SLIGHTLY HIGHER THAN NORMAL IDLE SPEED (MAY BE WIRING)

SLIGHTLY HIGHER IDLE SPEED

MODELS AFFECTED: 1983-84 SKYHAWKS WITH 2.OL ENGINES ---------------- (VIN CODE P) AND N40 POWER STEERING

CONDITION

Idle speed in the range of 1200 to 1625 RPM, in closed loop, in park or neutral with the steering wheel not fully locked either right or left, may be experienced. This slightly raised idle speed has no adverse affect on driveability or vehicle performance, but may be objectionable from a noise standpoint.

CAUSE

An open circuit in the signal to the Electronic Control Module (ECM) from the power steering pressure switch. Unlike the 1985 and later models which use a normally OPEN switch, the 1984 and earlier J-cars with the 2.OL engine use a normally CLOSED power steering pressure switch. If the ECM sees an open at any point in this circuit, it will interpret the open as a power steering load, and will raise the idle speed.

CORRECTION

Disconnect the power steering switch. If there is no change in idle speed, this condition is the cause of slightly higher idle. If the idle speed changes, the cause of the higher idle speed should be investigated through normal diagnostic methods.

Refer to the 1984 Service Manual, pages 6E2-150, 151 which is the Idle Air Control (IAC) Diagnostic Chart. The wiring diagram will lead to possible areas which may be open in the circuit, such as an open power steering pressure switch, an open A/C compressor clutch coil, an open A/C high pressure switch, an unplugged connector, loss ground connections, or a cut or pinched wire. Repair as necessary.

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.