OBD-II Code
P0374
Severity
Not yet reviewed
Nobody on our side has assessed this code yet, so we are not going to guess at how serious it is.
Can you drive it
We cannot say
Treat it as unknown until a shop reads it with live data. If the check-engine light is FLASHING, stop driving as soon as it is safe to — that means an active misfire, whatever the code.
Indicative cost (USD)
$220–$1,100
From this code's diagnostic notes. Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.
P0374 means the PCM is seeing NO pulses at all on the high-resolution timing reference (CKP-B or secondary crank input) — the signal is dead, not intermittent.
How a shop works this
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed.
Note every code that is set, not just this one.
Codes that appear together usually narrow the cause faster than any one of them read alone.
Read the freeze frame — the conditions the fault was recorded under.
Cold or warm, idle or load, road speed and engine speed. A fault that only appears cold is a different fault from one that only appears under load, even with the same code on the scanner.
Confirm the fault is current rather than history.
Clear the code and see whether it returns under those same conditions. A code that does not come back may have been logged during a repair, a flat battery, or a bad connection that has since been disturbed.
Then follow the diagnostic notes further down this page, in the order they are written.
They are written in the order a shop works this code, cheapest checks first. Where they name a component, inspect its wiring and connector before replacing it.
If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.
Common symptoms
- Check engine light
Read the full diagnostic procedureP0374 means the PCM is seeing NO pulses at all on the high-resolution timing reference (CKP-B or secondary crank input) — the signal is dead, not int…
P0374 means the PCM is seeing NO pulses at all on the high-resolution timing reference (CKP-B or secondary crank input) — the signal is dead, not intermittent. This is a no-start or hard-start code on engines that require the redundant signal for injection timing.
Cheapest-first ladder
- key-on-engine-off, backprobe the CKP-B connector and verify reference voltage and ground — a Hall-effect sensor should see 5V or 12V on its supply pin and a clean chassis ground (under 0.1V drop); a VR sensor is passive and has only signal + return, so check continuity between the sensor pins (typical VR coil reads 500-2,000 ohms cold; open or shorted = sensor dead).
- Crank the engine while scoping the signal wire — zero output during cranking confirms a dead sensor or a broken signal wire upstream.
- Inspect the sensor tip for impact damage from a separated reluctor wheel or a thrown timing-chain guide fragment; a sheared sensor housing reads dead and looks fine until you pull it.
- Check the PCM-side connector for corrosion or backed-out pins — on diesel platforms the PCM lives in the engine bay and sees water intrusion through the firewall grommet. Expensive-misdiagnosis caveat: before you replace the CKP-B sensor and start chasing wiring, confirm the reluctor wheel is still on the crank — on Ford 6.0L Powerstrokes and GM Duramax LB7s, a broken keyway on the crankshaft pulley or a sheared reluctor-to-crank pin will produce P0374 with a perfectly healthy sensor and harness; replacing the sensor without pulling the front cover to inspect the reluctor wastes a $300 part and a half-day of labor.
Vehicle-specific patterns2003-2007 Ford 6.0L Powerstroke is the most common P0374 ticket in heavy-duty diesel shops — the CMP/CKP-B pair fails together as a heat-cycle wear p…
- 2003-2007Ford 6.0L Powerstroke is the most common P0374 ticket in heavy-duty diesel shops — the CMP/CKP-B pair fails together as a heat-cycle wear pattern, and the truck either won't start or stalls at hot idle and won't restart until cool; the fix is sensor + pigtail + reseal at the front cover.
- 2001-2004GM Duramax LB7 throws P0374 from the same general cause but commonly via a chafed wire at the harness clip behind the alternator.
- 2007-2014RAM 6.7 Cummins commonly throws P0374 when the CKP harness gets oil-soaked from a leaking front main seal — the oil migrates into the connector and breaks continuity.
- 2009-2015Mercedes Sprinter OM642 throws P0374 from a brittle sensor housing that cracks at the locating tab during a routine timing-cover R&R.
Estimated repair$220 to $1,100.
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