Cruise Control - Problem Repair

Group 65
Radio and Special Equipment



Bulletin Number
65 01 81 (511)



Montvale, NJ
March, 1981
Technical Dept.



Subject:
CRUISE CONTROL PROBLEMS - 6 AND 7 SERIES (IF EQUIPPED)

Please remove and discard S.I. 65-03-79 (419) and S.I. 65-02-79 (402) from your S.I. binder, as they are superceded by this bulletin.

The following problems may occur on cruise control equipped vehicles.

Problem

TOO FAST ACCELERATION WHEN CRUISE CONTROL IS ENGAGED (1981 MODELS ONLY

Repair

The vacuum reserve tank has been eliminated on 1981 model vehicles and the system recalibrated accordingly. In isolated tases, a vacuum reserve tank was inadvertantly installed on early production vehicles. Remove the vacuum reserve tank.


Problem

SURGING AT SET SPEED (1980 AND LATER MODELS ONLY), OR CRUISE CONTROL CUTS OUT MOMENTARILY and then returns to normal operation when the following electrical components only are operated:

a. Outside remote control mirror
b. Heating or air conditioning controls
c. Horn
d. Sun-roof

Repair





Install a new cruise control ECU with a "state of modification" number 03 or higher. ECUs are identified with a label as shown.



CAUTION:
ECUs with a "state of modification" number of 02 or lower (or with no number listed) labeled 11/80/01, 11/80/02, and prior should be installed only on 1979 and earlier vehicles. The part number remains unchanged.


Problem:


CRUISE CONTROL CUTS OUT MOMENTARILY and then returns to normal operation when the following electrical components only are operated (1979, and 1980 models only):

a. Instrument panel lighting intensity is varied

b. Headlight switch or low beam/high beam selector lever is operated


Repair:





Install a diode (part number 61-31-1-358-268). These wiring changes have been incorporated into 1981 models.


1. Remove the instrument carrier.

2. Remove the round multiple plug from the instrument carrier.

3. Remove the brown/blue wire from pin # 2 and blue/brown wire from pin # 6 on the round multiple plug.

4. Connect the brown/blue and blue/brown wires (from pin # 2 and pin # 6) to the positive (+) side of the diode.

5. Use a short length of wire to connect the negative (-) side of the diode to pin # 6 on the round plug. Pin # 2 is left open.

6. Reinstall the instrument carrier.

7. Test drive and verify that the cruise control now operates properly.



WARRANTY STATUS

Labor operation:
# 62 11 000 (6 FRU)

Additional work time:
(WT) to install diode and rewire - 2 FRU

Total time:
8 FRU

Defect Code:
65 71 00 12 00