Step | Action | Values | Yes | No |
---|---|---|---|---|
Schematic Reference: HVAC Schematics Connector End View Reference: HVAC Connector End Views DEFINITION: The auxiliary blower motor operates in at least one speed position from at least one auxiliary control. | ||||
1 | Did you perform the HVAC Diagnostic System Check? | -- | Go to Step 2 | |
2 |
Does the scan tool indicate that the Driver Override Switch parameter changes state? | Go to Step 6 | Go to Step 3 | |
3 | Test the Auxiliary HVAC Enable Control circuit of the front auxiliary blower motor switch for an open, short to voltage or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 22 | Go to Step 4 | |
4 | Test the Low Reference circuit of the front auxiliary blower motor switch for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 22 | Go to Step 5 | |
5 |
Does the volt meter read properly for each position? | Rear 5.0V Off-1.0V Pos.1 2.0V Pos.2 3.0V Pos.3 4.0V | Go to Step 16 | Go to Step 17 |
6 |
Important: Ensure that the front auxiliary blower control switch is in the REAR position during the remainder of this table in order to avoid misdiagnosis.
Does the scan tool indicate that the Rear Fan Up Button parameter changes state? | -- | Go to Step 7 | Go to Step 16 |
7 |
Does the scan tool indicate that the rear Fan Down Button parameter changes state? | -- | Go to Step 8 | Go to Step 16 |
8 | Place the auxiliary blower motor switch in each speed position. Does the auxiliary blower motor operate at the desired speeds? | -- | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 9 |
9 |
Does the test lamp illuminate and increase intensity? | -- | Go to Step 14 | Go to Step 10 |
10 | Test the battery positive voltage circuit of the auxiliary blower motor control processor for a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 11 |
11 | Test the ground circuit of the auxiliary blower motor control processor for a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 12 |
12 |
Important: Ensure that the auxiliary blower motor control processor and auxiliary HVAC control module connectors are connected during this step in order to avoid misdiagnosis.
Does the voltage continually decrease within the specified range? | 13.0-1.5 V | Go to Step 15 | Go to Step 13 |
13 |
Does the voltage measure near the specified value? | 8-12.5 V | Go to Step 16 | Go to Step 15 |
14 | Inspect for poor connections at the harness connector of the auxiliary blower motor. 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 22 | Go to Step 19 |
15 | Inspect for poor connections at the harness connector of the auxiliary blower motor control processor. 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 22 | Go to Step 20 |
16 | Inspect for poor connections at the harness connector of the auxiliary 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 22 | Go to Step 21 |
17 | Inspect for poor connections at the harness connector of the front auxiliary blower motor switch. 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 22 | Go to Step 18 | |
18 | Replace the front auxiliary blower motor switch. Refer to Blower Motor Replacement in Heating, Ventilation and Air Conditioning. Did you complete the replacement? | Go to Step 22 | -- | |
19 | Replace the auxiliary blower motor. Refer to Blower Motor Replacement in Heating, Ventilation and Air Conditioning. Did you complete the replacement? | -- | Go to Step 22 | -- |
20 | Replace the auxiliary blower motor control processor. Refer to Blower Motor Control Processor Replacement . Did you complete the replacement? | -- | Go to Step 22 | -- |
21 |
Important: Perform the recalibration procedure for the auxiliary HVAC control module. Replace the auxiliary HVAC control module. Refer to HVAC Control Module Replacement . Did you complete the replacement? | -- | Go to Step 22 | -- |
22 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Step 2 |