFF? | Go to Step 25 | Go to Step 9
8 |

1. Install the K52 relay.
2. Remove the K28 fan control relay.

Does the auxiliary engine coolant fan 2 turn OFF?

Go to Step 27

Go to Step 17

9 |

1. Install the K60 relay.
2. Remove the K87 fan control relay.

Does the auxiliary engine coolant fan 1 and auxiliary engine coolant fan 2 turn OFF?

Go to Step 12

Go to Step 10

10 |

1. Install the K28 relay.
2. Remove the K26 fan control relay.

Does the auxiliary engine coolant fan 1 and auxiliary engine coolant fan 2 turn OFF?

Go to Step 21

Go to Step 18

11 | Disconnect the secondary cooling fan temperature switch. Does the auxiliary engine coolant fan 2 turn OFF? | Go to Step 29 | Go to Step 13
12 | Inspect circuit U2, U3, or U4 of the K87 relay for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 35 | Go to Step 23
13 | Reconnect the secondary cooling fan temperature switch. Inspect circuit XM122, XM123, XM124 or XM997 of the secondary cooling fan temperature switch for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 35 | Go to Step 14
14 | Disconnect the a/c compressor refrigerant pressure switch. Does the auxiliary engine coolant fan 2 turn OFF? | Go to Step 31 | Go to Step 20
15 | Disconnect the ECM connector. Does the auxiliary engine coolant fan 1 and auxiliary engine coolant fan 2 turn OFF? | Go to Step 33 | Go to Step 19
16 | Repair circuit XU3 of the K52 relay for a short to voltage. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 35 | --
17 | Repair circuit AM4 or AM5 of the K28 relay for a short to voltage. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 35 | --
18 | Repair circuit AM1, AM12 or AM13 of the K26 relay for a short to voltage. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 35 | --
19 | Repair circuit XY107, XY380 or BP1 of the ECM for a short to ground. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 35 | --
20 | Repair circuit XM10, XM20 or XM999 of the a/c compressor refrigerant pressure switch for a short to ground. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 35 | --
21 | 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 35 | Go to Step 22
22 | 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 35

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23 | Inspect for poor connections at the K87 relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find the problem? | Go to Step 35 | Go to Step 24
24 | 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 K87

Did you complete the repair?

Go to Step 35

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25 | Inspect for poor connections at the K60 relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find the problem? | Go to Step 35 | Go to Step 26
26 | 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 a/c compressor relay K60.

Did you complete the repair?

Go to Step 35

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27 | Inspect for poor connections at the K28 relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find the problem? | Go to Step 35 | Go to Step 28
28 | 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 K28.

Did you complete the repair?

Go to Step 35

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29 | Inspect for poor connections at the secondary 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 35 | Go to Step 30
30 | Replace the secondary cooling fan temperature switch. Refer to Engine Cooling Fan Control Switch Replacement . Did you complete the repair? | Go to Step 35 | --
31 | Inspect for poor connections at the A/C compressor refrigerant pressure switch . Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find the problem? | Go to Step 35 | Go to Step 32
32 | Replace the A/C compressor refrigerant pressure switch. Refer to Air Conditioning (A/C) High Pressure Cut-Out Switch Replacement in Heating, Ventilation and Air Conditioning. Did you complete the repair? | Go to Step 35 | --
33 | Inspect for poor connections at the ECM . Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find the problem? | Go to Step 35 | Go to Step 34
34 | Replace the ECM. Refer to Engine Control Module Replacement/Programming in Engine, Engine Controls. Did you complete the repair? | Go to Step 35 | --
35 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2