NEED HELP Unknown Driver and No Start

[aaserv]

The airbag light should not be staying on but for a few seconds but that shouldnt stop it from starting.
You said you tried replacing the ECU....Have you put the original back in it?

If you just want to try the starter circuit to see if it works try this.....https://www.youtube.com/watch?v=iMzdYCA0s2w

It really sounds like your going to need a knowledgeable mechanic to ck it out. Its very hard to diagnose the problem from whats going on with a cluster thats known to do crazy things to begin with. I know the crew here doesnt like to be stumped but with so much also being lost in translation this 1 is very hard to solve..

 

[Mramses]

Just to be certain..... No picture you have posted shows the "check engine" light.

View attachment 96491

I understand friend I must make sure. Is right

 

[Mramses]

I know this is a longshot but you didnt have a new key made by chance???

I only have a friend key and the control has a 1 on the back. I must make sure of what they have been telling me. It is true. I am not sure I notice the "check engine" light.

 

[Mramses]

if i try with another pcm should i turn on the CHECK ENGINE light? Or should it not activate as it must be programmed?

 

[aaserv]

You are aware there is a relay missing here???

 

[Mramses]

If they changed my PCM for another, should it give me these faults?

 

[Mramses]

You are aware there is a relay missing here???View attachment 96492

Yes, this relay is W/S WASH. can that relay cause my problems friend?

 

[aaserv]

Yes, this relay is W/S WASH. can that relay cause my problems friend?

If thats what it is then No. thats only the windsheild washer relay. I just noticed there was a missing relay.

Others here know more about swapping out ecu, pcms but I did read the other day about someone swapping 1 and his Envoy would do nothing after installing it.

 

[Mramses]

Yes, this relay is W/S WASH. can that relay cause my problems friend?

I understand my friend. Today I will try with the other pcm to see if it is the same and I am going to upload photos of the cluster so that they have a better reference.
Could they have changed the pcm of the truck and generated this fault?
or it has nothing to do if the pcm is replaced by another? Should I turn on the same or have this fault friends?
thanks for all your answers and stay tuned friends

 

[budwich]

NOTE: this post got skewed by the "quote system"... it refers to the pictures of the two instrument panel displays. not sure what happened.

I think If you look back thru some other threads, you will find that there has been some "differences" in how the instrument panel "layout / wiring" has been set. I do believe in this thread that there appears to be the "icon" as opposed to the "words" and it is on the right side. Either way, there is no indication of a "check engine" during the post key on sequence. The OP should do a careful check of the connectors at the PCM in terms of pin conditions / alignment. Further, voltage checks of the appropriate pins at the pcm is required to at least ascertain that it is indeed getting proper electrical input to start. Go from the results.

 

[TJBaker57]

do believe in this thread that there appears to be the "icon" as opposed to the "words" and it is on the right side

I hold that the light which is above the oil pressure gauge is "reduced engine power" indicator. Regardless whether it be written or represented by icons.

Check engine indicator should be just outside the 55 km/h of the speedometer. The outline of the not-illuminated "check engine" icon can even be seen in post #31.

I agree, all of the PCM connectors should be checked for proper voltages and bent or pushed back pins.

 

[Mramses]

NOTE: this post got skewed by the "quote system"... it refers to the pictures of the two instrument panel displays. not sure what happened.

I think If you look back thru some other threads, you will find that there has been some "differences" in how the instrument panel "layout / wiring" has been set. I do believe in this thread that there appears to be the "icon" as opposed to the "words" and it is on the right side. Either way, there is no indication of a "check engine" during the post key on sequence. The OP should do a careful check of the connectors at the PCM in terms of pin conditions / alignment. Further, voltage checks of the appropriate pins at the pcm is required to at least ascertain that it is indeed getting proper electrical input to start. Go from the results.

Should I turn on the "check engine" light?
Should I check if the pcm pins are making contact with the wiring leading to the pcm?
I have the supply and ground voltages present in the wiring that reaches the PCM. the engine sensors also provide continuity to the pcm connection wiring.
Why does it activate the fuel pump and throttle body when the key is turned ON?

