Installing OnStar..... - GMC Terrain Forum
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post #1 of 2 (permalink) Old 03-05-2017, 08:40 PM Thread Starter
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Installing OnStar.....

Hey all, here is a guide to add full digital OnStar to your vehicle, and even tips on upgrading. I decided to move everything from my thread about me upgrading to new topics to make them easier to view and search.... The old post will be deleted and have a reference to my new posts instead....

What you'll need is a GMLAN generation 2 based VCIM (OnStar version 7.0 and above made after 2006), an antenna module foot from another Theta platform vehicle that had OnStar as well as the interconnect cable from rear to front for voice, data, and GPS, the mirror, dome light cover with microphone, and wire harness length from at least the mirror to the rear quarter panel, a wiring harness with long enough wires on it (suggest an Impala harness due to length), a connection cable from module to antenna interconnect, and some extra wire for extensions (suggests CAT5 cable and 2 wire with shielded audio cable.

Please remember to solder and tape all of your connections. DO NOT USE WIRING CONNECTORS. You will need to either add up to 3 wires to you radio's current wire harness (if your vehicle did not come equipped with OnStar) , or, purchase a splice harness that can also allow to add an amplifier without damaging your original factory radio wiring. I suggest the harness from iSimple known as PGHGM1. This harness has every connection and wire in it. Just remember to cut off the plug that runs into an iSimple device and to bridge the wires together that it connects in between by lining up the male and female plug ends. You'll have to add 3 more wires to your radio's wire harness if you are upgrading to a Navigation or MyLink radio as well as detailed here:


If using the wiring from an Impala, there is a terminator resistor in the wiring from the small plug and it will make it look like that there is more that one data-bus plain tan wire coming from it. Remove that resistor, or, DO NOT CONNECT IT. This resistor will cut off the data bus at the OnStar module.

As for the mirror, any OnStar mirror made after 2006 without map lights will work. Try pulling the mirror and wiring from a 2007 or newer Saturn VUE. They usually came with the compass, temperature, and auto-dimming mirror, however, you may want to run a separate temperature sensor for it. Pull the wiring as well all the way to the rear quarter panel of the vehicle. You do not need to pull the entire cable, just run this cable down the inside of the driver's side front window pillar and into the dash to where the OnStar Module is to be located.

The antenna comes in 3 parts. Pull the entire interconnect double coaxial line antenna cable from another Theta platform vehicle rear to front on the passenger side. Preferably one with the double connector on the dash to receiver end and the triple connector on the antenna end. You'll also want to remove either the entire antenna or just the base. Take note that if the base has a larger antenna screw in socket, you'll have to de-solder the socket/cap from your old base and solder it into this one. You also may want to find a base/Antenna with all connections built in like AM/FM, XM, Navigation, and OnStar inside. If the base is missing something like the XM antenna, you'll have to take both your old base and new base apart and install the antenna into the new base. When installing the interconnect cable, run it down the driver's side for easier access to the VCIM. You may not be able to pull the interconnect to receiver part of the cable connecting to the VCIM from the double connector. You may have to pull it from another vehicle such as an Impala. If not able to, pull out as much as you can from a Theta and cut it, and solder splice it with the antenna cables you pulled from and cut from another vehicle to the VCIM.

A brief description of each port of the VCIM:

Now we're ready for actual installation of the wiring:

From the Module:

Red/White wire is main power positive. If you want to connect this as actual OnStar power from the OnStar fuse in the block in the center console, you may have to remove and take apart the fuse block and add a wire to the trace from the OnStar Fuse location. This trace should have a hole in it where a thin wire can be put through to it from the other side, and soldered into place. The black wire is the ground of course. You may also tie this in with the ground wire from the mirror and connect them to another ground wire connected in the vehicle.

The large black plug on the OnStar VCIM has Tan and Tan/Black GMLAN high speed wires. Connect those to the Tan and Tan/Black wires on the Body control module in the blue plug between the black and the white plug. If you have a BCM where both sets of GMLAN high speed wires in Tan and Tan/Black, these wires go into the upper ones in pins 8 and 9 on that BCM.

The small white plug on the OnStar VCIM may have either Brown and Brown/Black or Tan and Tan/Black wires. These connect to the other 2 wires similar in color on the BCM in that same blue plug.

Both sets of lines are actually connected as a module pass through, so, only the first set of lines might be required to be connected to retrieve data, however, it is always better to connect both sets and get a better data signal.

