All dash lights on

[jmonica]

On my way to work today, out of the blue, every light on my dashboard lit up.

I was just cruising along at about 60mph.

Like when you turn the key on before you start it. CEL, Traction control etc.. every warning light. Also, all if my gauges went dead. At the same time, my radio shut off.

I turned the key to start while I was driving. That reset the lights and gauges started working.

The car continued to run fine. I felt no adverse affects to drivability when it happened. No stumble, no nothing. Just lit up like a pinball machine.

The radio would not turn back on until I stopped, turn the car off and then turned the key back on

Any thoughts on what could possibly cause this?

Thank You

 

[Mooseman]

I'd check the usual suspects, ignition switch and grounds.

Btw, you can turn the switch to the start position while running to reset everything. I do that for the stabilitrak light because of the flaky SWPS.

 

[budwich]

I'd check the usual suspects, ignition switch and grounds.

Btw, you can turn the switch to the start position while running to reset everything. I do that for the stabilitrak light because of the flaky SWPS.

I assume you are referring to "drive" mode as opposed to "engine running" mode.

 

[mrrsm]

Some added Diagnostic Suggestions:

(1) Inspect and Check the Battery Terminals for signs of Corrosion and Tightness.

(2) LOAD-STRESS Test the Battery via a Visit to AutoZone for their FREE Diagnostic.

 

[Mooseman]

I assume you are referring to "drive" mode as opposed to "engine running" mode.

Either. You can do this while driving too.

 

[jmonica]

I'd check the usual suspects, ignition switch and grounds.

Btw, you can turn the switch to the start position while running to reset everything. I do that for the stabilitrak light because of the flaky SWPS.

Thanks Moose. That's exactly what I did to reset everything, because I do that to get rid of the Stabilitrac light as well. I've replaced the SWPS twice and the light went away for a month or two both times, but came back. I'm not buying a third one.

I can't help but feel there's a ground problem somewhere causing multiple problems. Gonna spend the day trying to find every ground and cleaning / repairing all of them before I do anything else.

I had bad ground on the left frame rail that caused my braking system warning lights to come on.

 

[jmonica]

Some added Diagnostic Suggestions:

(1) Inspect and Check the Battery Terminals for signs of Corrosion and Tightness.

(2) LOAD-STRESS Test the Battery via a Visit to AutoZone for their FREE Diagnostic.

Thank You. I'm going to do a thorough check of all of the grounds and have the battery tested.

 

[Drec]

Did you solve this problem? I'm experiencing the a similar situation.

Several weeks ago, the dash lights started coming on and then flashing. They did that off and on for about a week, then the radio switched off. The radio is a replacement (Kenwood), that I installed about a year ago.

Since the radio started shutting off, the dash lights haven't turned on during driving. When the radio shuts off, I can put the car in neutral, shut it off and start it back up and the radio works, for a few minutes. Other than this the car works fine.

 

[Drec]

Looking around for the last couple of days for an answer, without any luck. Went out today and the same thing happened. Shut off the car and then had no instruments or radio. Got back home and did a body control module reset, now I have instruments and radio. I’ll just have to wait and see what happens in the next few days.

 

[mrrsm]

This sounds suspiciously like a "Class 2 Network Problem..." probably caused by One, Single Module Shorting either by being Pulled to Ground or Jacked up to 12 Volts B+. This issue is well delineated and solved with Basic Diagnostic Tools, Some Interesting Techniques (and a few Top End Ones will help, too) by Will Robinson in this eponymous YouTube Video that EVERYONE will be glad to Download and Keep Handy:

And another Spot-On Class 2 Instructional for Trailblazers from "Trained By Techs":

And from @TJBaker57 using a Cell Phone Terminal APP:

Using The DLC to pick up the Class 2 Network Traffic on a K-Body via the 4 Channel Oscilloscope on the Snap-On Verus High End Scan Tool:

For ALL the Dope & Data on "How To Use an Inexpensive Oscilloscope" view THIS Thread:

Thread 'How To Use PICO #2204A & HANTEK #1008C Oscilloscopes'

Oct 20, 2019

You don't need a Huge Bag of Coins in order to obtain and use an Oscilloscope for performing In-Depth Wave Form Analysis in Automotive Applications on everything from Problematic Electronic Fuel Injection to obtaining accurate Compression Tests to Diagnose Internal Engine Conditions.

