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P00B7 code at 43K miles

22K views 21 replies 9 participants last post by  mdonnelly4749 
#1 ·
This morning, as I was on my commute to work, the CEL came up, minutes later, a warning with "Engine Power Reduced" displayed. Driving for another 15 miles, the warning went away, but CEL was still there. 20 minutes after, that same warning came up again as I was slowing down on a traffic light.

When got to the parking lot, I checked the code and the reader said it's P00B7. Cleared the code. Will see if it comes back this afternoon.

Did some research, it's the Low Flow Coolant. Further digging around, it could be an issue with EGR. At 43K miles? Wow...

Anyway, called dealer to bring it in. Could not make any appointment yet.

I know some of you had mentioned about the same problem, same code. And EGR was mentioned in the message. What actually went wrong on yours?
 
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#6 ·
EHIDE...I have a theory I'm kicking around in my head on premature EGR Cooler failure and coolant loss. Especially in the 30-50k range.
Would you happen to have tested your coolant when adding with test strips? If not...do you have a digital multimeter and would you be willing to be a "easy test guinea pig"?
 
#3 ·
I checked on the feed tank and it showed about an inch above the Min level. However, I open the radiator cap , there was nothing in there. I filled it up last night. So far, I have not seen the CEL comes on again yet. Hope that was the problem, low on coolant.

Thanks,
 
#5 ·
HI,
As you know,, recommended Coolant change is required at 45K or 36 months.. Level in the Recovery Bottle should be when cold with outside temps being in the 60's at the half way or mid line where the Seam Lip is of the Bottle.. now it may be above or below it, but not much over 1/2 above or below that seam line.. of the bottle..

DTC CONSULT
(Trouble diagnosis content) DTC detection condition
P00B7
ENGINE COOLANT FLOW
(Coolant level - data valid but below normal operating range - moderately severe level)
1 Diagnosis condition Continuously when key is ON, or engine is running
Signal (terminal) — Threshold Coolant level sensor voltage:• >≥ 3.00 V
Diagnosis delay time Diagnostic runs continuously when the engine is running
POSSIBLE CAUSE
• Low coolant level
• Coolant level sensor
• Harness and connectors
The coolant level sensor is a switch and is used to measure the level of the engine coolant in the radiator top
tank. The coolant level sensor is immersed in the coolant and returns a different signal voltage when
immersed in coolant verses being out of coolant. The Engine Control Module (ECM) monitors the change in
the signal voltage to determine the level of the engine coolant.
 
#7 ·
Not Sure about using the MM... maybe this would be interesting: Knowledge.. ??
https://app.box.com/s/mc3kaetdmj38ebzomyscxe9wt8rvotdg Why MM not.
Now I'm not an authority on anything... All I have ever seen and I have not seen it all.. is below from the Cummins side that I'm aware of: The way to decide on coolant change intervals can include:
- Coolant test strips check coolant pH / acid levels (corrosion risk)
- Owner’s manual service intervals
- Coolant maker’s change intervals
- Distance and time
To be safe, you can use a coolant change interval that is “de-rated”, like 25% less then the time recommended. This is because corrosion and aging of coolant is a 24 hour a day thing, even when the vehicle is parked. Corrosion damage to heater core, rad and head gaskets is cumulative and permanent.
Coolant appearance is NOT a good indicator. Few modern vehicles will ever have coolant that looks “dirty” unlike the old days.
As we know Fleetwood part of the Cummin's line.. offers some easy means for testing of Coolant for your Diesel.. see Below

https://www.cumminsfiltration.com/sites/default/files/LT15068.pdf

Now as far as the EGR and what's happening with loss of Coolant.. I wonder about the O'ring tube and Gasket associated with the components associated in that area.. There are more than half dozen O-rings and Gaskets in that area alone and under pressure, engine vibrations etc.. and being hidden and because where some are located you could be loosing and never know it during the normal operation of the engine..
I know I didn't solver anything here, but somethings to consider..

