[We Found 9 Causes] P207f Cummins- All About Reductant Quality Performance!

Are you struggling with the p207f cummins and wondering what this code means? The code indicates the reductant quality performance of a diesel engine.

So It is an OBD-II diagnostic trouble code p207f of Cummins diesel engine. Here the OBD stands for the on-board diagnostic system. A technician or mechanic can figure out the issue in the Powerstroke engine by observing the OBD fault code.

However, we will portray some essential and valuable information about this DTC of Cummins diesel engine. So without further delay, let’s move on to the main discussion.

P207f Cummins

The ‘P207f – reductant quality performance’ trouble code is one of the most common issues for the 6.7L diesel engine. The P207F error code signifies the reductant quality. Here the reductant means the DEF or diesel exhaust fluid.

In other words, this generic DTC mainly informs that the SRC system of the Powerstroke engine is not functioning correctly. So, the DTC code may appear when the SCR system doesn’t reduce the NOx output adequately. Or it can also pop up because of the quality of the diesel exhaust fluid.

However, this P207F is one of the problematic fault codes a Cummins Powerstroke engine can express. It is pretty confusing because it does not indicate any specific problem. That is why the technicians might also face troubles while trying for a p207f reset or diagnosis.

Now  take a look at the possible causes of the P207f code 6.7 Powerstroke. And observe the symptoms for this DTC from the table below.

Potential CausesSymptoms
Faulty SCR catalyst.
Diluted, degraded, or contaminated DEF.
Leak in the exhaust system.
DEF injector issue.
NOx sensor issues.
Defective EGR system.
Damaged MAF & MAP sensor.
Dirty engine air filter.
Engine warning light ON.

Solutions To P207f Drive Cycle-

Faulty SCR Catalyst

The Cummins software named INSITE can do the automated SCR efficiency test. Make sure that the power control module is up to date. Reset the DPF parameter and perform one or two regenerations.

Diluted, Degraded, Or Contaminated DEF

Need to check the diesel exhaust fluid or DEF visually. Turn off the ignition and collect the DEF sample. Now check if there is any sign of contamination or dilution.

Also, test the quality of the reductant. If there are any contamination, debris, or hydrocarbons, replace the DEF with fresh fluid.

Leak In The Exhaust System

Leaks in the exhaust system may cause inconsistency in nitrogen oxide reading. You can visually inspect the whole exhaust system and see any leaks. It also causes boost related problems.

If you found any leaks in the exhaust system, execute the appropriate repair. If there isn’t any leakage, check the DEF deposit in the injector decomposition tube.

DEF Injector Issue

First, Check the diesel exhaust fluid injector. Reconnect the injector harness connector to check. Inspect the fluid sprayed by placing the injector in a container.

The fluid should not be dripping from the DEF injector during the test. It must be sprayed out as a mist.

NOx Sensor Issues

The p207f isuzu can also appear because of NOx sensor concerns. The 6.7L Cummins Powerstroke engine contains 2 NOx sensors.

The upstream NOx sensor is permanently connected to the turbocharger elbow. And, the downstream NOx sensor is permanently attached to the SCR catalyst. These sensors become damaged when they age.

Also Read: P0191 Cummins: What is The Meaning Of The Code and How To Fix it?

You should monitor both of the sensors while driving the truck. Both of these sensors should respond appropriately. Otherwise, replace it with a new one.

Defective EGR System

Also, an open and sticking EGR valve can lead to p207f link belt issue. In this case, verify if the EGR_a-A_POS is at 0% when the EGR_A_CMD is at 0%. Use any OBD scanner to verify these percentages.

Damaged MAF And MAP Sensor

The damaged MAF and MAP sensors can cause the Powerstroke to express P207F DTC. However, a dirty MAF sensor causes incorrect calculations because of unexpected air readings.

Similarly, the MAP sensor can be clogged up due to carbon buildup inside and cause damage. To eliminate this problem, clean the carbon out.

Dirty Engine Air Filter

If the engine air filter is dirty, make sure to clean it. The dirty engine air filter can cause combustion mixtures and unexpected air readings by the engine’s restricted air.

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Frequently Asked Questions (FAQs)

What is code P207F mean?

Code P207F means the reductant quality performance of a diesel engine. This generic DTC mainly informs that the SRC system of the Powerstroke engine is not functioning correctly. So, the DTC code may appear when the SCR system doesn’t reduce the NOx output adequately.

What is the reductant level?

Reductant means diesel engine fluid. The reductant level indicates how much DEF is left in the tank. Specific trouble codes express the particular issue in the reductant.

What are the potential causes of the P207F trouble code?

Possible reasons are contaminated DEF, damaged DEF injectors, NOx sensor problems etc. Besides, the fault code may appear if the EGR systems, MAF & MAP sensors are damaged. However, this trouble code can signify many causes, so be careful before diagnosis.


So that was all about p207f Cummins diagnostic trouble code. I hope it was helpful for you. The P207F is a conditional DTC that sets during certain conditions.

Sometimes the mechanics or technician might face difficulties to clear p207f code. However, before diagnosing the vehicle, understand the exact cause behind the trouble code. Read the description and manual carefully.

Besides, the fault code may still exist even after fixing the problem. So no need to worry about it.

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D Conroy

Meet our senior writer and content manager of Automasterx. He has worked in several mechanical garages and mastered different vehicle diagnoses and parts repair. He never stops until finding out the ultimate solutions for any vehicle fault code. However, ensuring the only solid solutions for each vehicle malfunction is his core part of the duty, alongside analyzing fault codes and signals.

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