INTERMITTENT LOW COOLANT INDICATOR LIGHT DURING TURNS

VEHICLES AFFECTED: 1989-90 J, N, 2.3, 2.0, 2.8, 3.1

CONDITION:

---------- The low coolant indicator light may illuminate during hard, left hand turns, or during acceleration if the surge tank coolant level registers as little as 1/2 inch below the "FULL COLD" mark when checked cold coolant at 15.6 DEG C - 32.2 DEG C (60 - 90 degrees F).

As a result of a low coolant level in the surge tank, movement of the coolant (slosh) can momentarily trigger the low coolant switch in the tank.

CAUSE:

------ Low coolant level can result from the normal process of trapped air purging from the cooling system, a cooling system leak, and/or variations in assembly plant fill.

CORRECTION:

---------- In most cases, adding coolant to the surge tank to bring the coolant level one (1) inch above the "FULL COLD MARK" (when checked cold) will correct this condition. However, be sure to visually inspect the cooling system for possible leaks. The system should also be inspected for any pinched, kinked or improperly routed hoses or lines that could prevent a proper coolant fill.

After filling the surge tank as described above, verify correction by carefully driving the vehicle through a series of sharp left hand turns and/or by making moderate vehicle accelerations. Should an intermittent low coolant light still exist, confirm that the low coolant switch in the surge tank is operating properly. Refer to Section 6B of the appropriate service manual.

If the low coolant switch is confirmed to be operating properly and coolant level is correct, install a new surge tank, part number 22538029. Refer to service manual Section 6B for surge tank removal and installation procedure.

NOTE: The new surge tank incorporates a revised internal switch and float mechanism. The revised switch and float mechanism allows coolant level in the surge tank to reach a point more easily distinguished as "LOW" when visually observed, before turning on the low coolant light. The new surge tank was released to production in early September, 1989. Although a new part number was not released, the new tank can be identified by a Julian Date code stamp of 2229 or greater. The date code is located on the top rear area of the tank.

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.