On the road with P0471 code

[caddo_diesel_fan]

I just pulled my travel trailer up to Colorado (from Texas) and my truck is showing a P0471 code (Exhaust Pressure Sensor 1 Performance). The truck seems to be running just fine. I am wondering if I need to go find the nearest Dodge Dealer, or if I can wait until I go home at the end of the week. I am in Leadville, and don't want to drive to Denver unless I have to.



Is anyone familiar with this code? What are the risks of driving the truck with this code thrown until I can get home and take it to the dealer on Monday, 14/Sept.



Thanks

 

[MullenaxM]

P0471

The Exhaust Gas Pressure Sensor is used to measure exhaust gas pressure in the exhaust manifold. The Exhaust Gas Pressure Sensor provides a signal to the ECM on the exhaust gas pressure sensor signal circuit. At key on, the readings for the exhaust gas pressure, intake Manifold pressure and ambient air pressure are compared. This fault code occurs if the exhaust gas pressure reading is different from the other two. During normal engine operation EGR position and Boost Pressure Sensor readings are used to calculate an estimated exhaust pressure. If the difference between the estimated and the value read from the Exhaust Gas Pressure Sensor is above a calibrated threshold for a calibrated period of time then an error is recorded. The key-on portion of the rationality will light the CHECK ENGINE light immediately after the diagnostic runs and fails. The rationality portion has to fail in two consecutive drive cycles for the CHECK ENGINE light to become illuminated. If this fault becomes active the ECM will light the CHECK ENGINE light immediately. During this time the ECM uses an estimated exhaust gas pressure. The ECM turns off the CHECK ENGINE light when the diagnostic runs and passes in 4 consecutive drive cycles.



If you have the capability to turn the CHECK ENGINE light off and clear the trouble code I would try that first. Keep in mind as stated above this is a two trip fault, meaning it takes two drive cycles for this code to become active and turn on the CHECK ENGINE light on.



Most of the time when I see this code I end up having to replace the Exhaust Gas Pressure Sensor.



As far as driving back to Texas with this problem, I think you will be ok. This is not one of the codes that will suspend a regeneration event from happening.



Mike

 

[caddo_diesel_fan]

Mike,



Thanks a bunch for the explanation and letting me know that this will not prevent a regen. I have found that there is a Dodge dealer in Silverhtorne, which I beleive to be about 50 miles from where I am camping. I am going to call them to see if they have the part(s) in stock. If so, I will take my truck to them tomorrow. If not, I'll take my chances on driving back to Texas later in the week.



Thanks again for the detailed and helpful reply.

 

[Bob4x4]

There is a TSB for that code,I have never had one come back after the tsb is performed (18-038-06)

 

[MullenaxM]

That bulletin, 18-038-06, applies to a 2007 cab and chassis.



Mike

 

[caddo_diesel_fan]

I called the dealer in Silverthorne, CO on Tuesday morning and the service writrer I spoke with insured me that I would be OK to drive the truck back to Texas. He told me pretty much the same thing Mike mentions above in regards to what this sensor does.



Thanks again for the input.

 

[oslaton]

The Exhaust Gas Pressure Sensor is used to measure exhaust gas pressure in the exhaust manifold. The Exhaust Gas Pressure Sensor provides a signal to the ECM on the exhaust gas pressure sensor signal circuit. At key on, the readings for the exhaust gas pressure, intake Manifold pressure and ambient air pressure are compared. This fault code occurs if the exhaust gas pressure reading is different from the other two. During normal engine operation EGR position and Boost Pressure Sensor readings are used to calculate an estimated exhaust pressure. If the difference between the estimated and the value read from the Exhaust Gas Pressure Sensor is above a calibrated threshold for a calibrated period of time then an error is recorded. The key-on portion of the rationality will light the CHECK ENGINE light immediately after the diagnostic runs and fails. The rationality portion has to fail in two consecutive drive cycles for the CHECK ENGINE light to become illuminated. If this fault becomes active the ECM will light the CHECK ENGINE light immediately. During this time the ECM uses an estimated exhaust gas pressure. The ECM turns off the CHECK ENGINE light when the diagnostic runs and passes in 4 consecutive drive cycles.



If you have the capability to turn the CHECK ENGINE light off and clear the trouble code I would try that first. Keep in mind as stated above this is a two trip fault, meaning it takes two drive cycles for this code to become active and turn on the CHECK ENGINE light on.



Most of the time when I see this code I end up having to replace the Exhaust Gas Pressure Sensor.



As far as driving back to Texas with this problem, I think you will be ok. This is not one of the codes that will suspend a regeneration event from happening.



Mike

I just got the P0471 code but also got the P0420 and P0137 along with it. They all seem to be related to the same sampling. Which one would the most likely suspect to be setting off the other two?

