According to this site it is the engine coolant temp sensor. Shocking, as it does not seem emissions related on a diesel. Sounds pretty easy to fix though.

https://www.obd-codes.com/p0118

https://www.obd-codes.com/faq/ect-sensor.php

 

Think you had the wrong code

 

Here is the table I found

 

Here is a picture of the code

 

DTC P118B Particulate Matter Sensor Temperature Not Plausible

Circuit/System Description
The particulate matter (PM) sensor monitors the amount of the particulates (soot) in the diesel exhaust gas exiting the tailpipe. The PM sensor is similar to the heated oxygen sensor with a ceramic element, but also includes an individually calibrated sensor control unit (SCU). The sensing element includes comb shaped interdigital electrodes (IDE), a heater and a positive temperature coefficient resistor for temperature measurement. The operation of the PM Sensor is based on the electrical conductivity characteristic of the diesel particulate. As the exhaust gas flows over the sensing element, soot is absorbed in the combs between the electrodes, eventually creating a conductive path. When the path is formed, it generates a current based on the voltage being applied to the element. The measurement process continues until a preset current value is reached. To avoid misleading readings, the sensor performs a regeneration where the soot is cleaned off by heating up the element, before the measurement phase begins. The amount of regenerations is based on vehicle strategy; when the calibrated number of regenerations is reached, the cumulative current readings are used to determine the amount of soot concentration in the exhaust gas which in turn determines the collection efficiency of the diesel particulate filter (DPF).

Conditions for Running the DTCs
DTC P142C, P142D, P142E, P142F, P1474, P1475, P1476, P1477, P1478, P16D7, P16D8, P16D9, P24B0, P24B1, P24B3, P24B5, P24B6, P24D0, or U02A3 is not set. The ignition is ON. The vehicle has had a minimum OFF time of 8 h. The ignition voltage is greater than 11 V. The reductant control module relay 2 is commanded ON. The DTC runs continuously when the above conditions are met.

Conditions for Setting the DTC
The particular matter sensor control unit detects an internal fault of the sensor.

Circuit/System Verification
1. Ignition On. Verify no other DTCs are set⇒ If any other DTCs are set Refer to Diagnostic Trouble Code (DTC) List Vehicle⇓ If no other DTCs are set 2. Verify DTC P118B is not set. ⇒ If the DTC sets Replace the B136 Exhaust Particulate Matter Sensor.⇓ If the DTC does not set 3. All OK

 

Thanks! Just got to keep on waiting for my parts to come in

I was worried it was something not emission related and I was going to be forced to go into the dealer.

 

More Emission sensor issues????

Please keep us advised of your findings

 

My findings will be removing it completely in about a week

 

Ah, so it was emissions stuff after all. Shocking, I know...

I suspect the software parameters for the sensors are incredibly tight, probably nothing wrong with the sensor itself.

 

I'm not tuned and I've got the "P24b0" Diesel Particulate Filter Sensor

I have to reset around every 50 miles, keeps coming back

It is my belief that based on the part being on b/o, the service guy was not surprised about the failure and somebody commented on another post that GM is using Delphi to make the new part I'd say the problem ls with the OEM part.

Hopefully Delphi can make a quality part that will last.

I don't want to go through this crap after warranty!

 

P118b code ??

Hi everyone

I’m getting this code repeatedly since about 19,000 klm even after resetting... sometimes after a day and sometimes it might be a week or so ? Who else is having the same issue with their Diesel 2.8 and what is the dealer saying?

Thanks

 

https://www.coloradofans.com/forums/226-diesel/338465-p118b.html

Sent from my Pixel 2 XL using Tapatalk

 

merged

 

Has anyone fixed trouble code P118B successfully? I keep getting the trouble code every other day after deleting it, even with the stock tune installed. 2017 Colorado 2.8l

 

I was getting P118B at 27k miles, still under warranty. The dealer ended up replacing both DPF sensors. During the course of the repair the tech broke off a sensor in the DPF which resulted in a whole new filter at 27k miles.

No more P118b

 

Brought the truck to the dealer and they changed the DPM sensor (sensor with black box attached) which is located in the S bend of the exhaust after the Cat. Fixed the issue for me. All was covered under warranty.

 

Hey y'all, I was getting a P11db so I replaced the upstream nox sensor. Cleared codes and almost immediately after startup I get an intermittent p1478 and one p118b. Does anyone have part numbers and locations for the fix?

 

I would caution everyone from clicking the link posted by jinix82 above. Most likely a spam/scam bot.

 

yeah a ".ru" it just wreaks of authenticity 🤣