OnStar delete attempt (2G)

[jummama]

Yesterday, I decided to try to remove the OnStar system. Sorry I forgot to take any pictures during the process, but I may pull it back out to do so if there's any demand for it. Here's a summary of what I found:

- In my 2002, the OnStar box is in the right side of the trunk, mounted to the back seat behind a beauty cover. It had 2 coax antenna connectors, and 2 wiring harnesses hooked up. There was a third wiring harness plug on the box that was not used at all.
- With the unit completely unplugged, there are no complaints from the DIC, and everything seems to work... Except the dimming function of the mirror . It went to a nearly full dim, and stayed there. The compass still worked fine. OnStar status light stayed off.
- Inside the box, there is a mainboard, and a second board obscured by a second cover under the main board. There are a total of 10 torx screws holding this second cover on, compared with the main cover having 4. This secondary board is the cellular modem.
- After removing the cellular modem, I used gorilla tape to keep the antenna pigtail from bouncing around and shorting things, then put everything else back together, and reinstalled it in the car, minus the antenna plugs. Dimming mirror works again! OnStar status light stays red. This is how my car currently is configured.

I'm wondering if anyone else here has any experience with this sort of change to the OnStar system? The FCCID on the cell board confirms that this is the old 800MHz analog OnStar, which you can't get service for, and which can cause a battery drain condition. I was hoping that removing the cell modem would rectify the possibility of a battery drain issue, but pressing the onstar button twice still seems to attempt to connect. First press plays the canned recording, second press results in silence, with a beep every 15 seconds or so. OnStar status is flashing red during this, and the OnStar can be cancelled by pressing the dot button.

Has anyone managed to make the auto-dimming mirror work without the OnStar box? That's the only thing preventing the box from being removed all together in this car. Theoretically, I could replace the mirror with something else, but I don't want to.

With the OnStar hooked up in a normal configuration, I was seeing a status light which was usually red, but sometimes would turn green. As I understand it, shouldn't it stay red if there's no analog service for it anymore?

[Paulaurora]

I never try to remove on star and check my mirror but i dont think they are related . The Mirror has the light sensor on a back of it. I will try to remove my on star and let you know. I think if u press and hold power button i believe on a mirror it will enable or disable auto dim .

[rorafan]

Y, it doesn't sound related...I am really surprised the mirror did that. I always thought for the mirror OnStar was just added-on controls with the guts elsewhere, and removing should/would have no impact on dimming.

Did you test it in a garage by chance? Was anything in the way of the mirror / sensors when you tested it? If the car is in the garage, it may have just done its thing and dimmed if you had the garage door open (light coming from behind) or a worklight in the car. Maybe try putting the car in reverse -- that should force it to "un-dim".

As for the red/green light, I used to see green on my Envoy every once in awhile. That was an '02 and also had the analog system. It was interesting to see over time how less and less frequently it would be green. Was mostly red when I traded it last year but would turn to green every once in a while

[jummama]

Yeah, it was kind of weird that the mirror would be affected. If anything, I thought maybe the compass would stop working, but I was outside, and I tested the mirror with a flashlight. It did not respond at all. My uncle also tried to get it to respond by flashing high beams at me from behind, and no effect.

Does the FSM have any pinouts for the wiring harnesses on the OnStar box? I know that it connects to Class 2 data at the least, but I suspect there's audio leads, and a few other possibly interesting things.

FWIW, I saw a thread on the Camero5 forums where people were finding that the ECM and BCM are linked THROUGH the OnStar module, so without it their cars don't start! Maybe there's something like that with the mirror on the Aurora to discourage people from taking it out?

Paul - Thanks for the tip about the power button. I'll pull the module back out some time this weekend to take pictures and I'll see if that does anything without the module in place.

[awehlage]

If you aren't in a hurry I can pull pin outs and wiring diagrams for OnStar. I will be attempting to remove the entire system as well very soon. I already have the OnStar unplugged because old analog system kept searching for a cell signal when car was off. My auto dimming feature still works and it's been a while since I unplugged the module.

