The numbers below refer to the step numbers on the diagnostic table.
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.
Verifies that the HVAC control module is providing ground to the vacuum control assembly.
Tests if ground is constantly being applied to the vacuum control assembly.
Step | Action | Values | Yes | No |
---|---|---|---|---|
Schematic Reference: HVAC 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 | |
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 speed position? | -- | 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 air flow with sufficient volume from the proper air distribution outlets in each mode position? | -- | Go to Step 6 | |
6 |
Does the recirculation door move from the recirculation to the outside air position? | -- | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 7 |
Does each vacuum solenoid turn ON and OFF with each command? | -- | Go to Step 8 | ||
8 |
Does the test lamp illuminate? | -- | Go to Step 9 | Go to Step 15 |
Does the voltage measure near the specified values for each commanded state? | 12 V (ON) 0 volts (OFF) | Go to Step 13 | Go to Step 10 | |
Does the voltage remain near the specified value with each command? | 12 V | Go to Step 12 | Go to Step 11 | |
11 | Test the suspect 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 18 | Go to Step 14 |
12 | Test the suspect 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 18 | Go to Step 14 |
13 | 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 18 | Go to Step 16 |
14 | 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 18 | Go to Step 17 |
15 | Repair the ignition 3 voltage circuit of the vacuum control assembly. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 18 | -- |
16 | Replace the vacuum control assembly. Refer to Vacuum Control Assembly Replacement . Did you complete the replacement? | -- | Go to Step 18 | -- |
17 |
Important: Perform the recalibration procedure for the HVAC control module. Replace the HVAC control module. Refer to HVAC Control Module Replacement . Did you complete the replacement? | -- | Go to Step 18 | -- |
18 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Step 2 |