C Codes
C1312 | Retarder request sensor circuit low
C1313 | Retarder request sensor circuit high
P Codes
P0122 | Pedal position sensor circuit low voltage
P0123 | Pedal position sensor circuit high voltage
P0218 | Transmission fluid over temperature condition
P0561 | System voltage performance
P0562 | System voltage low
P0563 | System voltage high
P0600 | Internal SPI diagnostics
P0602 | TCM not programmed
P0603 Internal control module keep alive memory error
P0604 | Control module random access memory (RAM) error
P0607 | Control module performance
P060C | Internal control module main processor performance
P0610 | Transid incompatible
P0614 | Torque control data mismatch – ECM/TCM
P0634 | TCM internal temperature too high
P0642 | Sensor reference voltage “A” circuit fault
P0657 | Actuator supply circuit voltage 1 open (HSD1)
P0658 | Actuator supply circuit voltage 1 low (HSD1)
P0659 | Actuator supply circuit voltage 1 high (HSD1)
P0701Transmission control system performance
P0703 | Brake switch circuit
P0706 | Transmission range sensor circuit performance
P0708 | Transmission range sensor circuit high
P070C | Transmission fluid level circuit low
P070D | Transmission fluid level circuit high
P0711 | Transmission fluid temperature sensor circuit
performance
P0712 | Transmission fluid temperature sensor circuit low
P0713 | Transmission fluid temperature sensor circuit high
P0715 | Turbine speed sensor circuit
P0716 | Turbine shaft speed sensor circuit performance
P0717 | Turbine shaft speed sensor circuit no activity
P071A | Neutral at stop input failed on
P071D | General purpose input fault
P0720 | Output shaft speed sensor circuit
P0721 | Output shaft speed sensor circuit performance
P0722 | Output shaft speed sensor circuit no signal
P0725 | Engine speed sensor circuit
P0726 | Engine speed sensor circuit performance
P0727 | Engine speed sensor circuit no signal
P0729 | Incorrect 6th gear ratio
P0731 | Incorrect 1st gear ratio
P0732 | Incorrect 2nd gear ratio
P0733 | Incorrect 3rd gear ratio
P0734 | Incorrect 4th gear ratio
P0735 | Incorrect 5th gear ratio
P0736 | Incorrect reverse ratio
P0741 | Torque converter clutch (TCC) system stuck off
P0742 | Torque converter clutch (TCC) system stuck on
P0751 | Shift solenoid 1 valve performance – stuck off
P0752 | Shift solenoid 1 valve performance – stuck on
P0756 | Shift solenoid 2 valve performance – stuck off
P0757 | Shift solenoid 2 valve performance – stuck on
P0761 | Shift solenoid 3 valve performance – stuck off
P0762 | Shift solenoid 3 valve performance – stuck on
P0776 | Pressure control solenoid (PCS) 2 stuck off
P0777 | Pressure control solenoid (PCS) 2 stuck on
P077F | Incorrect reverse 2 ratio
P0796 | Pressure control solenoid (PCS) 3 stuck off
P0797 | Pressure control solenoid (PCS) 3 stuck on
P07CE | NAS not functioning
P0837 | Four wheel drive (4WD) switch circuit performance
P0842 | Transmission fluid pressure switch 1 circuit low
P0843 | Transmission fluid pressure switch 1 circuit high
P0847 | Transmission fluid pressure switch 2 circuit low
P0848 | Transmission fluid pressure switch 2 circuit high
P0872 | Transmission fluid pressure switch 3 circuit low
P0873 | Transmission fluid pressure switch 3 circuit high
P0877 | Transmission fluid pressure switch 4 circuit low
P0878 | Transmission fluid pressure switch 4 circuit high
P0880 | TCM power input signal
P0881 | TCM power input signal performance
P0882 | TCM power input signal low
P0883 | TCM power input signal high
P088A | Transmission filter maintenance alert
P088B | Transmission filter maintenance required
P0894 | Unexpected mechanical gear disengagement
P0897 | Transmission fluid deteriorated
P0960 | Main pressure modulation solenoid control circuit open
P0961 | Main pressure modulation solenoid system
performance
P0962 | Main pressure modulation solenoid control circuit low
P0963 | Main pressure modulation solenoid control circuit high
P0964 | Pressure control solenoid (PCS) 2 control circuit open
P0965 | Pressure control solenoid (PCS) 2 control circuit
performance
P0966 | Pressure control solenoid (PCS) 2 control circuit low
P0967 | Pressure control solenoid (PCS) 2 control circuit high
