DTC code: P0705 (PRNDL Input-Engine and ECT) What could this mean?

[Jonas]

Hi everyone. My 2009 Vibe GT (Toyota 2.4L) did something odd earlier tonight. I was at a red light and the engine started revving higher than it should, my turn signals stopped working, the airbag light came on, and the digital gear indicator on my dash went blank. P0705 (PRNDL Input-Engine and ECT) was the pending code that later set the CEL on my way home. There was also code B1660 for the airbag. The care drove relatively fine on the way home, except for the engine revving too high at idle. The transmission shifted normally (automatically and manually).

My online research led me to the neutral safety switch. I located it, it was firmly in place and the electrical connector was snug, though I cleaned and re-inserted it anyway. Disconnecting/reconnecting the battery made no difference.
This just happened out of the blue, with nothing odd preceding it. Should I replace the NSS, or could there be something else to check/test first?
Thanks in advance,
Jonas

P.S. The engine is a 2AZ FE and the transmission is a U250E five speed automatic (Toyota), if that helps.

 

[zrxkawboy]

If the battery terminals are clean and tight, I would have the battery and charging system tested at a parts store.

 

[Creekside]

Clear the code and see if the code or symptoms come back. If it does I'd look at whatever communication circuit(s) those items share.

 

[Jonas]

If the battery terminals are clean and tight, I would have the battery and charging system tested at a parts store.

Good call. I just started the car and looked at live data. Battery (alternator) voltage was hovering around 12 to 12.2 volts. The battery terminals are clean and tight. I replaced the battery and the alternator recently with a reman Denso unit, but I'll look it over in the morning. Thanks!

 

[Jonas]

Come to think of it, the car started acting strange this past Sunday. I was on my way home from a family gathering, and as I was coming off the interstate, the car would idle too low at stops like it was about to die. I also had several misfires on cylinder 4 - not enough to trigger a CEL, though. The misfires cleared up, but a day or two later, it was idling rough again, and I saw that my alternator voltage was only about 13v, dipped quickly to 11, then back to 13.2 or so. Also running a bit lean (+7 LTFT at stops).

 

[wtd]

Those voltages sound low but on a lot of vehicles these days, the alternator is controlled by the computer and it only outputs what the computer deems necessary depending on driving conditions and electrical loads.

I would turn on a bunch of accessories that put a large load on the system and see if the charging voltages come up. If not, I would say you have a charging problem.

 

[CharBaby]

We had this situation(similar) on a 2006 Mazda 3. And the automatic tranny safety switch(called a Transmission Range Sensor/Range Finder) was out of position...just slightly.
I was able to adjust the safety switch by unscrewing the hold down screws and turning clockwise about 1/8". The holes a oval to allow small adjustments. It is tight working space but it can be done. So, it may need an adjustment or replacement.

 

[Thermo1223]

12-12.2 is not charging even my GM doesn't go that low. The would have the alternator bench tested. Sounds like the regulator is flakey.

 

[Jonas]

We had this situation(similar) on a 2006 Mazda 3. And the automatic tranny safety switch(called a Transmission Range Sensor/Range Finder) was out of position...just slightly.
I was able to adjust the safety switch by unscrewing the hold down screws and turning clockwise about 1/8". The holes a oval to allow small adjustments. It is tight working space but it can be done. So, it may need an adjustment or replacement.

I see the oval holes. Is it supposed to oriented like this in park? The little blade fin sticking straight up? Also, when I messed with it, the center hole was kind of loose and would move a little by hand. I'll look at it again, loosen/tighten it at a different angle. Thanks for the tip.

 

[Jonas]

12-12.2 is not charging even my GM doesn't go that low. The would have the alternator bench tested. Sounds like the regulator is flakey.

Yes, that's too low for my car too. The alternator usually never goes below 13.2 volts, and that's stopped in traffic with lots of accessories on. Although, when my old alternator went out-less than a year ago-everything drove and operated normally, just with the battery light on and the alt putting out less than 11.7 volts

 

[SC Maintenance]

13.6V is absolute minimum to charge anything. At least 1V over voltage which would be battery voltage +1V.

 

[Jonas]

13.6V is absolute minimum to charge anything. At least 1V over voltage which would be battery voltage +1V.

That's what I've always heard/thought. However, since I've owned my car 5+ years, it would often show as low as 13.2v at idle, although it puts out over 14v right after cold start like it should. I'm on my 3rd battery, 3rd belt, 2nd tension pulley, and second alternator, (probably didn't need to replace all of those things haha) and it hasn't given me any charging/running problems other than when those items needed to be replaced. I have noticed, my windows roll down faster right after starting than they do after driving a while, though. That's another mystery, but maybe related. FWIW, I'm a delivery driver and drive ~25k miles a year.

 

[dumkid]

The higher voltage after starting is because the battery will be drained slightly after sitting and starting the engine.

 

[Jonas]

No luck with adjusting the safety switch. I did see that the fin was off-center in neutral, and I had to move it as far over as it would allow, getting it lined up. Still no gear indicator on the dash, and all the other malfunctions. The gear indicator did briefly show when put in manual mode, but then disappeared. The car started fine, but again the alternator was only putting out 11.9-11.94 volts. I'm confused.

Cold start:

Spot next to temp is where prndl would be:

Boot/cap is missing, but i greased it and the connections are tight. (10 months old)

 

[dogememe]

11.94V running? Something is wrong with the charging system. I wouldn't bother messing with anything else until you resolve that.

Pine hollow auto diag on YouTube recently had a video on a Ford Escape with worn spark plugs. The computer didn't detect any misfires but the spark from the coil would backfeed into the computer instead of going through the spark plug due to the excessive gap and it would cause the voltage regulator in the alternator to die.

So I'm not saying your multiple issues aren't related but you have to start with one and I think starting with the charging system is the obvious one in your case.

 

[Jonas]

11.94V running? Something is wrong with the charging system. I wouldn't bother messing with anything else until you resolve that.

Pine hollow auto diag on YouTube recently had a video on a Ford Escape with worn spark plugs. The computer didn't detect any misfires but the spark from the coil would backfeed into the computer instead of going through the spark plug due to the excessive gap and it would cause the voltage regulator in the alternator to die.

So I'm not saying your multiple issues aren't related but you have to start with one and I think starting with the charging system is the obvious one in your case.

Interesting. I recently bought new plugs because my gas mileage was down, and the car was sluggish (everything else checked out). I suppose I'll go ahead and replace the plugs. Couldn't hurt. When my last alternator was going out, nothing weird happened except the battery light coming on sometimes.

 

[Jonas]

The gap is actually perfect on all of them, but they are oily/fouled (likely due to a leaking valve cover/spark plug tube gasket that was replaced while these plugs were installed). They were in for ~60k miles. Toyota says 120k. The misfires, I think were coincidental.

 

[Jonas]

*Update*
I installed a new alternator and the car is doing the exact same thing(s). It's holding steady at ~11.9 volts. My OBD reader says my battery is in poor condition, but that may just be because it's low from not being charged. The car still starts, but I suppose I could have someone jump my car as a donor and see if anything changes. Beyond that, I'm all out of ideas.

 

[dumkid]

Is the field coil getting power from the car? Does the car have a simple voltage regulator like the old dodge and ford trucks?

 

[Jonas]

Is the field coil getting power from the car? Does the car have a simple voltage regulator like the old dodge and ford trucks?

I don't know about the first question or how to find out. But, the alternator has a voltage regulator built into it.