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Vehicle Requirements

Supported Vehicles

Note that this table may not be complete. Please ask in Discord if anything is unclear, and we will update it.

Make	Model	Trim	2016	2017	2018	2019	2020	2021	2022	2023	2024	2025
Buick	Envision							N/A†	N/A†	N/A†	N/A†	N/A†
Buick	Regal	Essence		ASCM	ASCM	ASCM
Buick	Lacrosse	w/ ACC		ASCM	ASCM	ASCM
Cadillac	CT4							N/A†	N/A†	N/A†	N/A†	N/A†
Cadillac	CT5							N/A†	N/A†	N/A†	N/A†	N/A†
Cadillac	CT6	w/ LKAS		GM**	GM**
Cadillac	Escalade	w/ ACC		ASCM	ASCM	ASCM	ASCM	N/A†	N/A†	N/A†	N/A†	N/A†
Cadillac	XT4	Driver Assist Package								SDGM
Cadillac	XT5	w/ LKAS			GM**
Chevrolet	Blazer	w/ ACC
Chevrolet	Blazer EV										N/A†	N/A†
Chevrolet	Bolt	w/ SuperCruise
Chevrolet	Bolt	w/ ACC, w/o SuperCruise							GM	GM
Chevrolet	Bolt	w/ LKAS		GM**	GM**	GM**	GM**	GM**	GM**	GM**
Chevrolet	Corvette							N/A†	N/A†	N/A†	N/A†	N/A†
Chevrolet	Equinox	w/ ACC				GM	GM	GM	GM
Chevrolet	Equinox	w/ LKAS				GM**	GM**	GM**	GM**
Chevrolet	Malibu	w/ ACC		GM	GM	GM	GM	GM	GM	GM
Chevrolet	Malibu	w/ LKAS	GM**	GM**	GM**	GM**	GM**	GM**	GM**	GM**
Chevrolet	Silverado	1500 w/ ACC					GM	GM	N/A†	N/A†	N/A†	N/A†
Chevrolet	Silverado	2500					N/A‡	N/A‡	N/A†	N/A†	N/A†	N/A†
Chevrolet	Suburban	w/ ACC	GM**	GM**	GM**	GM**	GM**	N/A†	N/A†	N/A†	N/A†	N/A†
Chevrolet	Suburban	w/ LKAS	GM**	GM**	GM**	GM**	GM**	N/A†	N/A†	N/A†	N/A†	N/A†
Chevrolet	Tahoe							N/A†	N/A†	N/A†	N/A†	N/A†
Chevrolet	Trailblazer	w/ ACC						GM	GM
Chevrolet	Trailblazer	w/ LKAS						GM**	GM**
Chevrolet	Traverse	RS/Premier/High Country Trim							SDGM	SDGM
Chevrolet	Volt	w/ ACC		ASCM	ASCM	SDGM
Chevrolet	Volt	w/ LKAS	OBD**	OBD**	OBD**
Holden	Astra	w/ ACC		ASCM	ASCM	ASCM
GMC	Acadia	w/ ACC			GM	GM
GMC	Sierra	1500 w/ ACC					GM	GM
GMC	Yukon	w/ LKAS and ACC				GM	GM	N/A†	N/A†	N/A†	N/A†	N/A†

• **: This vehicle is not supported on stock openpilot and requires a fork such as OPGM.
• †: This vehicle is on GM's new Global B platform which has encrypted messaging. Currently there is no way around this.
• ‡: This vehicle does not have electric power steering so openpilot cannot steer the car.

Harnesses

• ASCM: This requires the OBD harness (sold by Comma) as well as a third-party harness known as the L&P harness. It can be purchased below. This hardware setup is deprecated and will be replaced at some point with a new all-in-one ASCM harness.
• OBD: This requires the OBD harness (sold by Comma). No L&P harness required. These cars may also work with the standard GM harness.

Unofficial Vehicles

Any GM vehicle 2016+, but before Global B (Encrypted Can Bus)

Need to have front camera and lane keeping. These will only control steering, not gas/brake. They will only work with custom forks, not with stock openpilot.

Volt '16, '17, and '18 without Adaptive Cruise Control

On Volt LT and Premier (No Radar and ACC), the car's firmware may be modified to enable full longitudinal control. Note that DIY firmware mods come at the risk of bricking your car.

Firmware modifications required for 2017 LT Volt Openpilot

There are also a few hardware modification necessary or optional depending on your car.

• Radar: Optional if you want to use Vision-Only ACC from OP
• Premier Steering Wheel Replacement: Required for LT, not for Premier with LKAS
• LKAS Camera Bypass Plug: Required for Premier with LKAS, not for LT

Hardware modifications required for 2017 LT Volt Openpilot

Cars with an ASCM and a SDGM

These cars are usually from 2019 to when the platform switched to Global B and have a front radar. A SDGM Harness is needed to connect to the comma and is located behind the OBD port.

Bolt

See the openpilot Bolt wiki.

Capabilities

Steering is unavailable under 6 MPH(10 KPH).

Model year differences

On Volt '17, initial engage with openpilot must be at a speed above 18 mph. Sometimes cruise faults at speeds below 18 mph. Auto-resume is supported, which means openpilot will resume following a stopped lead car when the lead car pulls away.

On Volt '18, initial engage starts at 1 mph. Auto-resume is not supported, so you need to either press RES button on control pad or the gas pedal to resume. Auto-resume using a comma pedal is currently WIP.

On Volt '19, control over steering may be accomplished with the SDGM Harness (instead of the OBD-II and ASCM harness combo listed below).

