OBD-II code P2691 indicates that the Powertrain Control Module (PCM) has detected incompatible, missing, or invalid calibration data for the fuel injector on cylinder 6. This typically occurs on vehicles that require specific injector trim or calibration codes to be programmed into the PCM after an injector replacement.
The cylinder 6 injector was recently replaced, but its specific trim or calibration code was not programmed into the PCM.
The calibration code entered into the PCM for cylinder 6 does not match the code printed on the physical injector.
The PCM's calibration data has become corrupted, causing it to lose or misinterpret the stored injector data.
An internal fault within the PCM is preventing it from storing or reading the injector calibration data. This is rare.
The vehicle may be drivable, but it can run poorly, misfire, or lack power. Driving with a misfire can potentially damage the catalytic converter, so it is best to address the issue promptly.
Usually no. This code almost always means the injector's calibration data was not programmed after an injector replacement, or the wrong code was entered. Replacing the PCM is a last resort and is rarely the actual fix.
It is a unique code printed on the injector that tells the PCM exactly how that specific injector delivers fuel. Programming it ensures the engine runs smoothly and the cylinders are balanced.
Not necessarily. The injector itself may be functioning perfectly, but the PCM lacks the correct data to operate it properly. Verifying and entering the correct code often resolves the issue.