Soarer and Celsior cruise limit removal - Written by Robert Hayden with images by Peter Scott at Planet Soarer October 2003


Here's a sure fire way to remove that annoying 108 km/ph limit on the standard Soarer cruise control.
This fix will allow you to set the cruise control at any speed above 40 km/ph.

Tools: 10mm socket with an extension bar (about 200mm ), constant velocity joint and a torch.

The unit is located above the pedals and slightly to the right of the steering column. It's a black box about 5 inches across. You may have to remove the lower cover tray under the steering wheel to see it properly. To remove the cover simply undo the three screws and then pull down gently. There is a large spring clip that locates around the steering column. Disconnect the puddle light by turning it anti clockwise. It will come straight out. Then remove the internal diagnostic plug unit by turning this anti clockwise about 30 degrees and the lift it out also.

The cruise unit should now be visible. It is held in place with two 10mm bolts, remove these and the wiring plug and then the unit should come out.  The wiring plug has a small clip on it you need to push this in to remove the plug.

Once you have the unit out remove the metal bracket. Use a small screwdriver to do this, and gently pry the metal bracket cage away from the black plastic body of the cruise control ECU. Once the cage is clear, prise out the plastic rectangular plastic piece around where the plug entry point is. The cover strip is held in by 4 plastic clips you can see these and should be able to figure them out if you have got this far.  Once the cover strip is removed the board will just slide out.

To remove the limit you need to you need to put a wire across the two points indicated as J300. The location is shown in the picture below, the jumper is circled in red.

Refitting is simply a reversal of the removal process so just put it all back together and cruise at whatever speed you like.

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We have all been having issues with our Celsior's being 108km/ph limited also but until recently there was no defined process or fix for the Celsior.

Fortunately for us all, Steve Irlam up in Katherine, NT, purchased a USA spec from an early LS400. He pulled it apart and sat it side by side with his Celsior unit to try and find a solution. After some searching he found that there was a link wire on the Celsior unit that was simply not there on the USA spec one. From what he could see, this was the only difference so he removed the Celsior wire to match the USA configuration and popped it back in the car. Wallah! Unlimited cruise speed.

The message soon got out to the Celsior owners and Pete Scott gave it a try on his Celsior. Words and pictures below:

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The carpet can stay where it is - the bottom panel can come out - three screws and I pulled it forward and out.

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A single 10 mm bolt holds the cruise control box in place.

The only bolt holding the box.

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The speed control box out.

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Earth cable removed ( I nearly forgot to re-attach it!)

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Out slides the board of mystery.

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There's the J1 jumper that Steve discovered.

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Ah hah! Even I can tell where the J1 jumper is.

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The two capacitors either side are only about 4mm apart so there isn't much room to get tools in here. If you have access to a small soldering iron you can remove the wire. Use any means available to snip the wire. If a soldering iron is handy, this is a neater way to remove the wire!

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Tools of the trade.

Refit the unit back into the car and cruise away.

Many thanks to Steve Irlam for taking the plunge and buying the USA spec unit and then discovering the difference.
Thanks to Peter Scott for these great pictures.