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2018 LT Diesel "REGEN"

23K views 12 replies 6 participants last post by  Cwilson884 
#1 · (Edited)
I got a check engine light about a week ago at just over 9000 miles, soon after I got a notice from Onstar regarding a problem with the emissions systems, "please return to dealer for service".
I took it in yesterday and it was determined by the codes pulled (?), that the vehicle needed to be "regenerated" and the service would take about an hour.
They parked it outside with the engine running and had a black box hooked up to the OBDII port. I went out to see what was going on and found the vehicle running at an idle but apparently the black box is communicating with a computor inside the building and I have a suspicion that the RPMS are raised and lowered.

The technician said that it is not unusual for the diesel vehicles that are used for local trips to need this service because the catalytic converter gets gummed up. He said that he wouldn't be surprised if I would need this service on a regular basis with the type of use we give it. He said the vehicle should be driven at highway speeds for an hour or so every so often.
I do this but apparently not enough.
I've seen a couple of posts regarding carbon build up on direct injection vehicles and mentioned that to the tech.. He said that the condition, I had, was diesel only.
Anybody else heard of this??
Howard
P.S. If this happens again I'm going to try running it down the interstate at 75mph to visit a friend that lives over 100 miles away to see if this clears the fault. Comments?
 
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#2 ·
Diesel Particulate Filter (DPF) Service Regeneration
Circuit/System Description
A service regeneration of the diesel particulate filter (DPF) is required when the scan tool DPF Accumulation Status parameter displays 30 grams or more of accumulated soot. When commanded, the engine control module (ECM) controls the service regeneration as follows:

 1. The exhaust system is warmed up for about 8 min. Engine speed is slowly increased to 2 000 RPM and then to 2 500 RPM.
 2. Once the DPF reaches its calibrated regeneration temperature, the ECM maintains engine speed between 2 000–2 500 RPM for about 20 min until regeneration is complete, is cancelled by the technician, or is aborted due to abnormal conditions.
 3. The ECM then slowly decreases engine speed to 1 600 RPM, then to 800 RPM, and finally to normal idle speed over a 5 min period. This is done to allow the DPF to cool down.
The DPF Service Regeneration will be terminated if any of the following conditions occur:

•The DPF Service Regeneration is commanded OFF using the scan tool
•The scan tool is disconnected from the vehicle
Conditions for Running
The following conditions must be met in order to enable DPF Service Regeneration:

•DTCs P2463 is the only active DTC.
•The battery voltage is greater than 10 V.
•The engine speed is between 500–2 700 RPM.
•The vehicle speed is 0.
•The transmission is not in Drive or Reverse
•The exhaust gas temperature sensors 1 is between 20–500°C (68–932°F).
•The exhaust gas temperature sensors 3 is between 20–735°C (68–1,355°F).
•The engine coolant temperature sensor is greater than 70°C (158°F).
•The fuel temperature is less than 150°C (302°F).
•The BARO pressure is greater than 40 kPa (5.8 PSI)
•The APP sensor is less than 1%.
•The diesel exhaust fluid temperature is greater than −7°C ( +19°F).
•The diesel exhaust fluid tank is not empty.
•The brake pedal and accelerator pedal are in the released position.
•The transmission is in Park or Neutral.
Diagnostic Aids
The scan tool DPF Regeneration Inhibit reason parameter will display a reason for not enabling or aborting the DPF service regeneration. Refer to the reasons that are displayed and the corrective action for each reason.
 
#3 · (Edited)
According to the manual you should have seen some messages in the DIC telling you to keep driving if possible when it has failed to complete a regen a number of times...if the driver does not heed that warning then you get the CEL to have a manual regen done.
And yes this is why newer diesels are cleaner than DI gasoline...because of the DPF it cleans the particulates and burns it to CO2... where DI gasoline spews it out. there are talk of GPF and legislation in Europe at least being thought to require that.

Here is the manual info about the Regen...(page 29 says it should take 30 mins of driving).

