GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1999 🢒 GMC K Sierra - 4WD 🢒 Engine 🢒 Engine Controls - 4.8L, 5.3L, and 6.0L 🢒 Air Inlet Valve Actuator Inoperative

Step

Action

Value(s)

Yes

No

IMPORTANT:

    •  Inspect the condition of the HVAC fuse (located in the left bussed electrical center LBEC). If the fuse is open, replace the fuse. Retest the system for intermittent fuse failure. If the fuse continues to fail locate and repair source of overload. Refer to Power Distribution Schematics.
    • Ensure that the A/C compressor is free to rotate and the drive belt is properly installed and in good condition.
    •  Ensure that the A/C system is properly charged.
    • Ensure that ground G203 is clean and tight.
    •  This diagnostic table assumes that the mode and temperature door motors are operating normally
    • Inspect for any binding or obstructions with the system doors or actuators. Refer to Air Inlet Actuator Replacement .

1
  1. Turn the ignition switch to the RUN position.
  2. Disconnect the connector at the recirculation door motor connector.
  3. Connect a test lamp between CKT 341 (BRN) cavity 5 and ground.

Does the test lamp light?

--

Go to Step 2

Go to Step 5

2

Connect a self-powered test lamp between CKT 2450 (BLK) cavity 7 and ground.

Does the test lamp light?

--

Go to Step 3

Go to Step 6

3
  1. Connect a test lamp between CKT 1614 (DK GRN) cavity 6 and ground.
  2. Place the blower switch in the LO position.
  3. Actuate the recirculation push button on the HVAC control module.

Does the test lamp light?

--

Go to Step 7

Go to Step 4

4
  1. Disconnect connector C1 at the HVAC control module.
  2. Connect a self-powered test lamp between CKT 1614 (DK GRN) cavity D and the recirculation door motor connector cavity 6.

Does the test lamp light?

--

Go to Step 8

Go to Step 9

5

Repair the open in CKT 341 (BRN) between the recirculation door motor and LBEC.

Is the repair complete?

--

Go to HVAC Air Delivery System Check

--

6

Repair the open in CKT 2450 (BLK) between the recirculation door motor and G203.

Is the repair complete?

--

Go to HVAC Air Delivery System Check

--

7

Replace the recirculation door motor. Refer to Air Inlet Actuator Replacement .

Is the repair complete?

--

Go to HVAC Air Delivery System Check

--

8

Replace the HVAC control module. Refer to Control Assembly Replacement .

Is the repair complete?

--

Go to HVAC Air Delivery System Check

--

9

Repair the open in CKT 1614 (DK GRN) between HVAC control module and the recirculation door motor.

Is the repair complete?

--

Go to HVAC Air Delivery System Check

--