want to know more about fault code 2637

[DVT873]

ISC CM2150 ESN 46817049 2008 M2 Freightliner 1FVACWBS98DZ89079 Cummins code 2637 QuickServe says this is an inferred code. It refers to the three aftertreatment temp sensors. Doesn't say much else. Have had this code come up a few times Then a soot level light will come. on. It says while 2637 is active, active regen is stopped. Twice inspection of the DOC has showed a clean face.

Last time this happened it was a pretty cold day. Maybe 15 degrees. Truck had plowed and salted parking lots for about 10 hours. Set 2637 and 2639 but did not shut down. Cleared 2637 and ran a regen. Regen got to 1400 degrees on the outlet side. EGR tuneup has been done recently. DPF was replaced, the old one appeared original but had a crack.

That was back on Dec 26th. No problems since. Want to get connected to it this week to check regen history. About 10,000 hours on engine. No evidence of demandate or hotrod programming.

Anyway I would like to know more about what goes into the ECM deciding to set 2637.

[hookliftpete]

At those hours I’d be rid of the mandate, same engine here, constant regen issues no matter how clean the egr, etc, and after new dpf/doc. Mr. Hagg did it right. These early emissions engines are no good with emissions.

[Signature620]

I highly recommend you get the engine checked for boost leaks and EGR leaks.

Also check if oil or coolant are getting into the exhaust system.

These engines do not enjoy light loads and idling as the DPF can't regenerate passively without constant exhaust temperature.

[DVT873]

We did smoke test it at low pressure. Builds good pressure. When it is back will stick 30 psi in it. it runs great. other than this one hick up on the 26th. Thanks.

[Rawze]

Fault Code: 2637 ,...

The front face of the aftertreatment diesel oxidation catalyst has been detected to be plugged with soot.
It is the cry home to mamma alarm, same as the CM871 has. It usually always is accompanied with other faults.

Have BOTH the DOC and DPF been replaced and/or cleaned out? -- (Baked, de-ashed, and flow tested)? ... and if so, was the ecm reset with the "New DPF Install" procedure? ? if not then you will continue to get tis alarm as there is a soot counter that needs resetting and makes this alarm even if the system is clean if no one reset the counter.

====================

Fault code 2639 ...

Catalyst Face Plugged - Root Cause Not Known. The front face of the aftertreatment diesel oxidation catalyst has been detected to be plugged with soot.


Just some reference:
The DPF Delta-P densor is not reading right or the DPf is actually getting clogged up. Pull the DOC and DPf can and take pictures of the faces. Number one cause of these issues is the doser injector tip clogged, too much oil consumption in eninge, too much idling, excess soot due to egr valve sticking open or sooty mis-reading sensore (egr-tuneup stuffs) or coolant getting into the engine or exhaust system.

If you pulled the cans out and had them flow-tested and they are good, maybe it is a ghost alarm. On some trucks, depending on how the DPF Delta-P sensor is mounted, it may have clogged feed-tubes, or bad bushing going to the sensor, etc... or the sensor may be going bad.

[Signature620]

Rawze's post reminded me...

I forgot to mention you need to check that the DPF differential pressure is reading zero with the engine off. They often read low numbers above zero and throw off the aftertreatment monitors in the ECM.

[DVT873]

DOC has beeen cleaned and flowed. DPF is new. {aftermarket-dpf name removed} yeah I know. All EGR Tuneup sensors new. EGR new. Need to check that zero reading on the DPFDP but I think it was zero. Talked to some schoolbus people. This code can ghost in and be a PIA. Time will tell. Thanks to all for the info.

[Rawze]

could be that chineese aftermarket DPF your running. Those things do not last very long and have only half the precious metals in them. I have no idea why someone would install one on their truck except to waste money.

they are the ones who also sell that snake oil fuel catalist garbage and all sorts of other rip-off products.

[DVT873]

No 7th injector. In cylinder dosing. Customer choice on DOC. Vendor that supplied DOC does DPF and DOC cleaning and nothing else. They have been at it about 5 years now. They log and save arrival, intermediate and final flows on all units. Do several thousand a year. Have had overall good service but of course mileage varies. Understand the potential difference between OE and others. I do not trust any reman DOC, even OEM. So it has to be new. Medium duty is a bit different than on highway longhaul. The truck in this post won't see 10K a year. Maybe not even half. I do the best I can to lay out options but can't forcibly spend someone else's money. That said I appreciate what I have learned and still learn on this site. Thanks to all.