What does it mean?
OBD II fault code P000A is a generic code that is defined as “”A” Camshaft Position- Slow Response Bank 1”, and is set when the PCM (Powertrain Control Module) detects either that the actual position of the camshaft labelled “A” (usually the intake camshaft) does not match the desired position, or, that the camshaft is slow to respond to commands to advance or retard the valve timing on the bank of cylinders that contains cylinder #1.
Note that this code only applies to applications that are fitted with VVT ( V ariable V alve T iming), or VCT ( V ariable C am T iming). On applications that are fitted with VVT or VCT, the PCM has the ability to rotate each camshaft relative to a fixed reference point in order to alter the valve timing.
The practical advantage of this is that at low engine speeds, the valve timing can be set to produce maximum power, while at higher engine speeds the valve timing can be altered to improve the engines’ volumetric efficiency to improve fuel economy, while reducing emissions at the same time.
In practice, each camshaft is fitted with an actuator that uses pressurized engine oil to change the position, or phasing of the camshaft relative to the crankshaft to produce different power delivery characteristics at different engine speeds. In terms of operation, each camshaft actuator is fed with pressurized oil through a solenoid that is controlled by the PCM.
As a practical matter, the PCM uses input data from the engine speed sensor, throttle position sensor (or throttle pedal position sensor on drive-by-wire systems), various transmission sensors, and others to calculate an appropriate valve timing strategy based on the current engine speed, as well as on the rate of the throttle plate’s movement.
Based on these inputs, the PCM will open the oil control solenoid, which allows the actuators to rotate the camshaft to a position (relative to a fixed reference point on the crankshaft) to either advance or retard the valve timing, and that is calculated to produce improved power delivery and fuel economy.
This position is referred to as the camshafts’ desired position, and the rotation of the camshaft is monitored by a dedicated position sensor that alerts the PCM that the desired position has either been reached, or not, as the case may be. Conversely, when the PCM needs to return the camshaft to its base setting, it will reverse the flow of pressurized oil through the oil control solenoid to relieve the pressure on the camshaft actuator.
Nonetheless, if the camshaft does not reach the desired position, or takes too long to complete a movement, the PCM recognizes that the camshaft is out of phase with either, or both the exhaust camshaft and the crankshaft, and it will set code P000A and illuminate a warning light as a result.