3

I am experiencing symptoms that have led me to track down and diagnose the neutral switch on my 2008 Mazdaspeed3 (6-speed MT/2.3L Turbocharged). These symptoms include:

  • DTCs of P0507 and P0850
  • When starting the car in neutral with foot off clutch, RPMs usually descend from about 1.2k to about 600 over the course of several minutes; currently, it remains high, but drops when the clutch is depressed
  • Coming to a stop in neutral, engine occasionally dies

I've attempted to use online manuals to locate and identify this switch (1, 2), but when I look in the described location (passenger-side behind No.1 engine mount) there are no wires or switches (image).

I did look around and found some potential candidates, though. This image, toward the top of the image, has wires going to two identical-looking objects that resemble the switch I'm looking for (closer view here and here), with the major distinguishing characteristic that one's harness comes in from the side and the other from the top.

I would appreciate anybody who could either confirm/deny one of these switches, or otherwise direct me to the correct location. Furthermore, since the documentation I was following was wrong to this point, I also question whether I can trust the torque specifications provided:

Tightening torque

19.6-29.4 N·m

{2.0-2.9 kgf·m, 14.5-21.6 ft·lbf}

Pᴀᴜʟsᴛᴇʀ2
  • 165,084
  • 32
  • 259
  • 508
Justin Bell
  • 151
  • 4

1 Answers1

2

I ended up diagnosing those connectors by disconnecting them from their respective harnesses and doing continuity tests while they were plugged in. Thankfully, the switch was still working (turns out the problem was a cut harness further up the line, probably the result of a recent trip to the mechanic).

The port at the bottom of the transmission is the neutral switch, which is closed when the transmission is in neutral and open when in gear. The top switch ended up registering as closed when the transmission was shifted into reverse, and open at all other times.

Justin Bell
  • 151
  • 4