P0335 on a 5.7 Hemi: Crankshaft Position Sensor and What Actually Causes It

TL;DR: P0335 is a crankshaft position sensor circuit fault, not a verdict on the sensor itself. On a Gen III 5.7 Hemi the code is thrown by the powertrain control module when the crank signal disappears, drops out, or stops agreeing with the camshaft signal — and a failed sensor is only one of at least five things that produce that result. Before ordering parts, check the connector for oil, inspect the harness near the bellhousing, and note whether a cam sensor code is stored alongside it. If you do replace the sensor, finish with the crank/cam variation relearn or the code can come straight back.

What P0335 actually means on a Gen III Hemi

The 5.7 Hemi is a pushrod overhead-valve V8: camshaft in the block, hydraulic roller lifters, pushrods to shaft-mounted rocker arms, two spark plugs per cylinder. It needs two timing references to run: the crankshaft position sensor tells the module where the crank is and how fast it is turning, and the camshaft position sensor tells it which stroke each cylinder is on. The module compares the two, and if the crank signal is missing, noisy, or out of the expected relationship with the cam signal, it sets a crank position circuit code.

That gives you three broad categories of failure behind one code:

• The sensor is not producing a usable signal. Genuine sensor failure, usually heat-related and usually intermittent before it becomes permanent.
• The signal is produced but does not reach the module cleanly. Wiring, connector, ground, shield or module-side problem.
• The signal reaches the module but is wrong. A damaged tone ring or flexplate reluctor, or a mechanical timing problem that puts crank and cam out of the relationship the module expects.

Those three call for completely different repairs, which is why "P0335 means replace the crank sensor" throws parts at a large share of the vehicles that show it. Parts live under engine sensors and 5.7 Hemi parts — but read the rest before buying.

The symptom pattern tells you more than the code does

Write down exactly how the vehicle misbehaves. On this engine family the pattern is the diagnosis, far more than the code number itself.

That last row catches people out. If cranking speed is low enough, the module can fail to establish sync and log a crank position code even though every component in the circuit is fine. Test the battery and starter draw first — a marginal battery rules itself out in five minutes.

The five causes worth checking in order

1. Oil in the connector. The one most often missed. Oil escaping a valve cover or rear seal travels down the block and wicks into the sensor pigtail, then along the wire strands inside the insulation toward the connector. The result is an intermittent, temperature-dependent fault that survives a new sensor. Unplug the connector and look inside it. If you find oil, a new sensor alone will not fix the vehicle — the connector and often a section of the pigtail need attention, and the leak that supplied the oil needs to be found and repaired. Valve cover and seal parts sit under gaskets and seals.

2. Harness chafe and connector fit. The sensor lives at the back of the block near the bellhousing flange, where the harness passes close to hot and moving hardware. With the vehicle safely supported, follow the wiring back toward the main harness and look for rub-through, heat damage, a broken lock tab, or a previous repair with a poor splice. Wiggle-test with the scope connected. See harnesses and PCM/ECM.

3. The sensor itself. These sit in a hot location and fail more often by heat-soak degradation than by dying outright. The classic signature is a vehicle that runs perfectly cold and stalls once it is up to temperature. Confirm rather than assume: watch RPM on the scan tool while cranking a no-start. No engine speed shown while the starter turns means the crank reference is genuinely missing; RPM shown and still no fire means the problem is elsewhere.

4. The tone ring or flexplate reluctor. The sensor reads teeth on a target. A damaged tooth, a flexplate cracked around the reluctor, or a torque converter bolt that has been hammering the assembly makes the pattern irregular and the module rejects it. Uncommon but real, and usually accompanied by a noise or a history of transmission work. Inspect through the bellhousing access before ordering another sensor — see flexplates and flywheels.

5. Grounds and supply. Corroded engine-to-body grounds and a poor block ground strap produce noise that looks exactly like a failing sensor. Check them with a voltage-drop test, not by eye — a ground can look perfect and still drop enough voltage under load to cause trouble.

Testing it properly, and the step people skip afterward

The honest test is a scope on both the crank and cam signals at once, captured while the fault is present. A meter tells you the circuit is not shorted; only a waveform tells you whether the pattern is clean, whether it dropped out for a few teeth, and whether crank and cam still line up. If the vehicle only fails hot, get it hot first — a cold test on a heat-sensitive sensor proves nothing.

Scan tool and electrical test equipment is under engine tools. Confirm any replacement sensor part number against the manufacturer catalogue for your exact model year and build — this family had running changes, and the wrong-but-similar sensor is a common source of repeat failures.

Then do the step that gets skipped: after replacing a crank or cam position sensor on this engine family, run the crankshaft/camshaft variation relearn with a capable scan tool, following the procedure in the service information for that model year. Skip it and the module keeps comparing against stale correction values, which can leave a driveability complaint or bring the code back. Any fastener disturbed during the job gets torqued in the factory sequence to the value published in the service manual, not to feel. Related components are grouped under Gen III Hemi parts.

Frequently Asked Questions

Can you drive a 5.7 Hemi with a P0335 stored? Not safely. A crank signal that is dropping out will eventually cut the engine without warning, usually at the worst moment. Treat an intermittent P0335 as a stall waiting to happen.

Does a bad crankshaft position sensor cause a no-start every time? No. The most common presentation is intermittent: runs cold, stalls hot, restarts after cooling. A permanent no-start with no engine speed on the scan tool while cranking is the later stage of that failure, or an open circuit.

Why did P0335 come back after I replaced the sensor? Three usual reasons: the fault was in the wiring or connector rather than the sensor; the crank/cam variation relearn was not performed after the replacement; or the replacement part was not the correct one for that model year and build. Check for oil inside the connector before doing anything else.

Is P0335 the same as a camshaft position sensor code? No. P0335 is the crankshaft position circuit; camshaft codes are separate. But the module compares the two, so both codes stored together point at the relationship between them rather than at one component.

Where is the crankshaft position sensor on a 5.7 Hemi? At the rear of the block, near the transmission bellhousing flange, reading a target on the rotating assembly. It is not the sensor on the front timing cover — that one is the camshaft position sensor. Confirm the exact location for your model year in the service information before removing anything.

Do I need a scan tool to finish the repair? Yes. You need one to confirm engine speed during cranking, to read pending codes with freeze-frame data, and to run the variation relearn afterward. A reader that only pulls and clears codes is not enough here.

Sources

Written from Core Powertrain Parts technician experience with Gen III Hemi driveability and no-start diagnosis, cross-checked against this store's own catalogue structure for the categories linked above. Every torque figure, relearn procedure and part number is deliberately left to the manufacturer's service information for your exact model year and build. Fitment questions: sales@coretransmissionparts.com.