Hi guys, I have a 07 classic 1500. I was wondering if anyone can confirm that some of the GMT800 trucks did not come with a factory theft deterant system? My truck does not have RPO code UA6 and does not have keys with chips. I have never had a key fob. I might be replacing the PCM soon and read that I might have to relearn the alarm. I don't think I have one. That's why I ask. Any info would be appreciated, thank you!
Theft deterant system.
- Thread starter Blusey
- Start date
Marky Dissod
Well-Known Member
If you're gonna buy a new pcm,
[email protected]
but you ought to be sure that the pcm is your underlying issue; don't use pcms for diagnostic puropses.
[email protected]
but you ought to be sure that the pcm is your underlying issue; don't use pcms for diagnostic puropses.
AuroraGirl
Well-Known Member
Always take advantage of a shipper to you programmed pcm with mods that you want. For example maybe you lowered your truck and you want to raise you speed limiter (normally tires or driveshaft size and rotation rpm esp at 4wd angles dictates the limit ) , maybe you want the old school engine block heater that will work when it’s 0 out and not just -25 lol, the pcm would throw a light for the thermostat if you tried using a normal cord, use it to delete engine light for things your frankly not going to touch. Me would be small Evap leaks. I would also delete rear o2 codes from it depending on my setup. I have good cats rn so I’d keep converter efficiency codes as it stands now. Also vin has to be inserted. If you HAD passlock and wanted it gone you could disable it that way. You can have mild performance boosting ones. Your year has computer control charging so I’d delete that and run a normal alternator.
If you don’t have these options you want done and can’t find a site that builds to your liking we have a member(may have been Silveradoforum if not here ) who takes pcm shipped to him and will do that stuff for you.
But as was said. Don’t throw a computer at it for no reason
Also by the way the relearn for anti theft is done once the pcm is installed. So user -procedure. This is to prevent hot swapping a vehicles pcm since vin are prominently displayed and someone could order a pcm directly and then swap it in 5 min after opening the interior and hood. Not a hard thing to do if you know the habits of the owner and you look like you belong.
If you don’t have these options you want done and can’t find a site that builds to your liking we have a member(may have been Silveradoforum if not here ) who takes pcm shipped to him and will do that stuff for you.
But as was said. Don’t throw a computer at it for no reason
Also by the way the relearn for anti theft is done once the pcm is installed. So user -procedure. This is to prevent hot swapping a vehicles pcm since vin are prominently displayed and someone could order a pcm directly and then swap it in 5 min after opening the interior and hood. Not a hard thing to do if you know the habits of the owner and you look like you belong.
Thank you for the info. I didn't really give any thought to modifying the PCM, I just want it to run right. I still have a few more things to check before I purchase a PCM and was just doing homework. My problem is a high idle problem and has been going on for a year and a half intermittently. I found broken wires to the IACV. Fixed and replaced with a new IACV and didn't help. Reset the IACV many times and no luck. Tried other IAC valves also. Turn the AC off and idles at 3000. Replaced and calibrated the CCM and no luck. The ABS light came on one day. I found a broken wire and fixed it. Also new bearings and ABS sensors. I thought the idle problem might be related to speed sensors because you can start driving it and then pull up at a stop light and the idle will drop alot and idle normal. Start rolling again or shut the truck off and restart and the idle screams. No luck. No codes other than P0507. I've tried idle relearns with codes cleared and no luck. Reset the IACV with no luck. No vacuum leaks. One day when the idle dropped down after driving I unplugged the IACV and left it unplugged and it will idle and drive fine between 800-1400 RPM at idle with no check engine light lol. Bought this truck for $500 bucks with 315k miles. Drives great, shifts great, does not smoke or rattle or burn oil. With all that said that's kinda what made me this I might need a PCM but I haven't purchased one yet. Not complaining but I miss my old trucks lol. Any advice appreciated.
AuroraGirl
Well-Known Member
you have a 4.3 nice, older tech which i like more
Thank you for the nuggets of info, here you go
Thank you for that info. I never had a SES light turn on that I know of. I did check the IACV connector with a computer safe test light and they appeared to blink and respond to throttle movement. I will learn how to test to read the voltage. I just looked up the P1400, and that opens up more possibilities. Throttle cable and butterfly are clean and feel great. I have been all over the service manual but never thought to look for a TSB. I have had over 60 cars in my life and this is the newest one and it has been kicking my but lol. I am glad I asked here. It might take a while to check it all out but I will post back what I find. Thanks again.
Marky Dissod
Well-Known Member
If you merely settle for GM OE, it'll 'run right', but it'll also be plug&play if you buy it from pcmperformance.com, UNLESS you ask for a tune.
There are such things as 'conservative' tunes, by the way, although
you'll still notice improved throttle response from the engine & transmission,
you'll still get longevity/durability benefits that won't be immediately obvious,
and your highway MpG will improve if you can keep your foot out of it.
In other words, even for those who erroneously think 'tunes' are for 'fun', the tune would be worth it.
At BlackBear Performance, that is called a "traditional tune". I have one and I love it. Another reason I love it is that I got it for free. A couple Christmas's ago, BlackBear had a drawing at the Tahoe/Yukon Form and I won.
