GM Service Manual Online
For 1990-2009 cars only

INTERMITTENT HIGH IDLE SPEED MAY BE CONNECTION AT IAC VALVE

Models Affected: 1988 LeMANS

Some of the subject vehicles may exhibit an occasional higher than normal idle speed.

This condition may be caused by a poor electrical connection to the idle air control (IAC) valve or in a few cases, deterioration of the IAC valve bearing.

Corrective action for vehicles exhibiting the described idle condition is to disconnect the electrical wiring connection at the IAC valve and inspect the harness connection terminals for damage and presence of foreign material.

Repair terminals as necessary, following detailed repair procedures in Section 8 of the service manual; remove any foreign material from the connector. Reconnect the IAC valve harness connection to the IAC valve. Following the diagnostics procedure for Code 35 (Code 35 may not have been set due to the idle speed fluctuation existing for less than 20 seconds including the steps described in the Diagnostic Aids verify the correct operation of the IAC valve. Replace valve if test indicates valve operation is incorrect following service manual procedures.

Warranty Information

Labor Operation: T1351 Labor Time : .5 Hours

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.