C.L.A.S.S. Repair

I have been interested in reading about the different repairs/fixes from several members about various Computer Leveling Air Suspension System (CLASS) related problems, in particular, compressor failures. Having had only intermittent use of my CLASS system last year and complete failure this year, I decided it was time to go to work on the compressor. When the system would fail to operate, I would get different error messages on the controller; E 1, E 2, E 3, and E 4 in no particular order. This is on a 1983 Royale with 35,000 miles when the trouble first appeared. Removal and cleaning of compressor was simple and took in the hour and half time range. The factory service manual is more than adequate in the removal and replacement of the compressor; however it does not go into disassembly or give a break down of the compressor itself. The only caution I have here is to be sure and pay particular attention to how the two reed valves are placed under the head and above the compressor's piston. They could easily be installed backwards and in the wrong sequence. After reassembling the compressor, it was bench tested for operation and then reinstalled.

CLASS still would not operate. Back to the service manual to troubleshoot the CLASS system. The first item was to remove the controller from the right-hand side of fairing and check for battery input voltage which was present. Next item was to check for sensor output voltage, the valve output voltage for front forks, rear shock and decrease pressure valve. At first no output voltage was present but as I would move the controller to test the different value voltage, the voltage would come and go. My first thought was the electrical connector plug to the microcomputer in the controller was not making good contact. Further tests proved the connector contacts to be good. This left the microcomputer as the cause. I then recalled the article by Buck Parrot in the April 1992 issue of Venture Road about cold solder joints. I disenable the controller to get to the circuit boards of the microcomputer. A caution here; you can handle the circuit boards by the edges with no problem but be sure and don't touch any of the components on the circuit boards themselves. They are very sensitive to static electricity from your body and can cause damage to the components. They are not particularly fragile from rough handling but to the static electricity charge itself. Upon inspection with a magnifying glass, 4 cold solder joints were found on the under side of the electrical connector where the solder connection was made to the printed circuit board. Using a low wattage soldering iron, the cold solder joints were resoldered. The controller was reassembled and installed and the CLASS was returned to proper operation.

One final thought on the compressor; I'm not so sure if it wouldn't be a good idea when you or your dealer performs your regular maintenance on the dryer and the suction filter of the compressor to use a little WD-40 or Break Free in the suction filter pipe on the compressor to lubricate the inside of the compressor and thus eliminate the necessity of the complete disassembly of the compressor.

Dwight E. Dowds #00186
Yuba City. CA

? A good way of finding cold solder joints is to spray them with a freeze-type solution (available from electronics stores).

CLASS System Tips

One of the many great features of the Venture is the CLASS system (Computer Leveling Air Suspension System). With the push of a button you can adjust the front or rear suspension to one of three preset levels, or manually to anywhere in between. The correct way to make an adjustment is to first put the Venture on the center stand. Make adjustments to the front first, then the rear. Otherwise the high pressure from the rear will flow into the front forks. This ensures correct air pressure readings. I generally use one of the three presets (low, medium, or high), although I have used the manual mode. When travelling with the Venture fully packed and copilot Renee on board, I generally set the suspension to the high setting, both front and rear. However, this setting can be too stiff when the road surface gets bumpy, as on Prince Edward Island, Canada, where the road is particularly rough. There I manually lowered the rear suspension until the ride softened enough for us to be able to enjoy the scenery without every bump jarring our teeth!

The damping adjustment should be set to coincide with the CLASS setting. When the CLASS system is set to "low," the damping should be set to a 1" or 2". With the CLASS at "medium," damping should be set at 2" or 3", and with CLASS at "high," damping should be at 3" or 4".

Be careful not to set the suspension too low. The Venture, which is a great handling motorcycle, will lose all of its manners in the corners if the suspension is not set high enough. Trust me, I know!

Perhaps the most important check is the air pressure in the tires. Check it frequently!

Tom deGuehery #07113
Durham, NC

E2 Error January 1992, page 27


During the later part of summer this year, my CLASS system started to give me a "E2" message when I tried to adjust the air pres­sure in the rear suspension on my 1989 Ven­ture. The message appeared when the pressure reached approximately 50 p.s.i.

I checked the outlet valve on the compres­sor unit and there was nothing wrong. I de­cided to remove the compressor and check it more thoroughly. After removal and disas­sembling it, I found that the piston and piston ring was dry. I put some compressor oil in it and connected it to a 12 volt source and let it run for a few seconds. After that, I cleaned it completely and put in new oil. I closed the unit and replaced it. It worked perfect.

If anyone gets an E2 error message on their CLASS system, they might want to try this solution.

Peter Johanson, #05958

Deceleration Wobble? Aug. 1989, pg 13

Want to fix that deceleration wobble? I'll tell you what worked for me on my 1984 Venture Royale.

After more than I 7K miles on my first set of Dunlop K491 's, they began to talk to me, vibrate and wobble when decelerating be­tween 45 and 35 mph. Time for a new set of skins, even though the wear bar was not showing.

The new tires were installed last fall and they were okay except you guessed it  the wobble was still there and worse than be­fore.

Back to the tire dealer who rebalanced and rebalanced until I gave up. Static balanc­ing and spin balancing helped but still there was a noticeable wobble. I figured what the heck, most gold Wings and Harleys I know wobble. I'll ride it out and switch brands next spring.

In the meantime, the bike went into the shop for a good going over and tune up. Among other things, they greased and rebushed the mono shock mounts. They did not touch the tires which had been purchased elsewhere.

Want to guess again? Well, that wobble is completely gone and the Venture handles better than new, even with 34K miles on it.

Erwin E. Gerhard, #06441

Error Code September 1991, Page 22

If you have a CLASS (Computer Leveling Air Suspension System) that displays the "E4" error code, the pressure sensor or an open circuit is the most likely cause. Some­times, however, the open circuit is in the print board behind the CLASS controller module. This is especially true if you have an intermit­tent "E4" error code, or even a flickering "88" error code. And it's a problem that is hard to spot unless you know what to look for.

The Print Board Assembly 2 has a multipin connector on the back. The solder joints on the multipins can be damaged from rough handling while unplugging the connec­tor. Also, on 1986 and later models, the wires flex every time the cover is opened or closed to check coolant. Over time, this could also damage the solder joints. A damaged joint can cause an open circuit and the error code.

This bulletin provides diagnostic and re­pair information for this problem.