GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2001 🢒 Seville 🢒 HVAC 🢒 HVAC Systems - Automatic 🢒 Air Delivery Improper - Auxiliary

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. This step tests for a blower motor that does not operate regardless of the desired blower motor speed.

    2.

  2. This step tests for a blower motor that operates, yet does not accurately respond to the desired blower motor speed.

Step

Action

Yes

No

Schematic Reference: HVAC Schematics

DEFINITION: Air does not flow correctly from the auxiliary air distribution outlets.

1

Did you perform the Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - HVAC Systems - Automatic

2
  1. Turn ON the ignition, with the engine OFF.
  2. Place the auxiliary blower motor switch in the OFF position.

Is the blower motor OFF?

Go to Step 3

Go to Auxiliary Blower Motor Always On

3

  1. Place the front blower motor switch in the maximum speed position.
  2. Place the front mode switch in the vent position.
  3. Place the auxiliary blower motor switch in each speed position.

Does the blower motor operate at all?

Go to Step 4

Go to Auxiliary Blower Motor Inoperative

4

Does the auxiliary blower motor operate in each speed position?

Go to Step 5

Go to Auxiliary Blower Motor Malfunction

5

Place the auxiliary mode switch in each position.

Is the air flow sufficient from the correct outlets in each mode?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 6

6

Test the ignition 3 voltage circuit of the auxiliary mode actuator and the auxiliary HVAC control assembly for an open, short to ground or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 7

7

Test the ground circuit of the auxiliary mode actuator and the auxiliary HVAC control assembly for an open, short to voltage or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 8

8
  1. Turn OFF the ignition.
  2. Disconnect the auxiliary mode actuator.
  3. Turn ON the ignition with the engine OFF.
  4. Measure the voltage between the auxiliary mode actuator control circuit and ground.
  5. Place the mode switch in each position.

Does the voltage change for each position selected?

Go to Step 10

Go to Step 9

9

Test the auxiliary mode control circuit for an open, short to ground or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 12

10
    • Inspect the mode door and any attaching linkage for binding.
    • Inspect the ducts for debris that would prevent air flow through the duct.

Did you find and correct the condition?

Go to Step 15

Go to Step 11

11

Inspect for poor connections at the harness connector of the auxiliary 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 15

Go to Step 13

12

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 15

Go to Step 14

13

Replace the auxiliary mode actuator. Refer to Auxiliary Mode Valve Actuator Replacement .

Did you complete the replacement?

Go to Step 15

--

14

Replace the auxiliary HVAC control assembly. Refer to Auxiliary Heater and Air Conditioning Control Module Replacement .

Did you complete the replacement?

Go to Step 15

--

15

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2