Enjoy, Be Safe and Keep Burning Diesel
Ric

Enjoy
 
#13 ·
Hi Ric,one of the old school ways to do a "down and dirty"quick check for electrolysis in the cooling system is to use a MM. If acid levels are extremely high and electrolysis present it will register on a MM.
I also read the doc and link....problem with those guys is they were all over the board with their tests ..why they started with an analog meter I don't know...other than it shows a lack of understanding of meters and voltage.
Now ..this test with a digital MM is not meant to be an exact science or tell you when to change coolant..it's a down and dirty test to quickly check for high acidity and electroysis which generates voltage...a sound cooling system won't..
Every time I have used this test method..and VDC was present on the meter, and then cross checked with a coolant sample, the meter was right...everytime.
I guess those guys would also say we can't light a light bulb with oranges either,??
 
#12 · (Edited)
Arice, is correct on Voltage and Grounds and possible connection to Premature failures of the EGR system.. conductivity is no doubt a possible situation.. What your looking for is a voltage reading if above 0.3-0.4 volts of the coolant... however there are opinions on this.. Might I suggest Online do a search to give you an Idea best way to check what Arice is suggesting..

Here is Only One of Many Links to the Topic
https://www.familyhandyman.com/auto...e/coolant-testing-with-a-multimeter/view-all/

You can use a search like this in Google -" Checking Diesel coolant for dielectric voltage "

Enjoy Be Safe..

Ric
 
#19 ·
This morning, as I was on my commute to work, the CEL came up, minutes later, a warning with "Engine Power Reduced" displayed. Driving for another 15 miles, the warning went away, but CEL was still there. 20 minutes after, that same warning came up again as I was slowing down on a traffic light.

When got to the parking lot, I checked the code and the reader said it's P00B7. Cleared the code. Will see if it comes back this afternoon.

Did some research, it's the Low Flow Coolant. Further digging around, it could be an issue with EGR. At 43K miles? Wow...

Anyway, called dealer to bring it in. Could not make any appointment yet.

I know some of you had mentioned about the same problem, same code. And EGR was mentioned in the message. What actually went wrong on yours?
just the coolant reservoir sensor - that was it. Simple. It happened about a week after I did a preventative coolant flush so wondering if that caused it.
 
#20 ·
This morning, as I was on my commute to work, the CEL came up, minutes later, a warning with "Engine Power Reduced" displayed. Driving for another 15 miles, the warning went away, but CEL was still there. 20 minutes after, that same warning came up again as I was slowing down on a traffic light.

When got to the parking lot, I checked the code and the reader said it's P00B7. Cleared the code. Will see if it comes back this afternoon.

Did some research, it's the Low Flow Coolant. Further digging around, it could be an issue with EGR. At 43K miles? Wow...

Anyway, called dealer to bring it in. Could not make any appointment yet.

I know some of you had mentioned about the same problem, same code. And EGR was mentioned in the message. What actually went wrong on yours?
I’ve had the code on my truck for a long while. I finally got tired of it and went with some knowledge I found on YouTube. Someone said that it’s your overflow tank sensor. So I called the dealer and bought a new overflow tank because you have to replace the whole tank in order to replace the sensor, you can’t just buy it replace the sensor only. Anyways after replacing the overflow tank my p00b7 code finally cleared! The overflow tank runs about $167.
 
#21 ·
HI,
As you know,, recommended Coolant change is required at 45K or 36 months.. Level in the Recovery Bottle should be when cold with outside temps being in the 60's at the half way or mid line where the Seam Lip is of the Bottle.. now it may be above or below it, but not much over 1/2 above or below that seam line.. of the bottle..

DTC CONSULT
(Trouble diagnosis content) DTC detection condition
P00B7
ENGINE COOLANT FLOW
(Coolant level - data valid but below normal operating range - moderately severe level)
1 Diagnosis condition Continuously when key is ON, or engine is running
Signal (terminal) — Threshold Coolant level sensor voltage:• >≥ 3.00 V
Diagnosis delay time Diagnostic runs continuously when the engine is running
POSSIBLE CAUSE
• Low coolant level
• Coolant level sensor
• Harness and connectors
The coolant level sensor is a switch and is used to measure the level of the engine coolant in the radiator top
tank. The coolant level sensor is immersed in the coolant and returns a different signal voltage when
immersed in coolant verses being out of coolant. The Engine Control Module (ECM) monitors the change in
the signal voltage to determine the level of the engine coolant.
Hola, sabes cómo buscar ese sensor para cambiarlo, tiene algún número de parte?? Gracias!
 
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