Description

Volvo Trucks Truck 2005 Service Manual

You’ve got a truck throwing tachograph fault codes and the aftermarket wiring diagram is useless. I’ve seen it a hundred times. This Volvo Trucks Truck 2005 Service Manual is the real deal – 70 pages of OEM diagnostic steps for the TAC-DIG and TAC-DIG2 tachograph systems. No guesswork, no cross-referencing third-party data that might be wrong. This is the same binder Volvo Truck Corporation printed in 2005, order number 20030797, covering Group 38 Release 01. It starts with a foreword that warns you: procedures are based on designs up to April 2005, so check for later bulletins if your truck is newer.

Why would you trust anything else? Aftermarket manuals skip the Electrical data and tolerances. This one gives you the exact specs for the tachograph – voltage, resistance, signal ranges. Page 3 lists the tolerances and electrical data right under the Specifications section. If you’re chasing a fault code 19 (voltage failure) or code 30 (overspeed), you need the factory numbers, not a guess.

Tachograph Fault Codes: General Information

Before you start swapping parts, read the general information section. It explains how the tachograph stores and displays fault codes. The manual covers both TAC-DIG and TAC-DIG2 variants. It walks you through the fault code table starting on page 10, listing codes 02 through 57 and beyond – internal errors, sensor faults, security infringements, card conflicts, overspeed, voltage failures, printer issues. Each code gets its own subsection with a description and likely causes. For example, code 16 is a sensor fault. Code 39 is “Out of paper.” Code 56 flags a rest period violation. That level of detail is what you pay for with an OEM document.

Speedometer Sensor Specs and Tolerances

The speedometer sensor is a separate component but tied directly to the tachograph signal. The manual gives you the tolerances for the sensor output. If you’re getting a code 20, 21, or 22 – all sensor faults – you’ll need to verify the sensor’s electrical data. The manual tells you what to measure and where. Don’t rely on a generic wiring diagram. The connector pinout for the tachograph is on page 4, covering connectors A, B, C, and D. You want to measure between the tachograph and the cable harness? That’s page 4. Measurement against the harness? Same page. Get the pin numbers right or you’ll chase a ghost.

Special Tools Required for Tachograph Work

You can’t do this job with a test light and a prayer. The manual lists the special tools on page 7. It’s a short list, but it includes items like the Volvo diagnostic tool and specific breakout boxes. There’s also a section on other special equipment – things like a calibrated tachograph tester or a signal generator. If you’re a home garage guy, you might not own these. But at least you know what the dealer uses. You can improvise if you understand the signal requirements, but don’t skip the tool list. Safety warning: Never probe a connector with a sharp metal pin – you’ll widen the terminal and cause intermittent faults. Use proper breakout leads.

Why OEM Documentation Beats Aftermarket

Aftermarket manuals are written by people who have never torqued a bolt on a Volvo Truck. They copy from earlier editions, miss updates, and often leave out critical safety notes. This manual is printed by Volvo Truck Corporation. The foreword explicitly states: “All rights reserved. No part of this publication may be reproduced… without the prior written permission of Volvo Truck Corporation.” That tells you it’s the real document. The fault code table is complete – 50+ codes with exact descriptions. No generic language like “check wiring.” It tells you what to check and in what order. For example, code 10 “Internal fault” – the manual gives you the diagnostic path. You don’t guess. You follow the procedure.

Fault Code Table: 02 to 57 and Beyond

This is the core of the manual. Each code from 02 (internal error) to 57 (rest period violation) is listed with a dedicated page. You’ll see entries like “09 Calibration fault” and “12 Transfer fault.” The manual also covers codes that are entered manually, like “Error entered.” and “Enter data.” These are not standard fault codes but operator actions. If you’re getting a code 45 “Time overlap,” the manual explains the condition – likely a driver card issue. The table is laid out in the same order as the bookmarks: fault code number, name, description, and sometimes a reference to the electrical data. Have the manual open on your bench while you work. You’ll save time and avoid misdiagnosis.

Does This Manual Cover the Entire Electrical System?

No. It focuses on the tachograph system (TAC-DIG, TAC-DIG2) which is part of the electrical system. It includes wiring diagrams, connector pinouts, signal descriptions, and a full fault code table from 02 to 57. If you need other electrical systems like ABS or engine control, check the Volvo Trucks Service Manual – Fault Codes MID 140. For transmission-related speed sensor info, the tachograph gets its signal from the transmission output shaft – a manual transmission will have a speedometer sensor that feeds the tachograph. Understanding manual transmission fundamentals helps, so refer to Manual Transmission and Manual Transmission for background on how the sensor is driven.

Related Manuals

• Volvo Trucks Group 35 LCM Fault Codes Service Manual
• Volvo Trucks Service Manual – Fault Codes MID 140
• Volvo Trucks Truck 2012 Operators Manual – OEM Factory Specs

FAQ

How many pages does this manual have?

70 pages.

Does this manual cover the tachograph calibration procedure?

It covers the fault codes and diagnostic procedures for the tachograph, including calibration fault code 09 and general information about calibration. However, the manual does not contain a step-by-step calibration procedure – that is typically done with a specialized tool (listed in the special tools section). If you need to actually calibrate the tachograph, you’ll need the Volvo diagnostic software and a certified calibration station. The manual will tell you which fault codes indicate a calibration issue, but it expects you to have the proper equipment to perform the calibration. For that, you may want to reference the Volvo Trucks Truck 2012 Operators Manual – OEM Factory Specs for newer model specifics.

Bottom line: if you’re working on a Volvo Truck from 2005 with a TAC-DIG or TAC-DIG2 tachograph, this is the manual you need. It’s OEM, it’s 70 pages of factory-specific fault code data, and it will keep you from throwing parts at a truck that has a simple card conflict or a voltage dip. Access the Factory Manual now and get the diagnostic tree that Volvo intended.