Dodge >> Ram Truck 5.9/6.7L Turbo Diesel (2003 – 2008)

Model Year Engine identification System
Ram Truck 5.9/6.7L Turbo Diesel 2003-08 ETC/ETH  (VIN  8 = A)   Cummins CM845

General information

  • Malfunction indicator lamp (MIL) will illuminate or flash if certain faults are recorded .
  • ECM operates in backup mode if sensors fail , to enable vehicle to be driven to repair shop.


• Trouble codes can only be displayed by using a Scan Tool connected to the data link connector (DLC) 1


• Trouble codes can only be erased by using a Scan Tool connected to the data link connector (DLC).

Trouble code  identification

Scan code Fault location Probable cause
PO,P2,UO Refer to OBO·II trouble code tables
P113C Oxygen sensor (02S), control module Wiring, connections, 025 control module
supply voltage circuit malfunction
P125A Power enable control circuit -voltage low Wiring, ECM
P125B Power enable control circuit -voltage high Wiring, ECM
P1272 A/C compressor clutch, circuit 2 -voltage low Wiring, A/C compressor clutch, ECM
P1273 A/C compressor clutch, circuit 2 -voltage high Wiring, A/C compressor clutch, ECM
P1274 A/C compressor clutch, circuit 2 -open circuit Wiring, A/C compressor clutch, ECM
P1275 A/C compressor clutch, circuit 2 –circuit malfunction Wiring, A/C compressor clutch, ECM
P1277 Starter control circuit 2 voltage low Wiring, starter, powertrain control module (PCM)
P1278 Starter control circuit 2 -voltage high Wiring, starter, powertrain control module (PCM)
P1279 Starter control circuit 2 -open Wiring, starter, powertrain control module (PCM)
P127A Starter control circuit 2 -high resistance Wiring, starter, powertrain control module (PCM)
P127C Fuel pump, circuit 2 -voltage low Wiring, fuel pump, ECM
P127D Fuel pump, circuit 2 -voltage high Wiring, fuel pump, ECM
P127E Fuel pump, circuit 2 -open circuit Wiring, fuel pump, ECM
P141A Exhaust gas temperature (EGT) sensor 1 & 2 -interchanged Wiring, connectors swapped, diesel particulate filter (OPF)
P144E , Exhaust gas recirculation (EGR) -circuit voltage low Wiring, EGR valve, ECM
P144F Exhaust gas recirculation (EGR) -circuit voltagehigh Wiring, EGR valve, ECM
P1451 Diesel particulate filter (DPF) full EGT low, mechanical fault, exhaust leak
P1484 Diesel particulate filter (DPF) temperature toohigh Fuel, injector, EGT sensor, mechanical fault
P1506 Crankcase pressure sensor range/performance Crankcase pressure sensor
P1507 Crankcase pressure sensor range/performance Crankcase breather filter
P1508 Crankcase pressure sensor range/performance Crankcase breather filter, mechanical fault
P1652 CAN data bus -short circuit to ground Wiring, connected system, ECM
P1740 Torque converter clutch (TCC)/overdrive solenoid -performance problem Other trouble code(s) stored, TCC, overdrive solenoid, transmission mechanical fault
P1756 Governor pressure not equal to target (35-40 PSI) Wiring, valve body, sensor supply wire open circuit, transmission fluid level, governor pressure sensor, governor pressure solenoid, transmission mechanical fault, TCM
P1757 Governor pressure not equal to target (above 3 PSI at 0 mph) -pressure malfunction Wiring, valve body, sensor supply wire open circuit, transmission fluid level, governor pressure sensor, governor pressure solenoid, transmission oil contaminated, transmission mechanical fault,TCM
P1762 Governor pressure sensor -incorrect signal Wiring, supply wire open circuit/short circuit, governor pressure solenoid, governor pressure sensor, transmission fluid level, transmission mechanical fault, TCM
P1763 Governor pressure sensor -signal high Signal wire short circuit to positive, supply wire open circuit, transmission fluid level, governor pressure sensor, TCM
P1764 Govemor pressure sensor -signal low Signal wire short circuit to ground, supply wire open circuit, transmission fluid level, governor pressure sensor, TCM
P1765 Transmission system relay Wiring open circuit/short circuit, transmission system relay, TCM
U1403 Fuel level, serial communication -implausiblesignal Wiring, instrument panel, CAN data bus,multifunction control module front, ECM
U1412 Vehicle speed, serial communication -implausible signal CAN data bus, ABS control module, ECM
U1421 Fuel volume, serial communication implausible signal Wiring, instrument panel, CAN data bus, multifunction control module front, ECM