Engine Code 37 High/Erratic Idle

Look in the exhaust breakdown. Find no. 18.

Okay I found a solution to this problem! When talking with the Yamaha dealer they informed me that they replace the whole throttle body! That's insane for $95 part, not to mention the down time. So after doing some testing and research I found the part that works as a replacement for the IACV.

Part:
Unlimited Rider Throttle Body Stepping Motor Idle Air Control Sensor Valve IAC ISC For Kawasaki BRUTE FORCE 750 4X4I 08-2021, BRUTE FORCE 750 4X4I EPS 2012-2021, TERYX TERYX4 14-21 Replace 49116-0021

Amazon Link to Part
FYI-There is a cheaper part that looks almost like this one, but it will not work.
This takes 10 min to replace and I tested it over the weekend while riding for over 7hrs and worked perfect!
Just a note this is for my 2021 YXZ 1000R XT-R

So I’m having the same issue with high idle/reving/code 37 & I purchased the above Idle Air Control Sensor, as I thought that would fix my issue, but after swapping it in, it ran for a minute or two & then went right back to high idle & throwing code 37 again.

It’s really an odd one for me, as I hadn’t driven my YXZ for maybe a month or so & upon starting up, that’s when it started having this issue. Didn’t happen during riding or anything, just one day was fine, sat for a month & then now can’t seem to get her to cooperate.

Does anyone know what next steps I should check/try, if I’ve already replaced the sensor?

CwickStylz said:

So I’m having the same issue with high idle/reving/code 37 & I purchased the above Idle Air Control Sensor, as I thought that would fix my issue, but after swapping it in, it ran for a minute or two & then went right back to high idle & throwing code 37 again.

It’s really an odd one for me, as I hadn’t driven my YXZ for maybe a month or so & upon starting up, that’s when it started having this issue. Didn’t happen during riding or anything, just one day was fine, sat for a month & then now can’t seem to get her to cooperate.

Does anyone know what next steps I should check/try, if I’ve already replaced the sensor?

Click to expand...

Is your car stock or have or do you have a turbo? What year is your car?

No turbo, just exhaust & DynoJet AutoTune. It’s a 2017 SS.

I literally just spent the last 3-4 hrs tearing the vehicle down, checking each & every connector, hoping that it might’ve been something that easy, but to no avail…

it’s driving me absolutely crazy, as I am OCD as heck & meticulously maintain her…she ran perfectly the last time I drove her, then it sat for about a month, on a battery tender & when I fired her up…3,500RPM idle & sometimes bounces sort of all over the tach…😔

I have seen others complain about the throttle cable sticking on the turbo installs. Also, 2016s had a problem with the cable hanging up to the point that Yamaha still has a recall and free replacement on them.

Just trying to make heads or tails of what could be causing this issue, as I feel like I neurotically maintain my machine…

The only thing I did before tucking her away on the battery tender for about a month was install some new cube lights, so could this possibly be caused by an electrical problem? Maybe my dumbass has a bad ground or something, but I don’t know if that could even hypothetically cause error 37 or not?

Like I mentioned previously I spent hours coming through all electrical connectors cleaning and diaelectric greasing them, to ensure not a dirty connector, so could it actually be that the throttle body is truly “stuck” open, instead of the sensor just reading that it is? I don’t know if that’s even remotely possible, but kind of at a loss after swapping the sensor & getting exact same result…

Have you even checked the throttle cable? It's a known problem and worth a look.

I did take a peek at it & did a small adjustment to it, but maybe I should try lubricating it, so I doesn’t possibly get stuck? Is the only place to adjust/lubricate the front drivers side spot or should I follow the cable to anywhere else it could hypothetically get hung up? Thanks so much for the help, hopefully can get this figured out!

The only way to tell is to take one end loose and move it by hand to see if it's binding. The cable rusts inside causing it to hang up.

3Yamigos said:

Okay I found a solution to this problem! When talking with the Yamaha dealer they informed me that they replace the whole throttle body! That's insane for $95 part, not to mention the down time. So after doing some testing and research I found the part that works as a replacement for the IACV.

Part:
Unlimited Rider Throttle Body Stepping Motor Idle Air Control Sensor Valve IAC ISC For Kawasaki BRUTE FORCE 750 4X4I 08-2021, BRUTE FORCE 750 4X4I EPS 2012-2021, TERYX TERYX4 14-21 Replace 49116-0021

Amazon Link to Part
FYI-There is a cheaper part that looks almost like this one, but it will not work.
This takes 10 min to replace and I tested it over the weekend while riding for over 7hrs and worked perfect!
Just a note this is for my 2021 YXZ 1000R XT-R

Click to expand...

Where exactly that part located. Driver side next to the throttle body? Tks

CwickStylz said:

So I’m having the same issue with high idle/reving/code 37 & I purchased the above Idle Air Control Sensor, as I thought that would fix my issue, but after swapping it in, it ran for a minute or two & then went right back to high idle & throwing code 37 again.

It’s really an odd one for me, as I hadn’t driven my YXZ for maybe a month or so & upon starting up, that’s when it started having this issue. Didn’t happen during riding or anything, just one day was fine, sat for a month & then now can’t seem to get her to cooperate.

Does anyone know what next steps I should check/try, if I’ve already replaced the sensor?

Click to expand...

I have had on them 2 separate yxz's with code 37 that turned out to be faulty ecu's. 2017 yxz1000r 3 pedal. Both of these cars were sold new in 2020 by Yamaha Australia as run out models and have about 20hrs of run time on them. Replacing the ecu fixed both cars.