For 1990-2009 cars

#### Improper Air Delivery or No Mode Shift

Step | Action | Yes | No
--- | --- | --- | ---
1 | Perform the function test. Refer to Function Test . Did you find the air delivery incorrect? | Go to Step 2 | System OK
2 | Inspect the affected valve actuator for the following conditions:

• | Correct vacuum hose installation

• | Proper linkage connection

Are the installations and connections correct?

Go to Step 4

Go to Step 3

3 | Reinstall the valve actuator or repair the connections as needed. Refer to Vacuum Hose Harness Replacement . Does the condition persist? | Go to Step 4 | System OK
4 |

1. Disconnect the actuator from the valve.
2. Inspect the valve for the following conditions:

• | Proper travel

• | Proper effort

• | Spring correctly installed

Is the valve operating properly?

Go to Step 6

Go to Step 5

5 | Repair the valve as needed. Does the condition persist? | Go to Step 6 | System OK
6 |

1. Remove the control assembly from the dash. Refer to Control Assembly Replacement .
2. Inspect the violet vacuum hose for engine manifold vacuum while the engine is operating.

Is the vacuum present?

Go to Step 7

Go to Step 8

7 | Using a hand vacuum pump test each vacuum hose to the actuators and the actuators for leaks? Did you find and repair the condition? | System OK | Go to Step 9
8 | Inspect for vacuum source to the vacuum tank. Did you complete the repair? | System OK | --
9 | Replace the control assembly. Did you complete the repair? | System OK | --