P000B Camshaft 1/2 Position slow response

P000B code - The actual camshaft position does not match the desired camshaft position during camshaft for approximately 30.0 seconds. Default Actions P000B code, 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 P000B code is active.

P000B

When monitored P000B 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.

Possible causes P000B code

  • 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 exhaust solenoid 1/2 faulty or intermittently binding/sticking.
  • Camshaft 1/2 oil control valve faulty or intermittently binding/sticking spool valve.
  • Camshaft tone wheel misaligned.
  • Camshaft 1/2 phaser faulty or intermittently binding/sticking.
  • Powertraint Control Module (PCM).

Diagnose code P000B Camshaft 1/2 Position slow response


(Sorry!!! Step 1-2, see code P000A)
Step 1. Engine oil/engine mechanical
Step 2. Check the engine oil pressure and engine mechanical condition

Step 3. Verify an active condition by checking the cam phaser position
If cam phaser or oil control valve is stuck, there may also be a crankshaft/camshaft timing misalignment and/or multiple cylinder misfire DTC present.

With the scan tool, monitor and compare the exhaust Cam 1 desired position value with the exhaust Cam 1 actual position value with the engine running at idle. After comparing the two values at idle, check and compare the values at several different engine speed. The best way to do this is to raise the engine speed quickly and hold steady for up to 30 seconds and monitor the actual and desired values. Then lower the engine speed and hold steady at a level above idle (off of lock pin) for up 30 seconds and monitor the actual and desired values. Repeat this a few times up and down, monitoring the values and then allow the engine to come back to idle and monitor the actual position to verify that the phaser is coming back to lock pin.

Note : There are few things to monitor for during testing. One is for the phaser not coming back to lock pin at idle (this could indicate a faulty phaser or oil control valve that is permanently stuck off lock pin or  VVT solenoid that electrical stuck on). A second is for the actual position lagging or moving slowly toward the desired position (this coul indicate a faulty phaser or tarnished oil control valve that is dragging). The third thing to monitor for would be the actual position lagging and than overshooting the desired position (this could indicate a faulty phaser, oil control valve or VVT solenoid taht is intermittently sticking or binding and then overshoot when the condition goes away).

Is the different between the actual and teh desired value reading more than 6.0 degrees at idle or is the actual value lagging behind or overshooting the desired value ?

YES, the difference is greater than 6.0 degrees at idle indicating that the camshaft will not return to lock pin, go to step 4.

YES, the actual reading is lagging or overshooting when changing the engine speed indicating a binding or sticking, go to step 5.

NO, this fault is occuring due an PCM intermittent condition. The problem could be due to an intermittent sticking or dragging condition of one of the timing component listed in the possible causes table. The issue could be temperature related (incorrect or broken down oil affecting operation during a cold start, or a tolerance issue in a component that is affected after a cold start/heat soak or after the engine is warmed to operating temperature). The issue could also be occuring during certain specific driving conditions, It may be necessary to test drive the vehicle under different load conditions to duplicate the issue.

Step 4. Determine if the Cam phaser issue is electrical or mechanical
While the engine is at idle, disconnect the VVT exhaust solenoid 1/2 harnes connector. The exhaust Cam 1 actual position value should change to lock pin with the selenoid disconnected. The exhaust Cam position should be at approximately 117.0 degrees at lock pin.

Did the exhaust Cam 1 actual value change to lock pin position with the selenoid unplugged ?

YES, check the VVT exhaust control 1/2 control circuit for a short to voltage. If the circuit is not shorted to voltage, replace the Powertrain Control Module and perform the Powertrain verification test.

NO, go to step 5.

Step 5. Check the Camshaft 1/2 oil control valve operation
Turn the ignition off, remove the VVT exhaust solenoid 1/2. Inspect the spring loaded spool valve on the oil control valve.

Note : The spring loaded spool valve should be flush with the surface of the oil control valve when at rest.

Push and release the spring loaded spool valve againts the return spring with a small punch.

Note : The spring loaded spool valve should move freely without binding and return to the flush position if there are problems with the oil control valve.

Was the spring loaded spool valve flush and to move freely without dragging or sticking ?

YES, go to step 6.
NO, replace the Camshaft 1/2 oil valve, perform the Powertrain verification test.

(Sorry!!! Step 6-8, see code P000D)
Step 6. Check the VVT exhaust solenoid 1/2 operation
Step 7. Verify that the VVT exhaust solenoid 1/2 is able to move the phaser
Step 8. Check the exhaust camshaft 1/2 tone wheel

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