Hello Joe
At some stage someone has has the vehicle in 4 wheel (especially if it have a 'Low Shift)' and has done a tight circle. When that happens the inner wheel in the turn tries to turn slower or even backwards. To fix it. Chock the front wheels and with the truck in neutral, jack up each rear wheel and let is spin and untangle itself. If you have a trolley jack, you can lift both sides
replaced the control head wow, some cars now must be married first(swaps)
to the other computers onboard, the FSM covers this.
use a scan tool first a real one that does chevy, factory codes.P1,p2, up are factory code unique to one model car. (buy one)
first things first.
1: check fuses. ( omg really,yes)
2: check wiring connections for loose or burns or rodent damage.
3: scan the PCm and BCM scan it all. first. DO NOT SKIP this step okay.?
4: Read the FSM next and read only your model only, and read the HVAC pages, see if modules must be married to work.(paired)
read if the HVAC has self test like my jeeps do. check this in the FSM first Factory service manual buy one read it and heed the words,or fail you will. This is not 1980s cars or older..
one reason for the marry, thing is some cars have 3 HVAC system options, and must be configured to work with YOUR options.
so swaps fail not done this.
Get a real ASE shop to fix it or dealer. both are good.
this is not your fathers Oldsmobile. (omg gone)
This forum is very difficult to maneuver around on...the question about the 2004 envoy and vacuum diagram...
i have a 2005 trailblazer that has the same engine that your envoy has in it..did a search online for the vac diagrams because idk if there's any vacuum lines on these things other then the brake booster check valve to plenum hose...I'm not having any luck finding any info..and I've done ALOT of repairs in my trailblazer engine and trans and tc and have never ran into any vacuum lines on it...I think they're all electronic..??
I take help from online websites that have this service like helping in repair some like reliable-store have instant help.. others are a bit slow which I don't prefer... rest is up to u.. U can also get free manuals
The crank sensor is needed for the coils to fire. It is on the drivers side, mounted in the engine block back by the transmission. The injectors are under the plenum. The plenum wraps around them. I wouldn't worry about them right now. And your probably right about being flooded. I would throw new plugs in it when you replace the sensor.
Powertrain relay ? Maybe you mean IGN 1 relay ? This supplys B+ power to the coils . relay # 58 in the under hood fuse box .
Is there B+ voltage at the coil's pink wire ?
Evaporative Emission (EVAP) Canister Purge Solenoid (LL8)
On the left side of the engine block
Engine Controls Component Views in Engine Controls - 4.2L
Engine Controls Connector End Views in Engine Controls - 4.2L
Evaporative Emission (EVAP) Canister Purge Solenoid (LM4)
On top of the engine, toward the front
Google picture of solenoid so you know what your looking for .
Crankshaft position sensor,cam sensor . your vehicle should have coil on plug , a coil at each spark plug !
Ignition Coils
Each ignition coil has an ignition 1 feed and a ground. The PCM supplies an ignition control (IC) circuit. Each ignition coil contains a solid state driver module as its primary element. The powertrain control module (PCM) signals the coil driver to initiate a firing event by applying a signal to the IC circuit at the appropriate time. When the signal is removed, the coil fires the spark plug. The spark plugs are tipped with platinum for long wear and higher efficiency.
During normal operation the powertrain control module (PCM) controls all ignition functions. If either the crankshaft position (CKP) or camshaft position (CMP) sensor signal is lost, the engine will continue to run because the PCM will default to a limp home mode using the remaining sensor input. As mentioned above, each coil is internally protected against damage from excessive voltage. If one or more coils were to fail in this manner, a misfiring condition would result. Diagnostic trouble codes are available to accurately diagnose the ignition system with a scan tool.
If a crank sensor is replaced a Crankshaft Position System Variation Learn must be done and a scan tool is need to do this.
if their is a check engine light have the code read ------no such thing as lock down mode you have limp mode which will let you limp vehicle home or to a shop or off road safely sounds like a transmission problem check fluid --look and smell if it looks burnt brownish and or smells burnt try a flush with a fluid and filter change may gey lucky ---look under vehicle and check the selector cable and connections sometimes disconnect or rot away lastely possible internal problem which would need a transmission specialist to look at
? 4:17
https://www.youtube.com/watch?v=WWi-_-kY-dM
Sep 5, 2012 - Uploaded by davesgarage512
I have a 2003 GMC Envoy and my issue is when I shut the blower off it still ... Can this issue also be remedied ...
Start by ensuring fluid level for transmission is correct. Is the check engine light on? If so, the transmission control module may have code stored in it to point you in the right direction. You can also try disconnectint/reconnecting battery which will reset transmission module.If problem corrects itself,keep driving to see if it reoccurs. If problem occurs immediately, recommend transmission diagnostics b efore costly repairs develop
Who did the testing & did both the
battery & alternator fail at one time?
Auto Zone has a repair facility & did the work?
What codes are present?
Did anyone look at a data base, to see what
the message your getting was & the solution?
This means that the engine's PCM detected that the engine has not reached the required temperature level within a specified amount of time after starting the engine. The intent of the P0128 code is to indicate a faulty thermostate if its not overheating get it to a mechanic its probly stuck open
its most def a purely transmission issue i believe its the solenoids. have it taken to a reputable trans shop near and have them diagnose it with there speciall code reader.
Good place to get a vacuum gauge hooked up and identify problems using that tool. Without the gauge, check your exhaust and see how much if passing through the converter. You can do this by testing the temperature of the exhaust before and after the converter making sure the converter/exhaust isn't restricted. As the vehicle warms up a bad converter can cause the symptoms you are describing.
2CarPros
https://www.2carpros.com > ... > Location
Dec 27, 2021 - Hello, this vehicle has two oxygen sensors, the rear one is behind the Catalytic Converter. Below is a picture of its location to the right side .
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The C0292 code in your 2004 GMC Yukon Denali XL indicates a communication issue between the Powertrain Control Module (PCM) and the Electronic Brake Control Module (EBCM). Here are some steps to diagnose and potentially fix the problem:
Check Ground Connections:
Inspect the ground connections related to the PCM and EBCM.
Follow the ECM ground and ABS module ground.
Check the ground on the firewall (driver's side) and the frame rail under the driver's seat.
Also, verify the engine ground on the driver's side.
Inspect Wiring and Connectors:
Visually examine the wiring harness and connectors associated with the EBCM.
Look for any signs of damage, such as broken wires or corroded pins.
Ensure that the connector pins are not bent or pushed out.
Pay attention to any loose or poor electrical connections.
Consider the Tune:
If you've recently modified the vehicle's tuning, consider reverting to a different tune.
Sometimes, a specific tune can cause communication issues.
If you suspect the tune, contact the tuner for further guidance1.
Professional Diagnosis:
If the above steps don't resolve the issue, it's advisable to seek professional help.
A qualified mechanic can perform a thorough diagnosis using specialized tools.
Keep in mind that diagnostic costs typically range from $75 to $150 per hour.
It is not legal to 'adjust' speedometers.
Fit the correct sized rims and tyres and the speedometer reading will be correct or use a satnav for real time speed.
