From 2f72faaabc4c4ffe02f9c286bbf13cf9ff69db50 Mon Sep 17 00:00:00 2001 From: Alexander von Gluck IV Date: Thu, 20 Jan 2022 20:07:06 -0600 Subject: [PATCH] onstar: Refine Onstar sections after further analysis --- README.md | 37 +++++++++++++++++++++++++++++-------- 1 file changed, 29 insertions(+), 8 deletions(-) diff --git a/README.md b/README.md index 79f9ae2..4f69ed4 100644 --- a/README.md +++ b/README.md @@ -13,16 +13,11 @@ OnStar is a built-in 4G LTE-based data service which also lets you make phone ca Every Bolt EV comes with at least 5 years free of "EV Mobile Command". This lets you control the car, and see battery state of charge through the built-in 4G LTE modem. -#### OnStar API 8-request Lockout +### OnStar Instability -After 8 requests for diagnostic information (battery state of charge, charging status, etc), you are no longer allowed to query this information until your vehicle is physically powered on again. +OnStar in 2017-2019 Bolt EV's has a habbit of going into periods of failing to serve requests for diagnostic information. -> This was tested from the 5-year free "EV Mobile Command" package. It is possible this limitation doesn't apply to paid OnStar plans... but hasn't been tested yet. GM doesn't document any of this. - -This was discovered via [onstar2mqtt](https://github.com/michaelwoods/onstar2mqtt/issues/103). - -Onstar2mqtt will request diagnostic health once per hour, after 8 hours it begins failing with "error: Error" from Onstar. -Powering on your vehicle will allow functionality to resume. +The end result is the battery SoC stops refreshing in the myChevrolet application, and API calls (for example via [onstar2mqtt](https://github.com/michaelwoods/onstar2mqtt) stop functioning until the vehicle is physically powered on again. **Observations:** @@ -32,6 +27,32 @@ Powering on your vehicle will allow functionality to resume. * Plugging vehicle into a Level 2 charger - get_diagnostic request still failing * Getting into vehicle, powering car on - get_diagnostic requests working again +After extensive trial-and-error, there doesn't seem to be a fixed set of conditions leading to this event. There also is no fix beyond physically powering the vehicle on via the start button. + +### Disabling OnStar + +OnStar can be disabled by powering the vehicle off (important per the repair manual, it has a battery) and pulling the OnStar fuse from the fuse panel under the drivers steering wheel. +Once disabled, [a blank filler plate](https://thingiverse.com/thing:5199130) can be 3d printed to replace the physical OnStar buttons. + +Overall, the vehicle works as expected with the OnStar module disabled except for one problem. The in-vehicle microphone for bluetooth telephone calls will no longer function. +The microphone runs through the OnStar unit which seemingly amplifies or re-encodes the audio signal for the radio. + +It might be possible to "bridge" the microphone directly to the radio unit via the following pins of OnStar X2 connector: + +* 9 B24 Cellular Phone Microphone + +* 10 B24 Cellular Phone Microphone ground + +* 6 Radio / Navigation Microphone + +* 12 Radio / Navigation Microphone - +* 5 Radio / Navigation Microphone ground + +Connecting 9/10 to 6/12 might provide a functional in-vehicle bluetooth audio experience. Untested. + +### Physical Access to OnStar module + +The OnStar module (K73 Telematics Communication Interface Control) is physically located directly behind the central infotainment screen. +Access is not easy as you will need to remove the dash trim (containing the AC vents), then unscrew and remove the infotainment screen assembly. + ## Dealer TechLink * [How to fix the Bolts tires](https://techlink.mynetworkcontent.com/wp-content/uploads/2018/03/GM_TechLink_05_March_2018.pdf)