[jummama]

I noticed that there was space on the mounting bracket for 2 discreet modules, though there was only one module in my car. Is yours a 2 module system? I think the 2 module system has the processing board in one box, and the cell modem in the other, so maybe you just unplugged the cell module, similar to what I effectively ended up doing, or maybe this is just a difference between the 2001 and 2002 OnStar system in our cars?

Definitely no hurry, as I haven't been seeing any battery drain from it before or after my removal of the cell modem, and I already have saved whatever power the cell modem would use.

If we can get those pinouts, and can figure out a way to make everything work without the module (though it apparently works fine in yours!), it may be interesting to find a JTAG port on the processing board, and find out how it would have been able to send messages to the DIC with the nav subscription, and how it sends audio to the radio. I'm thinking along the lines of CoStar, but open source, and tailored to our cars, using an Arduino or somesuch. Only thing stopping me from trying to bench test the module to try to JTAG is that I don't want to fry it while I need it, and I'm not sure how to power it up. Also, the fact that I need to get/build a JTAG cable...

[rorafan]

Jan 15, 2015 19:02:53 GMT -6 jummama said:

I tested the mirror with a flashlight

Did you cover the sensor at the back of the mirror (facing the front of the car)? This is what senses if it's dark outside. Not dark = no dimming. Apologies if you covered this or tested at night...just really surprised the mirror would behave that way.  

[jummama]

There's a separate light sensor on the mirror side of the mirror for glare dimming. The flashlight test works fine with the OnStar box installed. I'm just as confused by that as everyone else!

[awehlage]

Jan 15, 2015 19:31:13 GMT -6 jummama said:

I noticed that there was space on the mounting bracket for 2 discreet modules, though there was only one module in my car. Is yours a 2 module system? I think the 2 module system has the processing board in one box, and the cell modem in the other, so maybe you just unplugged the cell module, similar to what I effectively ended up doing, or maybe this is just a difference between the 2001 and 2002 OnStar system in our cars?

Here is the documentation I pulled from the 2001 FSM. The version of OnStar in my car is (2.6) with two modules consisting of the Vehicle Communications Unit (VCU) and Vehicle Interface Unit (VIU). It seems that the late 2002 model got an upgraded version to (F1) which only consists of one module, the Vehicle Communications Interface Module (VCIM). I think this may be the switch over from analog to digital. Not sure though.

OnStar Description and Operation Version 2.0 and 2.6

OnStar Description and Operation Version 2.6 and F1

Electrical Connector End-Views - Same for all versions according to FSM.

VIU and VCU Location VIU is #5 in diagram. VCU is #6 in diagram.

VCIM Location

@ Jummama - I have disconnected both connectors C1 and C2 to my VIU to prevent parasitic drain on the battery. I still have the VCU connected. I will try unplugging when I'm in the rear seat/trunk area again and report what happens.

[rorafan]

Courtesy of Marc, there's also a diagram of the mirror portion floating around on the forum. This is apparently from a 2001 manual also.



More: aurorah.proboards.com/thread/24973


What's interesting is the diagram from Marc shows pins 1 - 3 used for the power portion to the mirror but the other diagram does not show this. Seems it should have a direct power input, along with the "un-dim in reverse" signal (pin 3 in diagram from Marc above). Was there a MANUAL dimming OnStar mirror offered? That would only have the OnStar wiring as shown.

But where is the mic in this diagram? Ah, this is a strange one...

[Marc]

rorafan.....Right. That is from the 2001 FSM.