From page 225 in the manual:


If the vehicle is used for numerous
short trips or extended slow-speed
operation, the engine computer may
not be able to adequately heat up
the exhaust system to clean the
DPF effectively. The engine
computer has been designed to
continuously monitor the condition
of the DPF. When the engine
computer detects that the DPF is
nearly full of particulates and that
the vehicle is not being operated in
a manner that would allow effective
automatic DPF cleaning, a Driver
Information Center (DIC) message
will display. Start the cleaning
process as soon as possible.
Cleaning Process
To activate the cleaning process,
continue driving safely, and keep
vehicle speed above 50 km/h (30
mph) until the warning message in
the DIC turns off.

If the vehicle continues to be driven
with the DPF warning message on,
and the exhaust filter is not cleaned
as required, the malfunction
indicator lamp and the ENGINE
POWER IS REDUCED message
will come on. Dealer service is
necessary.


 
#4 ·
Thanks to both of above. I only got an engine icon in the DIC. I use the manual regularly for info., wheel torque, capacities etc., but never thought faults were covered and since I, almost immediately, got a message from onstar saying take it to the dealer, I never thought to look in the manual. I'm just glad there's a way to correct the problem if it happens again. Thanks again, Howard
 
#5 ·
https://www.dieseltechmag.com/2018/05/common-problems-dpf-turmoil

Interesting article on diesel regen. Although it seems to paint a gloomy picture, it *does* say 2010 and later models have an upgraded design (with DEF and SCR) that “expedites the DPF cleaning process”.

But it sounds like more work needs to be done to come up with a way to clean that filter more transparently.

BTW - just checked RockAuto for a DPF for a 2018 Equinox diesel and they don’t list one. Is this part only replaceable as part of the catalytic converter?
 
#6 · (Edited)
#7 ·
I had a cel come on the other day and it went off. Today it came back on, said power reduced. I stop and it says to keep driving its cleaning the def filter. So I keep driving I notice it wont go above 2k rpms the message finally comes off about the regen. Everything seems fine but the cel is still on
 
#8 ·
I drive about 35 miles each way to work so it's not like I go short trips. Bought it NYE with 46 miles and have 6100 miles
 
#9 ·
'18 Terrain diesel w/19K

On Sunday my ck engine light came on with the message Engine Power Reduced...Must Continue Driving. I called OnStar and they told me to take it to dealer right away. The car would only go between 20-30 mph. Five days before this I had a trip to Canada where I drove over 1100 miles in 2 days. Shouldn't this amount of highway driving take care of this problem? The dealer was not much help. He said to do a manual regen it would cost me $129 because it was not covered under warranty. They apparently did an ECU update and said it would help with increase speed and might turn off the light. Told them not to do it. Got the car and the light was still on but speed was increased. It still would decrease on hills and at times the car would jerk. This was yesterday and I'm not sure what to do, either drive it for half hour hoping it will get to above 35 or take it to another dealer.
Any thoughts/suggestions????
 
#10 ·
From my reading of the manual if you got power reduced message you have to do a manual regen...
The regen by driving by driving can be done when you got a message "start the cleaning process as soon as possible".


Any diesel mechanic should be able to do that regen i believe. Remember the more you drive it in this state the more you are filling the DPF.



I do agree that driving 1100 miles on highways should have given it a good chance to do a regen but may be it got full only after you came back. Anyways somebody else on the forum here who drives a lot on the highway daily got the DPF full message ...and his problem was a exhaust pressure sensor malfunction.


https://www.equinoxforum.net/31-eng...-terrain-cel-def-filter-regen.html#post284303
 
#11 ·
Thanks tizan. I took it out yesterday hoping it would make it up to speed. It finally did on the freeway. I drove it about 40 minutes when I got another alert (could not cancel this alert) telling me to keep driving. Got the notice 2 more times and finally it went away. I got off the freeway and turned around at the exit and low and behold, it worked! The engine light was still on but it finally went off today. Just a very irritating situation when OnStar says one thing and the dealer says another.
 
#12 · (Edited)
That is good...i suspect the dealership just did the recall on the 2018 diesel that was there a year ago or more (reprogramming the ECM for emission control). Hence I suspect it will do the automatic regen now more smoothly.
The OnStar people are good just to tell you what the code is ...and they always tell you to go to the dealership (they are not experienced at all...so don't trust them to give you any good advice)
 
#13 ·
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