Def problem /limp mode

[Ltngdrvr]

That's pretty much what this diesel mechanic said when I told him about egress cleaning. He also said he would not leave it at that shop.

Yea I looked at harnesses today and found several around $100. I would have thought if harness problem it would have blown the Def fuse, but no fuses blown.

I'll get the diagnosis report tomorrow
and tell you exactly what it says.

Then the service writer first called, she said tech said egr cleaning caused the pump to go out. After the other mechanic said that is BS, not related, is when I went to pick truck up and insisted to see service manager AND service writer together. The manager admitted they were not connected and writer said, I just passed on what tech said. Then she tried to back up later but couldn't did herself out of the hole she had dug, with my help. Oh while talking about dealer, the manager said they could finance work, looked at that, and wanted, yes I'm not mistaken, 35% interest.

As said, brought truck home.

I want to thank each one for your help, just don't give up on me.

One more quick question on harness, can I remove harness and run ohm meter to check if there is a problem?

Trace the harness back to it's origin, checking along the way for damage that might cause a short to ground. If none found, you may be able to pull it and check with a ohm meter. You won't want to do it unless you can disconnect it, any feedback to the ecm could damage it. Check for dirty or corroded grounds too.

 

[Timd32]

You looked it up wrong bud, all those codes have to do with the DEF system.
There is an "A" after each of those numbers, P202A, 203A, etc,.

Figured was doing it wrong.

 

[Timd32]

I read the post at your link. Sounds like a ****ty way of trying to get more money for for repairs than is necessary.

I will send the P204a PDF over to you in your Inbox if you wanted to read thru that process.

 

[Wayne M.]

Still major problem. Took connection off Def pump, was really wet. Figured, hey found problem. Cleaned connection, even unplugged both negative battery terminals for 3 hours, didn't even reset radio, and nothing changed, says I have 13 miles to limp mode.

Wish I knew how to know for sure is bad $1000 pump and not electrical.

Still have errors p202a, 203, 204, 205.

I need a vehicle

Are you telling us that the DEF pump harness is wet with DEF? I have seen this on class 8 trucks where the DEF pump will fill up its electrical connection/ harness. If that’s the case, this harness is contaminated with DEF and is done. I’m sure since you found this and let air into the equation, it’s started to green up.
You need a pump and that harness. After that, a drive cycle to clear the codes.

 

[CToney]

In Agricultural equipment when the harness at the pump is wet with DEF the pump is done. Those are easily fixed. I’m not sure why the DPF can’t be left in place and the DEF derates eliminated so one can conduct business and then you can fix it when one is able. Derate elimination tune if you will. Still get codes just no creepy crawl mode. Dealers wouldn’t be able to hose a guy as bad then.

 

[MtnRider]

.... I’m not sure why the DPF can’t be left in place and the DEF derates eliminated so one can conduct business and then you can fix it when one is able. Derate elimination tune if you will. Still get codes just no creepy crawl mode. Dealers wouldn’t be able to hose a guy as bad then.

It can be done and the truck would run fine without the DEF, the NOx emissions would be up though so I'm sure it's a EPA compliance issue that they shut down the truck if it's not working. The EPA would rather have you stranded then polluting...


.

 

[CToney]

It can be done and the truck would run fine without the DEF, the NOx emissions would be up though so I'm sure it's a EPA compliance issue that they shut down the truck if it's not working. The EPA would rather have you stranded then polluting...
.

I understand they’d rather have you stranded than poluting. I guess they have to view the big picture. All it would take is one -30 to -40 Degree failure or stranding and one would understand those that hit a large bump. I’d rather some common sense go into programming logic. Dealers are few and far between in a lot of areas. If the systems were more reliable or had modified software the survival rate after 10 years would be greater one would imagine. But alas common sense and logic should not be used. Hopefully new technology will solve the NOx issue for Diesel engines. Ducted fuel injection holds promise to retrofit large diesels in ocean going vessels to reduce emissions.

 

[RammerJam]

In Agricultural equipment when the harness at the pump is wet with DEF the pump is done. Those are easily fixed. I’m not sure why the DPF can’t be left in place and the DEF derates eliminated so one can conduct business and then you can fix it when one is able. Derate elimination tune if you will. Still get codes just no creepy crawl mode. Dealers wouldn’t be able to hose a guy as bad then.

