For 1990-2009 cars

# SERVICE MANUAL UPDATE SEC. 8A ON-BOARD DIAG. PROCEDURES

#### SUBJECT: SMU - SECT. 8A ELECTRICAL DIAGNOSIS - REVISED ONBOARD DIAGNOSTICS PROCEDURES GAUGES CLUSTER UB7 AND DIGITAL CLUSTER U2A

#### VEHICLES AFFECTED: 1991 'C'

Page 8A-81-17, INSTRUMENT PANEL; GAUGES CLUSTER, UB7 and Page 8A-82-16, INSTRUMENT PANEL; DIGITAL CLUSTER, U2A - DIC ON-BOARD DIAGNOSTICS has been revised with the following procedure:

#### DIC ON-BOARD DIAGNOSTICS

o The following procedure must be performed before the Driver Information On-Board Diagnostics can be used. To enter the diagnostic mode, do the following:

1. With the Ignition Switch in Run, press the DEST key 2. Press RESET 3. Press 8192 (ETA, ECON, E/T, FUEL) 4. Press ENTER.

The DIC will now be in the diagnostic mode.

o Display position FF was not included in the Driver Information Reference Diagram, please add the following:

POSITION FF - Oil pressure, 0 to 99% of maximum pressure

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.