ELECTRICAL DIAGNOSTICS REVISED MISLABELED REFERENCES. Chevrolet Corsica 1991

For 1990-2009 cars

# ELECTRICAL DIAGNOSTICS REVISED MISLABELED REFERENCES

#### Subject: ELECTRICAL DIAGNOSTICS REVISED

#### Model and Year: 1991 CORSICA AND BERETTA

On 8A-64-1, circuit 901,.5 TAN and the Multi-Port Fuel Injection references are mislabeled.

On 8A-64-1 make the following changes:

From 901,.5 TAN to 495,.5 LT BLU/ORN.

From "Multi-Port Fuel injection Cell 22" to "Multi-Port Fuel Injection Cell 21 ".

Refer to attached pages 8A-64-1, 8A-64-7, and 8A-64-10 for changes.

#### CIRCUIT OPERATION

The A/C Compressor for the Air Conditioning. System is belt-driven by the engine through the A/C Compressor Clutch. The clutch allows the compressor to be disengaged when air conditioning is not required, or to remove the air conditioning load from the engine when necessary.

0peration of the compressor depends on the particular A/C mode selected by the driver. When the A/C Mode Selector is in MAX, NORM, BI-LEVEL or DEF, battery voltage is applied through Fuse 8 and the Heater and A/C Control Assembly Selector to the A/C Compressor Control Relay.

#### L4 VIN G

For vehicles equipped with the L4 VIN G engine, the path to the A/C Compressor Control Relay is through the A/C Low Pressure Switch and the A/C High Pressure Switch, which. are both normally closed. The A/C Low Pressure Switch opens if the refrigerant charge is too low for operation of the A/C Compressor Clutch without possible damage to it. The A/C High Pressure Switch opens when refrigerant pressure is too high for normal operation.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.