The dark green wire connects to the dark green wire in that same blue plug on the BCM.

When connecting the data wires, as suggested above, use CAT5 networking cable as an extension so that you have all the wires you need to connect all data channels, plus, connect the auto un-dimming mirror function as well if the mirror is equipped with auto-dimming.

Your data and power to the VCIM should now be connected, now, onto the mirror:

A basic mirror will have a yellow accessory power wire at which I suggest connecting to the RAP relay output on the fuse block, and, of course, a black ground wire.

Only 4 wires actually connect directly from the VCIM to the mirror and those are:

Dark Green/White (pin 11 on the mirror plug) is keypad signal.

Light Green/Black (pin 12) is keypad supply voltage.

Yellow/Black (pin 14) is the Green LED signal.

Brown/White (pin 15) is the red LED signal.

These wires all connect to the corresponding wires on the large black plug of the VCIM.

Microphone wiring should also be in this same harness:

Grey and a Bare wire usually wrapped in a shielded sheath and connects to the small white plug of the VCIM.

If you have a mirror with integrated compass and auto dimming:

Light Green (pin 9) is reverse lamp supply voltage. This auto undims your mirror when going into reverse. It connects to the Light Green wire of the pink plug between the brown and the grey plug on the BCM.

Light Green/Black (pin 6) is Ambient Temperature Sensor Signal positive. Make sure you identify this wire separately from the similar color wire for OnStar operation.

Grey (pin 7) is Ambient Temperature Sensor low reference.

Now, onto the audio wiring:

If connecting to a standard radio, you need to connect just 3 wires from the small plug of the VCIM to plug 2 of the radio:

Orange/Black is the OnStar left audio signal wire that connects to the rear speaker out radio plug in pin 7.

Light Blue is the OnStar left audio low reference wire that connects to the same plug on the radio at pin 15.

The Bare drain wire connects to the same radio plug at pin 11.

At this point, plug in everything and test your OnStar system by either hitting the phone button on the mirror, or, the Blue OnStar button once. The flashing light should be green if everything is connected properly and you should hear the automated prompts.

Now, for radios with MyLink/Navigation/Voice command capabilities, they use a grey plug that plugs into the black port of the OnStar Module to use OnStar's Microphone with the following 3 wires:

Pink is the Voice Recognition Audio Signal wire that connects to the Front speaker out (plug 1) radio plug in pin 4.

Pink/Black is the Voice Recognition low reference wire that connects to the same radio plug at pin 5. In some cases, this wire may also be grey and black.

The Bare drain wire also connects to the same radio plug at pin 11.

Here is a description of each and every radio pin:

Now, there is full description at how to connect the OnStar module. When mounting it, the bracket from any Theta platform vehicle works perfectly.


For activation, depending on route you take, if you want to do a self-activation, you will need the following:

A GM MDI clone for around $130 to $200 online (hint: do not look to eBay, look to other shops online), you can program it and activate it yourself using a 2 day $55 GM SPS subscription from here:

Self-activation without a dealer involves using an MDI and a 2 day SPS subscription, however, this type of activation does not change the VIN on the cellular telephone account or associate it with your vehicle, so, you'll have to advise OnStar on the actual VIN of your vehicle and other info. When you run the activation from the SPS program, it will tell you that automatic activation was not successful, and you have to call OnStar to finish. When you close that popup, you'll see a screen advising you to wait 24 hours for activation to complete... Actually wait 48 hours, then push the blue OnStar button twice. Tell the system that you have never had OnStar in that vehicle and you'll be taken to new activations.. and you'll get 3 months free. You'll have to advise them that the module is in a different vehicle than what is being reported by the system, and, they can somewhat correct it on their end.

Dealing with VIN Mismatch:

VIN Mismatch happens when you try to activate with a representative that does not know what they are doing....

If your OnStar system has a red LED after activation, it's actually indicating a trouble code or codes in the OnStar module itself. To find out what is exactly causing the issue, and, to clear the trouble codes, you have to either have a Tech2 scan tool, or, an MDI and Tech2Win. You can order Tech2Win permanently activated from here:

There is a program to correct the VIN associated with a newer OnStar Module with Bluetooth and have it matched to your vehicle. This matched VIN, but, new STID can appear as a brand new module to OnStar/GM and as a replacement, however, if you want it to appear as a New activation as well, perform the SPS steps as well once you have the module returned to you and installed. The program costs around $125 and here's the link:

Another thing the above program can do is clear your old module (even if it was an FMV) from your OnStar account and VIN, which, it appears OnStar reps cannot seem to at all.

