2004 gmc envoy will not turn over

[david ragan]

hi guys ,
ok so i recently had to replace my throttle plate, i also removed my pcm and throttle pedal inside the truck. my problem is now the vehicles dash will light up and the transmission will switch from p to n. but it will not even engage the starter. it acts like the battery is dead or like the starter isnt there. the battery is new the starter has never given me any issues at all. i did replace the neutral safety switch and shifter cable last year with no issues. im completely lost... im not paying the dealer $250 to "reflash" my factory pcm. any yall have any ideal how to fix this.

 

[16vcabman]

Hello, welcome, have you tried jumping the starter? There is a relay in the front fuse box for starter. How long was the car apart? Why did you pull the ecm? Give us a little more detail of why you did pull / replace components. We will try to help you get your Envoy ticking again.

 

[david ragan]

Hello, welcome, have you tried jumping the starter? There is a relay in the front fuse box for starter. How long was the car apart? Why did you pull the ecm? Give us a little more detail of why you did pull / replace components. We will try to help you get your Envoy ticking again.

Hello i did try to jump the starter it does jump and turn the engine but it just turns and turns. the truck has been down 6 months awaiting a radiator. my wife had lightly bumped a jeep in slow traffic miraculously only a minor bend on the hood and crack the top radiator reservoir. while it was down a friend need to " borrow" the e.c.m and the throttle pedal assembly to test a trailblazer he bought that didn't have either on it. and quite honestly i either misplaced the throttle plate or someone borrowed it either way i replaced it lol

i tried a relearn process i found on youtube. i tried this process 5 times tonight. it did not work the process is 3 cycles of 11 ,minutes with the ign on with 3 30 second off breaks then after the 3rd 11 on 30 sec off and 30 seconds on then start.. i will say after the second 11 minute on cycle each time i tried this the security light went off but the reduced engine power stays on. still no luck the truck will not even engage the starter after trying this




i do collect chevys and tinker with them im adjusted to the older ones and s-10s my dad left me this envoy and an aveo which i also cant figure out what its issue is. so if anyone knows any thing about aveos with the 1.6 engine in em holler at me
thanks for all the help lord knows i need it

 

[budwich]

well I think you are "screwed" with the "reduced engine power" light on. That light can be on with the engine running... of course, it won't run "full tilt" but will run. However, if the light is on and an attempt to start tries to happen, the "smart system" says "NOPE, I won't let you try ruin your engine and blame it on GM".... So you need to understand why that is on. Get a reader and check the codes, post back what you read "exactly" as opposed to your "interpretation" (ie. complains of o2 sensor, low high side on sensor X, etc). The forum then can readily move you forward hopefully to get the thing running. My initial guess just on the information about the "changes" is that either your "friendly swap" took out a component or you need to recheck your connections to make sure the pins / connectors are seated properly.

 

[david ragan]

Ok update I took off and cleaned (very dirty btw) the throttle plate I check and made certain all grounds were tight and corrosion free, I check the pins the cleanliness and connections. Now that I've done those things how do I get the s.e.s light off? If I could get that step tackled I believe the truck would go through the relearn process.


On a side note does anyone know what in the world all the air compressor shock looking devices are under the driver's seat of this thing? Also the t.v gets no reception and the rear radio does nothing. Y'all this thing seems like alot of trouble but I like it for some reason. On the plus side it's Friday and I got my truck engine in today!!

 

[mrrsm]

+1 --^-- Post #4 @budwich

“Limp Mode” will get invoked if any or all of these conditions occur… Noting that you have been working on two of these components via the R&Rs for your “friend’s” PCM/ACC issues:

PCM Failure
Accelerator Pedal Sensor Failure (The ACC has two electrical signals… One High, One Low)
Throttle Position Sensor Failure (TPS) Spray out connector with CRC Electrical Cleaner Spray.
MAF/IAT Sensor Failure (MAF) Spray out connector with CRC Electrical Cleaner Spray.

Short Circuits in their Wiring (Pulled, Stretched and Broken Wires inside the insulation) can occur @ the MAF & TPS Harness… and inside of their connectors as well. A careful “Tug Test” of each wire insert in those Connectors might reveal a loose or broken wire-to-pin problem. Without knowing what PXXX Codes you have been seeing/recording on your Code Reader… If your Envoy sports a “StabilTrak” system… then the PCM will turn it off when it enters into “Limp Mode”.

If these prove to be the culprits… The replacement MAF/IAT Sensors along with Replacement Wiring and Connector can be found here:

https://www.carid.com/2004-gmc-envoy-mass-air-flow-sensors/?filter=1&sub-model[Liter][]=4.2L

You should consider the possibility that your “friend's” problems might have been solved by your “loaners” of the PCM and ACC Pedal and that he may have given you back his old gear during the return...



“All Loving is Foolish… All Friendship… Folly.” William Shakespeare

 

[budwich]

Ok update I took off and cleaned (very dirty btw) the throttle plate I check and made certain all grounds were tight and corrosion free, I check the pins the cleanliness and connections. Now that I've done those things how do I get the s.e.s light off? If I could get that step tackled I believe the truck would go through the relearn process.


On a side note does anyone know what in the world all the air compressor shock looking devices are under the driver's seat of this thing? Also the t.v gets no reception and the rear radio does nothing. Y'all this thing seems like alot of trouble but I like it for some reason. On the plus side it's Friday and I got my truck engine in today!!

You will need a obd reader / clearer to clear the codes and warnings. NOTE: you need to read / recover any codes that are there to narrow down your issue.