Please teach me about jscan

[Phishs]

@jeeperjamie is correct. It will learn. Same thing when you regear and reprogram your PCM.

Sorry for the ignorance but would a reprogram of the PCM be recommended for a tire size change? I actually do not even know what reprogramming the PCM means. lol

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[ShadowsPapa]

jeeperjamie is correct. It will learn. Same thing when you regear and reprogram your PCM.

For sure. Mine had the PCM flash applied a little over a year ago - my bet the same flash others are now getting notice for.
Right out of the lot I noticed the truck behaved totally different - shifting was like some other vehicle, the whole thing acted differently. I loved how it shifted then after the flash. Then the danged thing relearned it's old crappy habits and acts like it used to. I wonder if I can get one that is not capable of learning LOL - I liked how it shifted before it got smart again.

 

[tysongladiator]

Sorry for the ignorance but would a reprogram of the PCM be recommended for a tire size change? I actually do not even know what reprogramming the PCM means. lol

I apologize for the jargon. you'll hear different terms from different people all the time. But to answer your question, yes. That's when you use Jscan to let your PCM know you have different size tires installed. Your PCM has current values for just about everything electronic on the vehicle. When you change something electronically, Jscan is used to change those values to let the PCM know that you've changed it. Tire size, regear, Halogen to LEDs, TPMS, etc.

 

[ShadowsPapa]

Sorry for the ignorance but would a reprogram of the PCM be recommended for a tire size change? I actually do not even know what reprogramming the PCM means. lol

It's not "programming" pre se - you set the correct tire size in the PCM settings and it adjusts from there.
All you do is go into the tire size settings, choose the correct size - can be done via software like jscan or AlfaOBD, or hardware like taser.

 

[Phishs]

Thanks for the info!

 

[Jimmy07]

Little misinformation going on here. Jscan doesn’t tell the PCM anything when you make changes, as the changes are being made to the BCM. Once the tire size is changed in the BCM, it’s the abs module that picks up on the change, and corrects the speed from each wheel speed sensor.
The transmission has it’s own control module (TCM), and the only way it would need a relearn is if the adaptive values have been reset via a TCM flash or replacement. A PCM flash would have no effect on those values.

 

[ShadowsPapa]

Little misinformation going on here. Jscan doesn’t tell the PCM anything when you make changes, as the changes are being made to the BCM. Once the tire size is changed in the BCM, it’s the abs module that picks up on the change, and corrects the speed from each wheel speed sensor.
The transmission has it’s own control module (TCM), and the only way it would need a relearn is if the adaptive values have been reset via a TCM flash or replacement. A PCM flash would have no effect on those values.

Yes, that's true. We tend to generalize and over-simplify.
Speed is determined by the rotation of the sensors at the wheels, which goes through the ABS module.

After the dealership did the PCM flash on mine, it DID shift totally differently. Shift points were delayed, it took more road speed and higher RPM for the transmission to shift and the transmission didn't hunt nearly as much as it did before - and it's actually gone back to hunting again, and I need to really push the pedal on hills or it loses speed because it tries to hold higher gears until it drops in road speed then it finally drops a couple of gears (yes, often 2) and then regains road speed.
They said PCM and wrote on the documents PCM and when I pulled in, they told me my VIN popped up for a PCM flash.

This event (picture below) - TOTALLY changed how my truck shifted, the shift points, how much it hunted, how long it held a gear before the next upshift and so on. My truck also no longer downshifts on hills to slow me when I hit the brakes. Prior to this visit - if I was going down a steep hill and hit the brakes just right, the truck would drop a gear or even two at times, and help hold the speed back. Now hitting the brakes in that way does not cause a downshift like it used to.
I even posted about it here in the forums after this dealer visit and PCM update - I posted about how it drastically improved how my truck shifted and how it helped with hunting - and it seemed "stronger" (then gradually went back to the same old way it was)

Yes, there's a transmission control module and system to this - but mine absolutely was a different truck after this (until it re-learned and started hunting and shifting too early again)

 

[Jimmy07]

Yes, that's true. We tend to generalize and over-simplify.
Speed is determined by the rotation of the sensors at the wheels, which goes through the ABS module.

After the dealership did the PCM flash on mine, it DID shift totally differently. Shift points were delayed, it took more road speed and higher RPM for the transmission to shift and the transmission didn't hunt nearly as much as it did before - and it's actually gone back to hunting again, and I need to really push the pedal on hills or it loses speed because it tries to hold higher gears until it drops in road speed then it finally drops a couple of gears (yes, often 2) and then regains road speed.
They said PCM and wrote on the documents PCM and when I pulled in, they told me my VIN popped up for a PCM flash.

This event (picture below) - TOTALLY changed how my truck shifted, the shift points, how much it hunted, how long it held a gear before the next upshift and so on. My truck also no longer downshifts on hills to slow me when I hit the brakes. Prior to this visit - if I was going down a steep hill and hit the brakes just right, the truck would drop a gear or even two at times, and help hold the speed back. Now hitting the brakes in that way does not cause a downshift like it used to.
I even posted about it here in the forums after this dealer visit and PCM update - I posted about how it drastically improved how my truck shifted and how it helped with hunting - and it seemed "stronger" (then gradually went back to the same old way it was)

Yes, there's a transmission control module and system to this - but mine absolutely was a different truck after this (until it re-learned and started hunting and shifting too early again)

All I can say is that from a technical standpoint, it is impossible for a PCM flash to have any affect on the transmission. Unless TCM update 21-034-20 was flashed in along with the PCM update.

 

[ShadowsPapa]

All I can say is that from a technical standpoint, it is impossible for a PCM flash to have any affect on the transmission. Unless TCM update 21-034-20 was flashed in along with the PCM update.

Would they not have had to document that to get reimbursed for that?
All they listed is the PCM update and number and time. Nothing else.
This was all performed 10-2020 on my truck.
I've never talked to the dealer about the transmission and never had a "loud whistle noise" when starting the truck.

 

[Jimmy07]

Would they not have had to document that to get reimbursed for that?
All they listed is the PCM update and number and time. Nothing else.
This was all performed 10-2020 on my truck.
I've never talked to the dealer about the transmission and never had a "loud whistle noise" when starting the truck.

Could be on their LOPs sheet they submit separately from a recall. It was out April 2020.

 

[GoDucksJR]

Is there a way to keep led DRLs full power with headlights on?

 

[jbeenemd]

Is it possible to get the 4 digit pin code from the Gladiator to try and program another transponder?

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