Slow response problem ongoing

[Wpolonavyguy]

So still chasing a problem. This point getting expensive with zero luck.

The engine light hasn't come back on since I replaced Amazon fuel pump I ordered a 3 port pump & my avy only has x2 ports for fuel.
The 3rd was air line for Tahoes or suburban? Fuel pump fixed Ritch fuel mix, but after new evap hoses, coal canister, and purge valve.
Anyway I've replaced transmission pressure switch, all solenoids and wiring under transmission which is part of/includes female transmission plug connector outside, new deep b&m pan, New torque converter, pre vin programmed tcm.
Throttle body new.
Sensors replaced New O2, map, maf, temperature x2 front radiator & coolant sensor by pwr steering fill. New ground sensor, speed sensor.
Cut & replaced all grounding points & wired together around the frame as extra measure. New battery grounding cable to frame & block.
New agm battery spark plugs New wires/braided heat sheilds added, k&n air filter. New cam shaft sensor and crankshaft sensor. Belt & tensioner just replaced aswell.

The truck not throwing engine light yet still rpms jump & correct slowly. Fan engagement rpms jump up then slowly fall to normal. When driving shifts well, accelerating great, only trouble seems like one second late the torque converter releases neutral?
The 4 cylinder mode usually does well when coasting hills or under low pressure. Stopping I notice majority the rpms drop under 500 until torque converter release then able to resume 650.
Only parts not new I can think of causing this is maybe the main PCM, Body Control module, or the junction block left of drivers foot?
I checked all fuses & cleaned connectors & pins underneath engine fuse box.
The Tpms sensors all havnt been programmed as Amazon sensors need a tool to preform wake up I can't find shop with compatible programer.
I believe the Body control module could be culprit but that may be complicated beyond my DIY fixing.
Anyone else have suggestions I'd like to hear, I was banking the TCM would correct this late neutral shift issue.

 

[Wpolonavyguy]

I recovered a driver side left foot junction box. Salvaged from an 07 avy in pick a part nearby. I still think it's my BCM taking a dump slowly enough to cost a fortune in DIY troubleshooting & buying new parts. I am stockpiling an assortment of good used parts so if any fails in future I'll have replacements.

I believe I'm going to try switching out the main junction box & see if any changes?
Before the BCM arrives in mail maybe see if something in the junction is going bad.
So far I don't think that switching the junction block will need any programming or special procedures.
Computer controlled engine & transmission rediclieous makes me want to buy older classic truck without Computer.
Miss being able to find & fix problems without buying scan tool for hundreds or thousands $. Then half the time scanner missing important functions.
Manufacturer purposefully makes cars differently so we have to keep paying for each special tool, Computer, scanner, program, etcetera.
Anyway I like my avalanche but frustrating the BS to swim through. I would like to see a vheicle with a central computer/touch-screen able to do all dealership level scanning/programming.
Internet or wifi connect ability would be nice for ability to update.

 

[Wpolonavyguy]

Update: tried replacing junction block without much luck. Still having slow torque converter response.
I might try taking for a long freeway drive & side road minimum 20min at 50-55.
Try get emissions & drive cycles completed again.
Gotta try get code or codes to set again. Going to need find shop or someone with scanner capabilities to set airbag, brake, & key security for pre programmed BCM.

Of course I'd have an issue/problem that could be any of the x3 computers not sending information or power correctly.

I believe could be bcm as I have seen door adjar message set when I know it's closed well, a few times radio has changed stations without any buttons pushed.
The a/C & heat door actuators fixed cleaning & reinstall could possibly have been bcm also.
Fingers crossed mail should arrive soon & I'll try new BCM.

 

[Wpolonavyguy]

I have a MDI2 I ordered to try programming but not ready to try myself yet. I can't have the truck in non running condition unfortunately no extra vheicle anymore.
Donated the Toyota camry to homeless brother inlaw who wrecked it within 4months of giving to him he didn't use money given to him to register in his name so I had to prove not my debts to tow yard & collections companies I gifted it.
Anyhow I have pre-programmed BCM and Engine Control Unit "PCM" to replace in my 07.
It's having power/Voltage issues to sensors mostly connected to PCM.
I see the BCM is Power mode master & controls / Translates signals from all over the vheicle so possibility that causing issues?
I believe I will try new PCM/ECU as a key relearning should be only thing needed when I Change it.

