For 1990-2009 cars

# SERVICE MANUAL UPDATE SEC. 5E1 ABS WHEEL SPEED SENSORS

#### SUBJECT: SERVICE MANUAL UPDATE - ABS - FIGURES 12 & 14 WHEEL SPEED SENSOR CIRCUIT REVISED TO CORRECT SCHEMATICS - REVISED CHART K (1 OF 2)

#### MODELS/YEARS: 1991 EIGHTY-EIGHT AND NINETY-EIGHT

#### FIGURES 12 AND 14:

In the 1991 Eighty-Eight and Ninety-Eight Service Manuals, Section 5E1, Antilock Brakes, Figures 12 and 14 WHEEL SPEED SENSOR CIRCUIT found on pages 5E1-16 and 18 have been revised to reflect the correct schematics. See the illustrations on the back of this bulletin.

#### REVISED CHART K (1 AND 2):

Antilock Brake System (ABS) Diagnosis - Page 5E1-31 Chart K (1 of 2) Antilock Indicator is On and No Codes Set, Second diagnosis box on left column needs to be revised with the following information:

o Ignition: Run o Disconnect main relay o Measure voltage from main relay harness connector terminal 5 to ground. o Is battery voltage measured?

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.