The Eaton Rail Position Sensor overview explains how Fault Code 51 is detected on the Fuller Advantage Heavy Duty transmission and what each FMI means. This TRTS0980 reference describes the X-Y Shifter sensor, its voltage thresholds, fallback behaviour and component wiring.
Official document details
| Brand | Eaton |
| Model coverage | Fuller Advantage Heavy Duty (and Fuller Advantage) automated transmissions |
| System / Group | Fuller Advantage Heavy Duty / DTCs |
| Publication no. | TRTS0980 |
| Year / Revision | 2016.06.20 (© 2016 Eaton) |
| Pages | 3 |
| File size | 0.86 MB |
| Format | |
| Language | English |
Document table of contents
- Overview of the X-Y Rail Position Sensor circuit
- Detection and monitored supply / return voltages
- Conditions to set Fault Code 51 Active (FMI 2, 3, 4, 10)
- Fallback behaviour and gear-display warning
- Conditions to set the code Inactive
- Possible causes by FMI
- Component identification and connector pin-out
Applicable truck models
This applies to Eaton Fuller Advantage Heavy Duty transmissions whose X-Y Shifter reports lateral shift-finger movement to the TECU as a voltage signal (J1587 MID 130 PID 60; J1939 SA 3 SPN 60). Broader product and specification detail is published on the Eaton Vehicle Group official website.
Eaton Rail Position Sensor detection logic
The TECU monitors both the 5-volt supply and the return signal. FMI 2 sets when the return voltage stays outside 0.5–4.5 volts for one second; FMI 3 when supply exceeds 5.25 volts; FMI 4 when supply drops below 4.75 volts; and FMI 10 for an abnormal rate of change greater than ±0.2 volts or ±0.093 inches of finger movement while in gear.
Who needs this Eaton Rail Position Sensor manual
Transmission technicians reading a Fault Code 51 need this overview to tell an electrical circuit fault from a mechanical X-Y Shifter failure before they open the isolation procedure, since the possible causes list points to the harness, the shifter or the TECU.
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