Duramax lost power

Forrest Fetherolf

Senior Member
What was the cause and what would you do?

Symptoms:

9 gallon remaining in tank, added 17 gallons at remote gas station.
DIC indicated 10% remaining fuel filter life.
25 miles later pulling steep incline, transmission would not shift down from 4th to 3rd.
Engine would not rev over 2000 rpms at full throttle.

Forrest

PS. I'll give you my answer after you give me yours.:confused:
 

ct0218

Well-known member
Yep, 2000 rpm is the max when in the limp mode, and most likely is the fuel filter. Remember to always carry several spares.
 
K

Ken Washington

Guest
I would guess fuel filter! What is limp mode?

Ken
 

Forrest Fetherolf

Senior Member
Good answers................

I suspected bad fuel and/or plugged fuel filter. I did not have an extra fuel filter.........had about every other spare part though..............
Luckily, I carry a OBD II code reader. The code reader indicated "Fuel Rail - Low Pressure." After clearing the code from memory the engine would rev and shift as normal. The same problem reoccurred later when passing a slow-mover uphill with the same 17 gallons. Cleared code and drove on. Not many auto parts stores open in the middle of "nowhere" Oregon, bought filter in Fallon, NV, installed that evening in Hawthorne, NV, continued on to Vegas the next day with full power.
My only unanswered question is.............if the fuel rail regains normal pressure will the computer allow the engine to rev and cancel the check engine light without manually clearing the code? If not, I would recommend carrying a code reader with "clear code function," might save unnecessary road side delays and a tow job.

I now have 3 spare fuel filters enroute to my current location in Boulder City, NV. ;)

Forrest
 

snuffy

Well-known member
Possibility you got some bad fuel and that is what caused the filter to clog. I always carry a spare but have never had to use it. I have a laptop with OBDII functions but I don't usually carry it with me. Sometimes I leave it in the rv.
Hope the new filter fixes you up. I have that fear of a breakdown pulling these things but so far have been lucky, knock on wood.
 

ct0218

Well-known member
There are several diagnostics that the computer runs and if certain operating conditions appear the computer automatically reduces power to prevent engine damage. Low fuel pressure is one, and in the past when that showed up for me (3 times) it was the fuel filter.
 

fishn2dmax

Well-known member
I have had a similar limp mode occur, but not due to the filter. I called on my On-star and they told me what the limp mode code was ( Torque converter sensor) My fault .... I forgot to drop my Edge Juice box out of level #3 while towing up a very steep mountain pass. On-star saved the day as I couldn't imagine being able to continue our trip to the next town in limp mode.
 

ct0218

Well-known member
Yeah, that will do it too. Most engine damaging conditions can cause the limp mode. When it is in limp mode it will only upshift a gear or two, so it will barely move itself along--let alone a heavy fifth wheel.
 

Uncle Rog

Well-known member
Forrest, where do you get a code reader, auto parts store? How did Fallon look? Did you see any Top Guns flying around? I will be going through there next week on my way to Winnemucca. I am not pulling the BH though. I am hauling the Rhino for the Chukar opener and staying at the very elegant Scott Shady Court. They allow or even encourage canine guests....................
 

Forrest Fetherolf

Senior Member
Roger,

I bought the code reader on line for about $159. I have used it several times to clear codes and turn off the check engine warning light. If a code is cleared and the condition reoccurs, the check engine light turn on and the code will reappear. What is nice with the code reader, you can clear a code stored in history that has corrected itself without driving down the road starring at the check engine light when nothing is wrong.

The roads were clear from Eugene, OR to Vegas. Observed some snow patches prior to Reno above 6000'. The Top Guns were resting on Sunday when we pulled through. We were a day ahead of the cold front coming down through WA and OR.

Forrest
 

Attachments

  • Code Reader.JPG
    Code Reader.JPG
    162 KB · Views: 26

jbeletti

Well-known member
The 3110 appears to come with a case too.

Forrest, from looking at Equus site, it looks as though each of those models can do a code reset - including the less expensive 3100. Is that how you understand it?

From the retail site listed a few threads ago, that site featured the 3100 but did not state it could do resets. They did plug another brand and model as being able to do resets.

I'd like to have a case - don't need the other language features but like to save money.

My daily driver has been a 1999 Toyota Avalon. Thing gives me a dash light weekly. Recently paid $100 to diagnose a $2 fuse. Ouch!

Getting a pretty constant engine light this week. I think I may make this investment. Be nice to have for the new truck too :)

Thanks for doing the homework for me. Now, the 3100 or the 3110? Hm.....

Never heard of The Tool Warehouse, but here are some nice prices and free shipping on orders over $99:

3100 - $106

3110 - $144

Jim
 

Forrest Fetherolf

Senior Member
Jim B,

The 3100 will work for you to read and clear codes. The 3110 has more displays for diagnostic, it is for those wanting to dig into things a little deeper. I bought the 3110 because I didn't know about the 3100.

Forrest
 

jbeletti

Well-known member
Thanks Forrest.

I applied to become an affiliate at The Tool Warehouse. Maybe I can be my own first customer in a few weeks :)

Jim
 

katkens

Founding Illinios Chapter Leader-retired
Forrest Fetherolf said:
Jim B,

The 3100 will work for you to read and clear codes. The 3110 has more displays for diagnostic, it is for those wanting to dig into things a little deeper. I bought the 3110 because I didn't know about the 3100.

Forrest
I think the 3110 has the option that can be updated from your puter and not with the 3100.....Ken
 

Forrest Fetherolf

Senior Member
Forrest Fetherolf said:
Good answers................

I suspected bad fuel and/or plugged fuel filter. I did not have an extra fuel filter.........had about every other spare part though..............
Luckily, I carry a OBD II code reader. The code reader indicated "Fuel Rail - Low Pressure." After clearing the code from memory the engine would rev and shift as normal. The same problem reoccurred later when passing a slow-mover uphill with the same 17 gallons. Cleared code and drove on. Not many auto parts stores open in the middle of "nowhere" Oregon, bought filter in Fallon, NV, installed that evening in Hawthorne, NV, continued on to Vegas the next day with full power.
My only unanswered question is.............if the fuel rail regains normal pressure will the computer allow the engine to rev and cancel the check engine light without manually clearing the code? If not, I would recommend carrying a code reader with "clear code function," might save unnecessary road side delays and a tow job.

After doing more research on my question, two mechanics advised, disconnect the battery cables for a few second and reconnect, this allows the computer to reboot, history codes will be erased and check engine light will go out.

If the check engine light is flashing............do not attempt to clear...........a fatal problem exists that can cause serious damage.

Forrest
 
Top