Engine code after long slow descent

[DMosby]

Truck is a 2008 RAM 2500 diesel automatic 4WD with 19,500 miles. Yesterday I visited a mountain top radio repeater site to swap out some batteries. This takes me from sea level to 2400 feet on 6 miles of steep and rocky road. On the trip down I let the engine hold me back by dropping the gear down to 1 or 2 depending on the grade. So I'm pretty much just idling down the mountain. Yesterday I was about 1/2 mile from the end of the road and the check engine light on the dash came on. Nothing on the overhead.



My Edge Insight read and displayed the code as "P2:01". If that is actually P0201 then my DTC code cheat sheet interprets it as "P0201-fuel Injector 1 Circuit/open".



Any thoughts on what this indicates and if the truck is not happy with a slow 6 mile climb and then a slow 6 mile descent in low gear?



The truck had DTC at 3,500 and turbo replaced. Another DTC at 5,300 and EGR replaced. The J35 ECM flash was done at 12,000 miles. Then a DTC at 15,000 miles and O2 sensor and exhaust wrap performed.



I'm on the northern Oregon coast. Truck has been serviced by a dealer in Portland so far and not very convenient now to make the trip into Portland (not to mention the $ in diesel it takes for the trip). I could try and clear the code or ignore it and see if it clears on its own, but I'd like to see Dodge keep working on it as long as the warranty remains. The Edge Insight just monitors the OBD2 port. Other than a really nice replacement back bumper, big front bumper and winch the truck is stock.

 

[HBarlow]

I would read the codes, if any, in your odometer then compare it to the official Ram DTC list.

I have never seen codes set by long geared down descents with exhaust brake closed, even with heavy trailers pushing and can't think of any reason why a long descent should set a code. Perhaps some component failed by simple coincidence.

 

[DMosby]

If someone can tell me how to display a trouble code in the odometer I will verify using that method. After some checking with Google I did not find the method. Model year 2008 RAM 2500 6. 7 diesel.

 

[TLane]

To read the codes from the odometer, turn the key on-off-on-off-on (don't start it, leave it on, complete the sequence within 5 seconds, door shut, feet on the floor). The codes will appear in the odometer, one after the other, followed by the word "done". If there are no codes, just the "done" will appear. Be careful to distinguish the letter "b" from the number "6". Codes may contain 0-9, a, b, C, d, E, and F.

 

[DMosby]

Thank you for the information on reading code via odometer. This shows the code as "P2A01". My code list describes that as "P2a01-o2 Sensor 1/2 Circuit Performance".

Any more detailed explanation of what this means and would a slow six mile descent with engine idling and low gear be likely to cause this? I suspect that with some higher speed driving this may clear itself.

 

[HBarlow]

If you had the automatic transmission in low gear was it actually idling or varying with road speed? Was the torque converter locked?

 

[DMosby]

Exhaust brake on as I always use it. Just used the +/- button on the shift lever to drop the transmission to lower gear to slow the descent without needing to use brakes. I selected 1 or 2 as the gear depending on how steep the slope and how slow I wanted to go. Enabled tow-haul about half way down though that did not seem to make much difference in drive. Was also in four wheel drive. When I say "idling" I really mean that I was not driving fast - there were some fairly level areas where I would give it some gas, maybe jump to 3rd, so yes, engine speed would vary with vehicle speed. But for most of the drive I had foot off the gas pedal and was just letting the truck descend quite slowly - that is what I mean by "idle", little gas pedal. I have no idea if torque converter was locked - I do not know how to determine that.

 

[HBarlow]

The torque converter was locked if the engine and drivetrain were holding the truck back.

The Aisin six speed automatic in my cab and chassis definitely locks and remains locked in 2nd through 6th but I don't remember if it remains locked in first. I'm thinking it does not but not sure. I don't know about your MOPAR six speed automatic. It may have unlocked and heated the fluid if you selected 1st/low range, I can't say.

Ignore it for a couple of days if it drives normally. The ECM is very sophisticated and will sometimes set codes and warnings for minor issues then clear them itself with no input required from you.

 

[Hoefler]

Torque convertor does not lock in first gear, exhaust brake does not engage unless the torque convertor is locked.

 

[SNGLESHOT]

I had that same code on my truck under similar circumstances. Dealer replaced the O2 sensor near the DPF and added a heat shield somewhere proximal to the sensor. I think there was a recall or a TSB on that also so check and see. I was operating in mountains in Arizona and ambient temps were high to say the least. I also descended with EB on and low gears. So my problem seems to be similar to your situation too. It was covered under warranty on emission side of the truck. Never had a problem since. Mechanic at dealership stated that my truck was possibly trying to do a regen and was not moving fast enough, excessive heat caused the sensor failure?? I wouldn't know, not an engineer or a mechanic either but it sounds logical. Good luck.

