Tuesday, January 21, 2014

Lotus immobilizer module bypass.

The Cobra-manufactured immobilizer that comes in the pre-’08 cars is a pretty handy piece of technology.  It can do interesting things such as: 
  • make your car more difficult for a thief to steal ,
  • make your battery go flat with a few days of non-use,
  • potentially prevent *you* from starting the car. 
Because of some these ‘features’, some owners will decide to bypass the immobilizer - especially dedicated trackcars. All kidding aside, it's a device that is sometimes troublesome and removing it will not disable your alarm.

The immobilizer is located behind the plastic bulkhead behind the seats.  To disable it, most people have traditionally unplugged the module and either plugged in a pre-built ‘Immobilizer Bypass’ module or created 2 small jumpers out of thin wire with some solder on the ends to flatten them out like pins.  These are installed into the farthest outside pins of the plug; #1 to #6 for the fuel pump, and #5 to #12 for the starter.

Recently, we had the Art Car back in the shop which had jumper wires.  We pulled out the bypass module that was on the car and tested it with a voltmeter to find a resistance change when the wires were wiggled.  To improve reliability, we clipped the wires on the car’s main harness just before the plug and soldered them together.  This allows us to not use the bypass module at all and eliminates a few more points of failure. 

Oh, and without the immobilizer bypass module, we’re saving 0.05lbs!

1 comment:

Frank Amoroso said...

Why not use the PIN code (assuming you have it) to deactivate the immobilizer?