The Eaton Gear Position Sensor overview describes how Fault Code 52 is detected on the Fuller Advantage Heavy Duty transmission and how each FMI is set. This TRTS0980 reference covers the X-Y Shifter sensor that reports fore-and-aft shift-finger movement, its voltage limits and its 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 | 0.90 MB |
| Format | |
| Language | English |
Document table of contents
- Overview of the X-Y Gear Position Sensor circuit
- Detection and monitored supply / return voltages
- Conditions to set Fault Code 52 Active (FMI 2, 3, 4, 7)
- 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 fore-and-aft shift-finger movement to the TECU as a voltage signal (J1587 MID 130 PID 59; J1939 SA 3 SPN 59). Wider product data is published on the Eaton Vehicle Group official website.
Eaton Gear 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 falls below 4.75 volts; and FMI 7 when the return signal is outside the physically allowed operating range of the Shift Bar Housing for one second or longer.
Who needs this Eaton Gear Position Sensor manual
Drivetrain technicians facing a Fault Code 52 use this overview to separate an electrical circuit fault from a mechanical X-Y Shifter failure, since the possible causes list points to the Transmission Harness, the shifter or an internal TECU failure before repair.
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