P1338 Fault Code

Jaguar – FUEL PUMP (FP) – FEEDBACK CIRCUIT MALFUNCTION

For Jaguar, fault code P1338 is logged when the powertrain control module (PCM) has detected an issue with the fuel pump circuit.

The fuel pump is responsible for pressurizing fuel in the fuel tank and sending it to the fuel injection system. This is a necessary step in both transporting fuel and helping pressurize it to increase the efficiency of the fuel injectors found in modern engines.

Because this fault code indicates that there is a circuit malfunction, the cause of the problem will likely be electrical in nature. This can include faulty wiring and various other issues.

However, there is the possibility that the components in the fuel system can be defective, causing the code. The fuel pump itself is the most likely culprit.

An issue with the fuel pump can result in low fuel pressure. This can cause the engine to run lean, which will noticeably decrease the performance of the vehicle.

Additionally, very low fuel pressure can result in the vehicle being unable to start at all. This means this fault code should be fixed as soon as it is logged to continue normal operation of the vehicle.

See generic codes: P0230, P0231, P0232

Audi – CAMSHAFT POSITION SENSOR, BANK 1

For both Audi and Volkswagen, P1338 represents the same issue. However, the VW code does give more information about the cause of the problem.

For more info and similar generic fault codes on this problem, see the below description for Volkswagen.

See generic codes: P0341

Volkswagen – CAMSHAFT POSITION SENSOR (BANK 1) OPEN CIRCUIT OR SHORT TO POSITIVE

For both Audi and Volkswagen, fault code P1338 is logged when the powertrain control module (PCM) has detected an issue with the camshaft position (CMP) sensor circuit in bank 1 of the engine.

The code further pinpoints the issue as an open or short circuit within the sensor’s circuit. This means that fixing this issue will likely involve fixing electrical faults like a blown fuse within the CMP sensor circuit.

The CMP sensor is responsible for relaying information about the camshaft to the PCM.

The PCM needs to know the position of all of the shafts in the engine at all times. This is to ensure proper performance and allow for optimizations by the computer. If the CMP sensor is not functioning correctly, the PCM cannot know the corresponding position.

The PCM also uses continuous position updates from the sensor to determine the speed of the camshaft it is monitoring. This is required to ensure all of the various shafts in the engine remain in time at all times.

This code does not specify which camshaft sensor is at fault. Most modern vehicles will have multiple camshafts, which means there will be multiple CMP sensors.

Without accurate information about the position and speed of the camshaft, the PCM cannot prevent serious damage from occurring to the various components in the engine.

This means it is very important to have this type of issue resolved as soon as it can be detected.

See generic codes: P0341