Unknown Driver?

MichEnvoyGuy

Original poster
Member
Dec 3, 2011
522
I have a deposit on a super clean 2002 Bravada with 130000 miles.

I went and test drove it yesterday. First I hooked up my Equus 3130. The truck runs very warm, a good 1/8" past the 210 mark on the gauge. The live data reads 220-225F. My 2002 Envoy would never get that warm. It appears to have the updated GM clutch fan.

No codes (present) stored.

However, there were about 5 codes that were "historical" stored. A few were saying something about the BUS losing data connection, one was the brake light circuit, etc. One code was U1100 IIRC.

When I started the truck the first time, a message came on the DIC "UNKNOWN DRIVER". Even though the truck was running, the instrument panel was dead. The guy goes "Oh, you didnt turn the key far enough". Knowing better but wanting to not be a smartass, I turned the truck off, and restarted it, this time everything worked and no UNKNOWN DRIVER message.

Im thinking the historical codes about the BUS not communicating has something to do with this. Anybody have any input?
 

gmcman

Member
Dec 12, 2011
4,656
Could be a failing ignition switch or........ you have a real-life "Christine" and you need to run far away from it :biggrin:
 

MichEnvoyGuy

Original poster
Member
Dec 3, 2011
522
gmcman said:
Could be a failing ignition switch or........ you have a real-life "Christine" and you need to run far away from it :biggrin:

:biggrin:

I did some poking around the site and it looks like it might have a bad gauge cluster. Theres one with similar mileage at my local salvage yard for $40 according to car-part.com. Hmmmmmmmm hope thats it, THAT I can fix. If its a short in one of the wire bundles, I'd be screwed.
 

MichEnvoyGuy

Original poster
Member
Dec 3, 2011
522
strat81 said:
Perhaps the fob you used was programmed to unlock but is not fully mated to the vehicle to identify driver 1/2?

I hope thats it because tomorrow Im bringing her home :wootwoot:

Ill be a T360 owner once again. This time, a REALLY orphaned T360...lol
 

MichEnvoyGuy

Original poster
Member
Dec 3, 2011
522
Ok I have an update....

Today I bought the truck, no sooner than the seller left my house I went to the truck to play in it (LOL) and when I started it, it did the same wonky "Unknown driver" and none of the gauges work, some warning lights stayed lit.

I then turned the key forward again to the start position (truck was already running), everything reset and was fine after that.

I'm putting my slot machine winnings on a ignition switch that is getting ready to shit the bed. :crazy:
 

strat81

Member
Dec 29, 2011
399
MichEnvoyGuy said:
Ok I have an update....

Today I bought the truck, no sooner than the seller left my house I went to the truck to play in it (LOL) and when I started it, it did the same wonky "Unknown driver" and none of the gauges work, some warning lights stayed lit.

I then turned the key forward again to the start position (truck was already running), everything reset and was fine after that.

I'm putting my slot machine winnings on a ignition switch that is getting ready to shit the bed. :crazy:

Wouldn't surprise me if it was a bad ignition switch.

Did you try mating the remotes to the vehicle?
 

MichEnvoyGuy

Original poster
Member
Dec 3, 2011
522
strat81 said:
Wouldn't surprise me if it was a bad ignition switch.

Did you try mating the remotes to the vehicle?

No I didnt but heres what Ive discovered: When you start the truck, if you dont turn the key forward firmly (read: hard), then it says "unknown driver" and the gauges dont work.

I ordered an AC-Delco ignition switch, should be here by Friday :thumbsup:
 

MichEnvoyGuy

Original poster
Member
Dec 3, 2011
522
I installed the ignition switch today and checked all of the grounds.

All day I drove around and it didnt do it once!! I was stoked that I fixed it.

Then I got home, removed the throttle body and cleaned it which necessitates disconnecting the battery so the throttle body can do a relearn of its position. Reconnected battery, go to start the Bravy, sure enough "UNKNOWN DRIVER" with the gauges dead and all kinds of warning lights on :mad:

When it does this, if I just turn the key forward one more time as the truck is running, the dash resets itself and life is good.
Im beginning to wonder if I have the gauge cluster corrosion on the circuit board like Ive read on the site :undecided:

OH when this happens, it puts:
* U1100 - Loss of communication
* U1301- Class 2 data short to battery
* U1064 - Lost communication with DIM (Whats DIM???)

in my history DTC codes. No CEL, but those codes show up and my cruise control wont work. :frown:

Help?
 

MichEnvoyGuy

Original poster
Member
Dec 3, 2011
522
New info:

I pulled off the knee bolster and pulled out the radio- the guy I just bought it from told me a few key items that are sticking in my mind.. :undecided:

He said he bought the truck last year with an aftermarket stereo and likes everything OEM so he removed the aftermarket radio, went to the junkyard and bought a stock stereo and put it in. This is verified by the writing in yellow on top of the radio that salvage yards do to identify a part. So that is true.

Second, he said he recently replaced the master switches on the drivers side door.

