OT-2004GMC Transmission update... codes

Update from post a day or so ago...
Got it down to a reputable guy here in town who checked it out - test drive, read codes, etc. No charge for that!
Well... that was the good news. Bad news - probably forward drive seal/drum issue. I hitnk thats the right terminology....
Codes were:
P0300 ( I think that was a misfire code that"s been popping up every now and then)
P0730
P1810
Bottom line looking at approx $2500 in work. Any thoughts on that?
Remember - I don"t work on transmissions, and the time is not there right now to even attempt it - especially one of the "automatic-voodo-boxes". Not an option.
Thanks
Tony

(quoted from post at 08:32:14 04/27/12) Update from post a day or so ago...
Got it down to a reputable guy here in town who checked it out - test drive, read codes, etc. No charge for that!
Well... that was the good news. Bad news - probably forward drive seal/drum issue. I hitnk thats the right terminology....
Codes were:
P0300 ( I think that was a misfire code that"s been popping up every now and then)
P0730
P1810
Bottom line looking at approx $2500 in work. Any thoughts on that?
Remember - I don"t work on transmissions, and the time is not there right now to even attempt it - especially one of the "automatic-voodo-boxes". Not an option.
Thanks
Tony

Click to expand...

I just replaced my 2004 1500 gmc trany. -$1590. I loaded an Oliver 77 on the trailer and was heading home when 3rd & 4th decided to go south.
No codes though, just no gears on the high end. The truck ran 42 mph in 2nd at 3500 rpm's. 145 mile ride home like that. Guy at the shop said GM
pickups are know for going out. He stocks a built up version of that trany. He said they lack an extra gear from the factory.

Tony,
First let me state I am no electrical pro on these new trucks...but...

P0300 is a misfire code. I would look at all your plug wires, coils, and miscellaneous wiring around there. If you know someone with a TechII they can detect which cylinder has a misfire.

P0730 is the PCM (Powertrain control module) is unable to detect what gear the transmission is in. I wonder if it is possible that the trans is in the wrong gear and it got smoked while you were driving it. i.e. not shifting back into 1st at a stop light.

P1810 sets when the PCM detects incorrect transmission fluid pressure.

I'm just throwing the idea out there that your transmission may indeed need a rebuild, but I would also look into the P0730 code too. Is the transmission sending that code, or do you have a short in the wiring between the trans and the PCM.

Just my thoughts from an electrical hack. I have seen some goofy things on the newer vehicles due to wiring issues. Maybe someone with more experience will chime in.

Rick

Brother just had one put in at the dealer for close to that much, dont know if the trans is the same one as yours or not, but his is an 02. I think his was 2900, but he got a better warranty than any of the local guys could offer.

Your guy is right on the money.
I spend my days at a GM dealer building transmissions.
I take it you have a 4L80E cause P0730 is not code that can set for a 4L60E.

P0730 is a gear ratio code.

P1810 is a fault with the manual position switch or a false code due to another concern in the trans.

• DTC P1810 can set from low pump pressure, a stuck pressure regulator, or unit refill from overhaul and pan removal.

• DTC P1810 can be set by a slipping forward clutch, allowing a 2.08:1 ratio, reverse, when the manual valve position is indicated as D4.

• DTC P1810 defaults to an elevated line pressure condition which may result in partial TCC apply. This may produce an idle surge that could stall the engine.


I see a lot of foward clutch packs slipping or direct clutches burnt up.

your issue is common for the forward clutch. Direct clutch issue usually shows up with NO reverse.

Most common fault of the 4L80E is the torque converter failing and causing a 150 to 300 RPM slip and DTC"s to set. Just a converter is needed for that type of failure if the unit is a low mileage trans.

I don"t repair units with more than 100K.

You need a new trans.

I'd say you were lucky to make it home. No TCC lockup in 2nd gear means lots of heat. Surprised you didn't fry it.

I assume $2500 is to fix your transmission.

Just get a rebuilt transmission put in, or install it yourself.

Not a huge job, just the driveshaft, a few bolts, and a few wires to undo. Better if you can get the truck up on a lift.

Price shop, the last I bought was for a Jeep and the dealer was 1000.00 cheaper than the local rebuilder.and I got a 3/30000 parts and labor warranty.(local was 12/12000)