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Low Power Mode 2008 H3

trad04

Member
Messages
11
Location
Virginia
Hello everyone, was looking for some help with the hummer I just purchased. I literally drove it home stopped amd tried to restart it, and it went into low power mode and started throwing a P1682 code. I tried finding a solution online, and stumbled upon the security system reset. I did that and was able to start but it was running very rough. I restarted and it seemed to be running better so I tood a drive and then Parkes. When I tried to restart it went right back into low power mode and then threw a traction control fault as well (traction control hadn't been working). I seriously a bunch of general GM info about potential issues with ignition system or ecm but wanted to ask if anyone had experienced this? Thanks in advance for the help.
 

H3TMO

Member
Messages
8
Location
63028
Check your wire harness on both sides of engine. I had a similar issue a few years ago. Turned out to be the smallest short on the wire harness from rubbing against a bolt.
 

trad04

Member
Messages
11
Location
Virginia
Check your wire harness on both sides of engine. I had a similar issue a few years ago. Turned out to be the smallest short on the wire harness from rubbing against a bolt.
Awesome thanks for the recommendation. Could you tell me what specifically you mean by "both ends" of the harness? Or do you mean just trace the whole harness?
 

H3TMO

Member
Messages
8
Location
63028
You'll find one ( facing the engine ) near the left back side near your fuel rails. The other runs on the battery side. Make sure your wire lume is in decent shape check the areas that look rough. I sure hope this helps!
 

H3TMO

Member
Messages
8
Location
63028
Code shows that it'll be on circuit two. If you can find a diagram it can be helpful for reference. Also check all your fuses.
 

alrock

El Diablo
Staff member
Messages
10,647
Location
Scottsdale
And whenever an H3 acts oddly, ALWAYs check your battery terminals and the condition of your battery. Low voltage or poor connections throws these vehicles into a tizzy.
 

trad04

Member
Messages
11
Location
Virginia
So the vehicle was taken to a dealership and they seem to think it is the fuel pump, but I'm finding it difficult to have that make sense. Haven't been able to get into to check wires over the last few days but I will try to do that today.
 

trad04

Member
Messages
11
Location
Virginia
So fuel pump was replaced and it drove fine for a day and then went to start and low power mode was back. I'm going to try to check the wiring and battery cable tomorrow. The battery is brand new, just put in 2 weeks ago.
 

trad04

Member
Messages
11
Location
Virginia
The positive terminal looked rough so I went ahead and replaced it. Was driving in the rain later that day and got a stab system traction failure and low power alerts. I found post about yaw sensors, throttle position sensors, and wheel sensors online so I guess I'll look at those tomorrow. I obviously have some kind of electrical problem somewhere.
 

650Hawk

Well-Known Member
Messages
542
Location
SoCal
The positive terminal looked rough so I went ahead and replaced it.
BOTH battery terminals should always be replaced on these trucks; first thing every owner should do. The OEM terminals are horribly notorious for not making a good connection, even if they look OK. H3's are extremely sensitive to any voltage variation, and will throw all kinds of temper tantrums.
 

Vaderdad

Probationary Member
Messages
4
Location
Tampa, FL
The positive terminal looked rough so I went ahead and replaced it. Was driving in the rain later that day and got a stab system traction failure and low power alerts. I found post about yaw sensors, throttle position sensors, and wheel sensors online so I guess I'll look at those tomorrow. I obviously have some kind of electrical problem somewhere.
Did you find out what the problem was? I am diagnosing a Stab Sys Off fault. My H3 is also in Limp mode and tires make the burn out noise when I make a sharp turn.
 
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