P0968 | Pressure control solenoid (PCS) 3 control circuit open
P0969 | Pressure control solenoid (PCS) 3 control circuit
performance
P0970 | Pressure control solenoid (PCS) 3 control circuit low
P0971 | Pressure control solenoid (PCS) 3 control circuit high
P0973 | Shift solenoid 1 control circuit low
P0974 | Shift solenoid 1 control circuit high
P0976 | Shift solenoid 2 control circuit low
P0977 | Shift solenoid 2 control circuit high
P0979 | Shift solenoid 3 control circuit low
P097A | Shift solenoid 1 control circuit open
P097B | Shift solenoid 2 control circuit open
P097C | Shift solenoid 4 control circuit open
P0980 | Shift solenoid 3 control circuit high
P0989 | Retarder pressure circuit low
P0990 | Retarder pressure circuit high
P1739 | Incorrect low gear ratio
P1790 | Gear shift module 1 calibration invalid
P1791 | Gear shift module 2 calibration invalid
P1891 | Throttle position sensor PWM signal low
P1892 | Throttle position sensor PWM signal high
P2184 | Engine coolant temperature sensor 2 circuit low
P2185 | Engine coolant temperature sensor 2 circuit high
P2534 | Ignition switch run/start circuit low
P2535 | Ignition switch run/start circuit high
P2637 | Torque management feedback signal “A” (SEM)
P2641 | Torque management feedback signal “B” (LRTP)
P2669 | Actuator supply circuit voltage 2 open (HSD2)
P2670 | Actuator supply circuit voltage 2 low (HSD2)
P2671 | Actuator supply circuit voltage 2 high (HSD2)
P2684 | Actuator supply circuit voltage 3 open (HSD3)
P2685 | Actuator supply circuit voltage 3 low (HSD3)
P2686 | Actuator supply circuit voltage 3 high (HSD3)
P2714 | Pressure control solenoid (PCS) 4 stuck off
P2715 | Pressure control solenoid (PCS) 4 stuck on
P2718 | Pressure control solenoid (PCS) 4 control circuit open
P2719 | Pressure control solenoid (PCS) 4 control circuit
performance
P2720 | Pressure control solenoid (PCS) 4 control circuit low
P2721 | Pressure control solenoid (PCS) 4 control circuit high
P2723 | Pressure control solenoid (PCS) 1 stuck off
P2724 | Pressure control solenoid (PCS) 1 stuck on
P2727 | Pressure control solenoid (PCS) 1 control circuit open
P2728 | Pressure control solenoid (PCS) 1 control circuit
performance
P2729 | Pressure control solenoid (PCS) 1 control circuit low
P2730 | Pressure control solenoid (PCS) 1 control circuit high
P2736 | Pressure control solenoid (PCS) 5 control circuit open
P2738 | Pressure control solenoid (PCS) 5 control circuit low
P2739 | Pressure control solenoid (PCS) 5 control circuit high
P273F | Retarder oil temperature sensor over temperature
condition
P2742 | Retarder oil temperature sensor circuit low
P2743 | Retarder oil temperature sensor circuit high
P2761 | Torque converter clutch (TCC) pressure control
solenoid (PCS) control circuit open
P2762 | Torque converter clutch (TCC) pressure control
solenoid (PCS) control circuit performance
P2763 | Torque converter clutch (TCC) pressure control
solenoid (PCS) control circuit high
P2764 | Torque converter clutch (TCC) pressure control
solenoid (PCS) control circuit low
P2789 | Transmission clutch life expired (clutch adaptive learning at limit)
P2793 | Gear shift direction circuit
P2808 | Pressure control solenoid (PCS) 6 stuck off
P2809 | Pressure control solenoid (PCS) 6 stuck on
P2812 | Pressure control solenoid (PCS) 6 control circuit open
P2814 | Pressure control solenoid (PCS) 6 control circuit low
P2815 | Pressure control solenoid (PCS) 6 control circuit high
U Codes
U0073 | CAN communication bus 1 off
U0074 | CAN communication bus 2 off
U0100 | Lost communication with ECM A
U0103 | Lost communication with gear shift module 1
U0291 | Lost communication with gear shift module 2
U0291 | Lost communication with gear shift module 2
U0304 | Gear shift module 1 incompatible
U0333 | Gear shift module 2 incompatible
U0400 | Invalid CAN communication
U0404 | Gear shift module 1 invalid data
U0592 | Gear shift module 2 invalid data
P Codes for 6th Gen Controls
P0652 | Sensor reference voltage “B” circuit fault
P070F | Transmission fluid level low
P075F | Transmission fluid level high
P076F | Incorrect 7th gear ratio
