VEHICLE FAILS STATE IMS TEST INSPECT. MAINTENANCE EMISSION. Saturn Saturn 1994

For 1990-2009 cars

# VEHICLE FAILS STATE IMS TEST INSPECT. MAINTENANCE EMISSION

#### SUBJECT: Vehicle Fails State Inspection Maintenance (IMS) Emission Test (Follow Recommended Test Procedures)

Due to the addition of 1995 Saturns, this bulletin supersedes bulletin No. 92-T-28B, which should be discarded.

#### MODELS AFFECTED: 1991-1995 Saturns

CONDITION: Vehicle fails part of state inspection maintenance (IMS) emission test.

CAUSE: Some states perform the basic idle speed emission test without preconditioning the vehicle before the test, and without any second chance preconditioning after a test failure. Due to this situation, Saturn vehicles may falsely fail during this type of test. This condition occurs when the vehicle is started and subsequently tested at idle, without depressing the accelerator pedal to obtain at least a 1.6 percent throttle position allowing the engine to go into closed - loop operation. Also, the vehicle may not be at proper operating temperature to perform this test.

CORRECTION: To avoid any false test failures when testing any 1991 - 1995 Saturn, perform the following steps before testing the vehicle.

PROCEDURE: Emission Test

Make sure that the vehicle is at proper operating temperature and in closed-loop operation before testing.

#### IMPORTANT: Proper operating temperature can be established by increasing the engine idle speed to approximately 2500 rpm for two minutes with the vehicle in Neutral or Park.

1. Increase vehicle idle speed to approximately 2500 rpm for at least 30 seconds.

2. Bring vehicle to curb idle speed or desired rpm for testing.

3. Perform emission test.

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.