 

[TollKeeper]

I will say it again, in his last pic of the cluster, the cluster has NOT done its self test. All gauges are still pointed in resting (below 0) point. Either the wake up signal has not been sent, or the module is still unplugged, or the data comb is still unplugged, or all the above.

 

[Mramses]

Just to be certain..... No picture you have posted shows the "check engine" light.

View attachment 96491

Yes friends today I confirm that. excuse me please
I'm going to take a new photo or make a better video where you can appreciate the activation of the cluster

 

[Mramses]

Today I will make a video of the activation of the cluster to clear up any doubts.
Thank you for being aware of my case friends I hope I can solve my case with your experience and knowledge

 

[Mramses]

I know this is a longshot but you didnt have a new key made by chance???

no friend I only have 1 key

 

[budwich]

IF we can believe the gages on the cluster, then one other thing that is indicated, is powering with key ON. The battery light is on along with the gage not showing an "adequate power level" (or anything). This potentially is a cause of things especially on these when inadequate power shows up at the PCM.

 

[Mramses]

Just to be certain..... No picture you have posted shows the "check engine" light.

View attachment 96491

why can't I post video?

 

[Mramses]

IF we can believe the gages on the cluster, then one other thing that is indicated, is powering with key ON. The battery light is on along with the gage not showing an "adequate power level" (or anything). This potentially is a cause of things especially on these when inadequate power shows up at the PCM.

friend I have two computers and with one if the CHECK ENGINE is activated and with the other it does not activate it friend
why can't I upload videos? I could already take a video with the two ecu

 

[Mramses]

IF we can believe the gages on the cluster, then one other thing that is indicated, is powering with key ON. The battery light is on along with the gage not showing an "adequate power level" (or anything). This potentially is a cause of things especially on these when inadequate power shows up at the PCM.

this is a sequence of photos since I turn the key to run and then to start

 

[Mooseman]

I know this is a longshot but you didnt have a new key made by chance???

It wouldn't matter. This is a Passlock system so no chip in the key. And the Lock symbol would be lit constantly if it was in error.

I'm thinking that there may be something with the PCM as it drives the gauges in the cluster after the bulb test. That or power is not getting to it.

If/when you do replace the PCM, it will need a Security Relearn. If you are not getting the Security Light, something is going on.

Edit: I'm late on this one as I didn't see the latest posts for some reason.

Another thing, when you turn the key to RUN without starting it, the Check Engine light should be on, which is normal, until the engine is started.

 

[Mramses]

hello friend thanks for answering. when I turn the key to run ae they activate the lights like the imagem and then without turning to start the lights remain the image, CHECK ENGINE, AIRBAG AND BATTERY.

does the computer need to be reprogrammed when it is replaced?

 

[Mramses]

the computer that does not turn on CHECK ENGINE I found it with two details.
1 a track has no continuity between two points
2 an integrated trapped that I show in the picture

 

[Mramses]

I will keep the ECU that activates the CHECK ENGINE light until I get the fault. I wonder, this computer if it was not the original should be reprogrammed or should I start the truck?

 

[Mooseman]

Like I posted, it would just need a Security Relearn.

 

[Mramses]

Like I posted, it would just need a Security Relearn.

Does it refer to the sequence of start, 10 minutes in run, wait 10 seconds, give start, return to run 10 minutes and repeat process? just that friend?

 

[Mramses]

the computer that does not turn on CHECK ENGINE I found it with two details.
1 a track has no continuity between two points
2 an integrated trapped that I show in the picture

the details that you observe in the ecu that does not give a check engine light are:
1. track in card connection flex there is no continuity between two points
2. track on integrated card with a track without continuity between two points
3.Top capacitor 475 20k 208 burst

 

[Mramses]

Like I posted, it would just need a Security Relearn.

Friend, because if the PCM requires relearning, I do not see the witness of the padlock or the anti-theft system?
Should the blocking message appear in the cluster or is the UNKNOWN DRIVER announcement announcing the incompatibility?