The Body control module shows Airbags , theft deterrent system key transponder, and breaks.
The PCM also might need a key transponder relearn when I switch it over.

Unfortunately I will probably need a shop with better equipment to do BCM Change if I do have to replace.
I will have spare depending on which one is causing power problems/ wasn't the TCM causing torque converter clutch issues, fingers crossed it'll shift & drive better when computer sensors get correct Voltages & signals.
Everything else has been replaced I've got quite a large stockpile of used parts still good for future use.

Anyone Change their PCM/ECU?
Did already programmed install easily?

I'll start checking into prosess to keep my keys working, hopefully the driver information display helps like remote programming?

 

[BainMan]

Wish I could help more... But, do you have or want service manuals?

 

[Thor Hammer]

A little late to the party here but it sounds like a strictly electrical issue. First thing to do is stop buying parts to throw at the problem. How have you kept track of so much already? Your head must be ready to explode!

Check all of your grounds. You say you have these intermittent issues. that points to a grounding problem. Check the ground stud on the firewall. They can develop rust behind them and cause all sorts of problems. Check and secure all of your grounds.

Take a look under the fuse box and check for damaged wires. Again, you have a wiring problem in my opinion. Not a BCM or ECM issue. Its so rare for those to go out. Hope you get it sorted.

 

[Wpolonavyguy]

All fuses checked, grounds cleaned / then cut crimp new loops to copper braiding to be sure connection/ then added a grounding wire along frame to every point to eliminate any frame resistance.
I have a pre programmed Engine Control Module and a pre programmed Body Control Module.
I thought could be electrical in the driver's foot connection block & switched that aswell just to eliminate as possibility.
I believe it's the BCM but everyone in my area I checked wants 250$ each programming job + labor on work preformed like switch the box/Module.
I'm only going to pay if I gotta get BCM programming finished to it as I don't have tool that will do Airbag breaks & additional theft security programming.

The Avalanche didn't like me leaving hood & drivers door open during programming keys to ECU I switched out today.
3rd time I did with hood & doors shut & started & ran both keys.
Although freaking crazy now with ECU pre programmed & paired to keys, started it & now the check engine light is illuminating didn't light up with original ECU.

Unfortunately I have the feeling ill be paying to get this replacement BCM put in I'm thinking of paying dealership troubleshooting fee to maybe better narrow the Gremlin.
The slow neutral shift from torque converter I was betting had to be TCM or the ECM as wiring checked ok & all internal solenoids/wiring/connector & the pressure control switch I replaced new when installed new Torque converter & deep B&M pan.
I have new parts just about everywhere & kept originals seemed still good unless broke during removal.
I like knowing parts are newer the computers on these trucks just can't believe codes mine has thrown falsely.

 

[Wpolonavyguy]

Crankshaft position sensor codes for not learned. After programming keys to new ECU. I believe I may need a professional scanner to do that learning process .
But will see my brother inlaw has foxwell scanner I borrowed that shows u codes & other codes that don't light dash check engine light.
I'll update when I figure out or when I pay to get dealership troubleshooting done.

 

[Wpolonavyguy]

So calling around the crankshaft learning the Chevrolet service department said 250$ for any programming no matter which procedure...
That's rediclieous I almost drove over to punch the arrogant jerk. The attitude he gave was most of the people I had even tho their charging policy has huge problems if 250$ for any program task.
Sensor relearn I don't see as a programming but he insisted both were the same.

Anyway I found a procedure to drive learn the crankshaft sensor. Has anyone done this with luck?
Screen shot attached.

Two other mechanics said will call me back if they can with their scantools.
Three shops said no they won't relearn sensors.
I may give the drive cycle thing a try but finding a road to coast to stop 4or5 times without breaking seems dangerous.
Here so cal drivers are not very nice people & even empty roads coast stop no breaks someone would find me & interfere or screw it up
Fingers crossed a local shop can do sensor learn without charging 250$
I still can't believe that high for a push of a button on a scanner tool.

