Technical Description of OBD-II Trouble Code
Malfunction in the Crankshaft Position Sensor B Circuit
What does that signify?
This diagnostic trouble code (DTC) is a generic powertrain code that is applicable to vehicles equipped with OBD-II. Although it is a generic code, the specific repair steps may vary depending on the make and model of the vehicle.
The crankshaft position sensor (CKP) is responsible for measuring the location of the crankshaft and transmitting this information to the PCM (Powertrain Control Module). The PCM uses this information to properly time the spark in some vehicles, while in others it is only used for misfire detection and does not control spark timing.
The CKP sensor is stationary and works in conjunction with a reluctor ring (or toothed ring) that is attached to the crankshaft. When the reluctor ring passes in front of the CKP sensor, it interrupts the magnetic field created by the sensor, generating a square wave voltage signal that the PCM interprets as the crankshaft position. If the PCM detects a lack of crankshaft pulses or identifies a problem with the pulses on the output circuit, it will trigger the P0385 code.
Other related trouble codes for crank position sensor B include:
Symptoms
NOTE: If the crank sensor is only used for misfire detection and not spark timing (this varies depending on the vehicle), the vehicle should start and run with the Malfunction Indicator Lamp (MIL) illuminated. In some cases, the MIL may not illuminate until the problem occurs frequently over time. If the crank sensor is used for both misfire detection and spark timing, the vehicle may or may not start. Symptoms may include:
Causes
A P0385 “check engine light” code could be caused by:
Possible Solutions
This code is essentially the same as P0335. The code P0385 refers to Crankshaft Position Sensor “B”, while P0335 refers to Crankshaft Position Sensor “A”. If you have the P0385 code, your vehicle is equipped with two crank sensors (CPS). Other crank sensor codes include P0016, P0017, P0018, P0019, P0335, P0336, P0337, P0338, P0339, P0385, P0386, P0387, P0388, and P0389.
