2021 Chevrolet Tahoe PPV / SSV and Suburban Wiring Diagram
Police (9C1 PPV), special service (5W4 SSV) and government Tahoe and Suburban.
★
Help build this pageWant to be famous?Share a wire color, a photo or a tip for this truck, and your name goes on this page.
Add yoursClose▾
Which wires give constant, ignition and ground on a 2021 Chevrolet Tahoe PPV / SSV and Suburban?
On a 2021 Chevrolet Tahoe PPV / SSV and Suburban, take constant power from the Red/Violet wire at the console harness between the front seats (circuit 842), ignition from the Violet/White wire at the console harness (circuit 4939), and ground to the Black wire at the console harness (circuit 7350). Meter every wire first.
Written by API Signal, fleet GPS and camera installers for 35+ years across Georgia, South Carolina and North Carolina, installing every major telematics and camera brand. Every wire on this page lists its source.
Test every wire with a meter before you tap it
No wiring information is ever guaranteed. Colors and locations change with trim, options and build date, and the manufacturer can change them in the middle of a model year. We share this as a starting point for installers, and you are responsible for confirming every connection on the truck in front of you.
This page covers the 2021 Chevrolet Tahoe PPV and SSV (police and special service), and government Tahoes and Suburbans, the first T1 year.
The ignition and accessory colors come from GM's UI Bulletin 183 for 2021 and newer. The other police harness colors come from GM's 2026 chart, and each row says whether GM's guide for this year lists the same circuit. Our own team has not yet metered these on a 2021 vehicle, and each row says so.
OBD-II portUnder the driver dash
Best power spotGM console harness
System voltage12V
Ignition typeKeyless start (SSV)
Need More Installs?
We send fleet installation work to independent installers. One job goes to one installer. Now adding network partners in North Carolina.
Where do I get constant, ignition and ground on a 2021 Chevrolet Tahoe PPV / SSV and Suburban?
Take constant, ignition and ground from the same area. Police and special service Tahoes carry two GM police harnesses, one between the front seats and one in the cargo area.
Option 1 Police harness
Console harness (CONSOL)
GM police harness coiled between the front seats, on PPV (9C1) and SSV (5W4) Tahoes.
Constant
Red/Violet
Console harness between the front seats (circuit 842)Battery feed. GM's chart says 50A, but GM's guide text lists 100A for this circuit; check the fuse. Color from GM's 2026 guide; GM's 2021 guide lists the same circuit. Meter it.
Ignition
Violet/White
Console harness (circuit 4939)Run/crank ignition. GM's UI Bulletin 183 covers 2021 and newer. GM's recommended feed for added equipment.
Ground
Black
Console harness (circuit 7350)Ground. Color from GM's 2026 guide; GM's 2021 guide lists the same circuit. Meter it.
Accessory
Violet
Console harness (circuit 2801)Retained accessory power. GM warns it drops when a front door opens or the start button is pressed; do not use it for GPS or cameras.
Brown/Yellow (820) brake, Yellow/Black (5813) park, Green/Gray (817) speed and Blue/Brown (8917) driver door are in the same harness.
Option 2 Cargo
Cargo harness (CARGO)
Left cargo floor behind the auxiliary battery.
Constant
Red
Cargo harness (circuit 742)Battery feed; GM's chart says 100A. Color from GM's 2026 guide; GM's 2021 guide lists the same circuit. Meter it.
Ignition
Violet/White
Cargo harness (circuit 4939)Run/crank ignition, same circuit as the console harness.
Ground
Black
Cargo harness (circuit 7150)Ground. Color from GM's 2026 guide; GM's 2021 guide lists the same circuit. Meter it.
Four customer relays sit in junction block X51AX above the brake pedal.
Power wires from GM's 2026 Tahoe 9C1 spec guide wiring chart (OEM) and GM UI Bulletin 183 (2021 and newer ignition and accessory).
What are the turn signal, reverse and light wires on a 2021 Chevrolet Tahoe PPV / SSV and Suburban?
Circuit
Wire color
Location and what it does
Left turnNot foundNot yet checked
Not found
Not foundNot in GM's police harness chart; no civilian source found for this generation.
Right turnNot foundNot yet checked
Not found
Not foundNot in GM's police harness chart; no civilian source found for this generation.
Park lightNot foundNot yet checked
Not found
Not foundNot in GM's police harness chart; no civilian source found for this generation.
HeadlightNot foundNot yet checked
Not found
Not foundNot in GM's police harness chart; no civilian source found for this generation. For surveillance mode, ground White/Violet (circuit 6821) in the console harness to kill the auto lamps.
ReverseNot foundNot yet checked
Not found
Not foundNot in GM's police harness chart; no civilian source found for this generation.
Dome lightNot foundNot yet checked
Not found
Not foundNot in GM's police harness chart; no civilian source found for this generation.
Each chip shows the main insulation color with its stripe. Each row names its source.
Where are the brake, door, speed and CAN wires on a 2021 Chevrolet Tahoe PPV / SSV and Suburban?
Circuit
Wire color
Location and what it does
BrakePositive +Not yet checked
Brown/Yellow
Console and cargo harnesses (circuit 820)Brakes applied, from the center high brake light circuit. Color from GM's 2026 guide; GM's 2021 guide lists the same circuit. Meter it.
