DIESEL: METERING VALVE SENSOR ADJUSTING HARNESS-VOLT. SPECS.

MODELS AFFECTED: ALL 1985 MODELS WITH DIESEL ENGINES

The Metering Valve Sensor adjusting harness, J-34678, has a MVS voltage table printed on the back of the box. The V-REF voltage readings are from 4.5 to 5.5. This tool was originally developed for use on 1984 model California diesels, which had reference voltages from 4.5 to 5.5. 1985 models, however, may have reference voltages in a range from 4.0 to 5.5. Refer to the chassis service manual for information regarding reference voltage readings in the 4.0 to 4.5 range rather than replace the ECM for a too low reference voltage.

The idle speed specifications shown on the label apply to the 1984 models only. Refer to the chassis service manual for 1985 idle speed specifications.

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.