[Barry Allen]

Driving south today in bitter cold, about -4ºF. I spent at least an hour of highway driving with the engine up to temperature. Halfway through the drive, the engine seems to start a regen cycle with fuel economy hovering in the 30s at highway or city speeds. The regen cycle was dragging on very long again, so I cycled the engine to restart and the regen continued. Driving an excessively long highway route to my parents' house did nothing to stop the regen.

Then, a block from their house, the CEL illuminates.

I guess today I'm going to the local auto parts store to get the code read, and then will see what happens after that. Overnight low might be down to -5ºF, so I'm going to fill the fuel tank up with a good dose of Power Service white bottle.

 

[TDCruze]

I am wondering if EGT are not able to get hot enough in that weather to burn the soot efficiently?

That being said no regen issues have happened in even colder temps with mine so don't know? I did have a cel for dpf pressure sensor.

Let us know the code.

If its failing to complete a regen the additive won't help. But as cold as it is I would use it as antigel insurance anyway.

 

[JLL]

If you have to go to an auto parts store to get the codes read because you don't have a scan tool, just take it to the dealer for diagnostics. You'll save yourself a lot of grief trying to figure things out yourself without the proper tools.

Just my opinion.

 

[Snipesy]

I am wondering if EGT are not able to get hot enough in that weather to burn the soot efficiently?

That being said no regen issues have happened in even colder temps with mine so don't know? I did have a cel for dpf pressure sensor.

Let us know the code.

If its failing to complete a regen the additive won't help. But as cold as it is I would use it as antigel insurance anyway.

Should work perfectly fine into the -50C territory. Even lower if you kept the fuel warm somehow.

The dpf is just a little 500C furnace. If the incoming temperature is say 30C vs 0C. That’s such a tiny difference it means little.

 

[Barry Allen]

If you have to go to an auto parts store to get the codes read because you don't have a scan tool, just take it to the dealer for diagnostics.

Oh, hush

It doesn't hurt to look.

 

[Barry Allen]

Two codes:

P244C: Exhaust Temperature Too Low for Particulate Filter Regeneration Bank 1
P144E: EGR Cooler Bypass Status Line Circuit Low

Code P244C indicates that during active DPF regeneration the PCM detected the exhaust gas temperature sensor 1 signal was lower than the minimum acceptable value.

Either it's too cold for the DPF to regenerate properly, or the sensor is having some screwy readings. Either way, I'll wait to see if the problem corrects itself in the next few days or the next couple weeks.

 

[JLL]

Oh, hush

It doesn't hurt to look.

 

[TDCruze]

Two codes:

P244C: Exhaust Temperature Too Low for Particulate Filter Regeneration Bank 1
P144E: EGR Cooler Bypass Status Line Circuit Low

Code P244C indicates that during active DPF regeneration the PCM detected the exhaust gas temperature sensor 1 signal was lower than the minimum acceptable value.

Either it's too cold for the DPF to regenerate properly, or the sensor is having some screwy readings. Either way, I'll wait to see if the problem corrects itself in the next few days or the next couple weeks.

Without seeing what the EGT was/is it's hard to say. Hope its a cold weather gremlin.

 

[Barry Allen]

Without seeing what the EGT was/is it's hard to say. Hope its a cold weather gremlin.

If the sensor itself is bad, it looks like a $35 part. That's not bad, but I wonder how difficult it would be to change it. The parts diagram shows it on or near the top of the DPF, so that might make it a job that isn't terrible to do myself.

 

[Barry Allen]

Without seeing what the EGT was/is

HOW WOULD I KNOW WHAT THE EGT WAS IF THE EGT SENSOR IS MALFUNCTIONING?!

LMAO - just a joke. Don't take my yelling at you seriously.

 

[TDCruze]

HOW WOULD I KNOW WHAT THE EGT WAS IF THE EGT SENSOR IS MALFUNCTIONING?!

LMAO - just a joke. Don't take my yelling at you seriously.

Need an ultragauge or scangauge type thing. Maybe a good investment for all the things going on with your car? I like my ultragauge.

Probably get a way off low reading. However, if it wasn't working in range, I would suspect the CELs would reflect that too. But, sometimes they don't make complete sense.

