For 1990-2009 cars

# POOR ENG.PERF.& DRIVEABILITY ADDITION OF NON OEM EQUIPMENT

#### MODELS AFFECTED: ALL MODELS/YEARS WITH ELECTRONIC FUEL INJECTION (EFI), DIGITAL FUEL INJECTION (DFI), COMPUTER COMMAND CONTROL (CCC OR CCCC), THROTTLE BODY INJECTION (TBI) OR PORT FUEL INJECTION (PFI)

In an effort to prevent customer dissatisfaction concerning engine performance, driveability and/or operation of vehicle systems due to the addition of equipment, the following information is being provided.

Cadillac engine control systems are designed to function with the electrical and vacuum system provided in the vehicle. The addition of non-original equipment or accessories, or non-Cadillac approved dealer-installed options may adversely affect the engine fuel and emissions control system operation and/or vehicle driveability.

Electrical connections should not be made to any of the engine fuel control electrical wiring for a 12-volt source or for a ground. See Serviceman Bulletin 85-52, filed in Group 6D for recommendations.

Equipment operated by vacuum can also affect engine performance and driveability because the equipment can allow unmeasured air (any air source not measured by the Mass Air Flow sensor on vehicles so equipped) to enter the engine, which can affect air/fuel mixture ratios.

If the addition of a component affects engine performance, driveability or operation, it is recommended that the customer be advised to disconnect the unit which is creating the condition and refer them to the persons responsible for making such installation.

The addition of any electrical or vacuum operated equipment that results in damage to the engine electronics or which creates driveability problems is not the responsibility of Cadillac Motor Car Division.

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.