[Marc]

I hope that I'm not asking a dumb question, but why would anybody want to remove the Onstar system? My 2001 didn't get it from the factory, it was built only a few days before Onstar was made standard equipment in the 2G. I always wanted it, and when the Onstar FMV mirror went on the market, I grabbed it immediately. It doesn't have all the features of factory Onstar, but it's better than no Onstar at all. I put it in back in 2011. See the below noted threads about that.

aurorah.proboards.com/index.cgi?board=Interior&action=display&thread=23408

aurorah.proboards.com/index.cgi?board=Interior&action=display&thread=23590

[jummama]

Thanks for the diagrams guys! My first guess from that is the keypad supply voltage being involved somehow. Perhaps it's a phototransistor in the mirror, which needs a bias voltage? I'll investigate and report back.

Marc: Interesting that your car didn't get factory OnStar, I thought all the 2G cars came with it installed. Did it have an auto dimming mirror from the factory? Perhaps the availability of a 2001 without OnStar would explain why awehlage's 2001 would have the dimmer totally independent of the OnStar controls, whereas my 2002 has them tied together to some degree?

As to reasons to remove OnStar, not a dumb question at all! I have a couple reasons. The system that came with the car cannot be activated, as it is an old style analog cell connection, so if I were to decide to buy service, I'd need either the replacement mirror like you've got (nice install by the way!), or a dealer upgrade of the OnStar hardware. As a result of the analog networks being switched off, these old boxes can cause power drain by constantly trying to connect. Additionally (tin foil time!), while the features OnStar offers can be pretty nice, I see it as a bit of a double edged sword. With NSA/CIA/local police using Stingray devices to set up imposter cellular towers, and the massive data collection efforts across the world, not to mention previous stories of OnStar actively collecting data from cars without service (which they've supposedly stopped), I'd just rather it not be there if I'm not using it. They wouldn't have any reason to spy on me in particular, but with modern surveillance being done in a warrant-less dragnet, why should I make it easier for them?

[Paulaurora]

Dealer said that if its 2001 cars they cant be upgraded it to new onstar and 2002-2003 can which is bull they just dont wanna bother with rewire. they told me it will cost 1200 for them to make onstar work on my 2001 when its just plug switch and the box. from 2 unit onstar to 1 unit. on some 2001-2002 3.5 and on some early 2001 4.0 didnt come with onstar . If car didnt come with on start i believe 90% that mirror is without autodim option its the manual one.

[sall]

Mirror Info....


Automatic Day-Night Mirror Description and Operation
Automatic Day-Night Mirror System Components

The automatic day-night mirror system consist of the following components:

An inside rearview mirror
A compass

Automatic Day-Night Mirror Operation

With the ignition switch in the ON position, ignition 3 voltage is supplied through the IGN 3 RR fuse to the inside rearview mirror. The inside rearview mirror uses 2 photocell sensors in order to determine light conditions in the front and the back of the vehicle. At night, with the automatic day-night feature enabled, the mirror automatically darkens to reduce the glare from the headlamps from behind. In the daytime, the mirror is in a normal state. With the gear selector lever in the REVERSE position, backup lamp supply voltage is supplied as an input to the inside rearview mirror. The inside rearview mirror will gradually change to a normal state as a result of the backup lamp supply voltage input. Ground for the inside rearview mirror is provided by G402.
Compass

The electronic compass includes a magnetic field sensor and a microprocessor. The microprocessor receives inputs from the sensor, processes these inputs, and provides a heading on the compass display.
Automatic Day-Night Mirror Switches (w/o OnStar®)

The automatic day-night mirror has two switches that perform the following functions:

The MIRROR switch is used to enable or disable the automatic day-night feature of the mirror. With the ignition in the ON position, depress the MIRROR switch to enable the automatic day-night feature of the mirror. A green indicator will illuminate on the mirror when the automatic day-night feature is enabled. To disable the automatic day-night feature of the mirror, depress the MIRROR switch.
The COMPASS switch is used to turn the compass on and off. With the ignition in the ON position, depress the COMPASS switch to turn the compass on. Depress the COMPASS switch again to turn the compass off. The COMPASS switch is also used to place the compass into a calibration or zone mode. For more information, refer to Compass Calibration and Variance Procedure .

