TSB 18-008-20 throttle lag

[J-Cooz]

I've noticed two things so far that I DO NOT like about this latest tune.

1) The truck would go into automatic high idle anytime I started it while the engine was cold and the temperature was basically in the 30s or below. Since the tune update, it has been 5 degrees one morning and 16 degrees another and the truck doesn't go into high idle anymore. That's a real bummer. I actually loved the high idle feature.

2) According to my Scan Gauge II, the maximum boost pressure is now being capped about 0.5 PSI lower than before. That's probably only a loss of <5 horsepower, but it's still a loss.

Who knows what else this update has changed that we haven't even discovered yet.

The lower boost could just be the cold weather. Denser air requiring less boost.

My truck still goes into high idle the same as before. Perhaps it's not quite cold enough for it to do it in your location. It's been -10 Celsius here and it does it everytime.

 

[WXman]

The lower boost could just be the cold weather. Denser air requiring less boost.

My truck still goes into high idle the same as before. Perhaps it's not quite cold enough for it to do it in your location. It's been -10 Celsius here and it does it everytime.

Well it was 5F here and it still wouldn't do it. So apparently they've removed that feature from my truck. I enjoyed that the way it was before. BUT....I remembered that my Tazer programmer has a "winch mode" feature where I can do a simple button press on the steering wheel and send it to high idle. So I guess that's a secondary option, albeit not a great one.

The boost shouldn't change. I was seeing the same max boost regardless of temperature before this. Now it's about a 1/2 lb. less regardless of temp. 5 degrees, 40 degrees, it's still the same. I wonder why they decreased that? Padding their measure of safety against warranty claims?

 

[Sascwatch]

Well it was 5F here and it still wouldn't do it. So apparently they've removed that feature from my truck. I enjoyed that the way it was before. BUT....I remembered that my Tazer programmer has a "winch mode" feature where I can do a simple button press on the steering wheel and send it to high idle. So I guess that's a secondary option, albeit not a great one.

The boost shouldn't change. I was seeing the same max boost regardless of temperature before this. Now it's about a 1/2 lb. less regardless of temp. 5 degrees, 40 degrees, it's still the same. I wonder why they decreased that? Padding their measure of safety against warranty claims?

I’ve had no issues with the high idle working, even at just above the freezing mark 2c it went into high idle when started this morning.

 

[NewLove]

High idle definitely has something to do if you leave your climate control on or not.

I suggest leaving it on when you shut the truck off. When you go and start it up the next time, see if the truck goes into the high idle.


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[Hrspwr88]

For those of you that still have the high idle; does it still come on pretty quick? Personally I'd like if the engine gave itself a bit of time to warm up before going to high idle. Move some oil around a bit first... lol

 

[WXman]

High idle definitely has something to do if you leave your climate control on or not.

I suggest leaving it on when you shut the truck off. When you go and start it up the next time, see if the truck goes into the high idle.


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My climate controls are always on Auto mode, and my heated seats and wheel are programmed to come on automatically with temperature. The high idle is definitely missing from my truck now.

 

[WXman]

For those of you that still have the high idle; does it still come on pretty quick? Personally I'd like if the engine gave itself a bit of time to warm up before going to high idle. Move some oil around a bit first... lol

Ironically that's the very reason for the high idle. Even on modern tractors the owners manual tells you to adjust the throttle to half way when you start the engine on a cold morning to promote oil flow.

 

[Sascwatch]

Within 30 seconds of starting my truck goes into high idle mode when it is cold. Not sure what the temperature threshold is yet, but at 2C high idle still kicks in.

I have my heat set to defrost/feet at 20C and fan speed of 3, if I remote start the truck the fan goes full blast until I get into the cab.

 

[Hrspwr88]

Ironically that's the very reason for the high idle. Even on modern tractors the owners manual tells you to adjust the throttle to half way when you start the engine on a cold morning to promote oil flow.

Ya makes sense. My previous diesel was a GM where is would idle for a minute or so prior to high idle. Made me feel a bit better that the rpm was lower for a bit.

 

[NewLove]

Can anyone attach a printable version of the TSB.. Searched with google with no luck.


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[Rebelguy2020]

You waited 14,500km to do your first oil change? I would never have gone half that distance on a factory fill. Do you plan on keeping your truck very long or is it a lease?

