Allison
Allison WTEC II Fault Code: 54 PID: SPN: 83 FMI: Oncoming ratio test (after shift), N1 to 3
Posted by PerDiezel Solutions on
Main code 54 indicates a failed oncoming ratio test. N1?3 shift The ratio test after a shift is failed when the ECU has commanded the end of a shift and has not seen the transmission shift into the target range (comparing turbine and output speeds). Erratic readings from speed sensors are a likely cause of an oncoming ratio test failure. If conditions for a shift still exist, the shift will be retried one more time. If the ratio test is still not met, a code is logged and the DO NOT SHIFT response is commanded. If the code is set...
Allison WTEC II Fault Code: 54 PID: SPN: 85 FMI: Oncoming ratio test (after shift), N1 to 5
Posted by PerDiezel Solutions on
Main code 54 indicates a failed oncoming ratio test. N1?5 shift The ratio test after a shift is failed when the ECU has commanded the end of a shift and has not seen the transmission shift into the target range (comparing turbine and output speeds). Erratic readings from speed sensors are a likely cause of an oncoming ratio test failure. If conditions for a shift still exist, the shift will be retried one more time. If the ratio test is still not met, a code is logged and the DO NOT SHIFT response is commanded. If the code is set...
Allison WTEC II Fault Code: 54 PID: SPN: 86 FMI: Oncoming ratio test (after shift), N1 to 6
Posted by PerDiezel Solutions on
Main code 54 indicates a failed oncoming ratio test. N1?6 shift The ratio test after a shift is failed when the ECU has commanded the end of a shift and has not seen the transmission shift into the target range (comparing turbine and output speeds). Erratic readings from speed sensors are a likely cause of an oncoming ratio test failure. If conditions for a shift still exist, the shift will be retried one more time. If the ratio test is still not met, a code is logged and the DO NOT SHIFT response is commanded. If the code is set...
Allison WTEC II Fault Code: 54 PID: SPN: 92 FMI: Oncoming ratio test (after shift), N2 to 2
Posted by PerDiezel Solutions on
Main code 54 indicates a failed oncoming ratio test. N2?2 shift The ratio test after a shift is failed when the ECU has commanded the end of a shift and has not seen the transmission shift into the target range (comparing turbine and output speeds). Erratic readings from speed sensors are a likely cause of an oncoming ratio test failure. If conditions for a shift still exist, the shift will be retried one more time. If the ratio test is still not met, a code is logged and the DO NOT SHIFT response is commanded. If the code is set...
Allison WTEC II Fault Code: 54 PID: SPN: 93 FMI: Oncoming ratio test (after shift), N3 to 3
Posted by PerDiezel Solutions on
Main code 54 indicates a failed oncoming ratio test. N3?3 shift The ratio test after a shift is failed when the ECU has commanded the end of a shift and has not seen the transmission shift into the target range (comparing turbine and output speeds). Erratic readings from speed sensors are a likely cause of an oncoming ratio test failure. If conditions for a shift still exist, the shift will be retried one more time. If the ratio test is still not met, a code is logged and the DO NOT SHIFT response is commanded. If the code is set...
