What did you do to your NBS GMT800 Tahoe/Yukon Today?

[MADPINTO08]

Are those RGB? I installed some in my bagged Silverado grill that are hooked to a controller along with my demon eyes that uses an app on my phone so I can CM them all to the paint color -it’s in the red spectrum which of course is illegal to drive with. I run them in a different color when I’m on the road.

Oh nice yeah I was trying to post a video of them flashing all the colors look pretty cool but it’s just something my kids talked me into doing and I think I like it

 

[Rocket Man]

Oh nice yeah I was trying to post a video of them flashing all the colors look pretty cool but it’s just something my kids talked me into doing and I think I like it

You have to host the video on YouTube or something similar and then post a link if you want to share video here.

 

[iddqd]

I was under the impression that it had to be done when the crankshaft sensor was replaced. First time I hear it needs to done when the harmonic balancer is replaced. I do have the Tech 2 to get it done

I attached GM Service manual extract, check out #12.

Basically, the crankshaft does not have a keyway, so balancer can be installed in any position, and since these parts are balanced separately, it can potentially throw off misfire detection due to slight fluctuation in RPM between cylinders.

 

[mattbta]

Dropped the Escalade roof rack end caps, vent caps and a door handle that have been sitting in the garage for many months off at a paint shop for color matching. Truck is 805K, Dark Spiral Gray Metallic....starting to second guess getting the rear vent caps matched instead of just black.

 

[Rocket Man]

I attached GM Service manual extract, check out #12.

Basically, the crankshaft does not have a keyway, so balancer can be installed in any position, and since these parts are balanced separately, it can potentially throw off misfire detection due to slight fluctuation in RPM between cylinders.

I saw where the SM states to perform the relearn but it doesn’t explain why, and even though you say it can potentially throw off misfire detection, I have yet to read anything that actually explains how it can just by R&R’ing the balancer. Why would that cause a slight fluctuation in RPM between cylinders?

 

[iddqd]

I saw where the SM states to perform the relearn but it doesn’t explain why, and even though you say it can potentially throw off misfire detection, I have yet to read anything that actually explains how it can just by R&R’ing the balancer. Why would that cause a slight fluctuation in RPM between cylinders?

My guess would be that the imbalance might cause slow down/speed up at some crankshaft positions. It's been a while since physics classes, I have a feeling it might happen, but I can't explain the physics behind it.

This is what GM has to say on this topic:
DTC P0315
Circuit Description
The crankshaft position (CKP) system variation learn feature is used to calculate reference period errors caused by slight tolerance variations in the crankshaft, and the CKP sensor. The calculated error allows the powertrain control module (PCM) to accurately compensate for reference period variations. This enhances the ability of the PCM to detect misfire events over a wide range of engine speed and load. The PCM stores the Crankshaft Position System Variation values after a learn procedure has been performed. If the actual crankshaft position variation is not within the Crankshaft Position System Variation compensating values stored in the PCM, DTC P0300 may set. If the CKP system variation values are not stored in the PCM memory, DTC P0315 sets.

The CKP system variation learn procedure is also required when the following service procedures have been performed, regardless of whether or not DTC P0315 is set:

• An engine replacement

• A PCM replacement

• A harmonic balancer replacement

• A crankshaft replacement

• A CKP sensor replacement

• Any engine repairs which disturb the crankshaft to CKP sensor relationship.

 

[Rocket Man]

My guess would be that the imbalance might cause slow down/speed up at some crankshaft positions. It's been a while since physics classes, I have a feeling it might happen, but I can't explain the physics behind it.

This is what GM has to say on this topic:
DTC P0315
Circuit Description
The crankshaft position (CKP) system variation learn feature is used to calculate reference period errors caused by slight tolerance variations in the crankshaft, and the CKP sensor. The calculated error allows the powertrain control module (PCM) to accurately compensate for reference period variations. This enhances the ability of the PCM to detect misfire events over a wide range of engine speed and load. The PCM stores the Crankshaft Position System Variation values after a learn procedure has been performed. If the actual crankshaft position variation is not within the Crankshaft Position System Variation compensating values stored in the PCM, DTC P0300 may set. If the CKP system variation values are not stored in the PCM memory, DTC P0315 sets.

The CKP system variation learn procedure is also required when the following service procedures have been performed, regardless of whether or not DTC P0315 is set:

• An engine replacement

• A PCM replacement

• A harmonic balancer replacement

• A crankshaft replacement

• A CKP sensor replacement

• Any engine repairs which disturb the crankshaft to CKP sensor relationship.

Lol. I read that too. It still doesn’t explain why, since they state the balancer is an individually balanced item, and it’s being installed right back in the same position fore and aft. I guess if it was a different balancer or say an under drive one that’s a different size but they say to do it even if you’re putting the same one back on. I know I should just probably say “fine, they said to do it so I will” but my mind wants to understand why. Is it just me?

 

[ratled]

Note to self..... when cleaning the throttle body DON'T drop the nut that bolts it on...... you know that one thats hidden under the throttle body and blocked by the alternator. But if you do, it's a #12-24 coarse thread. GM dosen't carry it anymore, none of the chain auto stores have it and the box hardware stores only go to a #10. Amzon can have it to you in about 3 days though.

Back to your regularly productive reads.....

 

[iddqd]

Note to self..... when cleaning the throttle body DON'T drop the nut that bolts it on...... you know that one thats hidden under the throttle body and blocked by the alternator. But if you do, it's a #12-24 coarse thread. GM dosen't carry it anymore, none of the chain auto stores have it and the box hardware stores only go to a #10. Amzon can have it to you in about 3 days though.

Back to your regularly productive reads.....

I always though American manufacturers switched to metric ages ago. That should be M6 nut. Any local HD definitely has them in stock.
Home Despot web site

 

[mountie]

I always though American manufacturers switched to metric ages ago. That should be M6 nut. Any local HD definitely has them in stock

What area of San Francisco do you hang? I grew up in Marin.