PCM Location/Wire Tap.
Thread Starter
Tech Contributor
Joined: Dec 2003
Posts: 19,384
Likes: 87
From: Horncastle Lincolnshire, England
2023 C5 of the Year Finalist - Unmodified
PCM Location/Wire Tap.
I need to tap into the Vehicle speed sensor for my new nav unit. I understand its the green/white wire at PCM C2.
Does the wire route through the radio area in the console. If not, where's the PCM located?
Grateful for any help.
Does the wire route through the radio area in the console. If not, where's the PCM located?
Grateful for any help.
Safety Car
Joined: Dec 2002
Posts: 4,010
Likes: 1
From: SE Idaho
St. Jude Contributor
PCM is located directly under the battery, in the right rear of the engine compartment. Can't obtain access to the GM system right now to verify, but I doubt if the speed sensor signal wire runs anywhere near the radio. Most likely you will have to run a wire out from the nav unit to the PCM wiring harness.
Thread Starter
Tech Contributor
Joined: Dec 2003
Posts: 19,384
Likes: 87
From: Horncastle Lincolnshire, England
2023 C5 of the Year Finalist - Unmodified
If anyone is interested, I finally hooked up to PCM C2 Pin 50. It's green/white and sits on the outside edge of the outer PCM bank. Tricky to get at. Haven't done the functional check yet as the unit is still out of the dash and the wiring looks like armageddon! 
Let's hope it works!
PS. Done the test and it works great. The speed is stable and the GPS tracks like a God!
Let's hope it works!PS. Done the test and it works great. The speed is stable and the GPS tracks like a God!
Last edited by DeeGee; Oct 16, 2004 at 08:28 AM.