:undecided:

Heres what I think - he bought the truck with the same gremlins Im having. He researched it, heck maybe even read the codes knowing that something was making the modules lose communication/maybe some module "jabber" going on with the U1100, U1301, etc codes. Then he started un-doing what the guy before him did (removed aftermarket stereo to try and get it back to normal, who knows what else was altered before he bought the truck.

So anyways, I dropped the knee bolster and heres what I found:

34jfa06.jpg


A single red wire tapped into a black wire on the main harness under the steering column. It was rigged tapped in .. somebody stripped the insulation on a black wire, then just wrapped this wire around it and put electrical tape on it :eek:
The wire went no where - it was just had electrical tape on the other end and was laying up behind the radio.

I removed it. However, the problem still remains. I notice that if I jiggle the key (BTW brand new ignition switch as of yesterday!!), it starts acting up.

Here is a video of what is happening:
http://www.youtube.com/watch?v=t_NkfmUrMVQ&feature=youtu.be

I am wondering IF the previous owner had an aftermarket stereo with one of those PAC interface whatever they are OR a remote start PASSKEY bypass module/alarm... and the module is causing confusion on the data bus, which would cause my intermittent problems??

I found a small "box" electrical taped up into the harness under the steering column. Can anybody confirm if this is factory or not?

v5dglu.jpg
 

gmcman

Member
Dec 12, 2011
4,656
Do these keys have chips impregnated in them? Have you tried another key? Some vehicles require a key mounted near the ignition when using a remote start, this likely wouldn't apply to ours but wanted to throw that out there just in case. Have you tried a security relearn, would this even be something to cure this?...I don't know but figured I would toss it out there.
 

CaptainXL

Member
Dec 4, 2011
2,445
MichEnvoyGuy said:
* U1064 - Lost communication with DIM (Whats DIM???)


DTC U1064 Loss of Communications with DIM
Refer to Data Link Connector (DLC) Schematics

Circuit Description
The class 2 serial data line communicates information between modules. Each module connected to the serial data line is assigned a recognition code, or address. This code is used in order to identify which modules are communicating. Modules communicate with each other by periodically sending state of health (SOH) messages. When the ignition switch is in RUN, each module communicating on the serial data line sends a SOH message every 2 seconds. This ensures that the system is operating properly. When the dash integration module (DIM) stops communicating on the class 2 serial data line, the SOH that is normally sent on the serial data line every 2 seconds disappears. The module, which expects to receive that message, detects the absence of the message. The module in turn sets DTC U1064 associated with the loss of SOH of the DIM.

Conditions for Setting the DTC
The module does not receive a state of health (SOH) message back from the DIM. The module retries the request 3 times, and then sets DTC U1064.
This DTC only sets if U1300 or U1301 is not current.
Action Taken When the DTC Sets
DTC U1064 is stored in the module.
The module uses the default values for the initialization data.
This DTC does not cause driver warning message to appear.

Conditions for Clearing the DTC
This DTC clears (status changes from current to history) under any of the following conditions:
The module detects a state of health message from the DIM.
At each ignition cycle.
A history DTC clears after 50 consecutive ignition cycles if the conditions for setting the DTC are no longer present.
Current and history DTCs may be cleared using a scan tool.
Diagnostic Aids
DTC U1064 does not normally represent a failure within the module.
When loss of class 2 serial data communication DTCs (DTCs with the letter U as the prefix) are stored as history DTCs, know all possible serial data DTCs set in each module before diagnosing the serial data line.
If U1064 is stored in the module memory, inspect for the same DTC stored in other modules capable of storing this DTC.
If the DTC is a history DTC, the problem may be intermittent.
Test Description
The numbers below refer to the step numbers on the diagnostic table:

U1064 is the result of loss of communication with the dash integration module (DIM). Note that other modules on the class 2 serial data line may also set U1064 if the DIM is not communicating with the serial data line.

Clear all DTCs after the repair procedure is complete.

Step
Action
Value(s)
Yes
No

1
Did you perform the Data Link Communications Diagnostic System Check?
--
Go to Step 2
Go to Diagnostic System Check - Data Link Communications

2
Use a scan tool in order to attempt the establish communication with the dash integration module (DIM).

Does the scan tool communicate with the DIM?
--
Go to Step 3
Go to Diagnostic System Check - Body Control System in Body Control System.

3
Inspect and repair the class 2 serial data line CKT 1807 (PPL) for intermittent connections. Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.

Is the repair complete?
--
Go to Step 4
--

4
Turn off the ignition switch.
Reconnect or install any connectors or components that were disconnected or removed.
Turn on the ignition switch.
Clear any DTCs.
Is the repair complete?
 

willn513

Member
Dec 4, 2011
918
MichEnvoyGuy said:
New info:

I pulled off the knee bolster and pulled out the radio- the guy I just bought it from told me a few key items that are sticking in my mind.. :undecided:

He said he bought the truck last year with an aftermarket stereo and likes everything OEM so he removed the aftermarket radio, went to the junkyard and bought a stock stereo and put it in. This is verified by the writing in yellow on top of the radio that salvage yards do to identify a part. So that is true.

