H0H-Crankshaft Position Sensor recall

Thanks Greg, also in for your thoughts on how the truck runs after the swap! Are you tuned?

 

Yes - I'd be especially interested in any measurements to determine how much of a size difference there is. based on the recall details, it seems we should expect to see a slightly smaller / shorter sensor to account for the coating that makes it a tight fit and thus static electricity?

 

Do you think you will see a physical different between the 89 CPS and the 98 CPS?

 

Sub'd.

 

This! Please take very detailed measurements if you could as the length could be ever so slightly different. I also talked to online place I ordered my "89" sensor from and they are kind of surprised at the different part number. Hmmmmmmm.

 

I'm in the same boat with you. Bought mine in Jan 2016 and not on the recall list. Can't figure it out.

 

In on the recall list with a November 15 build date. I have a spare sensor that I bought awhile back. I will need to check the part number.

 

Vehicle information:
Production Date: 09/16
ECU/TCU: Rev 1
Included in VIN Recall: No
Theorized Related Symptoms: Stumble/flutter around 1200-1500 rpms under low-moderate load, before a shift. Very rare but occasional hesitation/power loss on incline that goes away after releasing/re-engaging throttle

Physical dimensions are the same. Measurements between the two came out the exact same. Of note, however, was my stock CKP sensor did have light surface scratches.

Old left, new right.




visible scratches:


Number on old started 0971 - New was 0972. Unsure if this is a part number or an incremental lot number. May be nothing more than production numbers of the same part.


Hash mark present on old, not on new (two lines on new)


So far, Stumble/flutter is still there. Completely unchanged driving characteristics noted. Time will tell on the rare power hesitation, but it seems this is not the cure for at least the stumbles.

 

Thanks @Scooby24 - very detailed, more than I expected by far so thank you for taking the time to provide the pictures, measurements, etc., Somewhat concerning if the new sensor is the exact same size as the old one, and the old one was getting scratches from coming in contact with the crank rotor, how does replacing with one with the same propensity to come in contact with the rotor fix things.

Sorry to hear that didn't help with your stumble/flutter at all. Mine definitely decreased massively when I replaced my stock CKP with the "89" though it still does happen it's not as frustrating and persistent. Let us know if you get any better results with drive time.

Question: Did you reset the ECU when you replaced the sensor?

 

No I did not reset the ECU as I wanted immediate feedback if it was the sensor itself that was causing the problem. It's possible that abnormal readings, over time, have lead to learned behavior resulting in timing variances/stumbling as a result. Time will tell on that. Resetting the ECU immediately would give me a potential false sense of improvement as it had to go through the relearning phase. I may reset the ECU now that I've got an immediate result but I'm not optimistic.

 

I followed the directions in the FSM for the replacement and it stated to unplug the negative battery terminal prior to replacement so I did that. I wouldn't be surprised if resetting it does make a difference given those scratches, and in my experience this ECU has a slow learning curve and seems to take a thousand or more miles to adjust to anything. Regardless, sorry you didn't get positive results there. IF you do the ECU reset, in my experience it only takes 5-10 mins. just leave your door open and the lights will bleed out any remaining juice in the system!

 

This was the outcome I am afraid of with my truck. They are blaming the ckp sensor for the issues with the stumbling with the OV tune. I'm going to be very disappointed if it does not fix it. My sensor will be here tomorrow so I guess we will see. I will hope for the best since alot of people said the truck was different after changing the sensor.

 

I have confidence OVTune will be able to resolve the Stumbles. Keep in mind he has ONE tune released, an alpha tune....and he has no datalogging setup yet. Without datalogging, we could only hope to get a positive result from the first tune...the fact that the only real complaint folks have so far is a more prevalent stumble given all the handicaps with any Alpha release speaks volumes.

Once he starts seeing lots of folks datalogs and identifies the common trend, I think it will get fixed...especially finding out now that this wasn't related to the CKP sensor. Likely all in the tune.

 

I saw somewhere a detailed process with pictures of the removal and replacement of the CPS. Does anyone know where I might find that again. Thanks in advance

 

The instructions are in the OP. PDF file outlines it and anyone with basic tools can accomplish it in about 10-20 minutes.

 

Very disappointing that it didn't seem to help your stumbling problem. (yet)

 

Reset ECU and stumbles are gone. So, the stumbles are learned and replacing the sensor alone won't fix them. There's a very real possibility they will return after new learning however I will note something that is now unmistakably different.

I didn't mention it earlier because I thought it was placebo, but idle vibrations after changing the sensor were virtually gone which did stick out as different. After resetting the ECU they are gone, entirely. Like no vibrations at all. Shortly after buying my truck I thought there was something unusual about how much vibration you'd get at idle through the steering wheel. It was always there, but got noticeably worse at periods where I just chalked that up to the secondary injector cleaning cycle. However, after feeling the difference in idle vibrations now, I'm not ready to write off this new sensor. CKP sensors are notorious for having their problems with accurate readings in lower RPMs so the low rpm stumbles may be as a result of learned timing adjustments due to abnormal CKP readings, and the vibrations felt during idle may be symptoms of poor fueling/ignition due to inaccurate CKP readings at the lowest RPMs.

edit: Here's a thread I made last November about the vibration. Looks like I made the thread around 1k miles. Shouldn't take too long to know if this is a temporary thing or not.

https://www.tacomaworld.com/threads/idle-vibration-increase-recently.459127/

 

thank you

 

Positive sign, but we won't know for sure until you rack up some miles. Thank you for resetting the ECU.

 

For those resetting the learning / ECU where are you doing that in techstream and how exactly are you doing it?