tpocock

Since Corvettes seem to have issues with grounds, I have compiled a list of the Ground locations and the circuits attached with each ground for reference purposes. I thought others might benefit from this list.

Ground locations
From 2003 Corvette Shop Manual

engine ground strap top left frame behind left front wheel well

G101 left front frame (with SP101)
G102 right front frame (with SP100)
G103 left front of engine
G104 frame next to battery (with G108 & SP102)
G105 left lower engine block, engine ground strap & wire
G106 Battery negative pole
G107 Left rear head
G108 frame next to battery (with G104)
G201 bottom of A-pillar, left (with SP201 & SP203)
G202 bottom of A-pillar, rt, bolted at the bottom (with SP202)
G205 inside door pillar driver seat (with G301)
G301 inside door pillar passenger seat
G302 inside door pillar driver seat (with G205)
G401 left rear outer frame
G402 right rear inner frame
SP201 bottom of A-pillar, left (bolted with G201)
SP202 bottom if A-pillar, rt (bolted to G202)
SP203 bottom of A-pillar, left (taped to wire bundle, with G201 coming out of it)

G101: windshield washer fluid pump
Windshield washer fluid level switch
Brake fluid switch
Headlamp door assembly, left
G102: cooling fan, right
Cooling fan 3 relay 44
Horn assembly
Underhood lamp
Headlamp door assembly, right
Headlamp door control module
A/c compressor clutch
A/c compressor clutch diode
Secondary air injection pump
G103: Electronic brake control module (ebcm)
G104: battery negative pole
Splice pack SP102:
Marker lamp, right front
Marker lamp, left front
Park/turn signal lamp, right front
Park/turn signal lamp, left front
Turn signal lamp, right front
Turn signal lamp, left front
Splice pack SP208:
Body control module (bcm)
Instrument panel cluster (ipc)
Data link connector (dlc)
Inflatable restraint & diagnosis module
Inflatable restraint ip module disable switch
Park/neutral switch
Remote control door lock receiver
G105: fuel pump relay 35
Engine oil level switch
Heater O2 sensor, bank 1 sensor 1
Heater O2 sensor, bank 1 sensor 2
Heater O2 sensor, bank 2, sensor 1
Heater O2 sensor, bank 2, sensor 2
G106: battery negative pole
Ignition relay 42
Powertrain control modules (pcm, 4 wires)
Throttle actuator control module (tac)
Mass airflow sensor (maf)
G107: ignition control modules 1-3-5-7
Ignition control modules 2-4-6-8
G108: Electronic brake control module (ebcm)
G201: Splice pack SP201:
Data link connector (dlc)
Air temperature actuator
Instrument panel cluster (ipc)
Traction/suspension control switch
Driver door module (ddm)
Door latch, driver
Auxiliary power outlet
Windshield wiper motor
Steering column lock
Footwell courtesy lamp, left
Instrument panel cluster (ipc)
Hazard switch
Telescopic actuator switch
Splice pack SP203:
Remote CD changer
Fuse block I/P
Speaker, right door
Speaker, left door
Radio
G202: Splice pack SP202:
Passenger door module (pdm)
Door latch, passenger side
Body control module (bcm)
HVAC control module
IP compartment lamp
Footwell courtesy lamp, right
Vanity mirror lamp, left
Vanity mirror lamp, right
Inside rearview mirror
Bose relay 45
Ignition switch
Blower motor relay c60
Blower motor control processor
Hood ajar switch
Cigar lighter
A/t shift lock control solenoid
G205: seat belt switch, driver
Seat control module (scm), driver
Seat pump, driver
Seat belt switch, driver
Seat relay center, driver
G301: defogger grid
G302: Splice pack SP302:
Seat relay center, passenger
Seat pump, passenger
Rear compartment courtesy lamp, right
Rear compartment courtesy lamp, left
Rear compartment lid latch
Rear compartment lid latch, right
Rear compartment lid latch, left
Folding top lid latch
Folding top release switch
Fuel door lock actuator
Radio power antenna
G401: Splice pack SP400:
Fuel pump & sender assembly, left
Fuel level sender, right
Tail, stop, turn signal, rear left
Tail, stop, turn signal, rear right
Center high mounted stop lamp
Backup lamp, right
Backup lamp, left
License lamp, right rear
License lamp, left rear
Marker lamp, left rear
Marker lamp, right rear
G402 electronic suspension control module (esc)

385-C5

Excellant info. I was going to look this stuff up when I got home but this makes it easier. Thanks.

tpocock

You are welcome.
Actually, the shop manual does not list this info in a convenient manner.
The info is spread out over many pages of circuit diagrams.

385-C5

Yeah tell me about it. I was actually trying to find this stuff the other night. I kept going around in circles.

runamuk

thanks

JAY KOCH

Great info. Thanks for sharing.

385-C5

Could you clarify something for me. In the description on G104 it says battery negative pole. But above that where the locations are it says G106 is at the battery negative pole and G104 is on the frame next to the battery. I was looking for G106 today and couldn't locate it. I was a little confused on where to find it. Thanks

MDT

Thanks for that great compendium. I'm going to print it and place the list in the back of my Helms.

Mark

385-C5

TTT

tpocock

385-C5 -- you are correct, there seems to be an inconsistency in the 2003 repair manual. the illustrations do not agree with the schematics or the descriptions. I checked my 2003 ZO6 and what is in the car also does not agree with the illustrations.
I will run this by C4C5specialist to see if he knows about this.

jamesge

Awesome post! I had a problem with my front turn signals and DRL's; which also included flashing dash lights, fog lights coming on when turn signals were on, and no DRL's. I used your info and found the G104 ground was badly corroded. I cleaned and replaced this ground, PROBLEMS FIXED!

You the man!

385-C5

Thanks man.

Andy H

Great post! Thanks Tpocock!

Can anyonen tell me how to access the ground points located at the bottom of a pillar?

I'm having major code issues and need to check these locations.

Thanks.

tpocock

G201 is at the bottom of the left A pillar.
G202 is at the bottom of the right A pillar.
The A pillar is where the door hinges attach.
It is behind the plastic floor kick-up panel.

Andy H

Great. Thanks again.

Is the floor kick-up panel the one that runs front to back under the door? If so does it just "snap" into place or are there any fasteners?

tpocock

No, it is the plastic panel that wraps around the door jam below the door hinges. It should pop off, and the ground point should be bolted to the bottom of the verticle piece of metal that is under this plastic cover.

tpocock

Follow-up on G104 and G106.
There apparently have been corrections to the 2003 shop manual.

G106 is on the right side of the engine block above the starter.
It supplies PCM, TAC, MAF, ignition relay, and neg cable from the battery.

G104 supplies parking lamps, BCM, door lock reciever, IPC, air bag switch and module, DLC, and the engine compartment fuse box.

There are 3 wires connected to G104 which on the top of the right front frame just ahead of the battery.

dsmith4229

Thanks I am going to work on it now. Wish me luck.

yellowshark454

LOL I decided to clean up my rusted G104 the other day and snapped the earthing bolt. What a great post t was that started this thread. Thank you tpocock

73Corvette

tpocock thank you for the list... I hope I never need it!