Peterbilt 387 Instrument System Service Manual

Model 387 Instrument System Service Manual. Every effort has been made to keep the information in this document current and accurate as of the date of publication or revision. However, no guarantee is given or implied that the document is error-free or that it is accurate with regard to any specification. AMETEK Dixson reserves the right to modify product designs and specifications without notice.

Purpose and Scope
The purpose of this manual is to provide Peterbilt with the knowledge required to produce their own repair procedures. This manual contains the technical repair information necessary to diagnose and repair the Model 387 Instrument System (also referred to as simply the “instrumentation”). The information in this manual is not proprietary and can be used as Peterbilt sees fit.

The manual describes how to operate, service, and troubleshoot the instrumentation installed in vehicles that broadcast engine- and speed-related information over a public data bus (the SAE J1708 data bus). For information about the vehicle’s Electronic Control Unit(s), wiring diagrams, the SAE J1708 data bus, external sensors and other components that are not part of the instrumentation, please refer to the appropriate vehicle service documentation.

How To Use This Manual?
The manual is divided into six chapters:

  1. Introduction: Contains a brief introduction to the product and to the manual itself.
  2. Operation: A complete operator’s manual. Written for the vehicle operator, this chapter describes how to use the instrumentation and how to interpret the information it presents. If you are going to operate the vehicle, you should read and understand the information in this chapter.
  3. Functional Description: Describes the components that make up the instrumentation and how they communicate with other systems in the vehicle. An understanding of the information in this chapter will help you diagnose and find problems in the instrumentation. If you are going to service the instrumentation, you should read and understand the information in this chapter.
  4. Service: Describes how to remove, disassemble, and reinstall the components of the instrumentation. It contains a spare parts list, and other important information. Do not service the instrumentation until you have read and understand the information in this chapter.
  5. Troubleshooting: Provides detailed troubleshooting information that will help you identify faulty components within the instrumentation.
  6. Using the Handheld Diagnostic Tool (HDT): Describes the operation of the handheld diagnostic tool used to help diagnose problems with the instrumentation.

What Makes the Model 387 Instrument System Different?
In conventional instrumentation, each electrical gauge is connected to a sensor by a signal wire and a return wire. Additional wires for illumination, power, ground and warning lights could total as many as six wires per gauge. Thus, a panel with 10 gauges plus a speedometer and a tachometer could require up to 60 separate wires. By comparison, the Model 387 Instrument System uses a single 5-wire cable to connect all the gauges. This significantly reduces the number of wires behind the instrument panel and makes the system much easier to troubleshoot and service.

The instrumentation is easy to repair. The 2-inch gauges can be disconnected, removed from the panel, disassembled, reassembled, and reinstalled without tools, and they are maintenance-free. The instrumentation can also display warning messages and audible alarms, and has built-in diagnostic capabilities to help diagnose problems.

With the exception of the scaleplate, all 2-inch gauges are identical. Each scaleplate is coded and when installed in the gauge, configures the gauge to the function shown on the scaleplate. This reduces the spare parts inventory by requiring only a few blank gauges and a supply of inexpensive scaleplates rather than a complete spare gauge of each type.

Peterbilt 387
The Interface Module controls the instrumentation by collecting information from various sources and converting that information into gauge pointer information which it then sends to the gauges. It is an environmentally sealed unit and it is usually mounted beneath the cab and against the frame rail. It is connected to the J1708 data bus, and to switches, sensors and pressure/vacuum hoses throughout the vehicle.

Peterbilt 387 Instrument System Repair Manual

Peterbilt 387 Instrument System Repair Manual For Free

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