"Unknown Driver" - UPDATE

[MichEnvoyGuy]

I made a thread before about my 2002 Bravada and the "UNKNOWN DRIVER" message on the DIC, dead gauges, and several U-body codes.

Tonight I went over to my buddy's house, who has a Tech 2. Thankfully for me, hes been a GM repair technician for years and takes much pride in his job, because it didnt take him long to find the issue.

Before I reveal the "fix" for this issue, I want to entertain some guesses!

So what do you think would cause random dead gauge cluster, "unknown driver" message on the DIC, and U1000, U1064, U1301 codes.

Go on, take a shot.... anyone?

 

[gmcman]

Based on the discussion, and the codes.....I want to say there was a ground wire loose or corroded to the IC, or the BCM. Seems the state of health wasn't being communicated so could be the wire harness to the BCM but since there was some hack jobs behind the knee panel, an ignition switch harness or ground.

 

[MichEnvoyGuy]

Alright, got it.

1 vote from GMCman for bad ground to IC/BCM/other module or hack job under steering column.

Would love to entertain some more guesses!

(Ill give you a hint, GMCman didnt get it)

 

[Grimor]

You got too fat too fast and the vehicle thought you were someone else?

 

[MichEnvoyGuy]

You got too fat too fast and the vehicle thought you were someone else?

 

[MichEnvoyGuy]

Ok Im tired of waiting for your guesses, lol.

So I go over to my friends house, he hooks up his Tech2. Every module except for like 1 had DTC's. Loss of communication, data bus short, etc.

Strange though... one module is NOT communicating at all. Its dead. At first, I just figured the module went tits up, as they sometimes do on our platform, right?

Wrong!! Paul gets under the Bravada to check the ECBM (Brake Module). Its unplugged. He plugs it back in, suddenly my Bravada is content with its data bus communications. Heck, we cant even get it to replicate the "UNKNOWN DRIVER" and dead gauge nonsense!!

Go for a test drive and its apparent WHY somebody before unplugged it - the right front ABS sensor is whackadoodle, causing the ABS to activate under 10mph at every stop. Whether they disconnected it to sell it, hiding the problem, or were to cheap to fix it, who knows.

WHICH ties into my other thread about which wheel bearing is bad because one of them is humming pretty loudly Now I know its the passenger side fosho. I watched the data on the Tech2 and every time we slowed down below 12mph or so, the right front wheel sensor goes to 3mph, thus tricking the module into thinking that wheel is stopped/going slower than the rest, and activating ABS.

Whoever owned it before me, disconnected the ECBM so that the ABS wouldnt engage every time they stopped, due to a bad right front hub assembly.

All is good now and tonight I will be replacing the front right hub. Im sooooo glad that was an easy fix.

Without the help of my friend Paul and his Tech2, I dont know how long it would've taken me to diagnose the ECBM being disconnected. He literally found it within 5 minutes with the Tech2.

 

[xtitan1]

Ok Im tired of waiting for your guesses, lol.

So I go over to my friends house, he hooks up his Tech2. Every module except for like 1 had DTC's. Loss of communication, data bus short, etc.

Strange though... one module is NOT communicating at all. Its dead. At first, I just figured the module went tits up, as they sometimes do on our platform, right?

Wrong!! Paul gets under the Bravada to check the ECBM (Brake Module). Its unplugged. He plugs it back in, suddenly my Bravada is content with its data bus communications. Heck, we cant even get it to replicate the "UNKNOWN DRIVER" and dead gauge nonsense!!

Go for a test drive and its apparent WHY somebody before unplugged it - the right front ABS sensor is whackadoodle, causing the ABS to activate under 10mph at every stop. Whether they disconnected it to sell it, hiding the problem, or were to cheap to fix it, who knows.

WHICH ties into my other thread about which wheel bearing is bad because one of them is humming pretty loudly Now I know its the passenger side fosho. I watched the data on the Tech2 and every time we slowed down below 12mph or so, the right front wheel sensor goes to 3mph, thus tricking the module into thinking that wheel is stopped/going slower than the rest, and activating ABS.

Whoever owned it before me, disconnected the ECBM so that the ABS wouldnt engage every time they stopped, due to a bad right front hub assembly.

All is good now and tonight I will be replacing the front right hub. Im sooooo glad that was an easy fix.

Without the help of my friend Paul and his Tech2, I dont know how long it would've taken me to diagnose the ECBM being disconnected. He literally found it within 5 minutes with the Tech2.

Great to hear brother!

 

[MichEnvoyGuy]

Since the ECBM was plugged back in, I havent had any problems at all with the "Unknown Driver" message, dead gauges, or anything :wootwoot:

 

[The_Roadie]

1 vote from GMCman for bad ground to IC/BCM/other module

A disconnected connector counts as a bad ground. :wootwoot:

Owners who do that to sell a vehicle deserve to have their next TEN vehicles come to them with similar ticking time bombs.