 

[KLauber]

Welcome!

I just got the P0471 code but also got the P0420 and P0137 along with it. They all seem to be related to the same sampling. Which one would the most likely suspect to be setting off the other two?

Welcome to TDR! Please include your truck info so we can reach deep into our collective brain(s) and provide the right answer (hopefully)!



Cheers,

Ken

 

[oslaton]

Sorry. Still getting set up.

2007. 5 6. 7L Black 2500 Laramie Mega Cab. Still stock. Doesn't need anything else. 137,000 miles and only been to dealer to do TSB's

 

[KLauber]

Sorry. Still getting set up.

2007. 5 6. 7L Black 2500 Laramie Mega Cab. Still stock. Doesn't need anything else. 137,000 miles and only been to dealer to do TSB's

Ok that will help one of our knowledgeable members... I am knowledgeable enough to say I don't know what to tell you!



Cheers,

Ken

 

[dlmetzger]

I just got the P0471 code but also got the P0420 and P0137 along with it. They all seem to be related to the same sampling. Which one would the most likely suspect to be setting off the other two?

I hope the following helps. Its from the Dodge Service Manual.





P0137-O2 SENSOR 1/2 CIRCUIT LOW



Theory of Operation



The engine aftertreatment system monitors the O2 content in the diesel engine exhaust. The ECM monitors the exhaust gases for oxygen content and varies the rich/lean fuel mixture of the intake air fuel mixture to adjust the system. This diagnostic monitors the status message broadcast by the Smart O2 sensor module for the downstream O2 sensor circuit. The ECM will set the fault if it receives a FMI (Failure Mode Indicator) message from the Smart O2 Module. The ECM will illuminate the MIL lamp immediately when the diagnostic runs and fails. The ECM will turn off the MIL lamp diagnostic runs and passes in four consecutive drive cycles.



When Monitored:

This diagnostic runs when the engine is running.



Set Condition:

The ECM will set the fault if it receives a FMI (Failure Mode Indicator) message from the Smart O2 Module.





Possible Causes



(K299) 02 1/2 HEATER SUPPLY CIRCUIT OPEN



(K80) 02 1/2 HEATER RETURN CIRCUIT OPEN



(K734) 02 1/2 PUMP CURRENT CIRCUIT OPEN



(K904) 02 1/2 RETURN CIRCUIT OPEN



(K733) 02 1/2 PUMP CELL CURRENT TRIM CIRCUIT OPEN



(K141) 02 1/2 SIGNAL CIRCUIT OPEN



O2 SENSOR MODULE





P0420-CATALYST EFFICIENCY BANK 1



Theory of Operation



The aftertreatment diesel oxidation catalyst is designed to react with hydrocarbons in the exhaust stream, this chemical reaction reduces hydrocarbon emission levels and also produces heat. Periodically, the ECM will utilize the heat generated by this reaction in the aftertreatment diesel oxidation catalyst to actively regenerate and clean the aftertreatment diesel particulate filter. This diagnostic checks that the aftertreatment diesel oxidation catalyst is present and functioning correctly. The ECM monitors the efficiency of the aftertreatment diesel oxidation catalyst through interpretation of data received from the aftertreatment diesel oxidation catalyst inlet and diesel particulate filter inlet temperature sensors, the monitor checks for a temperature rise across the aftertreatment diesel oxidation catalyst. The ECM will set the fault if it detects that the aftertreatment diesel oxidation catalyst is not present in the aftertreatment/exhaust system. The ECM will illuminate the MIL lamp immediately when the diagnostic runs and fails. The ECM will turn off the MIL lamp immediately after the diagnostic runs and passes.



When Monitored:

This diagnostic runs when the engine is running, and performing an active regeneration of the aftertreatment particulate filter.



Set Condition:

The ECM will set the fault if it detects that the aftertreatment diesel oxidation catalyst is not present in the aftertreatment/exhaust system.





Possible Causes



AFTERTREATMENT DIESEL OXIDATION CATALYST HAS BEEN REMOVED FROM THE VEHICLE



AFTERTREATMENT DIESEL OXIDATION CATALYST IS DAMAGED OR NOT FUNCTIONING PROPERLY



AFTERTREATMENT DIESEL OXIDATION CATALYST INLET AND/OR OUTLET TEMPERATURE SENSORS ARE DAMAGED/FAILED



IMPROPER FUELING



WIRING HARNESS

 

[Rico R]

I have a 2008 sterling bullet 6.7 cummins ..check engine came on ..code p0471 was a confirmed on the scanner ..so i clean my exhaust pressure sensor clean out the soot and all that good stuff...put it back together for 2 codes to come on its the same code p0471 one code reads its confirmed and the other is pending ..i dunno what this means...thanks in advice for helping me have a solution for this issue