Western States Converters and Transmissions logo

OEM TROUBLESHOOTING GUIDE
FOR ALLISON WT TROUBLE CODES

A. Displaying Oil Level Information
B. Clearing Diagnostic Codes
C. Displaying Diagnostic Codes
Code Listings and Procedures
13 - ECU Input Voltage Low
13 - ECU Input Voltage Low (Medium)
13 - ECU Input Voltage High
14 - Oil Level Sensor
21 - Throttle Position Sensor
22 - Speed Sensors
23 - Shift Selectors
24 - Sump Oil Temperature Cold
24 - Sump Oil Temperature Hot
25 - Output speed Sensor and Reading
32 - C3 Pressure Switch Open
33 - Sump Oil Pressure Failure
34 - EEPROM
35 - Power Interruption EEPROM Write Interruption
3 - Hardware/Software Not Compatible
41 - Open or Short Ground in Celenoid Circuit
42 - Short in Battery Solenoid Circuit
43 - Solenoid Low Side Circuit, Open Driver, or Wire Shorted to Ground
44 - Solenoid Circuit Short to Ground
45 - Solenoid Circuit Open
51 - Offgoing Ratio Test (During Shift)
52 - Offgoing C3 Pressure Switch (During Shift)
53 - Offgoing Speed Test (During Shift)
54 - Oncoming Ratio Test (After Shift)
55 - Oncoming C3 Pressure Switch (After Shift)
56 - Range Verification Test (Between Shifts)
57 - Range Verification Test (C3)
61 - Retarder Over Temperature
62 - Retarder Temperature Sensor
63 - Input Function Fault
64 - Retarder Modulation Request Device Fault
65 - Engine Rating High (Computer-Controlled Engines Only)
66 - Seroal Communications Interface Fault
69 - ECU Malfunction

FAQ on How we check out your Off Highway Transmission (what we do)

 

Allison Transmission Troubleshooting Diagnostic Chart

 

1) Linkage check:
    (a) Check the Shift selector position at the transmission in all ranges
    (b) Check the modulator, modulator cable, vacuum modulator, air modulator, or electric modulator

2) Start engine (verify engine idle rmp)

3) Verify oil temperature

4) Verify oil level and for oil leaks

5) Install pressure guages

6) Road Test vehicle to confirm complaint.
    a) At idle reverse PSI
    b) First gear PSI
    c) Second gear PSI
    d) Third gear PSI
    e) Fourth gear PSI
    f) Fifth gear PSI
    g) Sixth gear PSI
    h) Lockup PSI

7) Remove the transmission oil pan for inspection, check to see if there is any foreign material, clean, varnished, water, metal, other.


Western States Converters and Transmissions logo
224 Jason Crt.
Corona, CA  91719
(951) 279-6393
(888) 463-3499
(951) 279-1847 Fax

email usEmail us: Sam Clemmons

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