Marky Dissod
Well-Known Member
After over 30+ years of pcm tuning, even I'm never quite sure of what a competent & thorough tuner means by a 'traditional' tune,
if only because the term 'traditional' still discourages those who think that even a basic mail-order tune is for 'non-conservative' or 'over & above' normal driving.
Although my focus remains staunchly on OBD1LT1 tuning, I am also adamant about making each tune specifically for each customer,
usually because each driver and each environment is slightly different
(an early lesson involved mail-order tuning Performance Mode for SanFran hills - yes, he wanted to eliminate excess shifts where Bullitt was filmed).
There are rare cases PRECISELY because the customer wants the tune to be as undetectable as possible,
as well as oddities like tuning for hypermilers who want most downshifts to be nearly inaccessible.
All that said, I'd begrudgingly admit that, if a customer countered,
'stop asking questions and just improve on GM OE as you see fit, regardless of who the various driverS may be in the future;
I may sell it to someone who might not want a tuned pcm', that'd be one of the 'cookie-cutter' templates I initially base my tunes on,
and I may do very little to it before sending it out; it'd be barely detectable under 25%TPS ... but I've yet to come up with a name for it, other than
'how GM could've / should've tuned it for anyone' ... 'basic' tune?
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AuroraGirl
Well-Known Member
When I get a pcm for my truck, im definitely taking advantage of feature changing and some tune changes. I HATE how this electronic throttle reacts, its way too slow for my lead-footed ness, and i can play with it like 2-3 strokes before a comensurate change in behavior when cruising, so much it plays with dropdowns and upshifts and starts to WOT then suddenyl stops... that alone will help my Mpg and experience, removing that lag. a cable would not have that lag. I also would bump the idle a tiny bit just because my exhaust leak and charging amount would benefit. (like 50-100 rpm max)
i also would be taking advantage of removing codes for certain things.
I noticed that downhill in Cruise will sorta engine brake after a while, vs cable throttle cars it will over-run the set speed but not apply any engine brake unless youre in a gear range for it and not hitting throttle of course. is this tune-out-able?
Marky Dissod
Well-Known Member
Electronic signal throttles don't really react. They send signals to the pcm / ecm, and based on a bunch of other info,
pcm / ecm DECIDES whether or not, and how quickly, to eventually do with the throttle what you did with your foot.
Luckily in the vast majority of situations this can be tuned to behave extremely similarly to a physical cable throttle in nearly all situations.
PPVs & SSVs turn up the idle a bit to keep all the extra electronics happy.
Idling @ up to 625RpM in gear & 725RpM in Park / Neutral is noticeable, but only for those paying attention.
Before the pair of '05 electrical fans / back when I was stuck with the '02 mech propeller,
turned the idle all the way up to 750RpM in gear to keep AC nipply-cold in June/July/August.
I actually remember this feature in my - formerly my - 2012 Yukon XL saving my @$$ during a very curvy downhill, brake pads were low,
powertrain braking helped me slow down.
Don't know if this is completely tune-out-able, but if it can't, bet it can be turned down from a scream to a whisper.
AuroraGirl
Well-Known Member
I dont mind the cruise thing except 2 minutes into my drive on a highway i take all the time, theres a giant hill down , and then subsequent rises and falls for like 2 miles, then its flat and mostly downhill slightly rest of the drive, id like to set and not turn off then re-enable since yo-yo'in the hill I Would be much more efficient if i could get to like 75 with a mild tail wind vs engine braking to 55 down it lol
And that reminds me, id think id like to try cooling fans on my 2005 if I get a PCM Too. but im not sure if the electric fans will suffice for towing, which isnt that frequent but id just leave the clutch in if the electrics out there wouldnt suffice towing
AC would appreciate it at stops for sure.
Marky Dissod
Well-Known Member
Depends on how heavy (and aerodynamically 'draggy') the thing you're towing is, and how hot and how uphill you're towing.
Also, there are several electrical fan pair options, for heavy / intense hot towing up steep long hills you'd need to research
GMT900 electrical fan pairs with upgraded (thicker gauge) electrical wiring and a GMT900 alternator.
If you're towing under 6000lb with 3.73 or 4.10 you don't need the most intense GMT900 electrical fan kit.
If you're towing over 7000lb with less than 4.10, you may want one of the more intense GMT900 electrical fan kits.
AuroraGirl
Well-Known Member
id like to avoid the 2 pin alternator business, id stick to ad244 type alternators which have 4 pin , and then use the sense wire
I have 4.10 and towing above 6000lb occasionally but never like cross country but want to be able to take my trailer and truck and go like a few states over , any given moment if i can
Marky Dissod
Well-Known Member
If you've an LQ4 and a 4L80E, doubt you NEED a GMT900 pair of cooling fans,
although obviously 'more than you need' can't hurt so long as the fans have the wiring and alternator to back it up.
although obviously 'more than you need' can't hurt so long as the fans have the wiring and alternator to back it up.
AuroraGirl
Well-Known Member
so a pair of gmt800 cooling fans and relays would do it you think or is gmt900 generally the go-to here
Which ones pull more air?
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