Allison 3000 & 4000 Gen 4 Fault Code: P0973 Shift Solenoid 1 (SS1) Control Circuit Low
Allison 3000 & 4000 Gen 4 Fault Code: P0974 Shift Solenoid 1 (SS1) Control Circuit High
Allison 3000 & 4000 Gen 4 Fault Code: P0975 Shift Solenoid 2 (SS2) Control Circuit Open
Allison 3000 & 4000 Gen 4 Fault Code: P0976 Shift Solenoid 2 (SS2) Control Circuit Low
Allison 3000 & 4000 Gen 4 Fault Code: P0977 Shift Solenoid 2 (SS2) Control Circuit High
Allison 3000 & 4000 Gen 4 Fault Code: P0989 Retarder Pressure Sensor Failed Low
Allison 3000 & 4000 Gen 4 Fault Code: P0990 Retarder Pressure Sensor Failed High
Allison 3000 & 4000 Gen 4 Fault Code: P1739 Incorrect Low Gear Ratio
Allison 3000 & 4000 Gen 4 Fault Code: P1891 Throttle Position Sensor (TPS) PWM Signal Low Input
Allison 3000 & 4000 Gen 4 Fault Code: P1892 Throttle Position Sensor (TPS) PWM Signal High Input