PRXB exhaust brake on a 2004.5 48RE

[Motorhead]

I did get a check engine light, code P 1740. After a search, it seems common with the higher pressures in the trans due to a shift kit/upgraded valve body/ or upgraded torque converter. I cleared it and won't worry about it too much.

Does that code put either the engine or trans into LIMP mode?

 

[Superdawg]

Negative. Just the light.

 

[cerberusiam]

That codes is for TCC or OD solenoid performance, has nothing to do with pressures. Usually that means a bad harness, fluid in the connector, or a solenoid going bad. You might get it with a tight TC and some town driving when the TC locks. Could just be a random error or something developing.

 

[Superdawg]

Oh well. I thought I remembered reading something about pressures. Because of the shift kit and PRXB, the TC is locking up a lot more than it used to. When the trans shop installed the shift kit, one of the harnesses at the trans was broken and had to be replaced.
Another thing now that you mention it. When I wired up the PRXB and tapped into the trans connector wiring, there was quite a bit of fluid in the connector. I remember thinking that was somewhat interesting.

 

[cerberusiam]

If there was fluid in the connector the complete VB harness should have been replaced and the solenoids also. If that wasn't done could be the source of the code.

 

[Superdawg]

The harness that was replaced was given back to me. It matched the photos of a 48RE valvebody harness with solenoids. It was over a $100 and I trashed it last week.

 

[Superdawg]

The code showed up after running the exhaust brake for about a week. I cleared it yesterday and haven't seen it yet.

 

[cerberusiam]

The code is for TCC or OD solenoid performance. That means the ECU monitored a fault condition in that took the resistance under 5 ohms or over 100 ohms at some point. If the EB controller taps either of those circuits it could be doing the resistance wrong at times, or, you have a solenoid that is gong bad. Being new does not guarantee being good on the electronic parts anymore. It is all outsourced to cheapest manufacturer and there are many versions of the same thing floating around now. Bad out of the box is not longer the exception to the rule.

 

[Superdawg]

Its possible the original VB harness had leaked through the connector and sent oil into the female side of the connector. If the trans shop replaced the VB harness but not used contact cleaner in the female connector, there may be some residual oil in there.I will disconnect it and hit it with electrical contact cleaner.

 

[Superdawg]

After 3 weeks of the P 1740 code, the check engine light went out. Still loving the exhaust brake in the city. I can slow from 50 to 23 mph without using the service brakes. Have not had a chance to tow yet.

 

[Motorhead]

Towing is where the exhaust brake will "Shine". You'll say, "Why didn't I do this sooner?" My PRXB went on to my '07,5.9, G56 within the first year I had it. Only issue I had with it was the compressor wore out. I ended up installing a Large Viair 480c compressor and a 2.5 gallon tank.

 

[Superdawg]

Finished the first towing trip with the PRXB. Truck and trailer weigh about 18k combined. Came down from Hume Lake in the California Sequoias west on 180 which is about a 30 mile, mostly downhill grade. In L2, the truck held about 31mph with minimal service braking. Farther downhill, the grade is less steep and I put it in D with 4th locked out. The PRXB held the truck at 41 mph with minimal service braking. That was the most enjoyable downhill towing experience I have ever had. Hard to put a price on peace of mind. I like how the trans shifts firmer with the shift kit also. The P1740 code came back after I returned home after being off for over two weeks. Oh well.

 

[p-Bar]

I've never thrown a trans code . Must be Georend trans parts