Park Brake Switch problems set Eaton Fault Code 21 on the Fuller Advantage Heavy Duty transmission, which uses an auto-neutral function to drop into neutral when the vehicle stops in gear with the brake set. This two-page section of publication TRTS0980 defines the J1939 SPN 70 FMI 14 condition for both hard-wired and J1939 inputs, the speed and mismatch triggers, and the wiring and configuration causes. It underpins any auto-neutral complaint.
Official document details
| Brand | Eaton |
|---|---|
| Model coverage | Fuller Advantage & Fuller Advantage Heavy Duty automated transmission |
| System / Group | DTCs – Fault Isolation Procedures |
| Publication no. | TRTS0980 |
| Year / Revision | 2016 (Rev. 2016.06.20) |
| Pages | 2 |
| File size | 0.3 MB |
| Format | |
| Language | English |
Park Brake Switch table of contents
- Overview and fault description
- Detection method
- Conditions to set the fault code active
- Fallback and dashboard symptoms
- Conditions to set the fault code inactive
- Possible causes
- Component identification
Applicable truck models covered
This definition covers Eaton Fuller Advantage and Fuller Advantage Heavy Duty automated transmissions on any chassis OEM, including installations wired for either a hard-wired or a J1939 input. The switch must be normally closed, and its wiring, the 2-Way connector and the J1939 data link follow OEM routing. Transmission data is published on the manufacturer’s official Eaton transmissions website.
Who needs this Park Brake Switch manual
Chassis electricians and transmission technicians use this page when the Brake Switch circuit reports SPN 70 FMI 14 or the truck will not auto-neutral, to confirm a normally closed switch, the correct configuration and clean harness wiring before replacing components. The page also flags an operator cause, a driver who never sets the switch, alongside the electrical faults, which helps a workshop avoid replacing good parts on an intermittent complaint.
The complete PDF, published under Eaton document TRTS0980, is available in the DiagTechPro manuals library; a free account is required to download it.
Related manuals library
