ERRATIC ECC MODE CHANGE INSPECT VACUUM HOSE

SUBJECT: ERRATIC ECC MODE CHANGE OR CRUISE CONTROL UNABLE TO MAINTAIN SET SPEED ON HILLS (ENSURE HOSE CONNECTIONS)

VEHICLES AFFECTED: 1990-91 E,K

Some 1990-91 E and K vehicles may experience erratic Electronic Climate Control (ECC) mode change or cruise control may be unable to maintain set speed on hills due to a disconnected vacuum hose from the vacuum reserve tank. Refer to Figure 1. The hose may become disconnected due to snow or ice build up in the front wheel well area or during an underbody car wash.

To repair this condition ensure that the connection is fully seated as shown in Figure 2.

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.