P2121........................I get this one and P2122 and P2123 from time to time.  I really think it's got something to do with the fan clutch thing that I linked a while back in another thread.

 

Here's another link from CompD about it........http://www.competitiondiesel.com/forums/showthread.php?t=136329

 

Pay attention to TxDiesel007's posts about this.

Edited July 17, 201410 yr by dorkweed

Throttle position sensor

Lots of pickups have the fan code its nothing to worry about

I lifted my 03 and the wire attached to the clutch fan was severed and it throws codes all the time.  I never fixed it.  But with the wire unattached the air does not work when at idle on when going down the road.

 

Dork, is it just the codes or does the engine act up?

I lifted my 03 and the wire attached to the clutch fan was severed and it throws codes all the time.  I never fixed it.  But with the wire unattached the air does not work when at idle on when going down the road.

 

Dork, is it just the codes or does the engine act up?

 

When it codes, I get a really touchy accelerator.  Like nothing, and then it fuels hard all at once.  I've never checked the fan clutch wiring.  

 

This only happens maybe once per year.  There's no commonality as to when it happens either.................sometimes Summer, sometimes Winter etc.

 

I don't worry about it much, as I can clear the code with my Smarty...................then all is good.

I think the 03's have a lot of connector issues.  I just checked mine and found 9 codes..haha

Found my old list of codes today incase you don't have one.  Well not mine but a list I got online awhile ago.

 

 

 

Here is an "almost" complete list of 3rd Gen codes. Every year, as DC migrates more hardware to software, they invent new codes for those systems. This is what I have for my 2003. There are a few new ones for the 04.5 and up trucks that I can’t find right now. If anyone has the new additions, feel free to add.

 

There are two categories, P-Codes and C-Codes. P-Codes are engine related. C-Codes are support system related, as in your instrument cluster. When checking codes, "P" codes are self explanatory as it will show up with a "P" at the beginning. C-Codes will just give you two sets of numbers with a space in the middle, like "01 00". The first set of numbers is the code. The second set is the number of engine restarts that have taken place since the code was set. Gives you a good indication of how long ago it was.

 

 

P-Codes

 