After further research, found that the program or system used to match an OnStar module STID to a VIN is actually TIS2Web. Something that GM dealer shops are supposed to have access to, but, don't use it that often (or, may not know how).

Activation issues:

The most common and plaguing activation issue is Call-Drop during the process. This is NOT due to a VIN mismatch as it is more due to signal quality before the system is activated fully, especially if the module you installed has an MEID or ESN (Sprint Network) as opposed to an IMEI (AT&T Network). Before activation, these units only get a signal of 2 bars for voice and light data communication, plus, the early modules are only 3G capable at the most.

It's the same thing as activating a prepaid phone manually such as Boost Mobile (Sprint) and it may take several pushes of that OnStar button to complete activation. Once activated, your module will work as normal.

Activation through a dealer is similar, except that it costs $134, however, they will key your OnStar Account and module STID to your VIN in the process, and, you may not have to wait 48 hours and will not have to deal with call drops during activation.

I will be adding pictures of the wiring to this same post once I have completed it myself. Still working on getting the voice command connection from OnStar to the radio.

I hope this helps some.

Thank you,
Starflare5 is offline  
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post #2 of 2 (permalink) Old 03-05-2017, 08:41 PM Thread Starter
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Re: Installing OnStar.....

OnStar Issues that can occur:

The most infamous of all issues after activation is battery drain. This issue is technically caused by the backup battery in most modules in that, the module will switch to using the backup battery while the vehicle is off until the backup battery is drained, however, this issue also wakes the entire data bus and activates devices in background mode such as a radio and/or amplifier if equipped. The only modules affected by this issue appears to be those made by Continental and Motorola. This issue does not affect LG modules.

Here is the technical bulletin regarding this issue:


Bulletin No.: 09-06-03-003B

Date: June 15, 2009

Subject: Vehicle Will Not Start, Dead Battery (Inspect for Parasitic Draw)
2008 Chevrolet Colorado, TrailBlazer Models
2008 GMC Canyon, Envoy Models
2008 HUMMER H3 without Navigation Radio (RPO UM
2008 Saab 9-7X
All Equipped with OnStar(R) (RPO UE1)

This bulletin is being revised to correct the specification in Step 10.2. Please discard Corporate Bulletin Number 09-06-03-003A (Section 06 - Engine/Propulsion System).


Some customers may comment that the vehicle will not start due to a dead battery.


This concern may be due to a parasitic draw from one of the electronic modules, which does not enter low power mode (does not go to "sleep"). The draw remains present after the ignition key is cycled to the OFF position. The next ignition cycle may cause the module to reset.

1. Verify the customer's concern.

Depending on the magnitude of the parasitic draw, a no start condition could occur on a vehicle with a fully charged battery after it has been parked for a period of less than 48 hours.

2. Inspect the battery. Refer to Battery Inspection/Test in SI. If the battery passes the test, proceed to step 3.

Always check for aftermarket accessories (non-OEM) as the first step in diagnosing electrical conditions. If the vehicle is so equipped, disconnect the system to verify that these add-on accessories are not the cause of the condition.

3. Inspect for aftermarket accessories. Refer to Checking Aftermarket Accessories in SI.
4. Colorado, TrailBlazer, Canyon and Envoy models equipped with AM/FM stereo and CD/MP3 player (RPO US only - Refer to GM VIS to see if Customer Satisfaction bulletin 08134 applies. If the vehicle is involved and the bulletin has not been performed, reprogram the radio following the steps in Customer Satisfaction bulletin 08134.
5. Check for current/history DTCs. Document and clear all DTCs.

When troubleshooting for parasitic draws, be sure to connect the digital multimeter in parallel with the Parasitic Draw Test Switch (J 3875 and turn it ON before beginning the test. Failure to do so could cause any module potentially causing a draw to reset.

6. Install a Parasitic Draw Test Switch (J 3875 and a digital multimeter. Refer to Battery Electrical Drain/Parasitic Load Test in SI.

The test switch on the J 38758 is marked ON and OFF. When the test switch is in the ON position, the circuit is closed and electrical current will pass through the switch. When the test switch is in the OFF position, the circuit is open and electrical current will not pass through the switch.

