Juan el Mecánico

P0335

Crankshaft position sensor A circuit fault.

The computer lost or rejected the signal it uses to determine crankshaft position and speed.

What should be checked

01

Crankshaft position signal to inspect

The module needs a stable position-and-speed pattern; a missing, distorted, or inconsistent signal prevents it from using that reference.

In plain language: The computer may have lost the signal that tells it the crankshaft position and how fast the engine is turning.

How to check it
Compare the signal, power, ground, connector, reluctor wheel, and correlation against the exact engine procedure.
Before correcting it
Do not replace the sensor or disturb the timing system based only on the code name. The correction is decided only after locating and confirming the defect.
Related components
This diagnostic path may involve the crankshaft sensor, connector, wiring, power, ground, or reluctor wheel. None is confirmed.
When to stop
An engine that stalls, will not start, or requires measurements near moving parts should be inspected by a professional.

02

Mechanical synchronization or variable control to be checked

The mechanical relationship or variable control can cause a correct signal to arrive outside the expected time.

In plain language: The sensor may be reading well, but the engine parts may not be coordinated as the computer expects.

How to check it
Compare correlation and synchronization only with the exact engine procedure.
Before correcting it
Do not disassemble the distribution or actuators using generic markings or torques. The correction is decided only after locating and confirming the defect.
Related components
This path may involve the timing chain or belt, tensioners, sprockets, variable valve timing actuators, or oil passages. None has been confirmed.
When to stop
Consult a professional before the distribution or variable control is involved.
Crankshaft position signal to inspect
The computer may have lost the signal that tells it the crankshaft position and how fast the engine is turning.

Information needed for a more precise diagnosis

  • Exact brand, model, year, version and engine.
  • All the codes present and their OBD status.
  • Freeze frame and live data related to the system.
  • Symptoms, mileage and recent maintenance history.
  • Procedure and limits of an authorised source for that vehicle.

Where to find diagrams and manuals

Manufacturer repair information directory

Choose the make and open its official portal to find the manual, diagrams, cylinder arrangement, and bulletins for the exact vehicle.

Availability, registration, and cost depend on the manufacturer. The link does not grant permission to copy the manual.

Freedom to Fix: emissions service information

Understand which emissions-related service information manufacturers must make available for purchase.

Explains regulated access in the United States; it does not contain the vehicle-specific diagram or make the manual free.

Sources reviewed

  1. Audi A8/A8L/S8 Quick Reference Specification Book — Audi of America / archivo NHTSA. It supports the punctual definition of the code; It does not identify a cause, a part or a repair.
  2. Frequently Asked Questions About On-Board Diagnostics — U.S. Environmental Protection Agency. Supports the safety difference between a fixed breakdown lamp and a flashing lamp; It doesn't diagnose the cause.