QCV current too low is the Detroit DD Series fault-code troubleshooting sheet that documents a Quantity Control Valve error with current too low, which triggers the MIL and CEL lamps and a 25% engine derate on the Motor Control Module engine platform. This 2-page reference reproduces the fault-code identification and the factory decision tree so a technician can diagnose the concern before replacing parts.
Official document details
| Brand | Detroit |
|---|---|
| Model coverage | Detroit DD Series (EPA 2007-Current) |
| System / Group | DD Series (EPA 2007-Current) / DTCs |
| Fault code | FMI 6 under SPN 1077 (GHG14) |
| Source | Detroit fault-code literature via TruckFaultCodes.com, © 2017 |
| Pages | 2 |
| Format | |
| Language | English |
QCV current too low fault description
This two-page sheet lists the monitored parameter as the quantity control valve under rail-pressure closed-loop control, with the code setting when current stays under 200 mA for about two seconds. The technician disconnects the quantity control valve and measures resistance across pins 1 and 2; a value greater than 2 ohms calls for valve replacement. If the valve is good, the Motor Control Module (MCM2.1) 120-pin connector is disconnected and resistance is measured from each MCM2.1 pin to the matching valve pin to find an open circuit, ending in either MCM2.1 replacement or a wiring repair.
The QCV current too low sheet identifies the following likely causes and check points:
- Quantity control valve solenoid resistance above 2 ohms
- Open circuit between an MCM2.1 pin and the valve
- MIL and CEL illuminated with a 25% engine derate
Document table of contents
- Description and monitored conditions
- Quantity control valve resistance check
- MCM2.1 120-pin connector wiring checks
- Valve or MCM2.1 replacement
Applicable truck models
This troubleshooting sheet applies to Detroit DD Series engines built from EPA 2007 to current that use the Motor Control Module (MCM) and Common Powertrain Controller architecture. Confirm the engine’s emissions family and calibration against the manufacturer’s official documentation at the Detroit engine website before repairs.
Who needs this QCV current too low manual
Heavy-duty diesel technicians, fleet shops and mobile mechanics who retrieve this code on a Detroit DD engine need this manual to follow the factory decision tree instead of guessing. It is written for anyone using DDDL or an equivalent diesel diagnostic tool who wants the exact test values before condemning a component.
The full 2-page PDF of this procedure is available in the DiagTechPro manuals library; a free account is required to download.
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