For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
Schematic Reference: Radiator Shutter Schematics DEFINITION: The radiator shutters do not close when the engine coolant temperature is below 90.6°C (195°F).
1 | Did you review the radiator shutter system operation and perform the necessary inspections? | Go to Step 2 | Go to Symptoms - Engine Cooling
2 |

1. Turn ON the ignition, with the engine OFF.
2. Verify that the engine coolant temperature is below 90.6°C (195°F).

Are the radiator shutters closed?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3 |

1. Turn OFF the ignition.
2. Disconnect the radiator shutter/engine coolant temperature (RS/ECT) switch.
3. Turn ON the ignition.
4. Connect a test lamp between the coolant temperature signal circuit and the ground circuit of the RS/ECT connector.

Does the test lamp illuminate?

Go to Step 9

Go to Step 4

4 | Probe the coolant temperature signal circuit with a test lamp that is connected to a good ground. Does the test lamp illuminate? | Go to Step 8 | Go to Step 5
5 |

1. Turn OFF the ignition.
2. Connect a fused jumper wire between the coolant temperature signal circuit and the ground circuit of the RS/ECT connector.
3. Disconnect the radiator shutter valve assembly
4. Turn ON the ignition.
5. Probe the ignition 1 voltage circuit with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 7

Go to Step 6

6 | Repair the ignition 1 voltage circuit for an open, short to ground, or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | --
7 | Test the coolant temperature signal circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 10
8 | Repair the ground circuit of the RS/ECT switch for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | --
9 | Inspect for loose or poor connections at the RS/ECT switch. 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 13 | Go to Step 11
10 | Inspect for loose or poor connections at the radiator shutter valve assembly. 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 13 | Go to Step 12
11 | Replace the radiator shutter/engine coolant temperature (ECT) switch. Refer to Shutter Engine Coolant Temperature Sensor Replacement . Did you complete the repair? | Go to Step 13 | --
12 | Replace the radiator shutter valve assembly. Refer to Shutter Valve Replacement . Did you complete the repair? | Go to Step 13 | --
13 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2