This Detroit VSS open circuit reference documents the Detroit VSS open circuit diagnostic filed as SPN 84 FMI 3 on the EPA07 GHG14 platform. It is part of the DiagTechPro truck manuals library and preserves the original TruckFaultCodes.com Detroit fault-code library (Copyright 2017).
Official document details
| Brand | Detroit |
|---|---|
| Model coverage | Detroit DD Series (EPA 2007-current) engines; the same fault-code procedure is also filed under the Detroit Series 60 (DDEC VI, EPA 2007) group. |
| System / Group | DD Series (EPA 2007-Current) / DTCs |
| Fault code | SPN 84 / FMI 3 (EPA07 GHG14) |
| Source | TruckFaultCodes.com Detroit fault-code library (Copyright 2017) |
| Pages | 1 |
| File size | 0.2 MB |
| Format | |
| Language | English |
Document table of contents
- VSS open-circuit overview (SPN 84, FMI 3)
- Harness continuity checks
- Short-circuit test between CPC pins
- Sensor replacement decision
Diagnostic steps in the Detroit VSS open circuit document
After disconnecting the sensor, the technician measures resistance between Common Powertrain Controller connector #3 (21-pin) pin 13 and VSS pin 1, then pin 14 to VSS pin 2; readings above 3 ohms indicate an open wire to repair. A measurement across CPC #3 pins 13 and 14 above 3 ohms replaces the sensor, otherwise the harness short between those pins is repaired.
The Vehicle Speed Sensor (VSS) open circuit condition on Detroit DD Series trucks is read and cleared with DiagnosticLink (formerly DDDL); the SPN and FMI pair identifies the exact circuit and failure mode. Confirm the code is active and capture freeze-frame data before running the pinpoint tests, then clear it and road-test the truck to verify the repair has held.
Applicable truck models and engines
This document applies to Detroit DD Series (EPA 2007-current) engines; the same fault-code procedure is also filed under the Detroit Series 60 (DDEC VI, EPA 2007) group. For factory service data, parts and warranty information, consult Detroit’s official DD engine support.
Who needs the VSS open circuit manual
This page is for DD Series technicians confirming an open speed-sensor circuit on the EPA07 calibration using exact CPC pin references.
The complete PDF is available in the DiagTechPro manuals library; a free account is required to download it.
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