P000A Bank 1 Camshaft 1 position slow response

P000A code - The Variable Valve Timing (VVT)  system continuously varies the camshaft target position based on the engine operating parameters. Based on the parameters, the PCM calculates or models the optimum camshaft position. The camshaft angular position is varied by the oil control valve. The VVT solenoid pushes on a plunger (spring loaded spool valve) in the center of the Oil Control Valve (OCV) which directs oil pressure to the hydraulic actuator (Phaser) on the camshaft sprocket to change the camshaft position relative to the crankshaft position. The VVT solenoid, acting on the Oil Control Valve and phaser is controlled by the PCM. The CMP sensor is used to monitor the position of the camshaft.

A VVT diagnostic is performed to detect a Target Error and Slow Response of the camshaft, problems which could potentially increase tailpipe emissions. The diagnostic is primarily performed by comparing the actual camshaft position to that of a calculated model for the camshaft position. This diagnostic is continuous once the enable conditions are met, however the slow response and target error conditions are not performed simultaneously.

• The target error diagnostic : evalutes the actual camshaft position versus the modeled position when the camshaft is in a relatively stable position. The difference between the to is considered to be the amount of ''error''. If the error amount is greater than a calibrated threshold, it is considered failing.
• The slow response diagnostic : is only peformed when the modeled camshaft position is moving (phasing) in a particular direction, advancing or retarding. The modeled camshaft phasing position is created to match only the worst possible cause of phasing camshaft position, If the actual camshaft phasing operates slower than the model by a calibrated threshold, it is considered failing.

If either of these diagnostics fail, the camshaft position slow response DTC will set. There are four camshaft and two camshaft position sensor. Each CMP sensor will detect the position of both camshaft on its correlating engine bank. When monitored P000A code, engine speed is at least 650 to 1400 rpm, depending on oil temperature, oil temperature is between -7°C to 139°C (19°F to 282°F), battery voltage is greater than 10.0 volts, no CMP sensor, CKP sensor or OBDI plausibility errors, cam phasing is being commanded. Set conditions P000A code, the actual camshaft position does not match the desired camshaft position during camshaft for approximately 30.0 seconds.

Default actions:

• The MIL light will illuminate.
• The PCM will attempt to return the camshaft phaser to lock pin when the fault is active.
• If the vehicle is equipped with the stop/start feature, the system will be disabled when this DTC P000A code is active.

Possible causes

• Engine oil level low.
• Engine oil aerated or contaminated.
• Incorrect engine oil filter.
• Insufficient oil pressure due to a mechanical filure in the oiling system.
• VVT intake solenoid 1/1 faulty or intermittently binding/sticking.
• Camshaft 1/1 oil control valve faulty or intermittently binding/sticking spool valve.
• Camshaft tone wheel misaligned.
• Camshaft 1/1 phaser faulty or intermittently binding/sticking.
• Powertrain Control Module (PCM).

Diagnostic test P000A code

Step 1. Engine oil/engine mechanical

Diagnose and repair any camshaft position selenoid circuit open or shorted DTC before continuing with this test. Diagnose and repair any oil pump solenoid or engine oil pressure sensor DTC before continuing with test. Diagnose and repair any system voltage DTC before continuing with this test.

Turn the ignition off.

The following items should be checked before continuing with this procedure. Failure to do so may lead misdiagnosis.

• Low engine oil level.
• Contaminated, dirty, aerated or deteriorated engine oil.
• Incorrect engine oil viscosity.
• Engine mechanical tolerances out of specification.
• Engine oil pressure out of specification.
• Incorrect engine oil filter (does not meet oem specification).

Where any of the above conditions present ?

YES, repair the engine oiling or mechanical condition (improper oil drain back, oil sludge, damaged oil pump, pick-up tube or seal, etc).

NO, Go to step 2.

Step 2. Check the engine oil pressure and engine mechanical condition

Install the applicable adaptor to the oil filter cap and install an oil pressure gauge to the adaptor, If the adaptor available, monitor the oil pressure reading with the scan tool. Star the engine and allow it to idle, monitor the engine oil pressure reading on the gauge or scan tool. If the oil is below 14 psi or oscillating excessively, it can cause a delay in cam phaser movement sufficient enough to set a slow response DTC.

Is the oil pressure reading stable and above 14.0 psi ?

YES, go to step 3.

NO, repair the engine oiling or mechanical condition (improper oil drain back, oil sludge, damaged oil pump, pick-up tube or seal, etc).

(Sorry!!! Step 3-5, see code P000B)
Step 3. Verify an active condition by checking the cam phaser position

Step 4. Determine if the Cam phaser issue is electrical or mechanical

Step 5. Check the Camshaft 1/1 oil control valve operation

(Sorry!!! Step 6-8, see code P000D)

Step 6. Check the VVT intake solenoid 1/1 operation

Step 7. Verify that the VVT intake solenoid 1/1 is able to move the phaser

Step 8. Check the intake camshaft 1/1 tone wheel

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