For 1990-2009 cars

Table 1: | Pontiac and Oldsmobile w/o Outside Recirculated Air Option
Table 2: | Outside Recirculated Air Option (Oldsmobile Only)

Perform the Functional Test and the diagnostic tests in order to verify the following systems:

• | Air conditioning

• | Electrical

• | Vacuum

• | Refrigeration

1. Operate the blower motor at all speeds with the mode lever in any position, and engage the compressor clutch. This will indicate that the electrical circuits and the vacuum circuits are functioning properly.
2. With your hand, feel the temperature of the evaporator inlet pipe and the accumulator surface of an operating system. The system will be properly charged if these temperatures feel the same.
3. Operate the heater and A/C control selector (mode) lever, which distributes air from the appropriate outlets. Verify that the lever operates correctly and smoothly.

#### Pontiac and Oldsmobile w/o Outside Recirculated Air Option

Control Settings | System Response
--- | ---
Fan Switch | Mode Switch | A/C Push Button | A/C Signal | A/C Indicator | Comments
ON | U, B, L | OFF | LOW | OFF | The A/C signal and the A/C indicator are on according to the position of the push button when the mode switch is in any of the following positions:

• | Upper

• | Bi-Level

• | Lower

ON | U, B, L | OFF | LOW | OFF
ON | U, B, L | ON | HIGH | ON
ON | U, B, L | ON | HIGH | ON
ON | M, BL, DF | OFF (3) | HIGH (1) | OFF | When in Max (Pontiac Only), Blend or Defrost mode, the following conditions occur:

• | The A/C signal defaults to high

• | The indicator lights according to the position of the push button.

ON | M, BL, DF | OFF (3) | HIGH (1) | OFF
ON | M, BL, DF | ON (3) | HIGH | ON
ON | M, BL, DF | ON (3) | HIGH | ON
OFF | U, B, L | (2) | LOW (1) | OFF | When the fan switch is OFF, the following conditions occur:

• | The A/C signal defaults to low

• | The indicator is OFF

OFF | U, B, L | (2) | LOW (1) | OFF
OFF | BL, DF | (2) | LOW (1) | OFF
1. Default Condition 2. Not Allowed 3. Previous Switch State
M-Max (Pontiac Only) U-Upper B-Bi-Level L-Lower BL-Blend DF-Defrost

#### Outside Recirculated Air Option (Oldsmobile Only)

Control Settings | System Response
--- | ---
Fan Switch | Mode Switch | A/C Push Button | OSA/REC Push Button | Recirculation Vacuum | Recirculation Indicator | OSA Indicator | Comments
ON | U, B, L | OFF | OSA | OFF | OFF | ON | The vacuum and the indicators are ON according to the position of the push buttons when the mode switch is in any of the following positions:

• | Upper

• | Bi-Level

• | Lower

ON | U, B, L | OFF | RECIRC | ON | ON | OFF
ON | U, B, L | ON | OSA | OFF | OFF | ON
ON | U, B, L | ON | RECIRC | ON | ON | OFF
ON | BL, DF | OFF (3) | OSA | OFF | OFF | ON | The vacuum defaults to OFF and the OSA indicator is lit when the mode switch is in the following settings:

• | Blend

• | Defrost

ON | BL, DF | OFF (3) | RECIRC (2) | OFF (1) | OFF | ON
ON | BL, DF | ON (3) | OSA | OFF | OFF | ON
ON | BL, DF | ON (3) | RECIRC (2) | OFF (1) | OFF | ON
OFF | U, B, L | (2) | OSA | OFF | OFF | ON | When the fan switch is OFF, the vacuum and the indicators follow the settings according to the position of the push buttons.
OFF | U, B, L | (2) | RECIRC | ON | ON | OFF
OFF | BL, DF | (2) | (2) | OFF (1) | OFF | ON
1. Default Condition 2. Not Allowed 3. Previous Switch State
U-Upper B-Bi-Level L-Lower BL-Blend DF-Defrost