← code lookup·All fault codes

SPN 723 — Engine speed (auxiliary sensor)

Safe to driveDrivable, but watch it yourself

J1939 code SPN 723. Below — how the fault is worded at the factory by DAF, Dongfeng, Isuzu and SITRAK, and what the second half of the code (FMI) means in the standard.

DAFDongfengIsuzuSITRAK

DAF

FMI 2Camshaft speed/position F558 signal missing/implausible
FMI 7Camshaft speed F558 misalignment relative to crankshaft sensor F552

Dongfeng

FMI 2No signal from the camshaft speed sensor
FMI 7Asynchronous signals from the two engine speed sensors

Isuzu

FMI 2Crank sensor fault (no signal) (P0335)

SITRAK

FMI 2Camshaft position sensor signal noise
FMI 4Loss of camshaft position sensor signal

What FMI means in J1939

SPN 723 FMI 2723/2 · 723.2data erratic or intermittent
SPN 723 FMI 4723/4 · 723.4voltage below normal or shorted to ground
SPN 723 FMI 7723/7 · 723.7mechanical system not responding

Can I keep driving

Safe to drive. Below — how much time you have and what happens if you keep going.

What happens if you keep driving

Time you have: Drivable, but watch it yourself

This is an electrical fault: an open, a short or a bad contact in the sensor circuit. The value it measures is most likely fine.

You can drive. But until the circuit is repaired this system runs blind and cannot warn you about a real failure.

Nearby: other

Scanner threw several codes at once? Paste the whole list — we will show which one is the root cause and which ones simply followed.