P0016 Crankshaft/Camshaft Timing Misalignment/Out-of-Sync

P0071 Ambient Temperature Sensor Performance / Rationality

P0072 Ambient Temperature Sensor Low

P0073 Ambient Temperature Sensor High

P0088 Fuel Rail Pressure Too High

P0106 Manifold Absolute Pressure Sensor Performance / Rationality

P0107 Manifold Absolute Pressure Sensor Low

P0108 Manifold Absolute Pressure Sensor High

P0111 Intake Air / Charge Temperature Sensor Performance / Rationality

P0112 Intake Air / Charge Temperature Sensor Low

P0113 Intake Air / Charge Temperature Sensor High

P0116 Engine Coolant Temperature Sensor Performance / Rationality

P0117 Engine Coolant Temperature Sensor Low

P0118 Engine Coolant Temperature Sensor High

P0128 Cooling System Error / Thermostat Rationality

P0148 Fuel Delivery Error

P0169 Water-in-Fuel Detected For Too Long

P0192 Fuel Rail Pressure Sensor Low

P0193 Fuel Rail Pressure Sensor High

P0201 Fuel Injector 1 Circuit

P0202 Fuel Injector 2 Circuit

P0203 Fuel Injector 3 Circuit

P0204 Fuel Injector 4 Circuit

P0205 Fuel Injector 5 Circuit

P0206 Fuel Injector 6 Circuit

P0217 Coolant Temperature Too High

P0219 Engine Overspeed

P0234 Turbocharger Overboost Condition

P0236 Turbocharger Boost Pressure Sensor Performance / Rationality

P0237 Turbocharger Boost Pressure Sensor Low

P0238 Turbocharger Boost Pressure Sensor High

P0251 Injection Pump Fuel Valve Feedback

P0300 Multiple Cylinder Misfire

P0301 Cylinder 1 Misfire

P0302 Cylinder 2 Misfire

P0303 Cylinder 3 Misfire

P0304 Cylinder 4 Misfire

P0305 Cylinder 5 Misfire

P0306 Cylinder 6 Misfire

P0335 Crankshaft Position Sensor Circuit

P0336 Crankshaft Position Sensor Performance

P0337 Crankshaft Position Sensor Circuit Low

P0338 Crankshaft Position Sensor Circuit High

P0340 Camshaft Position Sensor Circuit

P0341 Camshaft Position Sensor Performance / Rationality

P0381 Wait-to-Start Lamp Inoperative

P0461 Fuel Level Sensor 1 Performance / Rationality

P0462 Fuel Level Sensor 1 Low

P0463 Fuel Level Sensor 1 High

P0477 Exhaust Pressure Control Relay Low

P0478 Exhaust Pressure Control Relay High

P0480 Cooling Fan 1 Control Circuit/Open (Low Speed Fan Relay)

P0483 Cooling Fan Speed

P0500 Vehicle Speed Sensor 1 Circuit, or No Vehicle Speed Reference Signal 1

P0514 Battery Temperature Sensor Performance / Rationality

P0516 Battery Temperature Sensor Low

P0517 Battery Temperature Sensor High

P0521 Oil Pressure Sensor Performance / Rationality

P0524 Oil Pressure Too Low

P0532 A/C Pressure Sensor Low

P0533 A/C Pressure Sensor High

P0541 Intake Air Heater Relay 1 Low

P0542 Intake Air Heater Relay 1 High

P0562 Battery Voltage Low

P0563 Battery Voltage High

P0572 Brake Switch 1 Low

P0573 Brake Switch 1 High

P0580 Speed Control Multiplexed Switch 1 Low

P0581 Speed Control Multiplexed Switch 1 High

P0602 Control Module Programming Error/NotProgrammed

P0604 Internal Control Module RAM Integrity Failure

P0606 Internal ECM Processor

P0607 ECU Internal Performance

P0622 Generator Field Control Circuit

P0628 Fuel Pump Relay Circuit Low, or Fuel Lift Pump Control Circuit Low

P0629 Fuel Pump Relay Circuit High, or Fuel Lift Pump Control Circuit High

P0630 VIN Not Programmed in PCM

P0633 SKIM Key Not Programmed in PCM

P0642 Sensor Reference Voltage 1 Circuit Low

P0643 Sensor Reference Voltage 1 Circuit High

P0646 A/C Clutch Relay Circuit Low

P0647 A/C Clutch Relay Circuit High

P0652 Sensor Reference Voltage 2 Circuit Low

P0653 Sensor Reference Voltage 2 Circuit High

P0698 Sensor Reference Voltage 3 Circuit Low

P0699 Sensor Reference Voltage 3 Circuit High

P0700 Transmission Control System (MIL Request)

P0837 Four Wheel Drive (4WD) Switch Performance / Rationality

P0838 Four Wheel Drive (4WD) Switch Circuit Low

P0839 Four Wheel Drive (4WD) Switch Circuit High

P1652 J1850 Communication Bus

P2121 Pedal Position Sensor 1 Performance / Rationality

P2122 Pedal Position Sensor 1 Low

P2123 Pedal Position Sensor 1 High

P2127 Pedal Validation Switch 2 Low

P2128 Pedal Validation Switch 2 High

P2146 Fuel Injector Group 1 Supply Voltage Circuit

P2149 Fuel Injector Group 2 Supply Voltage Circuit

P2266 Water in Fuel Sensor Circuit Low

P2269 Water in Fuel Condition

P2502 Charging System Output Voltage

P2503 Charging System Output Low

P2504 Charging System Output High

P2509 ECM/PCM Power Input Signal Intermittent

P2607 Intake Air Heater Relay 2 Low

P2608 Intake Air Heater Relay 2 High

P2609 Intake Air Heater System Performance

 

 

C-Codes

 

01 Airbag warning indicator output circuit shorted. Refer to the appropriate

diagnostic information.

