Description

Scania Type A 1998 Workshop Manual

If you’re working on a Scania Type A 1998 Workshop Manual truck and the seat’s acting up – won’t adjust, heater dead, belt sensor throwing a code – you’re not going to fix it by guessing. I’ve seen too many guys throw parts at a seat rattle and end up with a bigger bill and a pissed-off driver. This 98-page factory book gives you the exact procedure, from reading fault codes on page 15 to swapping the solenoid valve on page 32. No aftermarket reprint here. You get the original Scania publication with the Swedish OEM part numbers and wiring color codes. That’s what keeps a truck earning money instead of sitting in the bay.

What This Covers: Seat Systems for Luxury A and Medium A

This manual splits the seat into two trim levels: Luxury A and Medium A. Each has its own exploded view on pages 50 and 52. You get the full description of operation – how the air spring, gas spring, shock absorber, and control unit work together. The ‘Air and electrics’ section on page 9 explains how the belt lock engages when you lower the backrest. Pay attention to that; I’ve had a driver nearly crash because an unlatched belt let him slide sideways during a turn. The part numbers and serial numbers are listed so you order the correct valve or potentiometer the first time. If you’re working on a Medium A seat with the ratchet tilt mechanism, the manual walks you through the cable adjustment for the gas spring. No parts cannon approach – you diagnose first, replace second.

Fault Diagnosis: Checking Codes with a Multimeter

Fault diagnosis starts on page 15. Scania gives you a list of fault codes for the control unit, but you need to know which version of the control unit you have – page 17 tells you how to identify it. The manual says ‘Check this first’ on page 16, and I’ve found that advice saves an hour of chasing ghosts. For electrical gremlins, you grab a multimeter and follow the steps starting on page 27. The ‘Colour designations on the cables’ page 29 is critical – Scania used a specific wire color code, and if you’re colorblind or using a generic wiring diagram, you’ll short something. The potentiometer test on page 30, solenoid valve on page 32, and control unit power checks on page 34 are laid out with expected voltage values. Use the ‘Starter key positions’ table on page 29 to know which terminals are live in each key position. This isn’t a generic ‘check for power’ – it’s exact.

Work Description: Removal, Refitting, and Spot Repairs

Once you’ve diagnosed the issue, the work description section (page 3 and onward) gives you: exploded views for both Luxury A and Medium A, spot repairs for common problems like a rigid shock absorber (page 54) or a seat that rattles (page 57), and full removal and refitting procedures. The ‘Warnings to be observed when working on the seat’ on page 59 are there because people have crushed fingers in the gas spring mechanism. Follow them. The manual covers everything from changing the whole seat (page 60) to replacing the heater pad in the backrest (page 38) and the air cushions for lumbar support. There’s even a repair kit for air hoses on page 58. Each step includes torque values where needed – yes, the seat bolts have a spec. The buckle, belt switch, inertia reel, and sensor in the seat squab are all covered individually. If you need to remove the side casing with or without control buttons, the manual shows the clip locations so you don’t break the plastic.

3 Reasons to Use the Factory Manual Instead of Aftermarket

1. OEM fault codes and wiring – Aftermarket manuals often truncate the code list or use generic color names. Scania’s chart on page 29 lists every cable color by its Swedish designation. One wrong wire and you fry the control unit.
2. Part numbers that match the truck – The ‘Part numbers and serial numbers’ section means you order the correct potentiometer or solenoid valve. I’ve seen aftermarket books list a part that has been superseded twice. This manual is from 1998 and references the original Scania numbers.
3. Factory sequence for disassembly – The order matters. If you pull the backrest before disconnecting the air lines, you’ll tear the air cushions. Scania’s step‑by‑step removal for the backrest on Luxury A versus Medium A is different – and they call it out. That keeps the repair time down to a reasonable billable hour.

One more thing: this manual does not cover the chassis, engine, or transmission. It’s strictly the seat system. If you need the drivetrain, check out the Scania 16-litre 2002 Workshop Manual – Factory Specs or the Scania D1LC & D1LCC Auxiliary Heater 2000 Workshop Manual for auxiliary systems. For transmission work, the Scania Opticruise 1995 Workshop Manual has the hydraulic and electronic controls. And if you’re comparing transmission types, Wikipedia’s article on Manual Transmission gives a good overview of how they differ from automated manuals – though the seat manual obviously won’t help you split gears.

Does This Manual Cover Electrical Components?

Yes – the electrical section runs from page 27 to page 48. You get diagnostics for the control unit, solenoid valve, potentiometer, heater pads, belt switch, button for adjusting height, buckle, inertia reel, and the sensor in the seat squab. Each component has a dedicated procedure. For example, the ‘Contact for the seat’s electrical connections’ on page 40 shows you which pins to probe and what resistance to expect. The ‘Switch for the heater pads’ on page 36 includes a continuity check. If you’re chasing an intermittent wiring issue, this manual gives you the endpoints. One warning: the colour designations use Scania’s own abbreviations – don’t mix them up with DIN or ISO standards. Page 29 lists them all.

FAQ

Is this manual for the whole Scania Type A truck?

No. It covers only the seat – both Luxury A and Medium A variants. You want engine, transmission, or brakes, you’ll need a different Scania workshop manual. This one stops at the seat mounting bolts.

Can I use this to fix a seat from a 2001 Scania?

This manual is for the 1998 Type A seat. While some components carried over, the control unit versions and part numbers changed. Check the ‘Versions of the control unit’ section on page 17 – if your truck has a different seat part number, you’ll need the later manual. However, the diagnostic approach – reading fault codes with a multimeter using the color designation chart on page 29 – is valuable for any Scania air seat. I’ve used this method on 2000 models and it works if you understand the wiring. Just don’t expect identical plug locations. Also note that the seat belt tightener systems for the US market (listed separately in the TOC) differ from European ones, so if your truck is US-spec, double-check the part numbers. For a broader perspective on manual gearboxes, you can read about Manual Transmission in general, but for the seat you need the correct year-specific book.

This manual has saved me from replacing a $400 control unit that only had a corroded ground wire. The factory wiring diagram on page 34 pinpointed the fault in ten minutes. That’s why I keep a copy at every bay. If you’re serious about keeping your Type A on the road without guesswork, Access the Factory Manual and keep it on your tablet or print it out. You’ll thank yourself the first time a seat sensor code lights up the dash.