Detroit DD15 GHG14 (2014-16) Fault Code: SPN 723 FMI 31 (MCM) Backwards Running Engine Detected

NOTE: This may be due to an engine temporary running in a reverse direction. Symptoms include smoke exiting from intake manifold and a low idle speed, possibly due to a leaky injector.

DESCRIPTION:
This code sets when there is no match of camshaft and crankshaft signals.

MONITORED PARAMETER:
Camshaft reverse direction rising edge signal.

TYPICAL ENABLING CONDITIONS:
Engine state and low idle and camshaft reverse direction error.

MONITOR SEQUENCE:
None

EXECUTION FREQUENCY:
Continuous when enabling conditions met.

TYPICAL DURATION:
Two seconds

DASH LAMPS:
1. MIL
2. CEL

ENGINE REACTION:
Derate 25% shutdown priority.

VERIFICATION:
Engine idle

NOTE: If any other codes for camshaft, crankshaft, or oil pressure are active fix those first.

NOTE: If codes for throttle pedal or idle validation switch are present, fix those before working on this code.

PROBABLE CAUSES:
1. Failed injector(s).
2. Failed starter (Isn’t doing at least 150 RPM).
3. Failed camshaft position sensor.
4. Gear train, camshaft, or flywheel failure/installation installed improperly.