In parkPositive +Not yet checked
Yellow/Black
Police harness (circuit 5813), fuse F34DR 5APark enable from the trans-in-park relay. Color from GM's 2026 guide; GM's 2021 guide lists the same circuit. Meter it.
Vehicle speedAC signalNot yet checked
Green/Gray
Console and cargo harnesses (circuit 817)4,000 pulses per mile, from the brake module. Color from GM's 2026 guide; GM's 2021 guide lists the same circuit. Meter it.
Driver doorPolarity: meter itNot yet checked
Blue/Brown
Console and cargo harnesses (circuit 8917)Driver door ajar. Color from GM's 2026 guide; GM's 2021 guide lists the same circuit. Meter it.
Customer relaysPositive +Not yet checked
Red/Green (relay 1, 25A)
Red/Gray (relay 2, 20A)
Red/White (relay 3, 20A)
Red/Yellow (relay 4, 25A)
Junction block X51AX above the brake pedalRelay load outputs. Coil grounds: Blue/Yellow, Green/Yellow, Gray/Yellow, Violet/Yellow. Color from GM's 2026 guide; GM's 2021 guide lists the same circuit. Meter it.
Parking brakeNot foundNot yet checked
Not found
Not foundNot in the police harness chart.
CAN busDataNot yet checked
Do not tap
Not a tap pointGM bulletins PIT5989A and C (2021 to 2025): lighting modules spliced onto CAN bus 1 caused power steering and no-crank faults, and GM sends the vehicle back to the upfitter.
Sources: GM's 2026 Tahoe 9C1 spec guide wiring chart (OEM), GM UI Bulletin 183 (2021 and newer), GM's 2021, 2024 and 2025 guide text, and GM bulletins PIT5989A and C. Turn, park, headlight, reverse, dome, lock and parking brake wires were not found for this generation.
Which years share wiring with the 2021 Chevrolet Tahoe PPV / SSV and Suburban?
This page2021GM Bulletin 183 plus the 2026 chart.
Same wiring2022, 2023, 2024, 2025 and 2026One generation (T1). GM's 2021, 2024 and 2025 guides list the same police harness circuits as the 2026 color chart.
Not this page2020 and olderOlder Tahoes are different generations with their own pages.
Where are the fuse boxes and ground points on a 2021 Chevrolet Tahoe PPV / SSV and Suburban?
Fuses and relaysUpfitter powerGM puts four customer relays in junction block X51AX above the brake pedal, fused F162 (25A), F163 (20A), F166 (20A) and F167 (25A).
PoliceGM police provisionsGM's police harness is the approved place for added equipment.
Ground pointsCargo ground studsGM M10 ground studs in the cargo area. Never the battery negative post.
Our team has not yet checked the fuses on a vehicle.
Where is the OBD-II port on a 2021 Chevrolet Tahoe PPV / SSV and Suburban?
OBD II
Diagnostic portOBD-II port: under the driver dashPlug-in GPS trackers and OBD harnesses connect here. Check the port before you plan the install.
Common questions about 2021 Chevrolet Tahoe PPV / SSV and Suburban wiring
What wire is constant power on a 2021 Chevrolet Tahoe PPV / SSV and Suburban?
Red/Violet at the console harness between the front seats (circuit 842). Battery feed. Meter it before you tap it.
What wire is ignition on a 2021 Chevrolet Tahoe PPV / SSV and Suburban?
Violet/White at the console harness (circuit 4939). Run/crank ignition. Meter it before you tap it.
Where is the brake wire on a 2021 Chevrolet Tahoe PPV / SSV and Suburban?
Brown/Yellow (positive +) at the console and cargo harnesses (circuit 820). Brakes applied, from the center high brake light circuit. Meter it before you tap it.
Where is the vehicle speed signal on a 2021 Chevrolet Tahoe PPV / SSV and Suburban?
Green/Gray at the console and cargo harnesses (circuit 817). 4,000 pulses per mile, from the brake module. Meter it before you tap it.
Where is the CAN bus on a 2021 Chevrolet Tahoe PPV / SSV and Suburban?
The wire color is not published. GM bulletins PIT5989A and C (2021 to 2025): lighting modules spliced onto CAN bus 1 caused power steering and no-crank faults, and GM sends the vehicle back to the upfitter.
Which years share wiring with the 2021 Chevrolet Tahoe PPV / SSV and Suburban?
2022, 2023, 2024, 2025 and 2026. One generation (T1).
Help build this page
Had the panels off on one of these? Show the next installer what you found.
No one has sent photos for the 2021 Chevrolet Tahoe PPV / SSV and Suburban yet, so yours could be the first. Every photo, wire color and tip we use goes on this page with your name on it, and it saves the next installer time under the dash.
1. Snap it
The plugs, tap points, fuse boxes and ground points. Phone photos are fine.
2. Send it
Tap "Add yours" at the top of this page. Your tip and your photos go in the same box.
3. See your name on it
We check every tip, then post it here "Compliments of" you, by name.
Compliments of
The installers who helped build this page.
★
Founding contributor spot: openThe first installer to confirm a wire or send photos for the 2021 Chevrolet Tahoe PPV / SSV and Suburban gets their name here, and it stays here.
★
Every tip we use gets a creditThe wire you checked is marked "Checked on a truck, compliments of" you.
Want to be famous?
Your name, right on this page, for everyone who uses it to see. Add your tip and your photos in one box.