 

[BodhiBenz1987]

Two codes:

P244C: Exhaust Temperature Too Low for Particulate Filter Regeneration Bank 1
P144E: EGR Cooler Bypass Status Line Circuit Low

Code P244C indicates that during active DPF regeneration the PCM detected the exhaust gas temperature sensor 1 signal was lower than the minimum acceptable value.

Either it's too cold for the DPF to regenerate properly, or the sensor is having some screwy readings. Either way, I'll wait to see if the problem corrects itself in the next few days or the next couple weeks.

This what AllData says for these codes:
DTC P244C
Catalyst Low Temperature During Regeneration
DTC P144E
Closed Loop Diesel Particulate Filter (DPF) Regeneration Control At Limit - Stage 2 Low Temperature

The second one is based on the difference between EGT sensor 1 and EGT sensor 2, so I think either of those could be bad. Or it could be an issue with the DOC/DPF itself or something else that's preventing it from getting up to temp. It should be able to regen even in really cold temps, though the cold temps could certainly exacerbate an existing problem. I think a ScanGauge or Bluetooth reader w/ BiScan/Gretio would really help if you want to attempt fixing it yourself, since you would be able to see what's going on with EGTs while it is trying to regen ... if one reading was really flaky or unrealistic it should stand out and you could try replacing the sensor.

 

[Barry Allen]

It should be able to regen even in really cold temps

Yes, we are not setting all-time record low temperatures here. This is well within a range of conditions where the car should function properly.

 

[Snipesy]

A clogged fuel filter can cause all these symptoms. I would 100% look into that first.

 

[Barry Allen]

A clogged fuel filter can cause all these symptoms. I would 100% look into that first.

The fuel filter still has 60% life remaining on the monitor. That, and the engine is running just fine and not starved for power.

That is, until the afternoon. A fresh tank of fuel and the car was parked for a few hours. It was about 9ºF and I left to get pizza for dinner. Pulling away from a cold start in 1st gear and the engine was shuddering at about 2,000 rpm. Letting it run slow a couple more blocks and then it was running fine.

I can't wait to see what -5ºF does tomorrow morning.

 

[TDCruze]

The fuel filter still has 60% life remaining on the monitor. That, and the engine is running just fine and not starved for power.

I can't wait to see what -5ºF does tomorrow morning.

Fuel filter "life" means nothing if you got a bad tank of fuel. It can clog it up quick. Still not sure what happened with mine, if it was gelled or moisture or just crud.

The low side fuel pressure was running higher than normal. Changed fuel filter, filled with different fuel and added 8 oz. power service white bottle. Having that ultragauge has been handy, only way I knew fuel pressure was off.

Started fine at -26F tonight, plugged in. No fuel pressure issues.

 

[Barry Allen]

How easy do you think it is to replace this sensor:

2017-2019 GM Temp Sensor 55595725 | OEM GM Parts

2017-2019 GM part # 55595725 - Temp Sensor

www.gmpartsoutlet.net

If I can put less than $50 into the car for an easy fix attempt, that might be worth doing myself.

 

[TDCruze]

How easy do you think it is to replace this sensor:

2017-2019 GM Temp Sensor 55595725 | OEM GM Parts

2017-2019 GM part # 55595725 - Temp Sensor

www.gmpartsoutlet.net

If I can put less than $50 into the car for an easy fix attempt, that might be worth doing myself.

Should be pretty easy to change out that sensor.

Take it the CEL has come back?

 

[Barry Allen]

Take it the CEL has come back?

It never went away. I didn't clear any codes. We are getting slightly warmer weather this week and I think above freezing by next weekend. On Saturday I'll do more interstate driving so it will give a chance to attempt another regen cycle and see if the CEL is just the result of really cold weather.

 

[TDCruze]

It never went away. I didn't clear any codes. We are getting slightly warmer weather this week and I think above freezing by next weekend. On Saturday I'll do more interstate driving so it will give a chance to attempt another regen cycle and see if the CEL is just the result of really cold weather.

Sometimes codes take several cycles without a recurrence to clear them indirectly.

It may give quicker results to clear it and see if it comes back?