OBD-II Diagnostic Trouble Code
P0335 — Crankshaft Position Sensor A Circuit
P0335 means the ECM is not getting a valid signal from crankshaft position sensor A, for example no pulses while the camshaft sensor shows the engine turning. The crank sensor gives engine speed and piston position for fuel injection timing, so losing it is serious on both diesel and gas engines.
Severity 5/5
Truck-relevant
Stop now
Severity
Stop now — do not drive
Crankshaft Position Sensor A Circuit
Code
P0335
Category
Powertrain
Subsystem
Ignition
Truck-relevant
Yes
What this means for truckers
P0335 — see existing entry.
Before you replace parts — try this first
P0335 on the Ignition system is most often failed crankshaft position sensor — not a dead part. On commercial diesels especially, work these in order before spending money on parts:
- Confirm the symptoms. Match what your truck is doing to the Symptoms section below. If the code is set but the symptoms are not there, clear the code and re-test after a drive cycle — it may not return.
- Clean and dry the sensor connector. Water, road salt, or oil seeping into a connector is the #1 fake sensor failure. Disconnect, look for green corrosion or moisture, spray with electrical contact cleaner, dry, reseat. Many faults clear here for $0.
- Inspect the wiring harness. Trace the wire from the sensor toward the ECM — look for chafing against the engine block, melted insulation near the turbo or exhaust, or pinch points where a clamp has rubbed through.
- Test the sensor before swapping it. Most Common Causes (below) list the expected voltage or resistance range — a $20 multimeter saves a $300 sensor swap that does not fix the problem.
- Only then, replace the part. Use the OEM or a tier-1 aftermarket. Cheap sensors throw the same code in two weeks.
Symptoms
Crank-no-start or a stall while driving, often with no tachometer reading while cranking. Some engines start and run on the camshaft sensor as a backup but crank longer and run with reduced power. Intermittent faults can cause random stalls, often when the engine is hot.
Common causes
- CommonFailed crankshaft position sensor ($150–$500)
- CommonDamaged, chafed or corroded sensor wiring or connector ($100–$500)
- OccasionalWrong air gap, metal debris on the sensor tip or a damaged tone wheel ($150–$1500)
- OccasionalShorted 5-volt reference shared with other sensors (on 3-wire sensors) ($100–$600)
- RareECM input fault ($1200–$3500)
How to fix
Check live engine rpm while cranking; if it reads zero, inspect the sensor connector and harness along its route
When to use: First step on a no-start
Test sensor resistance (magnetic type) or supply, ground and signal (Hall type), and scope the signal while cranking
When to use: To tell a sensor fault from a wiring fault
Remove the sensor, clean any metal debris, inspect the tone wheel and replace the sensor
When to use: When the signal is weak, missing or noisy
Check for a shorted 5-volt reference by unplugging other sensors that share it
When to use: When several sensor codes set together
Affects most
No specific vehicle pattern found in our complaint database. This code can appear on any vehicle that supports OBD-II diagnostics.
Related
- → Browse all DTC trouble codes
- → Decode a VIN to check codes for your truck
- → Owner-operator maintenance guides
- → P0300 — Random/Multiple Cylinder Misfire Detected
- → P0301 — Cylinder 1 Misfire Detected
- → P0302 — Cylinder 2 Misfire Detected
- → P0303 — Cylinder 3 Misfire Detected
- → P0304 — Cylinder 4 Misfire Detected
Frequently Asked Questions
Can I drive with code P0335?
No — P0335 is severity 5. Stop and tow if you're not near a service location. Continuing to drive can cause catastrophic engine damage. The cost of a tow ($300–800) is small compared to the cost of an engine rebuild ($15,000+).
How much does it cost to fix P0335 on a commercial truck?
Total repair cost ranges $100–$3500 depending on the root cause. The cheapest fix is usually the first one listed below — Failed crankshaft position sensor — which is also the most common. On commercial trucks the cost is usually higher than passenger vehicles due to part availability and shop labor rates ($120–185/hour at most truck shops, vs $90–130 at general auto shops). DIY-capable fixes (sensors, hoses, filters) are at the low end; major component replacements (turbo actuator, high-pressure fuel pump, transmission solenoid pack) are at the high end. Always diagnose with a scan tool BEFORE replacing parts — guessing wrong on a $1,500 turbo actuator when the actual issue was a $30 boost hose is a common expensive mistake.
Will P0335 fail a DOT inspection?
P0335 is generally not a direct DOT inspection fail item by itself. Inspectors focus on safety-critical systems (brakes, steering, tires, lights, hours-of-service). However, the check engine light alone can trigger additional inspection scrutiny. Best practice: fix the code and clear it before a planned inspection.
What's the difference between P0335 and related codes?
P0335 is closely related to: P0300 (Random/Multiple Cylinder Misfire Detected), P0301 (Cylinder 1 Misfire Detected), P0302 (Cylinder 2 Misfire Detected), P0303 (Cylinder 3 Misfire Detected). These codes share the same subsystem (ignition) and often appear together. If you see this code, scan for the full code list — fixing the root cause usually clears multiple companion codes at once. If only P0335 is set without the companions, the issue is more isolated.
How do I prevent P0335 from coming back after a repair?
For P0335 (Crankshaft Position Sensor A Circuit), prevention centers on the ignition system. Use OEM-spec injectors and spark plugs (gas). Address fuel quality issues immediately — bad fuel kills injectors. Cylinder balance test annually for early warning.