possible problem with transfer case somewhere

My truck is a 2000 4X4, now I hooked up the scanner again, apparently I had the wrong info, it was a Ford I was using in the scanner (my first time using one personally), ANYWAYS I put in the info for a 2004 Chevy (http://www.automotiveforums.com/vbulletin/#) Silverado 4X4 (year is closest the scanner had) and it came back with the code B2725 Active transfer Case Mode Switch Malfunction. This makes more sense to me as my "Service 4X4" light has come on several times over the past year, I took it in to the dealer and they said it is OK. Will this code make my truck shake going up hill? Should I replace the unit or check the solder on it? Please help, thanks for your patience.

My truck is a 2000 4X4, now I hooked up the scanner again, apparently I had the wrong info, it was a Ford I was using in the scanner (my first time using one personally), ANYWAYS I put in the info for a 2004 Chevy (http://www.automotiveforums.com/vbulletin/#) Silverado 4X4 (year is closest the scanner had) and it came back with the code B2725 Active transfer Case Mode Switch Malfunction. This makes more sense to me as my "Service 4X4" light has come on several times over the past year, I took it in to the dealer and they said it is OK. Will this code make my truck shake going up hill? Should I replace the unit or check the solder on it? Please help, thanks for your patience.

you do not give the engine in this 2000 4x4 ...most likely a v8 .

shaking going up hill /under load would indicate a missfire ...

the transfercase code / service 4wd LT is most likely the switch needs soldering..

this computer/pcm should have a failure code for the poor engine performance....since none check the fuel pressure ..follow the listed proceedure here at this forum ..

you do not give the engine in this 2000 4x4 ...most likely a v8 .

shaking going up hill /under load would indicate a missfire ...

the transfercase code / service 4wd LT is most likely the switch needs soldering..

this computer/pcm should have a failure code for the poor engine performance....since none check the fuel pressure ..follow the listed proceedure here at this forum ..

The engine is a V8, thank you for your help, can you also post a link as to where I can find the procedure for how to check the fuel pressure?

The engine is a V8, thank you for your help, can you also post a link as to where I can find the procedure for how to check the fuel pressure?

this is a good proceedure to check out your fuel delievery system ..

post back the results ..


The 5.3 has a lot of fuel pressure regulator problems.
Pull vac. hose off and look for fuel in vacuumn line.
If so replace pressure regulator.
Also.
Run a full fuel pressure check.
Hard to start cold or hot?
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
Later V6 and V8 gm engines should have 55-66 fuel pressure.
Cold start should be 55/62 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel.
Do not leave home without it.
Engine running should be 55/62 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak.
If pressure does not come up with return line pinched or blocked off.
Go to fuel filter and hook a gauge direct to a line at fuel filter.
Pressure should come up to 75 or more and will hold after fuel pump is turned off.
If it leaks down there after fuel pump is turned off it is LEAKING BACK THREW PUMP CHECK VALVE OR PUMP MODULE LINES.
Post back your fuel pressure readings.
MT 2500

this is a good proceedure to check out your fuel delievery system ..

post back the results ..

Thank you, I will

you do not give the engine in this 2000 4x4 ...most likely a v8 .

shaking going up hill /under load would indicate a missfire ...

the transfercase code / service 4wd LT is most likely the switch needs soldering..

this computer/pcm should have a failure code for the poor engine performance....since none check the fuel pressure ..follow the listed proceedure here at this forum ..

Sorry to keep bothering you but this morning I was doing about 80 kilometers per hour and I hit the tow/haul button. I was on a fairly flat stretch of road and the engine went from 16k rpm to 22k rpm, I hit the button again and it went back to 16k rpm. It doesn't do this all the time, also I replaced the transfercase switch on friday, 4lo light still flashes, the rest work. Any ideas? Thank you very much for your time. I still have yet to do the fuel pressure tests, I am buying a fuel pressure tester this afternoon.

this is a good proceedure to check out your fuel delievery system ..

post back the results ..


The 5.3 has a lot of fuel pressure regulator problems.
MT 2500
My engine is a 6.0, do they have the same problem as the 5.3 in regards to the fuel pressure regulator?

My engine is a 6.0, do they have the same problem as the 5.3 in regards to the fuel pressure regulator?

the fuel presure regulator has a diaphram that can leak..this then causes fuel to enter the vacuum line.

this is common ..most however have fuel pump failures rather than a defective regulator..with a rapid leak down this is a possiblity..just disconnect the vac line to it to see if it has ,have had gas/fuel in it.

I have a 2000 5.3L and have had no fuel issues ....125,ooomi. original owner.

SO true Jcat... My fuel pump died @ 120K miles while doing 70 in the freeway.
I'm at 180K now as an fyi.