Article by: RobRed

Applicable Models: 1998 – 1999 / 100 Series Land Cruiser or Lx 470

The 100 series Land Cruiser has a center differential lock switch which gives you manual control over your center differential behavior when the transfer case is set to High. The default for action for 1998 and 1999 model 100 series vehicles is when you shift the transfer case to the Low range the center diff locker is automaticly engaged whether you want it that way or not. The pin-7 mod disables the automatic engagement so you can choose to have an open center diff in the Low range. Giving you full control to use Low range on surfaces with high traction without drivetrain windup. This behavior is already incorporated into 2000 model year and beyond 100 series.

The 100 Series has the center diff control box in a different location (behind the glove box) than the 80 series, but otherwise the mod is the same as the 80 series.

  • 1. Remove the glove box door (two screws on the bottom)
  • 2. Remove the black plastic trim piece at the top of the glove box opening (3 screws)
  • 3. Remove the three bolts holding the main ECU (big silver box). You don’t have to unplug it, just move it out of the way so you can get to the transmission control relay on the right side.
  • 4. Find the black transmission control relay and unplug the wiring harness from the bottom. This is kind of tricky. There is a latch on the back and you have to pull down fairly hard. You may need pliers to pull down and use your finger to press the release latch.
  • 5. Remove the pin-7 wire (black with blue tracer). The pin numbers are marked on the plug, but they are very hard to see. See the link below for some pictures and how-to on this.
  • 6. Insulate the pin with 3m Super 33+ tape or heat shrink. Optionally label it with tape so it’s easy to identify.
  • 7. Reassemble.

 

For reference this modification has been done extensively on the 80 series Land Cruiser. Here is a popular link describing the procedure. It’s basically the same on the 100 series; http://www.sleeoffroad.com/technical/tz_cdl_pin7mod.htm