COMPUTER COMMAND RIDE/SPEED DEPENDENT SYSTEM UPDATE

SUBJECT: COMPUTER COMMAND RIDE (CCR) AND SPEED DEPENDENT DAMPING (SDD) SYSTEM UPDATE

MODELS AFFECTED: 1991 DE VILLES (WITH FX3), FLEETWOODS, ELDORADOS, AND SEVILLES 1989-1991 ALLANTES

Wiring Service Procedures and Parts:

The 1991 Computer Command Ride (CCR) and Speed Dependent Damping (SDD) systems incorporate new wiring technology which requires special wiring repair techniques. A new Hypertech three-pin connection system is used at each strut. Rear strut connections on Eldorados, Sevilles, and Allantes have a boot for added corrosion protection. Due to the size of the terminals and connector, if replacement of a terminal or connector is required a new pigtail or harness must be installed. Under no circumstances should terminals be removed from the connector, as permanent terminal damage may result. All CCR harnesses and cables may be repaired using existing repair techniques. Before replacing a CCR/SDD strut or module, the integrity of the connection at the affected strut should be checked by lightly pulling on each of the three wires at the strut connector. If the wire pulls out of the connector, it should be repaired per the following procedure.

Terminal and Connector Repair:

To repair front strut terminals or connectors use the following procedure:

1. Cut the harness four inches from the damaged connector.

2. Splice in the new strut connector from the strut connector repair kit using the crimp and seal splice sleeves provided in the kit. Refer to terminal repair kit instruction manual (J-38125-4) for proper splicing procedures.

To repair rear strut terminals or connectors replace the rear suspension harness on Eldorados, Sevilles, and Allantes. Replace the rear suspension jumper harness on DeVilles and Fleetwoods.

Repair P/N 1989 V 1990 V 1991 V 1991 C 1991 E/K ----------------------- ------- -------- -------- -------- -------- Front Strut Connector Kit 12080469 12080469 12116242 12116242 12116242 Rear Suspension Harness/ Jumper 12080401 12079572 12080491 22120609 12080415

Parts are currently available from GMSPO.

Front Strut Tower Cover:

The plastic strut tower covers (under hood) for 1991 Allantes have been deleted due to a possible interference with Speed Dependent Damping (SDD) wiring. The covers are for cosmetic purposes only. Do not install front strut tower covers on any 1991 Allante as it may create SDD problems as miles are accumulated on the car. Eldorados, Sevilles, DeVilles, and Fleetwoods will continue to have front strut tower covers.

Clearing Codes:

Prior to performing diagnostics, the "System Check" procedure should be completed to determine if the code(s) that are set are current or history codes. This is especially true on 1991 E/K/V vehicles because due to a programming effort, codes are not being erased at the end of line AIDL check. These cars will typically display codes 23, 25, 26, and 32. If codes are not cleared prior to diagnosis, it may lead to erroneously replacing a strut or control module.

Service Manual Corrections:

The following corrections should be made to the 1991 New Product Service Information Manual:

C, E/K, V In the first box of the trouble tree for codes 23, 24, 25, 26, change "does voltage fluctuate for approximately the first two seconds after key on" to "does drive circuit to high (battery voltage) for approximately the first two seconds after key on".

E/K In the code 32 electrical diagram, the lateral acceleration switch is shown in the open position. This switch is actually "normally closed" and opens when body roll is seen.

V In the electrical diagram and trouble tree for "service SDD system message displayed, no codes set" the correct pinout for the message signal from the BCM connection should be 1D7, not 1C5.

V In the electrical diagram and trouble tree for "service SDD system message displayed, no codes set" the correct pinout for the speed signal from the PCM connection should be 2Bll, not 2B12.

These corrections will be included in the Final Edition of the 1991 Service Information Manual.

WARRANTY INFORMATION

Operation VEHICLE SERIES Operation Description Number C D E J K V ---------------------------- ------- ---------------------------- CCR/SDD Control Module - R&R N5600 .5 .2 .2 .2 Lateral Accelerometer - R&R N5610 .4 .7 .7 CCR Telltale Bulb N5620 .2 Rear Chassis Wiring Repair N6113 .5 .5 .5 .5 Engine Wiring Repair N6270 .5 .5 .5 .5

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.