Automatic Day-Night Mirror Switch (w/ OnStar®)

Object Number: 671554 Size: SH
Click here for detailed picture of above image.

This is the on/off switch for the automatic day-night mirror. The on/off switch is used to perform the following functions:

To enable or disable the automatic day-night feature of the mirror. With the ignition in the ON position, depress and hold the on/off switch for 4 seconds to enable the automatic day-night feature of the mirror. A green indicator will illuminate on the mirror when the automatic day-night feature is enabled. To disable the automatic day-night feature of the mirror, depress and hold the on/off switch for 4 seconds.
To turn the compass on and off. With the ignition in the ON position, depress the on/off switch to turn the compass on. Depress the on/off switch again to turn the compass off. The on/off switch is also used to place the compass into a calibration or zone mode. For more information, refer to Compass Calibration and Variance Procedure .

[Marc]

Jan 16, 2015 16:01:00 GMT -6 jummama said:

Thanks for the diagrams guys! My first guess from that is the keypad supply voltage being involved somehow. Perhaps it's a phototransistor in the mirror, which needs a bias voltage? I'll investigate and report back.

Marc: Interesting that your car didn't get factory OnStar, I thought all the 2G cars came with it installed. Did it have an auto dimming mirror from the factory? Perhaps the availability of a 2001 without OnStar would explain why awehlage's 2001 would have the dimmer totally independent of the OnStar controls, whereas my 2002 has them tied together to some degree?

As to reasons to remove OnStar, not a dumb question at all! I have a couple reasons. The system that came with the car cannot be activated, as it is an old style analog cell connection, so if I were to decide to buy service, I'd need either the replacement mirror like you've got (nice install by the way!), or a dealer upgrade of the OnStar hardware. As a result of the analog networks being switched off, these old boxes can cause power drain by constantly trying to connect. Additionally (tin foil time!), while the features OnStar offers can be pretty nice, I see it as a bit of a double edged sword. With NSA/CIA/local police using Stingray devices to set up imposter cellular towers, and the massive data collection efforts across the world, not to mention previous stories of OnStar actively collecting data from cars without service (which they've supposedly stopped), I'd just rather it not be there if I'm not using it. They wouldn't have any reason to spy on me in particular, but with modern surveillance being done in a warrant-less dragnet, why should I make it easier for them?

Jummama.......My 2001 did not get Onstar because it was built on 6/28/2000. GM decided to make Onstar standard on the 2G a few weeks later, on 7/17/2000. It did have an auto dimming mirror with a compass from the factory, but I don't miss those 2 features, though. And thanks for the compliment.

[jummama]

So, my OnStar harness does not match with the plugs in awehlage's post. There's 2 plugs. One is 32 pin, the other is 24 pin. Based on the color code from that diagram, I unplugged the smaller one, leaving the one with the keypad supply voltage. The result of this is that the OnStar light is now off, dimming works properly, and the keypad buttons do not respond in any way. Still didn't get pictures, but I'll do that tomorrow. While I was in there, I checked what would happen trying to turn off the dimming with everything unplugged, and found that it does go back to a normal, no dimming mode.

I'll have to investigate further, but it looks like the color code matches up with the diagram, just not the plugs.

[awehlage]

I will look again for another connector end view but I tried all 2G years and the same thing came up. Might have missed it somewhere though!

[awehlage]

My apologies! Here is the correct connector end view for the (F1) Version.

Cellular Communication Connector End View - F1 Version

Also from the FSM (2002). Sall posted pretty much the same thing but this adds a couple other tid-bits:

Inside Rearview Mirror Description and Operation
Inside Rearview Mirror with the Automatic Day-Night Feature System Components
The automatic day-night feature system consist of an inside rearview mirror.

Power and Ground of the Inside Rearview Mirror
• With the ignition ON, ignition voltage is supplied to the mirror from the IGN 3 RR fuse in the rear fuse block.

