Well as a result of servive 4wd DIC... - Hummer Forums

Rusty_03 · #1 07-06-2012, 05:06 PM

I spent all night after I hot home from work splicing and repairing insulation on the mess mice made under my fuse box. Watched the sunrise while I was at it. Tomorrow I'll take a fresh look at it to make sure that I got everything, then put it all back together. Once that's done then I can do some testing/troubleshooting the 4WD service message. Hopefully tha mouse house in my fuse box was the cause of the internittant battery drain I've been having the last year or so. (Thank God that I paid attention to the electrical mechanics at work when they do repairs on the problems that I find when testing a new system when it comes on-line.

Glass guy came out today and replaced the windshield. Evidently it had been replaced before and the tech made a mess under the cover on the pass side.

MikeH

This ad is not displayed to registered members.
Register your free account today and become a member on Hummerforums!

Rusty_03 · #2 07-07-2012, 11:52 PM

Well, after 10 splices and 8 insulation repairs, the rats nest is done. But, the service msg is gone and now the AWD control module seems to be off line. The fuses aren't blown, but it won't shift modes and the indicator lights aren't responding. This thing has a CAN sstem it's gonna cost $80 to upgrade my scanner!
But, this is the first major problem we've had.
So now I get to see if the module or transfer case motor is toast, or just some more jacked up wiring.
MikeH

Rusty_03 · #3 07-09-2012, 01:09 AM

Well, battery won't hold a charge. 8 hours on the charger, 'charge complete' indicator lited on charger, but volt meter only comes up to 9 volts. It's a 7 yr unit and it's been in about 6.5, take it back tomorrow have it tested and get a new one.
MikeH

Rusty_03 · #4 07-11-2012, 05:55 AM

Ran through as much of the troubleshooting in the service manual as I could without a CAN scanner. Found out that there was no 5vdc reference to the circuit and backtracked to check the power in from the fuse box (TREC fuse). Pulled apart the fuse box again, pulled the fuse and read for continuity from the TCCM to the load side of fuse socket (nothing), good from input bus to the line side of fuse. Pulled the connector off the bottom side of the fuse panel and good from the connector to the TCCM input. read from top to bottom of fuse block (where the harness connector plugs in) good. Instaled fuse and guess what.....NO continuity. Since I pulled the INFO fuse for OnStar a long while back, I swapped the the pins for TREC and INFO, basically reassigning the fuses. AND IT WORKS!!!! No codes, the transfer case shifts like it's supposed to.
Thank god that 20 yrs of Navy training and experiance troubleshooting and reparing electronics and almost another 10 in a shipyard testing and troubleshooting new systems, cause it was actually usefull.
MikeH

Pappibri · #5 07-11-2012, 06:34 AM

Great job on the troubleshooting.. As we all know, wiring and the electrical aspects of autos can be a pain in the butt.. But you figured it out.. Good job.

H2CANEPADESIGN · #6 07-12-2012, 04:20 PM

Nice job, I would have been lost well before I got to that point.

twinmill28 · #7 07-12-2012, 09:23 PM

Thank God all you got was the "service 4wd" light and found the mice next instead of having a fire toast your truck---all too much of a reality.
Great job on the troubleshooting, sounds really in-depth. The Air Force taught me troubleshooting Avionics systems on F-16's, but I never liked all that wiring in miniature.

Rusty_03 · #8 07-17-2012, 06:40 PM

Yeah, them military systems are AFU. All the wires are white or black.......but usually labeled

MikeH

BuzzLightyear · #9 07-23-2012, 08:06 AM

I have recently been getting the Service 4WD on the DIC... I read in another post that it may be from not shiftin into 4WDHI/4WDLO or cycling through enough...I don't do any offroading with my 04' H2 so i don't need to switch it very often...the only time is in the winter when we had "Snowmageddon" here in the DC area... Could this be the issue and all I need to do is cycle it every once in awhile? 117544 miles on it as well... maybe just time to have it serviced and checked??? Any help would be greatly appreciated.

BuzzLightyear

Rusty_03 · #10 08-02-2012, 08:09 PM

Sorry, can't help you there. I tend to cycle the transfercase evry so often when I get to drive it. The only thing I have issues with is during "SnowMageddon". My driveway is steep and paved, when we more than 8" the snow won't compact all the way and gravity causes the middle to shear......and down the driveway we go. With the oem BFG AT's there is not enough tread void for mild wheel spin to clear the treads because the Traction Control kicks in and kills the wheel spin. The only time that I got it to spin fast enough to clear the treads and dig down to the road surface, I was two-footing it and T/C and ABS tripped off line. Need an 'off' switch for T/C in these things!
MikeH