Need help with a code?

Mike08Liberty · **Posted:** Mon Apr 11, 2011 11:09 pm

I was driving around today and threw an PO401 code. It's "EGR Flow Insufficient".
Anyone have any ideas? I only have 3700 miles on the truck.

Most of the research I've done I've seen the code related to diesel vehicles. Do non turbo-diesel engines have EGR valves?

I've cleared the code to see if it comes back. I'll keep you posted, thanks for any help.

Diggerfreek · **Posted:** Mon Apr 11, 2011 11:36 pm

Interesting....

I will see if I can find any thing for you...

Mike08Liberty · **Posted:** Tue Apr 12, 2011 2:29 pm

Driving around today and the code came back ... Dealership time???

Diggerfreek · **Posted:** Tue Apr 12, 2011 11:00 pm

Yeah, I would say it's time :furious:

The valve and solenoid are one unit

Mike08Liberty · **Posted:** Wed Apr 13, 2011 4:37 pm

The code is gone now ... I went and got gas lastnight and it seemed the gas cap wasn't fully snug which is odd considering I spin it a full circle after it locks. The code is now gone and hasn't come back yet. I'll keeo the thread posted if it comes back but if that was the cause I wonder the the "EGR" has to do with it. Correct me if I'm wrong but isn't EGR "Exhaust Gas Recirculation".

Diggerfreek · **Posted:** Wed Apr 13, 2011 7:51 pm

Yeah, that is what EGR stands for..... Also to my knowledge, the gas cap would set a different code pertaining to a vacuum leak or I think the KK will display a message in the instrument cluster....

Mike08Liberty · **Posted:** Thu Apr 14, 2011 10:29 pm

Thats what I thought too but that's all I could think of. It's gone an hasnt been back. It turned off on it's own and the only thing different is the gas cap. Weird ...

Diggerfreek · **Posted:** Thu Apr 14, 2011 11:11 pm

I want a KK that will fix it self :jester:

KK.SA · **Joined:** Wed Oct 27, 2010 3:17 pm **Posts:** 25

P0401-EGR SOLENOID CIRCUIT NEGATIVE DEVIATION.

Possible Causes as follow:-

AIR FILTER (check the air filter , check also the wires connected to the filter housing).

AIR RESTRICTION (check all intake and exhaust pipes and connection for restriction or lose connection).

CHECKING FOR AIR LEAKS (Remove the Crankcase Vent Heater.
Remove the Mass Air Flow Sensor from the turbocharger inlet tube.
Seal off and/or plug the turbocharger inlet tube where the MAF sensor was removed.
Connect smoke machine 84–04 to the Crankcase Vent Heater port in the intake duct and begin injecting smoke into the intake system.
Observe all intake system components for evidence of smoke leakage).

CHECKING THE EGR AIR FLOW CONTROL VALVE (require scan star tool to do the job)

CHECKING THE EGR COOLER AND TUBES (Turn the ignition off.
Gain access to and inspect the EGR Cooler and both tubes that connect to the EGR Cooler. Check tubes and cooler for damage, leaks, excessive carbon build up and other problems that could restrict or prevent proper exhaust gas flow.
NOTE: Compressed air ( at low pressure ) can be applied to the lower port of the EGR Cooler. When applying compressed air check for air to flow through cooler and out the upper port).

EGR VALVE

Hopefully this would help.

KK.SA · **Joined:** Wed Oct 27, 2010 3:17 pm **Posts:** 25

P0401-EGR SOLENOID CIRCUIT NEGATIVE DEVIATION.

Possible Causes as follow:-

AIR FILTER (check the air filter , check also the wires connected to the filter housing).

AIR RESTRICTION (check all intake and exhaust pipes and connection for restriction or lose connection).

CHECKING FOR AIR LEAKS (Remove the Crankcase Vent Heater.
Remove the Mass Air Flow Sensor from the turbocharger inlet tube.
Seal off and/or plug the turbocharger inlet tube where the MAF sensor was removed.
Connect smoke machine 84–04 to the Crankcase Vent Heater port in the intake duct and begin injecting smoke into the intake system.
Observe all intake system components for evidence of smoke leakage).

CHECKING THE EGR AIR FLOW CONTROL VALVE (require scan star tool to do the job)

CHECKING THE EGR COOLER AND TUBES (Turn the ignition off.
Gain access to and inspect the EGR Cooler and both tubes that connect to the EGR Cooler. Check tubes and cooler for damage, leaks, excessive carbon build up and other problems that could restrict or prevent proper exhaust gas flow.
NOTE: Compressed air ( at low pressure ) can be applied to the lower port of the EGR Cooler. When applying compressed air check for air to flow through cooler and out the upper port).

EGR VALVE

Hopefully this would help.

KK.SA · **Joined:** Wed Oct 27, 2010 3:17 pm **Posts:** 25

P0401-EGR SOLENOID CIRCUIT NEGATIVE DEVIATION.

Possible Causes as follow:-

AIR FILTER (check the air filter , check also the wires connected to the filter housing).

AIR RESTRICTION (check all intake and exhaust pipes and connection for restriction or lose connection).

CHECKING FOR AIR LEAKS (Remove the Crankcase Vent Heater.
Remove the Mass Air Flow Sensor from the turbocharger inlet tube.
Seal off and/or plug the turbocharger inlet tube where the MAF sensor was removed.
Connect smoke machine 84–04 to the Crankcase Vent Heater port in the intake duct and begin injecting smoke into the intake system.
Observe all intake system components for evidence of smoke leakage).

CHECKING THE EGR AIR FLOW CONTROL VALVE (require scan star tool to do the job)

CHECKING THE EGR COOLER AND TUBES (Turn the ignition off.
Gain access to and inspect the EGR Cooler and both tubes that connect to the EGR Cooler. Check tubes and cooler for damage, leaks, excessive carbon build up and other problems that could restrict or prevent proper exhaust gas flow.
NOTE: Compressed air ( at low pressure ) can be applied to the lower port of the EGR Cooler. When applying compressed air check for air to flow through cooler and out the upper port).

EGR VALVE

Hopefully this would help.

drjecod · **Joined:** Wed Jun 15, 2011 9:45 am **Posts:** 4

Just threw the same SES code at 2600 miles on my 2011. Our situations sound very similar, so it may be safe to assume that we were dealing with the same issue. I can say that all it took was a flash update for EGR performance at the dealership to remedy the problem for me - took about ten minutes if anyone else runs into the same problem.

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