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Cm2250 nox sensor power wire failing load test - Printable Version

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Cm2250 nox sensor power wire failing load test - Gcc - 10-17-2021

Hey guys been working on my 2013 pete 367 with a cm2250 it has really weak light on the 12+ for tye inlet nox sensor but the fuel pump kicks on and runs fine hardness casing looks good just wondered if there is a certain spot that it normally problematic before i start cutting the loom up


RE: Cm2250 nox sensor power wire failing load test - Gcc - 10-17-2021

Ok so I just double checked and realized that I must have had a bad groubd on other side of test light as it stays nice and bright. I hace fault code 3232. Spn 3216. Fmi 9. And a derate active. I have replaced inlet and outlet nox sensors, dpf differential pressure sensor, egr differential pressure sensor, egr orfice sensor, exhaust back pressure clean imap which wasn’t bad, replaced dpf doser and def doser. I notice that it only throws code under full throttle applications when the truck hits 580+ egt and then soon as temps drop back down 425-450 light goes out again its the only correlation I’ve been able to find. The fuel punp come on with key on for 30 seconds then it shuts off sound nice and health fuses are all good I’m probably missing something but dont know what and I cant get the dash to stop saying regen require even though a regen comes back what I think is decent compared to what I’ve read my differential is normally .1 after a regen I’m thankful for anything people can offer


RE: Cm2250 nox sensor power wire failing load test - Rawze - 10-18-2021

(10-17-2021 )Gcc Wrote:  Ok so I just double checked and realized that I must have had a bad groubd on other side of test light as it stays nice and bright. I hace fault code 3232. Spn 3216. Fmi 9. And a derate active. I have replaced inlet and outlet nox sensors, dpf differential pressure sensor, egr differential pressure sensor, egr orfice sensor, exhaust back pressure clean imap which wasn’t bad, replaced dpf doser and def doser. I notice that it only throws code under full throttle applications when the truck hits 580+ egt and then soon as temps drop back down 425-450 light goes out again its the only correlation I’ve been able to find. The fuel punp come on with key on for 30 seconds then it shuts off sound nice and health fuses are all good I’m probably missing something but dont know what and I cant get the dash to stop saying regen require even though a regen comes back what I think is decent compared to what I’ve read my differential is normally .1 after a regen I’m thankful for anything people can offer

Spn 3216. Fmi 9. ==> Is a J1939 communications loss issue, not a voltage issue.

Did anyone bother to check (+truck turned off for more than 2 minutes) to see if the J1939 can-bus #2 harness is at its proper 60-ohms at the 3-pin connector?. It is the triangle 3-pin plug on the intake side of the engine. It is referred to as the "Weather-Pack" connector.


ALSO.. you have to REPLACE the IMAP sensor.. not clean it.. there is no way to properly clean them...

ref: http://rawze.com/forums/showthread.php?tid=181&pid=1087#pid1087


RE: Cm2250 nox sensor power wire failing load test - Gcc - 10-18-2021

Checked whether pack and doesnt read anything after 10sec of key off


RE: Cm2250 nox sensor power wire failing load test - Rawze - 10-18-2021

(10-18-2021 )Gcc Wrote:  Checked whether pack and doesnt read anything after 10sec of key off

FIRST of all, I said TO WAIT 2 MINUTES OF KEY-OFF TIME SO THAT THE ECM CAN FULLY SHUT DOWN!!!!... IT TAKES AS MUCH AS 1.5 MINUTES FOR AN ECM TO SHUT DOWN FULLY, AFTER KEY-OFF!... READ MY POST ABOVE MORE CAREFULLY!

The green and yellow wires on the 3-pin "weather-pack" connector should read 60-ohms on an ohm meter when the ohm meter is set set to its correct range. If it does not read 60-ohms, or 120-ohms, or some other resistance then you need to find out how to use your ohm meter properly. You need to find out what the actual resistance is instead of saying a blanket statement like "it reads nothing"... this indicates that you do not know how to use an ohm meter properly.






RE: Cm2250 nox sensor power wire failing load test - Gcc - 10-18-2021

Well i guess ill have to try an get a different multimeter as i get 60 ohms at plug and sensor but after key is turned off in getting 0.00 ohms at the whether pack not my first time using an ohm meter either


RE: Cm2250 nox sensor power wire failing load test - Rawze - 10-18-2021

(10-18-2021 )Gcc Wrote:  Well i guess ill have to try an get a different multimeter as i get 60 ohms at plug and sensor but after key is turned off in getting 0.00 ohms at the whether pack not my first time using an ohm meter either
The terminating resistors (they are 120-ohms each) are 'NOT' hard-wired into the wiring harness themselves.

There are TWO different networks...
- For can#2 (The engine has its own separate J1939 nertwork), One of these terminating resistors is located directly inside the VGT turbo controller. The other is usually down at the DFP/SCR (emissions) system harnesses, far down at the other end.

Can#1 (the truck J1939 network) is separate form this, and communicates with the truck side of things. It is a separate network, and is the one that has the deutsch (big round plug) connector under the dash. It also has terminating resistors.. depends on the truck where they are at. Maybe one of them is in the truck OEM harness, up by the ecm, and the other one is usually down by any Automatic tranny harness, or bunk heating/a/c controller that the truck may have.

On the engine side harness, for can#2 ... The green and yellow twisted pair located at the 3-pin 'weather pack' connector, should read 60-ohms with the truck turned off.

Same thing with the can#1 harness green/yellow twisted pair at the deutsch connector under the dash.

There are 2 different, seperate networks for the engine/truck, and they BOTH have to be checked. They should BOTH read read 60-ohms with everything shut off after a few minutes.

For can#2, This should be true even if the ECM itself was completely unplugged from the engine harness!.


RE: Cm2250 nox sensor power wire failing load test - Gcc - 10-18-2021

The only way i can get codes to become active is with egt 550 plus. Below that for a few minutes or even running empty code goes inactive over 550 it come on almost like clock work only thing i can find correlating with it I’m watching everything on insite. I’m going to try another ohm meter tomorrow see if its different but key on i get 60 and when i turn key off u can watch it drop to 0.00 an the meter scans all the ohm settings automatically and shows 0.00 turn key back on bam 60 again


RE: Cm2250 nox sensor power wire failing load test - Gcc - 10-18-2021

Heres a pick of the codes after egt drops