DPF Pressure Sensor


 
 
DPF Pressure Sensor

This is where things get froggy and one has to experiment to figure out what works for their truck.

Generally when using a code clearing device such as the Edge J/A or PMT the pressure sensor should be left electrically connected but with the hoses removed like this.
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This is how I run with the old AG flash on my 07.5, I've run hundreds of mils without clearing codes and I've never seen a CAT FULL message or gone into derate mode.

Resist the temptation to connect the ports together as it can cause problems, if dirt is a concern hoses can routed up with little filters installed on the ends.

The 2nd way to do this is to unplug the sensor electrically (if you do this it really doesn't matter what you do with the physical ports) cover both connections with something to keep the elements out.

   


The downside to doing this is that it creates a 'hard code' that cannot be cleared with any of the usual code clearing mechanisms. It has been suggested that this might eliminate the CAT FULL messages and dinging on later flashes but will leave a constant CEL, I don't believe this will cause a derate.

Now for the DPF pressure fooler - this has allowed for 'code free' DPF delete operation on some trucks that do not have the EGR deleted, this has also eliminated the overhead CAT FULL messages and constant dinging on some trucks but the success of this mod seems to be related to which version of flash one has.

Parts required -

qty 1 390 ohm resistor 1/2 watt
qty 1 110 ohm resistor 1/2 watt

These can usually be found at Radio Shack but you might have to get the $6 grab bag of resistors to find them; if you got the grab bag for the EGT sim resistors then these values are probably in the bag.

Resistor color codes -

(The first 3 bands are most important and must match the pictures below) some have said that a 100 ohm will work in place of the 110.
   


Wiring -

Viewed as the plug is facing you while looking up at it.

   


One must be creative when wiring this in, several folks on here are trying to source the connectors so that this can be done the correct way.
slagburn is offline Quick reply to this message
   
 
 
CODES

Here is a summary of codes that I've seen with my DIY DPF delete - to the best of my knowledge these are harmless and they are all capable of being cleared with a code clearing box.

P2080-EXHAUST GAS TEMP SENSOR CIRCUIT PERFORMANCE - BANK 1 SENSOR 1
P2084-EXHAUST GAS TEMP SENSOR CIRCUIT PERFORMANCE - BANK 1 SENSOR 2
P242B-EXHAUST GAS TEMP SENSOR CIRCUIT PERFORMANCE - BANK 1 SENSOR 3 - DIESEL

These are sporadic, I'm certain that my connections are good and thus far the only thing I've come up with is that my ECM gets cranky when it see fixed EGT values that don't change with engine warm up. I've datalogged the EGT sensors when these codes occur and haven't seen anything that points to faulty connections as the culprit.

P244A-DIESEL PARTICULLATE FILTER DIFFERENTIAL PRESSURE TOO LOW
P2453-DIESEL PARTICULATE FILTER PRESSURE SENSOR A CIRCUIT PERFORMANCE

Both of these are regular codes for me, I assume they are because the DPF pressure sensor never changes since the ports aren't connected. I am NOT running a DPF pressure fooler (yet) so I don't know if using one would eliminate these codes.

P2454-DIESEL PARTICULATE FILTER PRESSURE SENSOR A CIRCUIT LOW

This code only came up when the DPF pressure sensor was electrically disconnected, it could not be cleared with a code clearing box and did not appear to derate the engine in anyway.

The following are bad codes and mean that an engine derate has occurred as a result of something not working correctly with the delete system.

P242F-DIESEL PARTICULATE FILTER RESTRICTION - ASH ACCUMULATION
P1451-DIESEL PARTICULATE FILTER SYSTEM PERFORMANCE

Generally these codes cannot be cleared with a standard scan tool, in some cases reinstallation of the DPF system and a long highway drive (enough distance for a successful regen to be performed) have cleared these codes and underated the engine.

 

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