Eaton Gen 2 (AutoShift) Fault Code: 58 PID: 191 FMI: 2 Output Shaft Speed Sensor

Posted by PerDiezel Solutions on May 12, 2026

Overview:
Fault Code 58 indicates an electrical problem in the Output Shaft Speed Sensor circuit. The signal from the sensor did not match the current operating conditions.

Detection:
A Speed Sensor is determined faulty when all Speed Sensor readings are compared and one sensor is inconsistent.

Fallback:
This fault causes a 5-speed fallback and the transmission stays in either low range or high range. When the vehicle comes to a stop, an attempt to shift into low range is made. The fallback causes a 1-speed fallback on transmissions with no auxiliary section.

Possible Causes:
1) Transmission Harness
2) Output Shaft Speed Sensor
3) Various transmission components
4) Transmission Controller
5) Failed or loose Tone Wheel

Shop Talk:
Select a forward gear and drive at a steady speed no slower than 10 MPH. It may be necessary to operate the vehicle for a prolonged period of time
if the cause of the failure is related to heat and vibration.

Eaton Gen 2 (AutoShift) Fault Code: 57 PID: 160 FMI: 2 Main Shaft Speed Sensor

Eaton Gen 2 (AutoShift) Fault Code: 56 PID: 161 FMI: 5 Input Shaft Speed Sensor

Eaton Gen 2 (AutoShift) Fault Code: 56 PID: 161 FMI: 2 Input Shaft Speed Sensor

Eaton Gen 2 (AutoShift) Fault Code: 52 PID: 59 FMI: 4 Gear Select Sensor

Eaton Gen 2 (AutoShift) Fault Code: 52 PID: 59 FMI: 3 Gear Select Sensor

Eaton Gen 2 (AutoShift) Fault Code: 52 PID: 59 FMI: 2 Gear Select Sensor

WARNING!