Auxiliary Blower Motor Inoperative W/Sunroof or Heat Only
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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This step tests for auxiliary blower motor operation in any speed setting.
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This step determines if the malfunction is in the control side of the system.
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Test both the auxiliary HVAC control assembly chassis ground circuit and ground loop circuit.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: HVAC Schematics DEFINITION: The auxiliary blower motor is inoperative in all speed positions. | |||
1 | Did you review the auxiliary HVAC operation and perform the necessary inspections? | Go to Step 2 | |
Does the auxiliary blower motor operate in each speed position? | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 | |
3 |
Does the test lamp illuminate? | Go to Step 4 | Go to Step 6 |
4 | Connect a test lamp between the auxiliary blower motor supply circuit and the auxiliary blower motor ground circuit. Does the test lamp illuminate? | Go to Step 11 | Go to Step 5 |
5 | Test the ground circuit of the auxiliary blower motor resistor assembly for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 18 | Go to Step 12 |
6 |
Does the test lamp illuminate? | Go to Step 7 | Go to Step 13 |
7 | Probe the auxiliary blower motor resistor assembly battery positive voltage circuit with a test lamp that is connected to a good ground. Does the test lamp illuminate? | Go to Step 8 | Go to Step 14 |
Does the test lamp illuminate? | Go to Step 12 | Go to Step 9 | |
Test the auxiliary HVAC control assembly ground circuits for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 18 | Go to Step 10 | |
10 | Inspect for poor connections at the harness connector of the auxiliary HVAC 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 15 |
11 | 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 18 | Go to Step 16 |
12 | Inspect for poor connections at the harness connectors of the auxiliary blower motor resistor 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 17 |
13 | Repair the ignition 3 voltage circuit of the auxiliary blower motor resistor assembly. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 18 | -- |
14 | Repair the battery positive voltage circuit of the auxiliary blower motor resistor assembly. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 18 | -- |
15 | Replace auxiliary HVAC control assembly. Refer to Auxiliary Heater and Air Conditioning Control Replacement - Front or Auxiliary Heater and Air Conditioning Control Replacement - Rear . Did you complete the replacement? | Go to Step 18 | -- |
16 | Replace auxiliary blower motor. Refer to Auxiliary Blower Motor Replacement in Heating, Ventilation and Air Conditioning. Did you complete the replacement? | Go to Step 18 | -- |
17 | Replace auxiliary blower motor resistor assembly. Refer to Auxiliary Blower Motor Resistor Replacement in Heating, Ventilation and Air Conditioning. 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 |
Auxiliary Blower Motor Inoperative W/O Sunroof
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
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This step tests for auxiliary blower motor operation in any speed setting.
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This step identifies if the auxiliary HVAC control module is commanding the auxiliary blower motor to operate at HI speed.
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This step verifies that power is being supplied to the auxiliary blower motor.
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This step tests for a possible open in the auxiliary blower motor ground circuit or a poor motor.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: HVAC Schematics DEFINITION: The auxiliary blower motor is inoperative in all speed positions. | ||||
1 | Did you review the auxiliary HVAC operation and perform the necessary inspections? | -- | Go to Step 2 | |
|
Important: The rear auxiliary HVAC control switch will only function if the front auxiliary HVAC control switch is placed in the REAR position.
Are both auxiliary control modules inop in all speeds? | -- | Go to Step 5 | Go to Step 3 | |
3 | Does only the front auxiliary control module operate? | -- | Go to Step 11 | Go to Step 4 |
4 | Does only the rear auxiliary control module operate? | -- | Go to Step 15 | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems |
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Important: Place the front auxiliary HVAC control switch in the REAR position. Place the rear auxiliary HVAC control switch in the HI speed position. Place the MODE selector in any position except AUTO. This will ensure a full speed condition when the auxiliary blower motor is commanded to an ON position. Failure to do this may result in a misdiagnosis.
Is the auxiliary blower motor PWM parameter at the specified value? | 98% | Go to Step 6 | Go to Step 17 | |
6 |
Does the test lamp illuminate and change intensity? | -- | Go to Step 7 | Go to Step 9 |
7 |
Does the test lamp illuminate and change intensity? | -- | Go to Step 19 | Go to Step 8 |
Test the rear blower motor control module ground circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 14 | |
Test the rear blower motor control module battery positive voltage circuit for an open or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 10 | |
10 | Test the rear Heater and A/C blower motor control module control circuit for a high resistance, open or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 12 |
11 | Test the blower speed control circuit between the front and rear auxiliary HVAC control modules. Did you find and correct the condition? | -- | Go to Step 20 | -- |
12 |
Does the voltage vary between the specified value? | 0.4-4.0 V | Go to Step 16 | Go to Step 13 |
13 | Inspect for poor connections at the harness connector of the rear 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 20 | Go to Step 15 |
14 | Inspect for poor connections at the harness connector of the auxiliary blower motor 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 20 | Go to Step 18 |
15 | Inspect for poor connections at the harness connector of the front 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 20 | Go to Step 16 |
16 | Replace the front HVAC control module. Refer to Auxiliary Heater and Air Conditioning Control Replacement - Front in Heating, Ventilation and Air Conditioning. Did you complete the replacement? | -- | Go to Step 20 | -- |
17 | Replace the rear HVAC control module. Refer to Auxiliary Heater and Air Conditioning Control Replacement - Front in Heating, Ventilation and Air Conditioning. Did you complete the replacement? | -- | Go to Step 20 | -- |
18 | Replace the auxiliary blower motor control module. Refer to Auxiliary Blower Motor Processor Replacement . Did you complete the replacement? | -- | Go to Step 20 | -- |
19 | Replace auxiliary blower motor. Refer to Auxiliary Blower Motor Replacement in Heating, Ventilation and Air Conditioning. Did you complete the replacement? | -- | Go to Step 20 | -- |
20 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Step 2 |
