Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Engine Cooling 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 | |
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 |
Does the auxiliary engine coolant fan 2 turn OFF? | Go to Step 27 | Go to Step 17 |
9 |
Does the auxiliary engine coolant fan 1 and auxiliary engine coolant fan 2 turn OFF? | Go to Step 12 | Go to Step 10 |
10 |
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 | -- |
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 | -- |
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 | -- |
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 | -- |
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 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 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 |
