Eaton Fuller Advantage (2017) Fault Code: 58 PID: SPN: 191 FMI: 5 Output Shaft Speed Sensor: Current Below Normal or Open Circuit

Overview:
The Fuller Advantage transmission is equipped with electronic speed sensors. The Input Shaft, Main Shaft and Output Shaft Speed Sensors are used to calculate gear ratios within the transmission. The Input Shaft Speed Sensor measures the rotational speed of the Input Shaft, taken from the upper countershaft drive gear. The Main Shaft Speed Sensor measures the rotational speed of the transmission gearing exiting the main case, taken from the auxiliary upper countershaft gear.

The Output Shaft Speed Sensor measures the rotational speed and direction of the output shaft, taken from the Tone Wheel. The Transmission Electronic Control Unit (TECU) compares these speeds to calculate the gear ratios of the main case, auxiliary case and overall transmission.

The Output Shaft Speed Sensor transmits a digital signal to the TECU based on the rotational speed of the Output Shaft Tone Wheel. The TECU compares Main Shaft Speed to Output Shaft Speed to confirm the gear ratio of the auxiliary case and compares Input Shaft Speed to Output Shaft Speed to confirm the overall transmission gear ratio. Fault Code 58 indicates an electrical fault within the Output Shaft Speed Sensor circuit or a speed value or rotational direction that is inconsistent with the calculated gear ratios.

Detection:
The TECU compares the values of the three speed sensors to determine sensor validity. The TECU also monitors the Output Shaft Speed Sensor circuit for any shorts to power, shorts to ground, open circuits or incorrect rotational direction of the Output Shaft.

Conditions to Set Fault Code Active:
The system can detect Output Shaft Speed Sensor faults when one of the following conditions is present for 1 second or longer:
FMI 5 – Current Below Normal or Open Circuit: TECU detects an open circuit or the Output Shaft Speed Sensor has high resistance

Fallback:
All FMIs
• “F” flashes in gear display.
• Service light flashes (if equipped).
• If fault occurs in low range, transmission still shifts up and down within low range, but will not complete the shift to high range.
• If fault occurs while in high range, the transmission still shifts up and down within high range. Once low range is reached, the transmission will not complete the shift back to high range.

Conditions to Set Fault Code Inactive:
All FMIs: TECU receives a valid signal from the Output Shaft Speed Sensor and detects no electrical open or short circuits for 2 seconds.

Possible Causes:
FMI 5
1) Output Shaft Speed Sensor
– Internal failure
– Physical damage or failure
2) Transmission Harness
– Bent, spread, corroded or loose terminals
– Wiring shorted to ground, shorted to power or open