Second, he said he recently replaced the master switches on the drivers side door.

:undecided:

Heres what I think - he bought the truck with the same gremlins Im having. He researched it, heck maybe even read the codes knowing that something was making the modules lose communication/maybe some module "jabber" going on with the U1100, U1301, etc codes. Then he started un-doing what the guy before him did (removed aftermarket stereo to try and get it back to normal, who knows what else was altered before he bought the truck.

So anyways, I dropped the knee bolster and heres what I found:

34jfa06.jpg


A single red wire tapped into a black wire on the main harness under the steering column. It was rigged tapped in .. somebody stripped the insulation on a black wire, then just wrapped this wire around it and put electrical tape on it :eek:
The wire went no where - it was just had electrical tape on the other end and was laying up behind the radio.

I removed it. However, the problem still remains. I notice that if I jiggle the key (BTW brand new ignition switch as of yesterday!!), it starts acting up.

Here is a video of what is happening:
http://www.youtube.com/watch?v=t_NkfmUrMVQ&feature=youtu.be

I am wondering IF the previous owner had an aftermarket stereo with one of those PAC interface whatever they are OR a remote start PASSKEY bypass module/alarm... and the module is causing confusion on the data bus, which would cause my intermittent problems??

I found a small "box" electrical taped up into the harness under the steering column. Can anybody confirm if this is factory or not?

v5dglu.jpg

Looks like a bypass to me. Lets you keep the factory chimes and stuff through the front drivers side speaker. Probably inoperable at this point if a stock radio is back in, but may have been easier to just leave it in there for the other guy. I would see if there's a plastic harness clipped into it and try to unplug it to see if that has any effect on your issue. Honestly, it probably isn't related. But if it IS a remote start or aftermarket alarm, that's possible.

Also- under the hood is there any type of big siren/speaker looking thing mounted? That could indicate that at some point there was/or still is an aftermarket alarm hooked up. Most(not all, but most) people don't opt to install a remote start and keep the factory alarm.

Another thought is that it could be an after market module to retain your steering wheel controls with an aftermarket stereo. Usually when you put a new radio, you loose stock wheel functions without adding one of these in.
Check out http://www.axxessinterface.com/steering_wheel_control_new.aspx for a better idea of what I mean.

EDIT- welcome back. Good to get back in a gmt I bet!
 

DDonnie

Member
Mar 26, 2012
2,631
See if there is anything tapped into the purple wire on the back of the obdII connector. That's the data wire that a lot of people will use when installing aftermarket alarms/remote starts.
 

CaptainXL

Member
Dec 4, 2011
2,445
DDonnie said:
See if there is anything tapped into the purple wire on the back of the obdII connector. That's the data wire that a lot of people will use when installing aftermarket alarms/remote starts.

Good idea. To the OP, I would unwrap that mess of electrical tape and see what is inside there. Probably the bypass module for the ignition that connects to the purple wire Donnie is referring to.
 

MichEnvoyGuy

Original poster
Member
Dec 3, 2011
522
Guys,

Thanks a ton for the info. I will unwrap the box tomorrow and report back. So just confirming - that electrical taped box does not look factory? I have nothing to compare it to.

Also on my radar: the ignition cylinder itself with the built in security (passkey?) sensor.

What I really need is my friend and his TECH II. Im going to text him tomorrow and see when we can hook up. That way he can tell me "exactly" what is setting the codes. Im pretty sure, when reading with the TECH II, it will tell what the code is and freeze frame data, what lead to that code setting. I know whenever the cruise control is commanded, but doesnt activate, it records "why" it didnt activate. Im hoping it is doing the same thing with the U1100, U1301 and the other code Im getting :undecided:
 

CaptainXL

Member
Dec 4, 2011
2,445
MichEnvoyGuy said:
So just confirming - that electrical taped box does not look factory? I have nothing to compare it to.

That's definitely not factory. A small word of caution before you proceed. I would pull the ignition fuses before working down there. The fuses are labeled IGN under the hood electrical center/fuse box.

Also, do you know if you have remote start or not? Did the previous owner tell you? If you know you have remote start and it is under any kind of warranty it might be better to have the installer look at it. Otherwise if you don't need remote start or know you don't have it then by all means proceed.
 

MichEnvoyGuy

Original poster
Member
Dec 3, 2011
522
CaptainXL said:
That's definitely not factory. A small word of caution before you proceed. I would pull the ignition fuses before working down there. The fuses are labeled IGN under the hood electrical center/fuse box.

Also, do you know if you have remote start or not? Did the previous owner tell you? If you know you have remote start and it is under any kind of warranty it might be better to have the installer look at it. Otherwise if you don't need remote start or know you don't have it then by all means proceed.

Nothing was mentioned and I have no special remote start FOBs. The key FOBs I have are the OEM originals.

When I go down there, I will disconnect the battery. Thanks for the tip.

Im excited to get this resolved. I HATE electrical gremlins and I especially hate that this problem is keeping me from doing fun mods like a pcm4l tune...lol
 

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