Subcode 41 is set when the states of the calibration inputs are different for a calibration number of consecutive updates. The inputs in this case are Pump/Pack Enable and Automatic Neutral For Refuse Packer. The service display will also be turned ON if selected by calibration. Allison WTEC II Fault Code: 63 PID: SPN: 40 FMI: Service brake status input failed on Allison WTEC II Fault Code: 63 PID: SPN: 26 FMI: Kickdown input failed on Allison WTEC II Fault Code: 63 PID: SPN: 00 FMI: Input function fault Allison WTEC II Fault Code: 62 PID: SPN: 23 FMI: Retarder...

Main code 64 indicates the ECU has detected a voltage signal from the retarder request modulation sensor (consisting of a module and a retarder control device) in either the high or low error zone. These codes can be caused by faulty wiring, faulty connections to the resistance module or retarder control device, a faulty resistance module, a faulty retarder control device, or a faulty ECU. Power wire 133 and ground wire 135 for the retarder modulation request sensor share a common power and ground with the TPS and OLS devices. A short-to-ground on the common power wire causes a ?sensor...

Main code 64 indicates the ECU has detected a voltage signal from the retarder request modulation sensor (consisting of a module and a retarder control device) in either the high or low error zone. These codes can be caused by faulty wiring, faulty connections to the resistance module or retarder control device, a faulty resistance module, a faulty retarder control device, or a faulty ECU. Power wire 133 and ground wire 135 for the retarder modulation request sensor share a common power and ground with the TPS and OLS devices. A short-to-ground on the common power wire causes a ?sensor...

Main code 65 indicates the engine horsepower/governor speed rating is too high. This code is set only when computer-controlled engines are used. Code 65 means the engine computer is able to tell the transmission, the engine horsepower and/or governor speed is beyond the transmission rating or does not match the transmission shift calibration. When a code 65 is set, no shifts out of neutral are allowed. It is possible the transmission calibration selected for this engine is improper. Contact local Allison Transmission Division distributor for assistance in selecting a proper calibration. If the engine is beyond transmission ratings, contact the...

Main code 66 indicates the ECU is expecting to get its throttle position sensor (TPS) signal across a serial communication interface from a computer-controlled engine. Either the engine computer is not sending the TPS information or the wiring between the engine and transmission computers has failed. Code 66 00 can occur when the transmission ECU remains powered when the engine ECM is powered down. The transmission sees this as a communication link failure. If a Code 66 00 is set and the ECU was programmed after 9/26/94, the SERVICE icon on the shift selector will be illuminated. Allison WTEC II...