SMU-SEC. 8A-33 & 34 - VEHICLE SPEED, SENSOR, CRUISE CONTROL

SUBJECT: SMU - SECTION 8A-33 AND 34 - VEHICLE SPEED SENSOR, CRUISE CONTROL ELECTRICAL DIAGNOSIS

VEHICLES AFFECTED: 1993 BRAVADA

The following represents new and/or revised information for Section 8A in the 1993 Bravada Service Manual.

DIAGNOSIS - VEHICLE SPEED SENSOR BUFFER

PRELIMINARY CHECKS:

1. Check condition of BRAKE Fuse. 2. If fuse is not blown, proceed If fuse is blown, locate and with diagnostics. repair source of overload. Replace fuse.

SPEED SENSOR COMPONENTS DO NOT OPERATE PROPERLY

TEST RESULT ACTION ---- ------ ------ 1. Place ignition switch in RUN Battery Voltage. GO to step 2. position and disconnect Vehicle Speed Sensor Buffer connector C255. Connect voltmeter from PNK/WHT (350) wire at Vehicle Speed Sensor Buffer connector C255 to ground. No Voltage. LOCATE and RE- PAIR open in PNK/WHT (350) wire,

2. Connect voltmeter from PNK/WHT Battery voltage. GO to step 3. (350) wire to BLK (150) wire at Vehicle Speed Sensor Buffer No Voltage. LOCATE and RE- connector C255. PAIR open in BLK (150) wire from Vehicle Speed Sensor Buffer conn- ector C255 to ground term- inal G102.

3. Properly support vehicle so drive A/C voltage reading GO to step 4. wheels are off the ground. Have engine running and gear selector in DRIVE. Connect A/C voltmeter No voltage CHECK for open from PPL/WHT (821) wire to LT in PPL/WHT GRN/BLK (822) wire at Vehicle (822) wires. Speed Sensor Buffer connector If wires are C255. good, REPLACE speed sensor.

4. Connect Vehicle Speed Sensor D/C voltage reading LOCATE and Buffer connector C255. Connect REPAIR open in A/C voltmeter from LT BLU/BLK LT BLU/BLK (824) wire at connector C212 to (824) wire BLK (150) wire at Vehicle Speed from Vehicle Sensor Buffer Connector C255. No voltage. Speed Sensor Buffer connect or C255 to I/P cluster. If wire is good, REPLACE in- strument cluster.

CRUISE CONTROL DOES NOT OPERATE PROPERLY

TEST RESULT ACTION ---- ------ ------ 1. Place ignition switch in RUN Battery voltage. GO to step 2. position and disconnect Vehicle Speed Sensor Buffer connector C255. Connect voltmeter from PNK/WHT (350) wire at Vehicle No voltage LOCATE and RE- Speed Sensor Buffer connector PAIR open in C255 to ground. PNK/WHT (350) wire.

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.