P085D | Gear shift module 1 direction mismatch
P085E | Gear shift module 2 direction mismatch
P27B2 | Internal control module transmission range control
performance
P27B4 | Output shaft direction plausibility
P27B6 | Output shaft speed sensor plausibility
P2813 | Pressure control solenoid (PCS) 6 control circuit
performance
U1401 | TSC1 Engine imposter detection
U1402 | TSC1 C brake imposter detection
U1403 | TSC1 E brake imposter detection
WTEC II and III Codes
1312 | ECU input voltage low
1313 | ECU input voltage medium low
1323 | ECU input voltage high
1412 | Oil level sensor, failed low
1423 | Oil level sensor, failed high
2112 | Throttle position sensor, failed low
2123 | Throttle position sensor, failed high
2214 | Engine speed sensor
2215 | Turbine speed sensor
2216 | Output speed sensor
2312 | Primary shift selector fault
2313 | Primary shift selector mode fault
2314 | Secondary shift selector fault
2315 | Secondary shift selector mode fault
2316 | Shift selector display inline fault
2412 | Sump fluid temperature, cold
2423 | Sump fluid temperature, hot
2500 | Output speed sensor @ 0 RPM, low
2511 | Output speed sensor @ 0 RPM, 1st
2522 | Output speed sensor @ 0 RPM, 2nd
2533 | Output speed sensor @ 0 RPM, 3rd
2544 | Output speed sensor @ 0 RPM, 4th
2555 | Output speed sensor @ 0 RPM, 5th
2566 | Output speed sensor @ 0 RPM, 6th
2577 | Output speed sensor @ 0 RPM, reverse
2600 | Throttle source not detected
2611 | Engine coolant source not detected
3200 | C3 pressure switch open in low
3233 | C3 pressure switch open in 3rd
3255 | C3 pressure switch open in 5th
3312 | Sump oil temperature sensor, failed low
3323 | Sump oil temperature sensor, failed high
3412 | Calibration compatibility wrong
3413 | Calibration block checksum
3414 | Power off block checksum
3415 | Diagnose queue block checksum
3416 | Real time block checksum
3417 | Customer modifiable constants checksum
3500 | Power interruption
3516 | Real time write interruption
3600 | Hardware/software not compatible
3601 | TID not compatible with hardware/software
3602 | TID did not complete
4212 | A solenoid shorted to battery
4213 | B solenoid shorted to battery
4214 | C solenoid shorted to battery
4215 | D solenoid shorted to battery
4216 | E solenoid shorted to battery
4221 | F solenoid shorted to battery
4222 | G solenoid shorted to battery
4223 | H solenoid shorted to battery
4224 | J solenoid shorted to battery
4226 | N solenoid shorted to battery
4412 | A solenoid shorted to ground
4413 | B solenoid shorted to ground
4414 | C solenoid shorted to ground
4415 | D solenoid shorted to ground
4416 | E solenoid shorted to ground
4421 | F solenoid shorted to ground
4422 | G solenoid shorted to ground
4423 | H solenoid shorted to ground
4424 | J solenoid shorted to ground
4426 | N solenoid shorted to ground
4512 | A solenoid circuit open
4513 | B solenoid circuit open
4514 | C solenoid circuit open
4515 | D solenoid circuit open
4516 | E solenoid circuit open
4521 | F solenoid circuit open
4522 | G solenoid circuit open
4523 | H solenoid circuit open
4524 | J solenoid circuit open
4526 | N solenoid circuit open
4621 | F solenoid circuit overcurrent
4626 | N & H solenoid circuit overcurrent
4627 | A-HI solenoid circuit overcurrent
5101 | Offgoing ratio test, low to 1
5110 | Offgoing ratio test, 1 to low
5112 | Offgoing ratio test, 1 to 2
5121 | Offgoing ratio test, 2 to 1
5123 | Offgoing ratio test, 2 to 3
5124 | Offgoing ratio test, 2 to 4
5135 | Offgoing ratio test, 3 to 5
5142 | Offgoing ratio test, 4 to 2
5143 | Offgoing ratio test, 4 to 3
5145 | Offgoing ratio test, 4 to 5
5146 | Offgoing ratio test, 4 to 6
5153 | Offgoing ratio test, 5 to 3
5164 | Offgoing ratio test, 6 to 4
5165 | Offgoing ratio test, 6 to 5
51XY | Offgoing ratio test, x to y
5201 | Offgoing C3PS test, low to 1
5208 | Offgoing C3PS test, low to N1
5232 | Offgoing C3PS test, 3 to 2
5234 | Offgoing C3PS test, 3 to 4
5254 | Offgoing C3PS test, 5 to 4
5271 | Offgoing C3PS test, reverse to 1
5272 | Offgoing C3PS test, reverse to 2
5278 | Offgoing C3PS test, reverse to N1
5299 | Offgoing C3PS test, N3 to N2
52XY | Offgoing C3PS test, x to y
