Test Description
The numbers below refer to the step numbers on the diagnostic table.
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Listen for an audible click or feel for the click when the vacuum control assembly operates. Command both the ON and OFF states. Repeat the commands as necessary.
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Test the control circuit of the solenoid that does not click ON and OFF. Verifies that the HVAC control module is providing ground to the solenoid in the vacuum control assembly.
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Tests if ground is constantly being applied to the vacuum control assembly.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: HVAC Air Delivery/Temperature Control Schematics DEFINITION: Air does not flow correctly from the air distribution outlets. | ||||
1 | Did you perform the HVAC Diagnostic System Check? | -- | Go to Step 2 | Go to Diagnostic System Check |
2 |
Is the blower motor OFF? | -- | Go to Step 3 | Go to Blower Motor Always On |
3 | Place the blower motor switch in each speed position. Does the blower motor operate in any of the speed positions? | -- | Go to Step 4 | Go to Blower Motor Inoperative |
4 | Does the blower motor operate in each speed position? | -- | Go to Step 5 | Go to Blower Motor Malfunction |
5 |
Does the scan tool indicate that each observed parameter changes state when the corresponding switch is activated? | -- | Go to Step 6 | Go to Step 15 |
6 |
Does the recirculation door move from the recirculation position to the outside air position? | -- | Go to Step 7 | |
7 |
Does the air flow from the correct air distribution outlets in each mode position? | -- | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 8 |
Does each vacuum solenoid turn ON and OFF with each command? | -- | Go to Vacuum Test | Go to Step 9 | |
9 |
Does the test lamp illuminate? | -- | Go to Step 10 | Go to Step 16 |
Does the voltage measure near the specified values for each commanded state? | 12 V ON 0 V OFF | Go to Step 14 | Go to Step 11 | |
Does the voltage remain near the specified value with each command? | 12 V | Go to Step 13 | Go to Step 12 | |
12 | Test the appropriate control circuit of the vacuum control assembly for a short to voltage or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 19 | Go to Step 15 |
13 | Test the appropriate control circuit of the vacuum control assembly 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 19 | Go to Step 14 |
14 | Inspect for poor connections at the vacuum control 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 19 | Go to Step 17 |
15 | Inspect for poor connections at the harness connector of the HVAC control module. 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 19 | Go to Step 18 |
16 | Repair the circuit 41 of the vacuum control assembly. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 19 | -- |
17 | Replace the vacuum control assembly. Refer to Vacuum Electrical Solenoid Replacement . Did you complete the replacement? | -- | Go to Step 19 | -- |
18 | Replace the HVAC control module. Refer to Control Assembly Replacement . Did you complete the replacement? | -- | Go to Step 19 | -- |
19 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Step 2 |
