P1396 Pontiac: Decoding the OBD2 Error Code

The P1396 Pontiac trouble code is a generic code related to the engine management system. More specifically, it indicates an intermittent problem in the camshaft reference circuit (Intermittent CMP Circuit). This sensor, crucial for the precise timing of fuel injection and ignition, sends erroneous or intermittent signals to the Powertrain Control Module (PCM), triggering this code and the Malfunction Indicator Lamp (MIL) on your dashboard. Understanding this code is essential for any owner of a Pontiac model (Grand Am, Sunfire, Grand Prix, Firebird, etc.) wishing to maintain their vehicle’s optimal performance.

Common Symptoms of Code P1396

When the P1396 Pontiac code is stored in the PCM’s memory, several symptoms can alert the driver. It is important to note that these signs can be intermittent, especially in the early stages of the problem.

• Hard Starting: The engine may take longer to start, or even stall immediately after turning over.
• Rough Idle: The engine may have noticeable misfires and run unevenly at idle.
• Loss of Power: A noticeable drop in performance and sluggish acceleration are common.
• Stalling: The engine may stall, especially at low RPM or under light loads.
• Increased Fuel Consumption: Poor timing leads to inefficient combustion.

Possible Causes of the P1396 Fault

The P1396 Pontiac code can be triggered by several failures. A methodical diagnosis is necessary to identify the exact source of the problem.

• Faulty Camshaft Position Sensor (CMP): The most common cause. The sensor itself may be defective.
• Wiring Problems: Damaged, loose, corroded, or shorted wires between the sensor and the PCM.
• Faulty Connector: An oxidized, poorly connected connector, or one with damaged pins.
• Problem with the Target (Tone Wheel): The toothed wheel on the camshaft that passes in front of the sensor may be damaged.
• Problem with the PCM: Although rare, a faulty control module could be the cause.

Diagnostic Procedure and Solutions

To effectively resolve the P1396 Pontiac code issue, a step-by-step approach is recommended.

1. Visual Inspection: Start with a thorough inspection of the CMP sensor wiring and connector. Look for any signs of damage, corrosion, or looseness. Ensure the connector is properly seated.

2. Sensor and Circuit Testing: Using a multimeter, check the sensor’s supply voltage and ground. Measure the output signal of the CMP sensor (usually an AC signal that varies with engine RPM) to confirm its proper operation. Consult the repair manual for specific values for your Pontiac model.

3. Replacement or Repair: Depending on the test results:

• Replace the faulty CMP sensor if the readings are out of specification.
• Repair or replace any damaged wiring.
• Clean the connectors or replace them if necessary.

4. Clearing the Code: After repairs, use an OBD2 scanner to clear the P1396 code from the PCM’s memory. Perform a road test to ensure the fault does not return.

Conclusion

The P1396 Pontiac code, while potentially concerning, is often resolved by replacing a faulty sensor or repairing a simple wiring issue. Ignoring this fault can lead to uncomfortable driving, excessive fuel consumption, and, eventually, other engine problems. For amateur mechanics, a visual inspection is accessible, but electrical testing of the sensor often requires the expertise and equipment of a professional for an accurate diagnosis and reliable repair.