Allison WTEC II Fault Code: 51 PID: SPN: 42 FMI: Offgoing ratio test (during shift), 4 to 2
Main code 51 indicates a failed offgoing ratio test. 4?2 downshift
An offgoing ratio test occurs during a shift and uses turbine and output speed sensor readings to calculate the ratio between them. The calculated speed sensor ratio is then compared to the programmed speed sensor ratio of the commanded range. After a shift is commanded, the ECU, after a period of time, expects the old ratio to be gone. If the ratio does not change properly, the ECU assumes the offgoing clutch did not release. The shift is retried if conditions still exist to schedule the shift. If the second shift is not successfully completed, Code 51 XX is set and the ECU returns the transmission to the previous range. Additional codes could be logged for other shifts where ?X? indicates the range from and ?Y? indicates the range to.
Related
-
Detroit Diesel Diagnostic Link DDDL 8.0 PRO PROFESSIONAL Software trucks
Detroit $25.00Rated 0 out of 5 -
CAT Engine Reprogramming Tool for flash programming C1.8, C2.4, C3.8 & C3.3B + Guide
CAT $50.00Rated 0 out of 5 -
PACCAR Electronic Service Analyst 5.4.3.0 SW files 27.03.2021 software trucks
PACCAR $60.00Rated 0 out of 5
Related products
-
Allison 1000 & 2000 Gen 4 Fault Codes: P0880 TCM Supply Voltage
1000 & 2000 Gen 4 $50.00Rated 0 out of 5 -
Allison 1000 & 2000 Gen 4 Fault Codes: U1301 J1850 (Class 2) Serial Data Communication Link Low
1000 & 2000 Gen 4 $50.00Rated 0 out of 5 -
Allison 1000 & 2000 Gen 4 Fault Codes: P0122 Pedal Position Sensor Circuit Low Voltage
1000 & 2000 Gen 4 $50.00Rated 0 out of 5 -
Allison 1000 & 2000 Gen 4 Fault Codes: U1300 J1850 (Class 2) Serial Data Communication Link Low
1000 & 2000 Gen 4 $50.00Rated 0 out of 5 -
Allison 1000 & 2000 Gen 4 Fault Codes: P0847 Transmission Pressure Switch Solenoid D Circuit Stuck Closed
1000 & 2000 Gen 4 $50.00Rated 0 out of 5 -
Allison 1000 & 2000 Gen 4 Fault Codes: P1779 Engine Torque Delivered To TCM Signal
1000 & 2000 Gen 4 $50.00Rated 0 out of 5 -
Allison 1000 & 2000 Gen 4 P0719 Brake Switch ABS Input Low
1000 & 2000 Gen 4 $50.00Rated 0 out of 5 -
Allison 1000 & 2000 Gen 4 Fault Codes: P0872 Transmission Pressure Switch Solenoid E Circuit Stuck Closed
1000 & 2000 Gen 4 $50.00Rated 0 out of 5 -
Allison 1000 & 2000 Gen 4 Fault Codes: P1891 Engine Throttle Position Sensor Pulse Width Modulation (PWM) Signal Low Input
1000 & 2000 Gen 4 $50.00Rated 0 out of 5 -
Allison 1000 & 2000 Gen 4 Fault Codes: P1688 Unmanaged Engine Torque Delivered To TCM Signal
1000 & 2000 Gen 4 $50.00Rated 0 out of 5 -
Allison 1000 & 2000 Gen 4 Fault Codes: P0876 Transmission Reverse Pressure Switch Circuit Stuck Open
1000 & 2000 Gen 4 $50.00Rated 0 out of 5 -
Allison 1000 & 2000 Gen 4 Fault Codes: U0031 J1850 (Class 2) Serial Data Communication Link Low
1000 & 2000 Gen 4 $50.00Rated 0 out of 5 -
Allison 1000 & 2000 Gen 4 Fault Codes: P0873 Transmission Pressure Switch Solenoid E Circuit High
1000 & 2000 Gen 4 $50.00Rated 0 out of 5 -
Allison 1000 & 2000 Gen 4 Fault Codes: U2105 CAN Bus ECM Error
1000 & 2000 Gen 4 $50.00Rated 0 out of 5 -
Allison 1000 & 2000 Gen 4 Fault Codes: P2773 Torque Control Request Ignored – ECM/TCM
1000 & 2000 Gen 4 $50.00Rated 0 out of 5