Allison WTEC II Fault Code: 56 PID: SPN: 22 FMI: Range verification ratio test, 2nd
Main code 56 indicates a failed range verification speed sensor ratio test. Range verification ratio test (between shifts) 2
The ratio test occurs after a shift and determines if a clutch has lost torque carrying capability. If output speed is above programmed output speed for a range but the correct speed sensor ratio is not present, the DO NOT SHIFT response is commanded and a range which can carry the torque without damage is commanded or attempted. Turbine and output speed sensor readings are used to calculate the actual ratio that is compared to the commanded ratio.
Main code 56 can also be caused by the EEPROM being calibrated for a close ratio transmission and installed in a wide ratio transmission, or vice versa.
![download Hitachi Construction Machinery MPDr Ver 3.7.0.0 [10.2020] Diagnostic Software](https://i0.wp.com/www.ecuforcetruck.com/wp-content/uploads/2023/05/MPDR-3.7.00.png?resize=300%2C300&ssl=1)
![download Hitachi Construction Machinery MPDr Ver 3.7.0.0 [10.2020] Diagnostic Software](https://www.ecuforcetruck.com/wp-content/uploads/2023/05/MPDR.png)
Related products
-
-
-
Allison 1000 & 2000 Gen 4 Fault Codes: P2773 Torque Control Request Ignored – ECM/TCM
1000 & 2000 Gen 4 $50.00 -
Allison 1000 & 2000 Gen 4 Fault Codes: U1300 J1850 (Class 2) Serial Data Communication Link Low
1000 & 2000 Gen 4 $50.00 -
Allison 1000 & 2000 Gen 4 Fault Codes: U1301 J1850 (Class 2) Serial Data Communication Link Low
1000 & 2000 Gen 4 $50.00 -
-
-
Allison 1000 & 2000 Gen 4 Fault Codes: P0873 Transmission Pressure Switch Solenoid E Circuit High
1000 & 2000 Gen 4 $50.00 -
-
-
-
-
Allison 1000 & 2000 Gen 4 Fault Codes: P0123 Pedal Position Sensor Circuit High Voltage
1000 & 2000 Gen 4 $50.00 -
-
Allison 1000 & 2000 Gen 4 Fault Codes: P0122 Pedal Position Sensor Circuit Low Voltage
1000 & 2000 Gen 4 $50.00