 

[Wpolonavyguy]

Boy maybe close to an answer after buying almost all new electronics & sensors.
I still want to change my BCM possibly something inside.
I'm going to get my cats checked for back pressure & think time for transmission expert to find why TCC seems slow release.

 

[Wpolonavyguy]

So I saved $ buying all x4 tpms sensors on Amazon but tire shop I purchased tires from didn't have ability to activate.
I finally found a shop that has compatible program tool to do wake up it cost 150$ to get it done but now tpms readings work without DIC display constantly saying service.

I bought a new lock ring & tool for wrench as I was unable to spin fuel pump ring completely through my access door.
Hard to use rubber mallot in lil area.
I have a suspicion tiny intermittent leak at fuel pump will check it when I put new ring on pump.

I do want to inquire if anyone had intermittent ABS module issues without setting codes?
I'm still seeing delay downshifting & abs/traction control DIC display during slowdowns like the abs not telling computer breaks were applied.
I'm supposed to tow trailer in few weeks & want to fix before trip.
I may have to pay diagnosis fee

 

[BainMan]

So I saved $ buying all x4 tpms sensors on Amazon but tire shop I purchased tires from didn't have ability to activate.
I finally found a shop that has compatible program tool to do wake up it cost 150$ to get it done but now tpms readings work without DIC display constantly saying service.

I'm sorry to tell you after the fact, and maybe there is something I'm missing from your issue and you already know this part... But the TPMS relearn can be started from the key fob. No tool necessary.

Tutorial here:

 

[Wpolonavyguy]

I tried that a few times, supposedly the original wake up on sensors needed done by the program tool.
I'll make sure to read more about sensors before buying next time.
Some sensors self wake up if centripetal force determines they are on vheicle 40mph or so.
I'm hopeful these batteries will last long time did all 4 instead of one by one as old batteries died.
I'm thinking about maybe getting x2 rear wheel speed sensors new possible those could be old. I replaced one vss of the two on transfer case might order another vss to have new on.
I'll have to get professional troubleshooting done if still getting traction control & stabilitrak intermittent during coasting and downshifting
Maybe professional tool can determine if it's the abs breaking module or transmission internal speed sensor?
On my brother inlaw meter live data might try driving & see if it will show any sensor #'s not matching to throw stabilitrak off.
It still could be BCM I have new pre programmed but Airbag breaking & theft deterrent programming have to be done after changing it.
I'm hoping it's same process as keys when I changed PCM/ECU.
I should buy tool that can program all these extra functions damn shops or dealers overcharge to plug in & push a button .

 

[EXT4ME]

Helpful or no?

Perhaps an apple and oranges comparison, but maybe my personal observations might present a slight clue.

When I bought my used 2004 EXT with the TPMS system back in 2012, the truck was completely without any TPMS sensors in the wheels.

Since it became obvious that previous owner(s) were not interested in maintaining this vehicle in like-new status, it was not surprising to find simple rubber valve stems installed.

Shortly after purchasing the truck, I took it in to my trusted Goodyear tire shop for it's first good under side inspection.

It was at that time I was made aware of why I was not able to perform the simple owner reprogram of the TPMS sensor location and remove the Service Tire Monitoring System error message in the DIC.

The truck is not happy not having functional TPMS sensors installed, that's for sure.

The shop acquired four new OEM TPMS sensors from the local Chevrolet dealership parts department and installed them into the wheels.

I honestly can not tell you the exact procedure that the shop used to "turn on" the sensors and there is no telling how long the "asleep" sensors had sat unused on the dealer's parts shelf before they were installed and activated on my truck.

What I can tell you is these very sensors have been installed in my EXT since 2012 and have over 125K miles on them.

Even now, with the truck having sat for the most part undriven since March of 2020, when I do take the truck out for a drive, I get no errors indicating the batteries have died from years of sitting around.

I have assumed that with the truck just sitting idle for so long, the batteries have been in sleep mode and not drained as fast as some that got used every day.

Now, the TPMS system in the first gen EXT trucks does not indicate tire pressures at any given tire location.

They do, however, throw a message if one of the tires is significantly deflated compared to the other tires.

I have had the system warn me of one tire that was curiously lower than the others.

I think someone had been goofing around out on a hotel parking lot since the tire had been checked before the trip and held air from then on once I managed to get to the first gas station.