The people that make these rules simply don't like you and they REALLY don't like your trucks. They honestly could not care less if you get stranded in a blizzard or the middle of the desert. How come Karen's Toyota doesn't go into limp mode when one of its O2 sensors takes a dump?

If you ever get the chance, go to Ann Arbor and hang out there for a while. You'll understand what I mean. They just don't like you and they don't care that you know it.

Just the way it is.

 

[J Larry]

Trace the harness back to it's origin, checking along the way for damage that might cause a short to ground. If none found, you may be able to pull it and check with a ohm meter. You won't want to do it unless you can disconnect it, any feedback to the ecm could damage it. Check for dirty or corroded grounds too.

 

[J Larry]

Will attempt to remove harness soon, wish me luck..... NO, say a prayer lol

 

[Ozymandias]

Exactly what truck is this on?
Those codes all point to a disconnection of some kind in the harness to the DEF tank.
Will your code reader not clear the codes?
Disconnecting the battery won't do it.

You can Not clear DEF, Exhaust related codes with a simple reader, only wiTech can do this.

 

[Ozymandias]

In Agricultural equipment when the harness at the pump is wet with DEF the pump is done. Those are easily fixed. I’m not sure why the DPF can’t be left in place and the DEF derates eliminated so one can conduct business and then you can fix it when one is able. Derate elimination tune if you will. Still get codes just no creepy crawl mode. Dealers wouldn’t be able to hose a guy as bad then.

Mandatory by law aka. EPA.

Everything that makes emissions worse has to force a limp mode. That's the law.

 

[RammerJam]

Mandatory by law aka. EPA.

Everything that makes emissions worse has to force a limp mode. That's the law.

Not to be a pedant, but they are not laws. They are regulations set by an agency that is not representative of The People. Laws are passed by a Legislative Branch and signed by a Chief Executive. All of whom are voted into Office by The People.

The EPA is an unregulated, unaccountable agency that sets rules by simple fiat. Unless they run into a recalcitrant Farmer, Rancher, business or another government agency, then they--

...work hand in hand with environMENTAL groups by.... This is how they do it, the enviroMENTAL groups gets together with the EPA by suing them and designs a fix to something that they agree on (what DON'T they agree on). They pre-arrange a settlement and then go to Court to Codify it in front of a friendly judge.

Sorry to interrupt with a dose of harsh reality. carry on

 

[Ltngdrvr]

You can Not clear DEF, Exhaust related codes with a simple reader, only wiTech can do this.

Well, don't tell my code reader that, I have cleared a number of emissions related codes on my truck over the years.

 

[Wayne M.]

You can Not clear DEF, Exhaust related codes with a simple reader, only wiTech can do this.

Well, don't tell my code reader that, I have cleared a number of emissions related codes on my truck over the years.

Some codes cannot be cleared by any scan tool. As it is with OBDII Gasoline, what you’re claiming is like saying you can clear code P1000 with a scan tool, which is impossible. Some of these codes can only be removed by the proper drive cycle. The SCR system must see NoX conversion within a certain window. It’s just another monitor to run.

 

[sag2]

Well, don't tell my code reader that, I have cleared a number of emissions related codes on my truck over the years.

You just have not had the proper code. It is correct, there are several DPF/DEF codes that require the truck be repaired, then the monitor run successfully to clear the code.

 

[J Larry]

My question I've asked several times and the one that I don't think I've gotten an answer to, if I replace the harness, or whatever and it is correct to repair the problem, how will I know it's repaired if the exception will not reset the error code? Will the countdown stop if repaired. Will at least the codes stop saying will go into limp mode in X number of miles.

 

[Wayne M.]

You should be able to see pump pressure and other related PIDs with the right scan tool (Alfa?) but if you made the repairs, and run the drive cycle properly, the derate should just disappear. On a Ford, I fooled the drive cycle by doing a stationary regeneration. Bottom line is that it saw Nox conversion at a specified time.

 

[J Larry]

You should be able to see pump pressure and other related PIDs with the right scan tool (Alfa?) but if you made the repairs, and run the drive cycle properly, the derate should just disappear. On a Ford, I fooled the drive cycle by doing a stationary regeneration. Bottom line is that it saw Nox conversion at a specified time.

 

[J Larry]

Ok, i personally don't have any scan tool. I've just been trying to find a solution but see so many talking how this tool can erase this and this tool can erase that, but never have someone say that if I fix problem at least I will know by not telling me in X number of miles I will go into limp mode