Removing the 180km/h Speed Limiter on Japanese SVX

[b3lha]

I've just done this so I thought I would post the method incase anybody else wants to try.

You need an S22 Speed Converter chip from http://www.svashop.com. It costs about £35. It's essentially a frequency divider. The signal from the speed sensor is a 5v square wave, the frequency of which is proportional to the speed of the car. The chip divides the frequency by 1.6 so that "kilometers" become "miles". The speed limit therefore becomes 180mph.

1) Locate speed sensor #2. Put your hand down the back of the engine on the driver's side. There is a small oval plug (B9) below and behind the two fat square ones. If you remove it, it is yellow inside and has three wires. One of the wires is yellow with a red stripe.
2) Locate MPFI (Engine ECU). It's a silver box in the driver's footwell, just above the brake pedal with 4 yellow connectors going into it. Pin 11 of the 12 pin connector (B60) is a yellow wire with a red stripe. Use a multimeter to check that it is connected to the yellow/red wire on the speed sensor under the bonnet.
3) Cut the wire about two inches from the MPFI connector. Solder the loom side to the "Speed In" wire of the S22 chip. Solder the connector side to the "Speed Out" wire of the S22 chip. Connect the "ground" wire of the S22 to a nearby bolt. Connect the "12v" wire of the S22 to a wire which is live when the ignition is on. I used pin 6 (Green/Yellow) of the Black connector (B39) which is behind the mirror controls. (You have to remove the panel above the driver's shins for this, the screws are behind the coin box and mirror control switch).
4) To make the speedometer and odometer read in mph instead of km/h, locate connector (B40) which is a white connector behind the mirror controls. Pin 6 should be a white wire, check it is connected to the yellow/red wire on the sensor and then cut it and wire the connector side to the "Speed Out" wire of the S22.
5) To make the Cruise control operate above 70mph, remove glovebox. There are two units above the glove box. The one nearest the centre of the car is the cruise control (the other is the central locking). On top of the cruise control unit, out of sight there are two connectors. Pin 7 of the larger one (B83) should be a yellow wire with a red stripe. Check this is connected to the wire on the sensor and then cut it and solder the connector side to the "Speed Out" wire of the S22.

I haven't yet had the opportunity to drive the fast enough to check the limiter is gone, but certainly the speedo is reading in mph now and the cruise control engages above 70.

If anybody wants to try this, mail us for more detailed info.

Phil & Belha.

[svxistentialist]

I will get this and change mine after I have passed tthe NCT, our version of your MOT.

Joe