The appearance of the P1395 code on your Audi is a serious warning that should not be ignored. Unlike some generic codes, this one points directly to a vital component for engine synchronization: the camshaft position sensor. Its malfunction can quickly immobilize your vehicle. To resolve this issue, it is essential to understand the Audi Fault Code P1395.
Meaning of Code P1395 on an Audi
The Audi Fault Code P1395 indicates a problem that requires immediate attention.
On Volkswagen-Audi (VAG) group vehicles, the P1395 code is defined as:
“Sensor G40 – Range/Performance – Intermittent Signal”
- G40 is the internal technical designation at Audi/Volkswagen for the camshaft position sensor (Camshaft Position Sensor or CMP in English). It is also often called the PMA sensor in French.
In simple terms: The engine control unit (ECU) detects that the signal sent by the G40 sensor is erratic, intermittent, or outside the expected value range. Without this reliable signal, the ECU can no longer perfectly synchronize fuel injection and ignition spark, which severely degrades engine performance.
Symptoms of Code P1395 on an Audi
The symptoms are often severe and immediately noticeable:
- Illuminated check engine light (MIL): The code is stored in the ECU’s memory.
- Extremely difficult or impossible starting: This is the most classic symptom. The engine cranks but fails to start because the ECU doesn’t know when to inject fuel or trigger the spark.
- Engine stalling: The engine may stall randomly, especially at idle or low speed.
- Very irregular idle (rough idle): The engine shakes and runs erratically.
- Significant power loss and jerking during acceleration.
- Increased fuel consumption.
Probable Causes of P1395 Fault on Audi
The causes focus on the sensor itself and its electrical circuit:
- Faulty G40 Sensor: This is the most common cause. The sensor, subjected to high heat and vibrations, eventually fails.
- Wiring Problem: The electrical harness connecting the G40 sensor to the ECU may be damaged. Common causes:
- Wires rubbed against a metal part.
- Wires burned by contact with the exhaust.
- Insulation chewed by rodents.
- Cut or stretched cables.
- Defective Connector: The sensor connector may be:
- Improperly seated or loose.
- Oxidized or corroded (moisture, salt).
- Broken, with bent pins or pins out of the housing.
- Mechanical Problem (rarer): The target wheel (or “tone wheel”) on the camshaft that is read by the sensor could be damaged or dirty.
Diagnosis and Solutions
Warning: These procedures require knowledge of automotive mechanics. If you are not comfortable, consult a professional, especially an Audi/VAG specialist.
Diagnostic Steps:
- Visual Inspection (Most Important Step):
- Locate the G40 sensor. On most Audi engines, it is located on the cylinder head, often at the front or rear of the engine, near the timing belt pulley.
- Disconnect the battery before any work.
- Inspect the connector and wiring meticulously for about 50 cm. Look for any signs of burning, rubbing, corrosion, or damage.
- Disconnect and reconnect the connector to ensure good contact.
- Contact Cleaning: Use an electrical contact cleaner to spray on the pins of the connector and sensor.
- Electrical Test (Multimeter required):
- Resistance Test: Measure the resistance (Ohms) between the pins of the G40 sensor. Expected values vary by model (consult!), but infinite resistance (open circuit) or zero (short circuit) indicates a faulty sensor.
- Voltage Test: With the ignition ON (without starting), check the supply voltage reaching the connector.
- Reading Real-Time Data (VAG Diagnostic Tool):
- The ideal tools are VCDS (VAG-COM), OBDeleven, or a professional scanner.
- Go to the engine modules and read the live data (Measuring Blocks). You can observe the G40 signal live while someone cranks the engine. An erratic or absent signal will confirm the failure.
Solutions:
- Replace the G40 Sensor: This is the most common solution. Use a quality OEM part (e.g., Bosch, Continental) or an original Audi part for optimal reliability.
- Repair the Wiring: If wires are damaged, they must be repaired by soldering and protected with heat-shrink tubing. Avoid using scotchlocks/crimp connectors.
- Replace the Connector: If the connector is damaged, the plug must be replaced.
Affected Audi Models
The P1395 code can appear on many Audi models equipped with petrol and diesel engines, including:
- Audi A3, S3
- Audi A4, S4, A4 Avant
- Audi A6, S6
- Audi TT
- Audi Q5, Q7
- (And equivalent Volkswagen, Seat, Skoda models)
Conclusion
The P1395 code on an Audi is a critical fault that directly targets the camshaft position sensor (G40). Ignoring this code will very likely lead to an immobilizing breakdown, with your car simply refusing to start. Although replacing the sensor is often the solution, a meticulous inspection of the wiring is an essential and free diagnostic step that can save you from replacing a part that wasn’t faulty. For an accurate diagnosis, using a specific VAG diagnostic tool like VCDS is highly recommended.