• Ground for the mirror is provided by G402.

Inside Rearview Mirror with the Automatic Day-Night Feature System Operation
The inside rearview mirror uses 2 photocell sensors. One sensor is the headlight sensor, located on the rear side of the mirror. The headlight sensor is used to determine light conditions present at the mirror face. The other sensor is the ambient light sensor, located on the front of the mirror or windshield side. The ambient light sensor is used to determine light conditions present at the mirror. With automatic day-night feature enabled, the mirror uses ambient light sensor to determine the exterior light condition. With a low light condition detected, and a high light condition from behind at the headlight sensor, the inside rearview mirror will automatically darken the face of the mirror.

In the daytime, the mirror is in a normal state because of the high light condition that is indicated by the ambient light sensor. With the gear selector lever in the REVERSE position, backup lamp supply voltage is supplied as an input to the inside rearview mirror. In night time conditions only, the mirror monitors this input to disable the automatic day-night feature which allows the face to gradually change to a normal state. This allows the driver to see objects in the mirror clearly when backing up.

Compass
The mirror uses two magnetic field sensors for compass direction. One sensor is for north and south, the other is for east and west. The mirror supplies a signal and low reference to each sensor. As the vehicle travels with or against the earth's magnetic pull, there will be a change in voltage on one or both sensors. As a result of the change in voltage, the mirror changes the heading on the compass display.

Switches of the Inside Rearview Mirror with the Automatic Day-Night Feature without Compass with OnStar®
The inside rearview mirror has 4 switches that perform the following functions:

• The on/off switch for automatic day-night feature of the inside rearview mirror is located at the left side of the mirror. The on/off switch is used to enable or disable the automatic day-night feature of the mirror. With the ignition in the ON position, depress the on/off switch to enable the automatic day-night feature of the mirror. A green indicator will illuminate on the mirror when the automatic day-night feature is enabled. To disable the automatic day-night feature of the mirror, depress the on/off switch.

• The three switches on the right side of the mirror are for OnStar® operation. For more information, refer to OnStar Description and Operation in Cellular Communication.

Switches of the Inside Rearview Mirror with the Automatic Day-Night Feature with Compass and OnStar®
The inside rearview mirror has 4 switches that perform the following functions:

• The on/off switch located at the left side of the mirror performs the following functions:

- To enable or disable the automatic day-night feature of the mirror. With the ignition in the ON position, depress and hold the on/off switch for 4 seconds to enable the automatic day-night feature of the mirror. A green indicator will illuminate on the mirror when the automatic day-night feature is enabled. To disable the automatic day-night feature of the mirror, depress and hold the on/off switch for 4 seconds.

- To turn the compass on and off. With the ignition in the ON position, depress the on/off switch to turn the compass on. Depress the on/off switch again to turn the compass off. The on/off switch is also used to place the compass into a calibration or zone mode. For more information, refer to Compass Calibration and Magnetic Variance .

• The 3 switches on the right side of the mirror are for OnStar® operation. For more information, refer to OnStar Description and Operation in Cellular

[awehlage]

Just a little update. I completely disconnected all modules relating to OnStar and removed from vehicle. No ill effects as I believe from memory power for rearview mirror and OnStar are on two different circuits.

[rorafan]

Jan 23, 2015 18:29:28 GMT -6 awehlage said:

No ill effects as I believe from memory power for rearview mirror and OnStar are on two different circuits.

I thought the same thing. The wiring diagram originally from Marc would seem to back this up. Back when I had my Envoy ('02 w/ analog Onstar) I disconnected everything OnStar and it had no impact other than to either turn the OnStar LED to red or shut it off entirely...I don't remember. Dimming was not impacted.

The dimming and compass part should really only need 3 wires to work - 2 for power and 1 for reverse sense, which I've always considered optional when I've added dimming mirrors to cars that didn't have them originally. What happened with jummama's car is just strange.