For 1990-2009 cars
HVAC Components
HVAC Air Delivery Schematics (Cell 68: IP Fuse Block, DLC - Pontiac)
HVAC Air Delivery Schematics (Cell 68: IP Fuse Block, DLC - Buick)
Handling ESD Sensitive Parts Notice

### Circuit Description

The HVAC programmer receives battery voltage through circuit 40 from the I/P fuse block , fuse 9C.

### Conditions for Running the DTC

• | The ignition is ON.

• | The circuit is open or shorted.

### Action Taken When the DTC Sets

• | Code 052 is set.

• | The HVAC programmer will not operate.

### Conditions for Clearing the DTC

• | Using a Scan Tool .

• | A history DTC will clear when 40 consecutive ignition cycles have occurred without a malfunction.

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the battery disconnected or recently discharged? | -- | Go to Step 2 | Go to Step 3
2 | Use Scan Tool to clear the DTC. Is the DTC clear? | -- | System OK | --
3 | Use the Scan Tool in order to clear DTC 052. Does the DTC reset when cleared? | -- | Go to Step 4 | System OK
4 | Inspect the IP fuse block fuse 9C. Is the fuse OK? | -- | Go to Step 7 | Go to Step 5
5 | Check CKT 40 for a short to ground. Refer to Testing for Short to Ground in Wiring Systems. Did you find a short? | -- | Go to Step 6 | Go to Step 7
6 | Repair the short to ground in CKT 40. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | System OK | --
7 |

1. Turn the ignition switch to the OFF position.
2. Disconnect the HVAC programmer.
3. Measure the voltage between the following HVAC harness connector terminals:

Refer to Measuring Voltage in Wiring Systems.

• | For Oldsmobile and Buick, measure between terminal E1 and terminal E13.

• | For Pontiac, measure between terminal C1 and terminal C13.

Refer to Measuring Voltage in Wiring Systems.

Is battery voltage present?

--

Go to Step 8

Go to Step 9

8 |

1. Inspect the HVAC programmer connector for proper terminal contact. Refer to Intermittents and Poor Connections .
2. If the contact is OK, replace the HVAC programmer. Refer to Programmer Replacement .

Is the repair complete?

--

System OK

--

9 | Repair the open in CKT 40. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | System OK | --