The appearance of the P1395 code in your Buick is a serious warning signal. This code indicates a problem with a component essential to the proper functioning of your engine: the camshaft position sensor. Understanding its meaning is crucial to avoid a breakdown that leaves you stranded. This problem is often related to the Buick Fault Code P1395.
Meaning of Code P1395 on a Buick
On the majority of Buick models (and General Motors models in general), code P1395 is defined as:
“Intermittent Camshaft Position (CMP) Sensor Signal – Bank 1 Circuit”
- CMP (Camshaft Position Sensor) is the English term for camshaft position sensor, often abbreviated as PMA in French.
In simple terms: Your Buick’s Powertrain Control Module (PCM) detects that the signal sent by the PMA sensor is irregular, intermittent, or outside the normal range of values. Without this reliable signal, the PCM can no longer accurately synchronize fuel injection and ignition spark.
Symptoms of Code P1395 on a Buick
The symptoms are often severe and directly related to engine performance:
- Check Engine Light illuminated (MIL): The code is stored in the PCM’s memory.
- Extremely difficult or impossible starting: This is the most characteristic symptom. The engine cranks but fails to start (“cranks but won’t start”) because the computer doesn’t know when to inject fuel.
- Engine stalling: The engine may stall unpredictably, especially at idle or low speed.
- Very irregular idle (rough idle): The engine shakes and runs erratically.
- Significant power loss and hesitation during acceleration.
- Increased fuel consumption.
Probable Causes of P1395 Fault on Buick
The causes focus on the sensor, its electrical circuit, and its environment:
- Faulty PMA (CMP) Sensor: This is the most common cause. The sensor, exposed to heat and vibrations, eventually fails.
- Wiring Problem: The wiring harness connecting the sensor to the PCM may be damaged. Typical causes:
- Wires chafed against a metal part.
- Wires burned by contact with the exhaust.
- Insulation chewed by rodents.
- Faulty Connector: The sensor connector may be:
- Improperly seated or loose.
- Oxidized or corroded (due to moisture or road salt in winter).
- Broken, with bent pins.
- Mechanical Problem (rarer): The toothed wheel (or “reluctor”) on the camshaft that the sensor reads could be damaged or excessively dirty.
Diagnosis and Solutions
Warning: These procedures require knowledge of automotive mechanics. If you are not comfortable, consult a mechanic.
Diagnostic Steps:
- Visual Inspection (Most Important Step):
- Locate the PMA sensor. On most Buick engines, it is located on the cylinder head, near the valve cover at the front or rear of the engine.
- Disconnect the battery before any work.
- Inspect the connector and wiring meticulously. Look for any signs of burning, chafing, corrosion, or damage.
- Disconnect and reconnect the connector to ensure a good connection.
- Cleaning Contacts: 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 sensor pins. An infinite resistance (open circuit) or zero resistance (short circuit) indicates a faulty sensor. Consult a repair manual for the specific value.
- Voltage Test: With the ignition in the ON position (without starting), check the supply voltage reaching the connector.
- Swap Test:
- On V6 engines (Bank 1 and Bank 2), there are often two identical sensors. You can sometimes swap them and clear the code. If the code changes from P1395 (Bank 1) to a code for Bank 2, you have identified the faulty sensor.
Solutions:
- Replace the PMA (CMP) Sensor: This is the most likely solution. Use a quality OEM or reputable brand part (like AC Delco, the official GM supplier).
- Repair the Wiring: If wires are damaged, they must be repaired by soldering and protected with heat-shrink tubing.
- Clean the Target: Gently clean the toothed wheel on the camshaft with a degreaser.
Affected Buick Models
The P1395 code can appear on many Buick models, including:
- Buick Regal
- Buick LaCrosse
- Buick Century
- Buick LeSabre
- Buick Park Avenue
- (And other GM models sharing the same engine platform)
Conclusion
The P1395 code on a Buick is a serious fault targeting the camshaft position sensor (PMA/CMP). Ignoring this code risks leaving your vehicle stranded, unable to start. Although replacing the sensor is often the solution, a thorough and cost-free inspection of the wiring and connectors is an essential diagnostic step. To avoid unpleasant surprises, always use quality parts to ensure the longevity of the repair.