5308 | Offgoing speed test, low to N1
5309 | Offgoing speed test, L to NCC
5318 | Offgoing speed test, 1 to N1
5319 | Offgoing speed test, 1 to rels
5328 | Offgoing speed test, 2 to N1
5329 | Offgoing speed test, 2 to N2
5338 | Offgoing speed test, 3 to N1
5339 | Offgoing speed test, 3 to N3
5348 | Offgoing speed test, 4 to N1
5349 | Offgoing speed test, 4 to N3
5358 | Offgoing speed test, 5 to N1
5359 | Offgoing speed test, 5 to N3
5368 | Offgoing speed test, 6 to N1
5369 | Offgoing speed test, 6 to N4
5378 | Offgoing speed test, reverse to N1
5399 | Offgoing speed test, reverse to N1
53XY | Offgoing speed test, x to y
5401 | Oncoming ratio test, low to 1
5407 | Oncoming ratio test, low to reverse
5410 | Oncoming ratio test, 1 to low
5412 | Oncoming ratio test, 1 to 2
5417 | Oncoming ratio test, 1 to reverse
5421 | Oncoming speed test, 2 to 1
5423 | Oncoming ratio test, 2 to 3
5424 | Oncoming ratio test, 2 to 4
5427 | Oncoming ratio test, 2 to reverse
5432 | Oncoming ratio test, 3 to 2
5434 | Oncoming ratio test, 3 to 4
5435 | Oncoming ratio test, 3 to 5
5442 | Oncoming ratio test, 4 to 2
5443 | Oncoming ratio test, 4 to 3
5445 | Oncoming ratio test, 4 to 5
5446 | Oncoming ratio test, 4 to 6
5453 | Oncoming ratio test, 5 to 3
5454 | Oncoming ratio test, 5 to 4
5464 | Oncoming ratio test, 6 to 4
5465 | Oncoming ratio test, 6 to 5
5470 | Oncoming ratio test, reverse to low
5471 | Oncoming ratio test, reverse to 1
5472 | Oncoming ratio test, reverse to 2
5480 | Oncoming ratio test, N1 to low
5481 | Oncoming ratio test, N1 to 1
5482 | Oncoming ratio test, N1 to 2
5483 | Oncoming ratio test, N1 to 3
5485 | Oncoming ratio test, N1 to 5
5486 | Oncoming ratio test, N1 to 6
5487 | Oncoming ratio test, N1 to reverse
5492 | Oncoming ratio test, N2 to 2
5493 | Oncoming ratio test, N3 to 3
5495 | Oncoming ratio test, N3 to 5
5496 | Oncoming ratio test, N1 to 6
54XY | Oncoming ratio test, N1 to 3
5507 | Oncoming C3PS test, low to reverse
5517 | Oncoming C3PS test, 1 to reverse
5527 | Oncoming C3PS test, 2 to reverse
5587 | Oncoming C3PS test, N1 to reverse
5597 | Oncoming C3PS test, NVL to reverse
55XY | Oncoming C3PS test, x to y
5600 | Low range verification test
5611 | 1st range verification test
5622 | 2nd range verification test
5633 | 3rd range verification test
5644 | 4th range verification test
5655 | 5th range verification test
5666 | 6th range verification test
5677 | Reverse range verification test
5711 | 1st range verification C3PS test
5722 | 2nd range verification C3PS test
5744 | 4th range verification C3PS test
5766 | 6th range verification C3PS test
5788 | N1 range verification C3PS test
5799 | N2 or N4 range verification C3PS test
6100 | Retarder oil temperature, hot
6212 | Retarder temperature sensor, failed low
6223 | Retarder temperature sensor, failed high
6232 | Engine coolant temperature sensor, failed low
6233 | Engine coolant temperature sensor, failed high
6300 | Input function fault
6326 | Kickdown input, failed on
6340 | Service brake status input, failed on
6341 | Pump/pack and neutral general purpose input
6347 | Rels input, failed on
6412 | Retarder modulation sensor, failed low
6423 | Retarder modulation sensor, failed high
6500 | Engine rating too high
6511 | Engine not responding to LRTP torque reduction
6512 | Engine not responding to default transmission torque limit
6600 | Serial communication interace fault
6611 | SCI engine coolant source fault
6622 | J1939 retarder requeste fault
6633 | J1939 driver demand torque fault
6634 | Engine not responding to J1939 sem control
6927 | A-high switch inoperative in ECU
6928 | F-high switch inoperative in ECU
6929 | N & H-high switch inoperative in ECU
6933 | Computer operating properly timeout in ECU
6934 | ECU write timeout
6935 | ECU checksum test
6936 | RAM shelf test in ECU
6941 | I/O ASIC addressing test in ECU
6942 | SPI output failure
6943 | SPI input failure
7012 | Minor loop overrun in software
7013 | Illegal write to address $0000
7014 | Major loop overrun in software
The Bottom Line
Allison parts are built like tanks—but even tanks need good diagnostics.
Let Reaction Force LLC help you fix it right the first time.