SERVICE MANUAL UPDATE SEC. 5 BRAKES (REVISED ABS CHART)

SUBJECT: SERVICE MANUAL UPDATE - SECTION 5, BR REVISED CHART

MODELS AFFECTED: 1990-91 REGALS WITH ABS BRAKES (OPTION CODE JL9)

THIS BULLETIN HAS BEEN REVISED TO CORRECT CHART, AND ADD 1991 MODEL YEAR. PLEASE REPLACE BULLETIN 90-5-1 WITH THIS BULLETIN.

The following Antilock Brake System (ABS III) chart replaces the chart found in the current 1990 and 1991 Regal Service Manuals on page 5E-25, Figure 20.

Please correct your service manuals.

CODE SET

| A023|A026|A031|A035|A044|A048|A056|A059|A062 PERFORM TEST(S) | A024|A027|A036| |A045|A049| | | ---------------------------- | A025|A028| | |A046|A050| | | | | | | |A047|A051| | | (A) Preliminary Inspection | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 (B) ABS System Functional | 2 | | | | | | 6 | | Check | | | | | | | | | (C) ABS Hold Function Check | | 2 | | | | | 5 | | (D) Low or No Boost Pressure | | | | 2 | | | 2 | 3 | (E) Pump Run Time Too Long | | | | 3 | | | | 4 | (F) Pump Off Time Too Short | | | | | | | 3 | | (G) External Leakage Check | | | | | | | 4 | 2 | (H) Fluid Leaking Into | | | | | | | | | Front Chamber | | | | | | | | | (I) Pump Motor Operational | | | 2 | | | | | | 2 Diagnosis | | | | | | | | | (J) Vehicle Pulls to One Side | | | | | | | | | During Braking | | | | | | | | |

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.