Help, Please. Po847 Error Code Limp Mode.

[maxzugkraft]

Hi guys,

Just had new wheels on and this happens!

This morning I had to limp home with 2,4 and 6 gears only.

Checked the Cobb which said error code trans PO847.

Disappointed.

Anyone with any experience? Do I need a trans rebuild now?

Thanks.

[turboadam]

Try checking at GTR life forum, the US guys will have seen that code.

[pree]

Hey Max,

I had this code twice, clutch pressure sensor B. located in the clutch mechatronic. It could also be piston seals in the clutch assy. Unfortunately the gearbox would have to come out. I used a second hand sensor first but that did not last long. Now I got the new WillAll sensors and seals that seem to work great. I fitted the sensors myself without a hoist. Not an easy task though.....

Pree

[rehab2010]

Simple fix - sensor shit itself, probably, only issue is that tranny needs to be dropped to access it. Hope it get's fixed quickly. Shouldn't cost too much though.

[rehab2010]

Pree, you got some pics of the replacement process?

Hey Max,

I had this code twice, clutch pressure sensor B. located in the clutch mechatronic. It could also be piston seals in the clutch assy. Unfortunately the gearbox would have to come out. I used a second hand sensor first but that did not last long. Now I got the new WillAll sensors and seals that seem to work great. I fitted the sensors myself without a hoist. Not an easy task though.....

Pree

[pree]

Yeah sure do, will attach some when I get a chance...

[maxzugkraft]

I hope it won't be too complicated or too costly. How long did it take you Pree?

Edited August 4, 2013 by maxzugkraft

[Speedah]

Simple fix - sensor shit itself, probably, only issue is that tranny needs to be dropped to access it. Hope it get's fixed quickly. Shouldn't cost too much though.

It is only a simple fix if the pressure sensors have been previously remotely mounted....if not then it is transmission out and split it to gain access to the pressure sensors.

[pree]

Hey Max, it took me one Saturday to jack, remove trans, split the box, install sensors and tsb clips. I waited till Sunday to connect the wiring as I wanted/needed high temperature heat shrink to insulate the wiring. Rejoined box feeding the remote sensors through the little gap. So now all three sensors sit in the pan. Thanks WillAll. Refitted everything by Sunday afternoon. Mind you this was done on jack stands. I needed a transmission jack which I hired. Not long but I enjoyed working on the car. I'm trying to add pictures from my iPhone, don't know how to do it yet. I need more time to investigate.

Cheers...

Edited August 5, 2013 by pree

[pree]

Sorry for the Hi-Res, only had time to add it quickly

Edited August 5, 2013 by pree

[maxzugkraft]

Thanks for the write-up Pree. That's bloody awesome - you could do that!

I don't have the hands-on know-how.

I'll be trucking my car to Martin at Willall.

Will let you know how it goes! Might convert to E85 too, while I'm there.

[pree]

Thanks Max and good luck man, Martin is good he helped me with my car..... Just pm if you need any help

Cheers

[JDM_R32_R35]

Could be what I had this year a broken seal.

The sensors are on the rear side of this assembly.

URL=http://imageshack.us/photo/my-images/221/sn3p0960a.jpg/][/url]

And another one on the valve body:

See right side

Edited August 7, 2013 by JDM_R32_R35

[maxzugkraft]

Yeah, getting Martin to checkout my tranny and clutch while it's opened up, after replacing the sensors, seals and wear-&-tear parts.

It actually had 2 codes: P0847 and P2715.

Doing injectors and pumps too while my baby is there. Will see what E85 power tastes like!

[maxzugkraft]

Just got my car back from Martin. He replaced the 3 sensors, gear stops, fasteners and clips. He also had to fabricate a new selector shaft. E85 tune is in (with ID1000 & DW65c) and the car drives like a frikkin beast out of hell!!! Love the meaty midrange pull - so smooth and aggressive. Haven't really had a chance to go WOT to the redline yet on normal roads. Need a strip or the track. Gear changes are now very responsive and smoother change. Martin also had to swap my 3rd gear synchro with the Reverse gear one, as the 3rd synchro was quite worn. Will post more on E85 power when I get more seat time. Dyno showed a massive gain on my previous 98ron renew tune. Plus an amazing 1072Nm of torque at 4650rpm! Overall - very worthwhile mod. Now I gotta re-calibrate my senses to all that power.

[niZmO_Man]

1,000Nm+ torque hahaha, you don't have a diesel engine mate. You shouldn't really take the torque figure seriously on chassis dyno.

[maxzugkraft]

Hmmm. Why can't you take it seriously? I'm not sure.

What about the power figure then?

[niZmO_Man]

Torque figures gets skewed due to the gearing (diff, trans, etc). That's why auto cars that are roller/chassis dyno'ed have high torque figures. The most accurate way to measure the torque is the stick the engine on an engine dyno .

Power figure is fine. But I like to worry about the area under the curve than the peak value. Like you said, the way it drives is the most important factor in any mod (unless you're going for dyno numbers only). You can see that jump around 80 km/h mark = good good .

But it's pretty cool to say that you car puts down over a thousand Netwon meters of torque hahahahaha.

[maxzugkraft]

Aahhh, I see.

For a moment I thought I was getting close to Bugatti Veyron magic!!!