Yes I plan on keeping my truck for the 84 months at 0% financing.
Part of my list of FCA vehicles
1994 Dodge Caravan 3L V6, had for 13 years, 296,000 km, regular oil, every 6,000 km, no engine issues
1996 Dodge Extended Cab 5.9L Magnum, had for 15 years, regular oil every 6,000km, no engine issues
2011 Ram Outdoorsman Crew Cab 5.7 Hemi, had for 9 years, regular oil when called for by the EVIC sometimes close to 10,000km, no engine issues
2014 Jeep Cherokee 3.2L V6, regular oil, when called for, always close to 15,000km, no engine issues
2019 Jeep Cherokee 2L I4 Turbocharged, full synthetic oil, just had it’s third oil change at 45,000km, no engine issues.
I had a total 10 FCA vehicles and never had engine issues.

 

[TacticalCucumber]

Interesting as the correlation makes ZERO sense

Yeah I agree...but somehow it does seem to help for me. It's not 100% resolved but at least tolerable.

 

[WXman]

So after several hundred miles, I can now say for certain that the 18-008-20 update did nothing significant for me. Dead pedal still happens. Lag still happens. Really the only thing I notice is that trans. shifting has changed slightly, and now there are certain times when I get a more harsh gear engagement between 1st and 2nd.

The high idle returned ONLY when I use remote start, which is odd. But if it's not in remote start mode the idle is always under 1,000 RPM now regardless of temperature. That sucks.

To me the truck doesn't feel quite as strong as before either. My Scan Gauge only shows a 0.5 PSI reduction in boost now, which could only be a few horsepower, so that's not the main issue.

In hindsight I would not get this update done to my truck if I could do it over again.

But, you never know until you try. Sometimes software updates make these trucks better, sometimes they make them worse.

 

[Sascwatch]

I got this update done a few months ago to hopefully fix the remote start issues when it is cold but it didn’t completely eliminate the issue.

Prior to the update I noticed under certain situations that there was a noticeable delay between throttle pedal activation to when the truck actually did something (almost like start/stop engine behaviour). The update mentioned in this tread seemed to eliminate the on/off throttle feel with no other noticeable changes.

Fast forward to this week when I had the dealer perform an oil change on my truck, and the throttle delay returned when accelerating from a dead stop. There is once again a noticeable delay when the throttle is first pressed to when the truck responds. I am 99% sure that the tech who did the oil change used the throttle pedal to reset the oil life which also caused the truck to relearn the throttle pedal position incorrectly.

The next day I performed the throttle pedal relearn myself by turning the truck to run and with the engine off I fully pressed and released the throttle pedal twice. This seems to have made it much better but it’s to early to tell.

 

[WXman]

I got this update done a few months ago to hopefully fix the remote start issues when it is cold but it didn’t completely eliminate the issue.

Prior to the update I noticed under certain situations that there was a noticeable delay between throttle pedal activation to when the truck actually did something (almost like start/stop engine behaviour). The update mentioned in this tread seemed to eliminate the on/off throttle feel with no other noticeable changes.

Fast forward to this week when I had the dealer perform an oil change on my truck, and the throttle delay returned when accelerating from a dead stop. There is once again a noticeable delay when the throttle is first pressed to when the truck responds. I am 99% sure that the tech who did the oil change used the throttle pedal to reset the oil life which also caused the truck to relearn the throttle pedal position incorrectly.

The next day I performed the throttle pedal relearn myself by turning the truck to run and with the engine off I fully pressed and released the throttle pedal twice. This seems to have made it much better but it’s to early to tell.

Is that the specific procedure to relearn the drive-by-wire throttle? Ignition in "run", depress the pedal twice? Then do you immediately shut the ignition off? Or can you go ahead and start the engine?

 

[Sascwatch]

Is that the specific procedure to relearn the drive-by-wire throttle? Ignition in "run", depress the pedal twice? Then do you immediately shut the ignition off? Or can you go ahead and start the engine?

I shut the ignition off afterwords to let everything reset, I’m not sure if it is required. Be careful not to press the throttle a third time as it will reset your oil life.

 

[WXman]

I shut the ignition off afterwords to let everything reset, I’m not sure if it is required. Be careful not to press the throttle a third time as it will reset your oil life.

OK I was just checking because on a lot of FCA (now Stellantis) vehicles, the procedure was to hold the throttle pedal at 100% for 20 seconds, then slowly depress.

 

[NewLove]

Truck is in for “Hard Start, Remote Start hit and miss, and loud fan running after driving”
Let’s see what’s happens.


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[Chris3058]

Do you have a link to this by any chance? I can’t find it online.

Just had 18-008-21 done. Noticeable improvement in throttle response.
And my front sway bar bushings were toast with 10k kms on them. Sigh.

 

[NewLove]

Just had 18-008-21 done. Noticeable improvement in throttle response.
And my front sway bar bushings were toast with 10k kms on them. Sigh.

Lift or leveled?..


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