 

[Mooseman]

If you are not getting the security light, then either the PCM is not getting power or is not communicating on the network. Another possibility is an issue with the Body Control Module (BCM).

Here's how it works. When you turn the key to START, the PCM asks the BCM "hey, is everything OK with security?" and if the BCM responds with "yes, all good, go ahead and start" and then the PCM will crank and start the engine. Now if the BCM detects an attempt to steal the truck, it will tell the PCM "Don't start!" and will illuminate the security light.

The UNKNOWN DRIVER message may be related. If the BCM is not working, the PCM can't get the OK message to start the engine. Why I think that's a possibility is because nothing else works in your truck (windows, radio, HVAC, etc.). Also, it's the BCM that would illuminate the security light so if it's not working, the light won't work.

Have you tried to read codes from the PCM?

 

[Mramses]

If you are not getting the security light, then either the PCM is not getting power or is not communicating on the network. Another possibility is an issue with the Body Control Module (BCM).

Here's how it works. When you turn the key to START, the PCM asks the BCM "hey, is everything OK with security?" and if the BCM responds with "yes, all good, go ahead and start" and then the PCM will crank and start the engine. Now if the BCM detects an attempt to steal the truck, it will tell the PCM "Don't start!" and will illuminate the security light.

The UNKNOWN DRIVER message may be related. If the BCM is not working, the PCM can't get the OK message to start the engine. Why I think that's a possibility is because nothing else works in your truck (windows, radio, HVAC, etc.). Also, it's the BCM that would illuminate the security light so if it's not working, the light won't work.

Have you tried to read codes from the PCM?

Good morning friend, today they are going to connect you with tech2 to see what errors it throws. I will inform you about the dtc codes read.

 

[Mramses]

Good morning friend, today they are going to connect you with tech2 to see what errors it throws. I will inform you about the dtc codes read.

No conexión ☹

 

[Mramses]

Good afternoon friends, today the truck was scanned with the tech2 but it did not give a connection with any module, no connection with pcm, no connection with bcm, no connection with abs
honestly it's frustrating but I ask for your best cooperation to come up with a plan and start the truck please

 

[TollKeeper]

Was your data comb under the back seat plugged in? Was the data comb in the dash plugged in?

 

[Mramses]

yes friend everything was connected

 

[aaserv]

Would you check fuse #13 under hood ?

 

[Mooseman]

So either one of two things. Power is not getting to all the modules or there is a communication problem on the network.

Try pulling the front splice pack comb and connect only the wires for the PCM and the OBD port with a small piece of wire. Try scanning with the Tech 2 again. Do the same for the BCM. Post your results.

 

[TJBaker57]

a communication problem on the network.

I just noted something in support of this idea. I was looking over the imagery to see what clues are there. I was looking for things that require class 2 connections like the temp gauge, oil pressure, fuel level. The MIL light has a direct connection so that doesn't help in regard to class 2. Same for the battery charge indicator. Then i noticed the PRND321 display. There is no indicator under any of the selections as there should be. There presumably should be a bar under P (ark). This value is sent from the PCM to the display system so the lack of that indicator suggests no class 2 communication from PCM to Instrument Cluster and possibly other modules as well.

 

[Mooseman]

This is an excellent video on how to diagnose a module that is taking down the whole network. Although this is for a 2008, the procedure is the same. Wire colours may be different.

 

[Mramses]

Would you check fuse #13 under hood ?

yes friend fuse # 13 ok Can you help me diagnose why it does not communicate with the pcm, bcm and other modules? How can I verify if there is a problem, the bcm could be damaged and therefore it does not receive the signals from the key

 

[Mramses]

So either one of two things. Power is not getting to all the modules or there is a communication problem on the network.

Try pulling the front splice pack comb and connect only the wires for the PCM and the OBD port with a small piece of wire. Try scanning with the Tech 2 again. Do the same for the BCM. Post your results.

understood friend. just those 2 items? the pcm and bcm?