Who knows.

I was lead to understand that the sensors will go to sleep after the vehicle has not been moved with the wheels rotating at a sufficient RPM.

The sensors will wake up and communicate with the computer within a specified period of time, or an error is thrown indicating a problem with the sensor.

This is why the often mentioned trick of placing the four sensors inside a closed and pressurized PCV pipe and tossing that pipe in a storage compartment in an effort to not have to install sensors in a winter tire set, does not work.

If the TPMS sensors do not wake up due to tire rotation, they will remain asleep and the computer will complain with an error message.

In the years after the sensors were installed, I have rotated the tires on the EXT in my driveway several times.

Each time, I was able to complete the relocation procedure in the manner shown in the first video above.

I was also made to be aware that the signal for both the TPMS sensors and the keyless entry key fobs was received and entered into the computer system through the Passenger Door Module.

At least on my generation trucks.

I don't know if any of this applies or not, so take it for what you will.

 

[Wpolonavyguy]

Tire shops wanted 125$each sensor to buy from them cheapest they offered plus their labor .
I ordered moresensors from Amazon got all 4 like 80to100$ much better priced.
I got new tires installed and the shop that installed tires said their tool wasn't compatible with sensors I purchased.
I told them to install sensors anyway & I'll find somewhere that had compatible tool.
Took months & luckily my friend who owns his own shop had compatible snap-on program tool to wake up.
I paid him full price to jump the line as his shop had 26 cars waiting to be worked on.
It helps having them programmed bcm& computers don't like missing inputs/signals.
I did my fuel pump through access hole but damn tool I ordered first didn't fit or work on lock ring. I tried to seal with non hardening goo but air still leaked caused rich mix & bad cold starts. I'm hoping other intermittent poor signals were domino effects of computers trying compensation?
I have new BCM to replace as still possible its not translating 100% like it should.
Only other possibility codes suggest is EBCM but more expensive part than computers were. That could be last but breaks shouldn't effect voltage to O2 sensors & fuel pump.
Few days driving I'll see what codes re appear if any...
Interior LEDs white lights were nice but one was flickering not working well, got blue super brights much different look.

 

[BainMan]

I tried that a few times, supposedly the original wake up on sensors needed done by the program tool.
I'll make sure to read more about sensors before buying next time.

Strange, I've done it on both the Avalanche and a Traverse, without a tool and without driving anywhere (centripetal force) and it worked right away. I used ACDelco GM Original Equipment 13598771 from Amazon, maybe the sensors you have are different.

And yes it's crazy what they charge at the shop for the sensors. OEM's were under $15 each last year both times I purchased..

 

[Wpolonavyguy]

Ya I'm hoping these last I'll definitely read carefully before buying future tpms sensors. It's getting better as I fix small issues trying not to add problems which sometimes happens . I do think I need to install new/pre-programmed BCM. It's still showing voltage hi/low codes to sensors & now invalid serial data from EBCM. The Translation functions I believe are slow/degraded, Break control module is priced higher than the other computers I've switched out.
Investing in a much better odb2 should be able to program it myself.
My Avalanche wants to stay busted I'm starting to believe, morphs & changes issues no matter what I fix or replace.
Getting closer to new replaced so many things.
Changing BCM if still gremlins ill have transmission shop diagnosis the break system or transmission might need rebuild? Acts like it can't quite figure out when to coast, neutral release & downshifting a bit slower than should be.
Fingers crossed

 

[Wpolonavyguy]

So I shouldn't have trusted new manifold seal to be air tight on its own. I removed intake manifold and used non hardening gasket sealant which resolved majority of the problems.
I just changed gastank lower rubber fill hose, got engine light off. Fuel tank pressure sensor reading is more stable now.
I still feel something tossing idle around not as stable as I'd expect.
Meter shows my bank 1 Sensor 2 is solid at 68.
Opposite side sensor 2 looks like it's operating & switches.
I now have to try a new sensor see if helps, that sensor had wire harness cut by front drive shaft spin . I used heatshrink soldier splices to repair wires but different opinions those or crimp connections changes resistance in wire.
I'm hoping sensor will fix issue as I'd not want to re/splice wires.