HANTEK makes (...and Amazon, eBay and OTHER Outlets sells) ALL of the discreet equipment components necessary to accurately conduct these types of Automotive Diagnostics ... and all can obtained on a Very Modest Budget.

The Basic Oscilloscope Hardware is listed below:

(1) Windows or surprisingly... a...

• mrrsm
• Replies: 112
• Forum: Technical Discussion

• 

 

[mrrsm]

...and for the sake of the Owners of Full Size Trucks with V-8 Engines, the same techniques can be used (with the added advantage of using a "BOB" (Break Out Box) to connect up the Diagnostic Autel Maxi-Scope Tool AND an Autel Scan Tool as well as a Decent Actron Model# CP-7677 "Day-Light" DMM to perform these Diagnostic Steps with a slightly different Splice Pack Design to get to the One Errant Module bringing down the entire Class 2 Network that in THIS case involved one that was either Shorted to POWER on one module... and or... Missing the Primary Engine Block Ground.

 

[Drec]

Update:
I ordered a Hantek 1008C yesterday and I'll be here tomorrow. Picked up a Dell Lap Top today and hopefully I'll be able to spend some time (hours/days) trying to learn how to use it. There appears to lots of videos on learning the Hantek.

After doing to module reset I drove the Envoy on about a 300 trip today, and experienced no issues with the dash lights. After a few miles driving the radio, stopped working; which happened every time that I restarted the car.

 

[mrrsm]

This is another "On Point On Topic" Video involving a Pro Shop Diagnostic with very similar symptoms on an Envoy that blends with yours ...and again... The Use of an Oscilloscope for the needed deeper dive into the Class 2 Network that should also be helpful as you get familiar with your New Hantec "O" Scope Hardware:

NOTE: The Use of a "BOB" (Break Out Box) will become -=very=- evident whenever attempting ANY DLC Diagnostics where more than one piece of Diagnostic equipment is being used:

*Spoiler Alert*

In this case... The Lift Gate Module...WHICH SUPPORTS 12 VDC on a Thick and Thin set of Orange Wires that pass through the Lift Gate to Body Grommet can Work Harden and BREAK and Short Out the Class 2 Network to 12 Volts DC B+:

 

[budwich]

Update:
I ordered a Hantek 1008C yesterday and I'll be here tomorrow. Picked up a Dell Lap Top today and hopefully I'll be able to spend some time (hours/days) trying to learn how to use it. There appears to lots of videos on learning the Hantek.

After doing to module reset I drove the Envoy on about a 300 trip today, and experienced no issues with the dash lights. After a few miles driving the radio, stopped working; which happened every time that I restarted the car.

You might be wise to look at some of the replies / threads from tjbaker57 on monitoring the data bus using an app and an OBD dongle.... basically for about 20-30$ you can look at the messaging that is happening to determine what's up. Having said that, you might also check the connections to the BCM to ensure they are clean and not cracked or otherwise. My take is that you have a connection issue at the bcm and / or ignition switch such that the "power mode" of the vehicle is changing causing the BCM to react with messages to systems that it is controlling. Have you ever changed the ignition switch?

 

[Drec]

Have you ever changed the ignition switch?

No, but I'll look at it.

 

[Drec]

Ordered a new ignition switch today. Received the Hantek today. The switch will be here by weekend, so it will be a while before I can get into this, I'll report back.

 

[mrrsm]

One additional "O" Scope Diagnostic for the IPC on the GMT360 Vehicles comes from a TRUE Legend among Automotive Diagnosticians --> Keith De Fazio of New Level Auto up in Staten Island New York who is in the same remarkable talent league with Dave De Corcia (Rest In Peace, Brother) where he shows us "How to Use an Oscilloscope to Diagnose a Truly Dead Dashboard" (IPC):

AND... Speaking of Power & Grounds Testing... Battery Stress Testing ...IF you have Intermittent No Starts with the IPC Gauges going "All Over the Place..."... Let's drop in at "Joe's Auto Electric" --> ANOTHER Awesome Diagnostician... and see what he figures out for THIS Trailblazer IPC Issue:

Who Knew THAT Particular Body Ground Location was so close to the Power Distribution Center at the Fender Well and could Cause SO MUCH TROUBLE ...and yet... is SO EZ TO DIAGNOSE and FIX? SWEET!