 

[DMosby]

A follow up after a call from the dealer. I am told that they read two codes: P0402 in addition to the P2A01 that I read from odometer. They say carbon build up want to replace EGR gaskets according to the service rep. No idea what that will do to solve the problem or more importantly prevent future problems -- as it is warranty work I just said go ahead, parts should show up around end of week. When I actually get a repair order in my hands I can post what they really did. This just hit 20K miles and it has had turbo replaced, EGR replaced, O2 sensor and exhaust wrap.

At this point I'm pretty much convinced that I won't be able to afford the truck - or perhaps not willing to - once it is out of warranty. I asked a sales guy at the dealership to take a look at it and give me a trade in estimate. Seems that I'll have to either ride this out until no more warranty and then pay to have all the emissions stuff removed or dump it now and find an older truck or go current year in gas rather than diesel. I'm curious to know how the earlier years automatics compare to the 2008 which I like quite a bit.

 

[tp0d]

Probably dont want to hear this, but my 2010 3500 has not had one issue in 28k miles, only was in the shop once for a new flash. And that wasnt even necessary, I wanted to try to get some better mileage, which didnt help.

Sounds like you mebe got a friday build truck, or its just the early emissions issues. I`d highly recommend looking at a 10 or 11 truck. .

good luck

-j

 

[HBarlow]

A follow up after a call from the dealer. I am told that they read two codes: P0402 in addition to the P2A01 that I read from odometer. They say carbon build up want to replace EGR gaskets according to the service rep. No idea what that will do to solve the problem or more importantly prevent future problems -- as it is warranty work I just said go ahead, parts should show up around end of week. When I actually get a repair order in my hands I can post what they really did. This just hit 20K miles and it has had turbo replaced, EGR replaced, O2 sensor and exhaust wrap.

At this point I'm pretty much convinced that I won't be able to afford the truck - or perhaps not willing to - once it is out of warranty. I asked a sales guy at the dealership to take a look at it and give me a trade in estimate. Seems that I'll have to either ride this out until no more warranty and then pay to have all the emissions stuff removed or dump it now and find an older truck or go current year in gas rather than diesel. I'm curious to know how the earlier years automatics compare to the 2008 which I like quite a bit.

You may not have heard correctly what the dealer service department actually plans to replace. If the dealership plans to replace EGR gaskets to cure carbon build up your greater problem is the dealer's service department.

How do you use your truck? If it is routinely used for daily short trips you are causing the problems by not working it sufficiently to allow the emissions crap to perform as designed. The early ISB6. 7s did not do well in grocery getter service.

 

[Hoefler]

You may not have heard correctly what the dealer service department actually plans to replace. If the dealership plans to replace EGR gaskets to cure carbon build up your greater problem is the dealer's service department.



How do you use your truck? If it is routinely used for daily short trips you are causing the problems by not working it sufficiently to allow the emissions crap to perform as designed. The early ISB6. 7s did not do well in grocery getter service.

My early 08, on delivery it had an O2 sensor replaced. Then around 12k miles, had the turbo clean, then replaced. I traded it with 62k on it and never had another issue since the turbo replacement. With only 20k on an 08, I doubt it is even broke in. Like Harvey has said above, the short trips ( aka: grocery getter's ) will have the most problems. These trucks where/are designed to be worked, and worked hard. On a 3300 mile trip pulling my fifth wheel, I only seen my 08 go into re-gen once. The short trips do not let things warm up let alone get hot enough to do any good.

 

[DMosby]

I got a call from the dealer and work is complete. The EGR was removed, cleaned, reassembled, test driven. Parts required were gaskets to permit the disassembly/reassembly. Covered by warranty but nothing to make me think that this is a fix for future problems.



For those that say "not driving it hard enough" I agree. But I'm on the Oregon coast with lots of twisty and slow roads. Not may places I can go fast here and I'm seldom towing. I track mileage and engine hours on every fill up. Have a spread sheet showing my MPG and also average speed on the tank. Top average speed ever was 49. 25 on a tank. More common is in the 30s. Last two fuel stops (13 and 9 gal) show 26 MPH as the average speed for both fills. Not very fast but that had me driving through some coastal towns and also up in the coastal mountains on logging roads. That is going to be slow.



If you are going to tell me that the 2008 6. 7 engine can not handle this use without dealer visits to remove soot please suggest a model year that will work. Having a nice automatic transmission is desirable. I really like the one in the 2008 RAM 2500.