Step | Action | Yes | No | ||||
|---|---|---|---|---|---|---|---|
DEFINITION: Improper air delivery.
| |||||||
1 | Were you sent here from Symptoms, or another diagnostic table? | Go to Step 18 | Go to Step 2 | ||||
2 | Did the customer concern mention that the air discharges out the correct ducts at first, but then changes during higher engine RPM? | Go to Step 11 | Go to Step 3 | ||||
3 | Cycle the HVAC controls through all the modes. Does the air come out of the selected outlet ducts now? | Go to Step 18 | Go to Step 4 | ||||
4 |
Is there engine vacuum? | Go to Step 5 | Go to Step 17 | ||||
5 | Take a vacuum reading at the vacuum supply line at the HVAC control head. Is the vacuum reading the same as engine vacuum? | Go to Step 6 | Go to Step 9 | ||||
6 | Take a vacuum reading at the output side of the HVAC control head, for the non-functioning mode setting. Refer to the vacuum schematic in HVAC Vacuum Schematics to determine the correct actuator operation. Is there vacuum at the output side of the HVAC control head? | Go to Step 7 | Go to Step 14 | ||||
7 | Disconnect the actuator vacuum line and apply vacuum to the actuator. Did the actuator retract? | Go to Step 9 | Go to Step 8 | ||||
8 | With the actuator disconnected, inspect the door for binding. Does the door move freely? | Go to Step 10 | Go to Step 15 | ||||
9 | Inspect for leaking or collapsed vacuum lines. Are the vacuum lines leaking? | Go to Step 16 | Go to Step 13 | ||||
10 | Replace the vacuum actuator. Refer to the appropriate repair: Is the repair complete? | Go to Step 18 | -- | ||||
11 | With the vacuum gage connected to the actuator vacuum line, turn the engine OFF. Does the system lose vacuum after turning OFF the engine? | Go to Step 12 | Go to Step 9 | ||||
12 |
Does the system lose vacuum after turning OFF the engine? | Go to Step 13 | Go to Step 14 | ||||
13 | Replace the vacuum reservoir tank. Refer to Vacuum Tank Replacement . Is the repair complete? | Go to Step 18 | -- | ||||
14 | Replace the HVAC control head. Is the repair complete? | Go to Step 18 | -- | ||||
15 | Repair the binding door. Refer to the appropriate repair. Is the repair complete? | Go to Step 18 | -- | ||||
16 | Repair or replace the collapsed or leaking vacuum line. Is the repair complete? | Go to Step 18 | -- | ||||
17 | Repair the no vacuum condition. Is the repair complete? | Go to Step 18 | -- | ||||
18 | Cycle the HVAC controls through all modes to verify proper operation. Did you find correct the condition? | System OK | Go to Step 2 | ||||