General experience

No steering under 6 MPH is barely noticeable unless you do a lot of gridlock traffic, since it is slow and does not take long to reach. Some curves are too tight to steer unless vision braking is enabled (see Twilsonco's fork). Highway to highway merges are generally fine. Lane changing is fine. Once on highway it's smooth sailing, interventions generally come down to other people doing the wrong thing, or if you're in the right lane and you need to slow for someone to merge.

Hardware

1. Comma 3x with OBD-II car harness (The one with USB-C connector)

ASCM Bypass (For Volt Premier with Stock LKAS and ACC)

In Volt with stock LKAS and ACC, radar and camera data will be sent to ASCM to process. ASCM needs to be bypassed to allow normal operation of OP.

2. ASCM wiring harness (DO NOT Buy if you have an LT or Premier WITHOUT ACC Radar)
   

Other ASCM Bypass Harness Methods

• Bypass ASCM and power the radar, choose one of:
  1. GM giraffe - $300-$500
     
  2. ASCM connector Amazon / Amazon alt - $7-10 + Cam molex connector digikey - $10
  3. 0.1" header homebrew harness

DIY ASCM Harness Examples

ASCM 14-pin stub

Camera stub

Connect switched +12V (e.g. ignition on, rearview mirror connector or driver fusebox) to pin 9 (radar power) of cam connector. This will turn on the front radar when the car is powered on.

Original instructions from Zoneos

Homemade OBD-II to OBD-C Harness

Map OBD-II to OBD-C female (at comma device) schematic

	OBD-II		OBD-C
4	GND	GND
6	CAN1H	A2	CAN0H
14	CAN1L	A3	CAN0L
3	CAN2H	A11	CAN1H
11	CAN2L	A10	CAN1L
12	CAN3H	B2	CAN2H
13	CAN3L	B3	CAN2L
16	12V	VBUS
		B8	SBU2 1kΩ to GND

Troubleshooting

CAN Error, OBD-C Connector Orientation

ODB-C cable orientation matters. If you receive a CAN Error, flip the OBD-C connector orientation 180º either at the male-to-male adapter or at the OBD-II car port.

Cruise Fault Warning on Volt (Brake Pedal Positioning)

An issue where ACC brake-pressed is not the same as openpilot brake-pressed. This causes a cruise fault or controls mismatched warning when engaging, tapping the brakes, or hitting bumps.

The pedal failure is addressed by service bulletin for 2016-2017 Volt Brake Pedal Push Rod Retainer (part 39081933), TSB 16-NA-147. If using the top of your foot to pull up on the brake pedal resolves the fault, this is likely the cause.

GM dealerships may fix this fault for free - just make sure to remove the OBD-II splitter and put the ASCM toggle switch in dealer mode before taking the Volt in for service.

This condition is often mis-diagnosed by service centers - their first diagnostic step is usually to re-flash the front camera and/or radar sensor. Politely referencing TSB 16-NA-147 should help guide the service department on the right path.

A loose brake pedal affected by this issue could theoretically be a huge issue. Imagine driving around a curve, and openpilot disengages randomly from this issue! Don't try to fix this issue in software, fix the hardware!!!

Forks that Play Nice with GM Vehicles

• OPGM (supports 3 and 3x)
• Twilsonco Volt GM Fork (supports 3, some branches supports 3x)
• FrogPilot (supports 3 and 3x)

Helpful Videos

• 2017 Volt Install
• 2018 Volt Install
• WatchJRGo Install and Demo Video

Terms

OpenPilot General Terms

See General-Terms.

GM Specific Terms

Term	Abbreviation	Definition
Active Safety Control Module	ASCM	Car computer/module that does sensor fusion from Radar and Camera to create ACC and LKA messages to PCM (powertrain control module). Typically located in the trunk.
Calibration	n/a	Packaged adjustments to running parameters of firmware running on GM vehicles. Updates available from SPS within TIS2Web
Developmental Programming System	DPS	Software application that allows direct programming of vehicle modules without an online connection. This allows the possibility of custom programming not otherwise supported by GM.
Diagnosis Trouble Code	DTC	DTC, General Motors OBD-II Trouble Codes
Firmware	FW	Base operating system for various devices throughout the vehicle. Updates available from SPS within TIS2Web
Global Diagnostic System 2	GDS2	GM system for advanced diagnostics and firmware flashing
GM Local Area Network	GMLAN	Single wire propriety interface present on the CAN connector in GM vehicles.
Multiple Diagnostic Interface	MDI	GM service device connecting the vehicle to a computer. Lower price generics exist such as vxdiag.
Serial Data Gateway Module	SDGM	Functions as a gateway to isolate the secure networks on the vehicle from unsecured networks. Isolating primary networks helps ensure advanced driver assistance systems and active safety features, such as enhanced collision avoidance, can all operate in conjunction with each other.
Service Programming System	SPS	Firmware and calibrations within the TIS2Web application. Updates can be seen for vehicles by VIN without cost here.
Tech2 for Windows	Tech2Win	Emulated legacy diagnostic interfaces for Windows. Runs in an emulated terminal.
Techline Information System	TIS2Web	ACDelco site providing diagnostics and firmware for cars on a subscription basis. Interacts with vehicle via GM MDI. Java webstart application.
Vehicle Intelligence Platform	VIP	VIP, which has also been referred to as Global B, is a new electrical architecture that has a five-fold increase in system capacity and responsiveness over the current Global A system that can provide the required electrical bandwidth and data processing power to run advanced driver assistance systems (ADAS) and supports over-the-air updates for the vehicle’s operating system, infotainment and more. Cybersecurity is another key aspect of the Vehicle Intelligence Platform, protecting GM vehicles and their users from data hacking attempts and other cyberattacks.