P0105 indicates the powertrain control module (PCM) has detected an electrical circuit malfunction in the manifold absolute pressure (MAP) sensor or barometric pressure sensor circuit. This sensor measures intake manifold vacuum/pressure to help the PCM calculate engine load, fuel delivery, and ignition timing. The code sets when the PCM sees an open, short, or voltage value that is impossible under normal operation.
The sensor itself has suffered an internal electrical failure such as an open circuit or short, preventing it from generating a valid signal voltage to the PCM.
Corroded, bent, or loose terminals in the sensor connector, or chafed and damaged wiring in the harness between the sensor and PCM, disrupt signal transmission.
The 5-volt reference supply wire from the PCM to the sensor is open, shorted to ground, or shorted to battery voltage, causing the sensor to operate incorrectly or not at all.
The sensor signal wire is shorted to ground or to battery voltage, or has high resistance due to corrosion, causing a fixed high or low voltage reading.
The sensor ground return path has high resistance or an open circuit, preventing accurate voltage reference and causing erratic or fixed sensor output.
Rarely, the PCM's internal analog-to-digital converter or output driver for the sensor circuit has failed; this should only be considered after the sensor and all wiring are verified good.
Short trips are usually possible, but the engine may run poorly with rough idle or hesitation. Prolonged driving can stress the catalytic converter due to incorrect air-fuel mixture, so repair should be scheduled promptly.
Not without testing first. While the sensor itself is a common failure point, wiring and connector issues are frequent culprits and should be inspected before purchasing replacement parts to avoid unnecessary expense.
Almost never. PCM failure causing this specific circuit code is rare. Only consider the PCM after the sensor, all wiring circuits, and connectors have been thoroughly tested and verified as functioning correctly.
P0105 indicates an electrical circuit problem such as an open, short, or invalid voltage. P0106 indicates the sensor is sending a signal that is implausible or out of range for current engine conditions (a performance issue rather than an electrical one).