The C5 Grounds

The C5 is knowed for its Ground problems. This is mainly due to the connection to the frame. Early C5 have a ‘stud’ at the frame. There is also what is called ‘Splice Pack’. The Splice Pack inner connections can become dirty with some green stuff. The best thing to do is to remove the ground to the frame and open the splice pack. Then you clean with a small metal brush and electric cleaner.  GM engeeners recommend to remove the ‘Stud’ and replace with a screw in the frame. It is also recommended to remove the Splice-Pack and to attach the wire together. Well, I will not do any of these recommendations unless I have a big grounding problem. I do not want to bastardize the car.

Here is a picture of the C5 grounds.



(1)    G201
(2)    G103
(3)    G101
(4)    G102
(5)    G104
(6)    G202
(7)    G302
(8)    G402
(9)    G401
(10)    G301
(11)    G107
(12)    G105
(13)    G106


(1) G201 I do not have a picture of (6) G202, but this is at the same location on the passenger side.



G201 Closer view. You can also see the Splice Pack.



(2) G103 I have not a picture of this one yet. More to come....

(3) G101


(4) G102


(5) G104 To access this one, you need to push the plastic panel around the battery



(6) G202   Same place than (1) G201, but on the passenger side.

(7) G302  I have not worked in that area so I do not have a picture.

(8) G402


(9) G401


(10) G301 I do not have a picture since I have not worked in that area yet.
(11) G107. I do not have a picture. I should I have took one when I change the oil pressure sensor....

(12) G105  This is on the engine block, driver side. The picture was taken from under the car.


(13)  G106  Engine Block closed to the Starter. Picture taken from under the car.


Here is a 'Splice-Pack'. You can find them every where in the car. They split one main ground wire into several other ground to ground different components. To clean these splice-packs, the bottom grey part needs to be removed. Then the pin inside needs to be cleaned.