Description

Volvo Trucks 2004 Service Manual – Group 35 LCM Fault Codes

You have a Volvo truck with a lighting circuit that’s acting up. Headlights flicker, turn signals stop, or you get a fault code you can’t decode. Without factory diagnostics, you’ll chase grounds and voltage drops for hours. This Volvo Trucks 2004 Service Manual – Group 35 – hands you the exact MID 216 fault code table, signal pinouts for the LCM, and the procedure to verify each circuit. It’s 108 pages of what Volvo expects their techs to use – no aftermarket shortcuts.

Fault Code Table: MID 216 and FMI Breakdown

This manual opens with the Specifications section that lists every SID and PSID related to the lighting control unit. You get the MID 216 fault code table and the full FMI table – FMI 2 through 13 depending on the component. For example, PSID 1 (headlight left side) lists FMI 5 and FMI 6. That tells you the exact failure mode: short circuit or open circuit. No guesswork. The manual then links each code to a diagnostic section with measurement steps.

Special Tools Required for LCM Diagnostics

Page 2 of the TOC says “Special tools” and “Other special equipment.” I’ve seen techs try to diag lighting faults with just a test light. Not enough. The manual lists what you need – specific breakout boxes, multimeters with duty cycle capability, and the PC tool for reading fault codes. If you skip the tool list, you’ll end up with inaccurate readings. That costs time.

Understanding the LCM Control Unit Signal Descriptions

Control unit outer lighting (LCM/SLCM) signal descriptions cover LC1 and LC2 input signals plus PC1 and PC2 output signals. Switch main lighting signal descriptions follow. These are the wiring maps. Without them, you’re probing blind. The manual pinpoints which pin does what, so you can verify voltage at the source. If you need to cross-reference with engine ECU diagnostics, check out Volvo Trucks MID 128 Engine Control Unit Fault Codes.

SAE J1939 and J1708 Communication Links – Factory Procedure

The manual dedicates sections to MID 216 SID 231 (SAE J1939 Control link) and SID 250 (SAE J1708 Information link). General information explains how the LCM talks to the rest of the truck. FMI 2 is common for these links – it means the data line has an issue. The diagnostic steps include checking the termination resistors and the wiring. For older Volvo passenger cars, 1995 Volvo 850 Service Manual – Suspension & Steering OEM Specs covers mechanical specs, but this truck manual deals with network faults.

Headlight and Lighting Circuit Fault Codes (PSID 1–24)

PSID 1 through 24 cover every exterior light: headlights, dipped beam, full beam, fog lights, spot lights, reverse lights, brake lights, turn signals, tail lights, parking lights, and trailer lighting. Each has its own fault code list with FMI numbers. For example, PSID 8 reverse light has FMI 5 and 6. The manual then gives the measurement procedure at the control unit and at the component. Do not skip the verification step. If you’re rebuilding a Manual Transmission, that’s a different manual – this one focuses on electrical diagnostics.

Volvo Trucks 2004 Service Manual: What 108 Pages Gives You

You get the complete Group 35 fault diagnosis for the external lighting control unit. The manual includes calibration memory EEPROM (SID 253), program memory (SID 240), and control unit internal faults (SID 254). It also covers the relay intermittent wiper (PSID 19) and instrument panel lighting (PSID 20). The Volvo Trucks 850 Service Manual – 37-Page Factory Schedule has a different scope, but this 108-page document is dedicated to lighting faults. Access the Factory Manual to get the OEM pinouts and test procedures.

Does this manual cover engine repair or transmission work?

No. It is strictly for lighting control unit fault codes – MID 216 LCM.

How do I use the fault code table to fix a problem?

Locate the PSID or SID from the truck’s diagnostic tool. Cross-reference with the FMI code. For example, PSID 1 with FMI 5 means headlight left side has an open circuit. The manual then gives measurement steps at the control unit and component. You need a multimeter and the pinout from the signal descriptions. Do not assume – follow the verification steps. That’s how you waste less time. If you need to understand a Manual Transmission rebuild, that’s a separate document. This manual gives you factory-level lighting diagnosis – no aftermarket shortcuts.

Access the Factory Manual now and get the exact procedure Volvo truck techs use. You’ll stop chasing ground faults and start fixing them on the first try.