7. Verify that the Test Switch (J 3875 is OFF and start the vehicle. Allow the engine to idle while in Park for no more than 2 minutes. Turn on all features and accessories. Cycle through all radio bands, including XM if equipped, and any other available radio features. Attempt, but do not complete, an OnStar(R) call. Cycle the HVAC modes, power seats and interior lights. Except for high load features (headlamps, heated seats and dome lights), leave the accessories on.
8. Quickly and in sequence, turn the ignition off, remove the key from the ignition, open the driver's door, exit the vehicle and close the door. Complete these steps in less than 15 seconds. DO NOT reopen the front doors or initiate any Class 2 communication (i.e. RKE lock/unlock) as this could reset any module potentially causing a draw.
9. Wait at least 30 seconds after completing Step 8. Turn the Test Switch (J 3875 ON. With a normal vehicle electrical draw less than or equal to 15 mA, the BCM should be in "sleep" mode after 15-20 minutes.
10. Repeat steps 7 through 9. If, after 20 minutes, there is a parasitic draw detected, perform one of the following:

Fully charge the battery prior to any programming event.

1. For a 350 mA - 400 mA draw with Current/History DTC U1301 present.

- Remove the OnStar(R) Vehicle Communications Interface Module (VCIM) fuse.
- If the parasitic draw drops to 15 mA or less, reprogram the VCIM. Refer to Communication Interface Module Programming and Setup in SI.

2. For a 350 mA - 400 mA draw with NO Current/History DTC U1301 present.

- Remove the OnStar(R) Vehicle Communications Interface Module (VCIM) fuse.
- If the parasitic draw drops to 15 mA or less, contact GM OnStar Technical Assistance for help in obtaining a replacement part. For VCIM removal and installation procedures, refer to Communication Interface Module Replacement in SI. These modules are on a parts restriction program and CANNOT be ordered directly from the ESC. Dealers are calling the ESC for a replacement part and are being denied the part without technical assistance intervention and this occurring as a result of the parts restriction.

3. For a 200 mA - 1400 mA draw on vehicles equipped with XM radio (RPO U2K).

- Remove the Radio fuse.
- If the parasitic draw drops to 15 mA or less, repeat the test with the fuse re-installed and the XM Module disconnected.
- If the draw follows the XM Module and the vehicle was built prior to February 4, 2008, replace the XM Module with GM P/N 15269740 through a GM authorized Electronic Service Center only. Refer to Bulletin GMP09-043 Updated Warranty & Goodwill Exchange for Electronic Products. For XM Module removal and installation procedures, refer to Digital Radio Receiver Replacement in SI.

11. For Colorado, Canyon and H3 models only - If the customer's habit is to turn the ignition key on and off very quickly, the Regulated Voltage Control Module may stay "awake" waiting for an ECM message to shut it down.

- To verify this, turn the ignition from OFF to ON to OFF in less than 5 seconds. An oscilloscope will show a 100 mA - 400 mA fluctuating parasitic draw. The digital multimeter in auto range mode may show a 100 mA - 230 mA consistent draw.
- If the parasitic draw can be identified through this test, reprogram the ECM.

12. Verify that the vehicle is repaired.

If you must use or have one of the VCIMs affected, to correct it at least temporarily until you can replace the module, the following might be required:

1. With vehicle off, open driver's side door to make sure that RAP remains off.

2. On passenger side, access the fuse panel and pull the OnStar fuse out for at least 15 seconds, then reinsert.

3. Close doors and start vehicle, then, turn key to "Off." You should notice that the OnStar buttons and light should shut off, however, other RAP devices, such as the radio will remain on until the time limit or a door is opened.

There is an exception to this: In some cases, the OnStar system will remain on in background mode until the entire data bus goes offline. If you have an amplifier, you'll notice a low hiss from the speakers. In some radios, you might see the wire filaments across the display dimly lit. To test and make sure it shuts off and stays off, close all doors of the vehicle and lock yourself in to monitor. Make sure your headlights are off as well. Look to your radio display or listen for the low hiss. After about 30 seconds to a minute, you may hear it/see it shut off once, then back on when switching security modes and/or dimming cabin lighting to off, then once again. Wait for roughly 2 minutes. If you hear or see the system power back on again, or, not power off at all, repeat the above steps.

You should only have to do this routine once if you have experienced that battery drain issue, then, your OnStar should function as normal, however if your battery fails another time or is removed, you may have to repeat the above steps, but, observe OnStar operation first.

I hope this helps some.

Thank you,

Starflare5 is offline  

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