02 Airbag warning indicator output circuit open. Refer to the appropriate

diagnostic information.

03 ABS indicator output circuit shorted. Refer to the appropriate diagnostic

information.

04 ABS indicator output circuit open. Refer to the appropriate diagnostic

information.

05 MIL indicator output circuit shorted. Refer to the appropriate diagnostic

information.

06 MIL indicator output circuit open. Refer to the appropriate diagnostic

information.

07 Wait to start indicator circuit shorted. Refer to the appropriate

diagnostic information.

08 Wait to start indicator circuit open. Refer to the appropriate diagnostic

information.

0B BTSI output circuit shorted or open. Refer to the appropriate diagnostic

information.

22 Headlamp switch input circuit shorted. Refer to the appropriate

diagnostic information.

23 Headlamp switch input circuit open. Refer to the appropriate diagnostic

information.

24 Turn hazard switch input circuit shorted. Refer to the appropriate

diagnostic information.

25 Turn hazard swiitch inpot circuit open. Refer to the appropriate

diagnostic information.

27 Courtesy/dome output circuit shorted or open. Refer to the appropriate

diagnostic information.

28 Glovebox/map lamp output circuit shorted or

open.

Refer to the appropriate diagnostic information.

29 Cargo lamp output circuit shorted or open. Refer to the appropriate

diagnostic information.

40 Wiper switch input circuit shorted. Refer to the appropriate diagnostic

information.

41 Wiper switch input circuit open. Refer to the appropriate diagnostic

information.

42 Wash/beam input circuit shorted. Refer to the appropriate diagnostic

information.

60 Passenger door lock switch input circuit

shorted.

Refer to the appropriate diagnostic information.

61 Passenger door lock switch input circuit open. Refer to the appropriate

diagnostic information.

62 Passenger door lock switch input circuit stuck. Refer to the appropriate

diagnostic information.

63 Driver door lock switch input circuit shorted. Refer to the appropriate

diagnostic information.

64 Driver door lock switch input circuit open. Refer to the appropriate

diagnostic information.

65 Driver door lock switch input circuit stuck. Refer to the appropriate

diagnostic information.

66 All door lock output circuit shorted to ground

or voltage.

Refer to the appropriate diagnostic information.

67 All door unlock output circuit shorted to

ground or voltage.

Refer to the appropriate diagnostic information.

68 Driver door unlock output circuit shorted to

ground or voltage.

Refer to the appropriate diagnostic information.

6C Driver cylinder lock switch input circuit

shorted.

Refer to the appropriate diagnostic information.

6E Driver cylinder lock switch input circuit stuck. Refer to the appropriate

diagnostic information.

80 Incorrect odometer value found. Refer to the appropriate diagnostic

information.

81 Remote radio switch input circuit high. Refer to the appropriate

diagnostic information.

82 Remote radio switch stuck. Refer to the appropriate diagnostic

information.

A0 Internal module FLASH memory checksum

failure.

Refer to the appropriate diagnostic information.

A1 Internal module bootloader failure. Refer to the appropriate diagnostic

information.

A3 Battery voltage open. Refer to the appropriate diagnostic information.

A5 TCCM messages not received. Refer to the appropriate diagnostic

information.

A7 VIN checksum error. Refer to the appropriate diagnostic information.

A8 VIN previously stored. Refer to the appropriate diagnostic information.

A9 PCI bus internal failure. Refer to the appropriate diagnostic

information.

AA PCM messages not received. Refer to the appropriate diagnostic

information.

AB TCM messages not received. Refer to the appropriate diagnostic

information.

AC ABS messages not received. Refer to the appropriate diagnostic

information.

AD FCM messages not received. Refer to the appropriate diagnostic

information.

AE ACM messages not received. Refer to the appropriate diagnostic

information.

AF SKIM messages not received. Refer to the appropriate diagnostic

information.

B0 RKE fob batteries low. Refer to the appropriate diagnostic information.

B1 RKE module communication link. Refer to the appropriate diagnostic

information.

00 Done All Diagnostic Trouble Codes (DTC) have been

displayed.