Step | Action | Values | Yes | No | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: HVAC Schematics DEFINITION: Air does not flow correctly from the air distribution outlets. | ||||||||||||||||
1 | Did you review the HVAC operation and perform the necessary inspections? | -- | 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 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 | Place the mode switch in each mode position. Is the airflow sufficient from the correct outlets in each mode? | -- | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 6 | ||||||||||||
6 |
Does the voltage measure near specified value? | 1-12 V | Go to Step 7 | Go to Step 10 | ||||||||||||
7 |
Does voltage measure near the specified value? | 5 V | Go to Step 8 | Go to Step 12 | ||||||||||||
8 |
Important: Ensure the mode actuator connector is connected during this step in order to avoid misdiagnosis.
Does the voltage measure within the specified values with a smooth transition between vent and defrost? | 0.5-4.5 V | Go to Step 9 | Go to Step 13 | ||||||||||||
9 | Inspect the mode door and the mode actuator for the following conditions:
Did you find and correct the condition? | -- | Go to Step 19 | Go to Step 15 | ||||||||||||
10 | Test the mode door control A circuit of the mode actuator for an open, high resistance, short to ground, or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 19 | Go to Step 11 | ||||||||||||
11 | Test the mode door control B circuit of the mode actuator for an open, high resistance, short to ground, or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 19 | Go to Step 16 | ||||||||||||
12 | Test the mode actuator 5-volt reference circuit of the mode actuator for an open, high resistance, short to ground, or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 19 | Go to Step 13 | ||||||||||||
13 | Test the signal circuit of the mode actuator for an open or a high resistance. 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 | Test the low reference circuit of the mode actuator for an open or a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 19 | Go to Step 16 | ||||||||||||
15 | Inspect for poor connections at the harness connector of the mode actuator. 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 | ||||||||||||
16 | 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 | ||||||||||||
17 | Replace the mode actuator. Refer to Mode Actuator Replacement . Did you complete the replacement? | -- | Go to Step 19 | -- | ||||||||||||
18 | Replace the HVAC control module. Refer to HVAC Control Module 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 | ||||||||||||