ECC/Cruise Control - Mode Change/Not Maintaining Speed

91buick06

Bulletin: 91-1-11

Date: June '91

Ref. No.: 91-211-1

Corp. Ret. No.: 116801R


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

MODELS AFFECTED: 1991 RIVIERA MODELS

FIGURE 1:

Some 1991 Riviera models may exhibit erratic Electronic Climate Control (ECC) mode changes or cruise control that will not maintain a set speed on hills. These conditions may be due to a disconnected vacuum hose. The hose which connects to the vacuum reserve tank, in the right front wheel well area, may become disconnected from snow or ice build up or during an underbody car wash.

To repair this condition ensure that the vacuum hose is seated a minimum of 15 mm (approx. 9/16 in.) onto the vacuum reserve tank connecting nipple.

1. Measure 15 mm (approx. 9/16 in.) from the end of the hose and mark a reference line with tape or white paint.

2. Push the hose onto the nipple until the reference line is flush with the edge of the nipple protector. Refer to Figure 1 and Figure 1, view A.

Ensure the proper seat with a moderate tug downward on the hose. If properly seated, the hose should remain secure.

FIGURE 2:

The vacuum reserve tank location shown in the 1991 Riviera Service Manual on page 1B-31, Figure 30 is incorrect. For the correct location, refer to Figure 2 in this bulletin.

WARRANTY INFORMATION:
Labor Operation No.: T6546
Labor Time: 0.2 hour
Trouble Code: 92