P000A – “A” Camshaft Position Slow Response

Reinier

By Reinier (Contact Me)
Last Updated 2018-09-15
Automobile Repair Shop Owner

Trouble CodeFault LocationProbable Cause
P000A A Camshaft Position Slow Response -

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What Does Code P000A 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 (Variable Valve Timing), or VCT (Variable Cam Timing).

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.

Where is the P000A sensor located?

The image above shows the location of the camshaft position sensors on a Mini application. The green arrow indicates the position of the intake camshaft’s sensor, while the red arrow indicates the position of the exhaust camshaft’s sensor.

It must be noted though that although the actual appearance of camshaft position sensors differ greatly between applications, these sensors are always located in close proximity to the camshaft(s) either on the valve cover(s), or in the cylinder head(s). However, since there may be other sensors located on the valve cover(s) or in the cylinder head(s) as well, it is important to refer to the manual for the affected application to locate and identify the camshaft position sensors correctly. Failure to do this could lead to a misdiagnosis, and quite possibly, the unnecessary replacement of parts and components.

What are the common causes of code P000A?

Some common causes of code P000A could include the following-

  • Damaged, burnt, shorted, disconnected, or corroded wiring and/or connectors in the camshaft position sensors’ control/signal circuit(s)
  • Dirty, degraded, or contaminated engine oil that prevents the free movement of either, or both the oil control solenoid and the camshaft actuator
  • Low oil level, or insufficient oil pressure
  • Defective oil control solenoid
  • Defective camshaft actuator
  • Excessive wear of the timing chain(s), and/or associated sprockets, guides, and tensioning devices
  • Defective camshaft position sensor
  • Defects in, or failures of any sensor that is involved in valve timing management, including throttle position sensors, engine speed sensors, and throttle pedal position sensors
  • Failed or failing PCM, but note that since this is a rare event the fault must be sought elsewhere before any control module is replaced

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