I know the definitions to them but I'm wondering if anyone has had similar troubles. Cruising down the interstate today and truck down shifted and seemed to go into limp mode with the CEL on, fuel pedal wouldn't respond, then truck shifted back into overdrive and pedal felt fine. Did it twice. Also the cruise control will not work now. The cruise light does light when turned on. 2 weeks ago I had dead pedal at start up when it was -20* out side for a few minutes and seemed to surge a few times, I thought it was the fuel slightly jelling cause it went away when i gave it a stiff fresh dose of power service. 2004.5 cummins. Recieved all the codes listed above by cycling key when I got home. Thanks

 

This is to help others that may have had similar issues.

P2121-PPS CONFORMANCE ERROR

P2123-ACCELERATOR PEDAL POSITION
SENSOR 1 CIRCUIT HIGH

P0524-OIL PRESSURE TOO LOW

P0148-HIGH PRESSURE COMMON RAIL
(HPCR) CHECKSUM

Dead pedal is probably from the P2123 and limp mode could've been caused by either or all 4 of the codes. Let me try and find out what caused the codes.

 

P0148
OTHERS DTC’S PRESENT
FUEL LEAKS
FUEL CONTROL ACTUATOR
FUEL PRESSURE SENSOR
CASCADE OVERFLOW VALVE
CHECK VALVE DAMAGED OR BLOCKED
FUEL RETURN LINES OBSTRUCTION, DAMAGE, OR DEBRIS
LIFT PUMP FLOW
AIR IN FUEL SYSTEM
LEAKING FUEL INJECTORS OR HIGH PRESSURE CONNECTORS
PRESSURE LIMITING VALVE
HIGH PRESSURE FUEL PUMP
INTERMITTENT CONDITION

P0524
LOW OIL LEVEL
(G6) SIGNAL CIRCUIT SHORT TO GROUND
OIL PRESSURE SWITCH
INTERNAL ENGINE DAMAGE

P2121
OTHER DTC’S
WIRING HARNESS OR CONNECTOR DAMAGED
APPS
INTERMITTENT CONDITION
ECM

P2123
(K167) APPS NO. 1 RETURN CIRCUIT OPEN
(K23) APPS NO. 1 SIGNAL CIRCUIT SHORTED TO (K852) APPS NO. 1 5-VOLT SUPPLY
(K23) APPS SIGNAL CIRCUIT SHORTED TO ANOTHER CIRCUIT
ECM
APPS
INTERMITTENT CONDITION

Can try and reset the APPS and to do that, turn the key on, but do not start. Depress the accelerator pedal all the way down slowly, then let off all the way slowly. Turn the key off, then start the truck. Chances are, a trip to the dealer.

 

Thanks for your reply! I reset the APPS as you said, still all 4 codes come up. Everything seems fine now except for the cruise control not working. It would make sense to me that the APPS circuit effects the cruise control. I have a TST, Edge & Air dog, besides that everything is stock. I don't think the dealer would be helpful with them after market products, as far as covering with warrenty. Should a person call the dealer and explain the trouble and after market products and see what they say? Does anyone know of a good mechanic for the cummins around Duluth Minnnesota??

 

Apps.