2008 civic si 5th and 6th gear lockout

So this morning I leave my house for work. 1st gear through 4th gear we're fine, then lockout on 5th and a grind and lockout on 6th. Speedometer shows "0" the whole time I'm driving. I tried double clutching, still nothing.
Power steering light came on this morning also. And most likely unrelated, DTC for ECT sensor 2 came on the other day.

Even when the car is parked and off, I can't get into 5th or 6th.

Thanks in advance for any help!

Hi there, sorry to hear that!
I'd check the linkages for any kind of binding, but any time I've had a manual transmission that wouldn't take a gear even with the engine off, the trans ends up being junk.
I sure hope someone here has a more positive opinion for you!

I've been trying to connect the power steering and the speedometer to the transmission issue, but I've got nothing. I'm banking on something wrong with the output speed sensor (no speedo), which is then shared over the F-CAN network to the power steering for variable assist purposes.

Still, doesn't explain the shifting problem. The fact that you can't get 5th or 6th even with the engine off screams internal problem to me. Perhaps 5th and 6th are on the same shift fork?

I meant to get back on here for an update.

It goes into 5th and 6th. the grinding was reverse. It is allowing the shifter to go all the way over to reverse while driving forward.

and now, my power steering light is on and is intermittent working/not working.
it is throwing a dtc for for coolant temp sensor 2. but my coolant temp bar on the dash is working normal.
and when shifting, it feels like I'm skipping a gear, eg. 2 to 4, 2 to 5, even though im not.
the throttle doesn't feel like its responding right either

from what I'm reading online its looking like the ECU could be faulty. But I don't want to drop 300+ on one if it is something else.

And on top of all this, I'm having my original parasitic draw problem on underhood fuse circuit "backup" (MICU, OBD port, door locks, moon roof, interior lights, stereo)

So after some investigating I found that the wires to my speed sensor were cut. I soldered them back together and wrapped them up. So my speedometer is working again, the reverse lockout is back to normal (the computer didn't register movement since the wires were cut) and my power steering issue is gone.

It is still throwing a code for the coolant temp sensor. I topped off the radiator, and overflow. I erased the code and it just came back. No over heating issues, runs at normal temp, and the temp gauge works like normal. So don't know what's going on there

SamMagiske wrote: So after some investigating I found that the wires to my speed sensor were cut. I soldered them back together and wrapped them up. So my speedometer is working again, the reverse lockout is back to normal (the computer didn't register movement since the wires were cut) and my power steering issue is gone.

Makes sense to me! I knew there had to be a connection. :lol: I didn't know that the reverse lockout was associated with the speed sensor, though. Interesting.

It is still throwing a code for the coolant temp sensor. I topped off the radiator, and overflow. I erased the code and it just came back. No over heating issues, runs at normal temp, and the temp gauge works like normal. So don't know what's going on there

If it's ECT2, then that'd be the sensor monitoring the thermostat for proper operation, and not the primary temperature input to the PCM. A hard code (one that comes right back) will make this much easier to diagnose.

First step will be to find ECT2 and take some voltage readings on both wires, plugged in and unplugged. Those tests will let us know if you have a sensor problem or a wiring problem.

For more info on thermistors, check out Chapter 6 in Engine Performance Diagnostics: