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P000B OBD Fault Code (Causes & Fixes)

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Last Updated on: 7th September 2023, 12:45 am

This is an OBD fault code standing for “(B) Camshaft position slow response bank 1”, this fault can trigger for multiple reasons.

Fault CodeFault LocationProbable Cause
P000B(B) Camshaft position slow response bank 1Low oil pressure, faulty camshaft position sensor, camshaft actuator solenoid, or camshaft adjustment valve 1, faulty VCT (variable cam timing) phaser, binding in the VCT unit, damaged / corroded connector terminal, wiring, or harness, faulty PCM or ECM

A P000B OBD fault code indicates the actual position of the camshaft differs from the position that the powertrain control module (PCM) expects.

“B” suggests that the exhaust valves on are the source of the issue, “bank 1” suggests its on the bank 1 side of the engine.

The PCM keeps track of the camshaft’s current position and where it will be in the future.

This code may also be accompanied by a P0010 fault, which suggests that bank 1 is the source of the issue.

P000A, P000C, and P000D are also related fault codes. Some other codes that may appear include the following; P0011, P0012, P0013, P0014, P0015, P0020, P0021, P0022, P0023, P0024, and P0025.

What P000B Means

Vehicle camshafts are used to open and close the intake and exhaust valves on the engine’s cylinders in order to maintain the engine’s smooth operation.

The timing of the camshafts is essential for the engine to operate efficiently.

When the vehicle’s computer generates the OBD code P000B, the timing of this activity is slower than expected.

The exhaust valves in bank 1 are the problem, as indicated by the letter “B”, “A” being the intake valves.

The PCM (powertrain control module) keeps track of both the camshaft’s current position and its future position.

If the camshaft position change is less than it should be during the diagnostic period, the PCM detects a shortfall. If the changes in response time continue over time, a P000B code will be set.

Possible Causes

There are a variety of potential causes for this code due to the substantial amount of moving parts in the engine and camshaft system, the following are the most common reasons for a P000B code.

  • Loose fuel cap
  • Low oil pressure (due to blockage in the oil route, a defective oil pump, low oil level, etc)
  • Faulty camshaft position sensor
  • Malfunctioning camshaft position actuator solenoid
  • Faulty VCT (variable cam timing) phaser
  • Binding in the VCT unit
  • Connection terminal, wiring, or harness that is rusted or damaged
  • A faulty PCM or ECM
  • Timing chain or belt issues

Signs & Symptoms

Typically the only sign accompanying a P000B error code is the MIL (check engine light) illuminating.

You may possibly notice an increase or change in engine noise, subpar engine performance, and/or increased emissions.

Sometimes, other fault codes will appear alongside a P000B code, such as P0010 or various other trouble codes.

How Serious Is It?

The car might seem to operate without any obvious serious issues and function smoothly.

But if the problem isn’t fixed right away, substantial harm could be done to components like the camshaft follower, necessitating future repairs that will be even more costly.

It is best to avoid driving the vehicle and have it diagnosed and repaired as soon as possible.


The diagnostic process should start with validating the P000B code and fixing any codes that were previously set. You should check the engine oil level and top up the oil if needed.

After then, the codes should be erased, and the car examined again to see if the error persists. If the code reappears then additional actions that could be necessary include the following.

  • Utilise an advanced OBD scanner to check the trouble code
  • Check engine oil levels and compare to manufacturer specifications
  • Check engine oil pressure
  • Check for clogs in oil passages
  • Visually inspect the wiring and circuits for signs of damage or corrosion
  • Visually inspect the camshaft advance mechanism
  • Test camshaft adjustment valve
  • Test the camshaft position actuator solenoid

Common Diagnostic Mistakes

Poor oil pressure is typically overlooked as the root cause of this error code, despite the potential that the problem may be with the camshaft mechanism itself or other parts.

If any of the oil pump connections deteriorate or if any of the channels clog, the decreasing oil pressure may trigger a camshaft position sluggish response code.

Therefore, it’s worth checking the oil level and topping up if needed to see if this solves the issue.

Step-by-Step Troubleshooting

In order to find out more about the issue, check for technical service bulletins (TSBs). If nothing is discovered, you could proceed to a standardised diagnosis of the system.

Because different vehicles require different testing for this code, the procedure that follows is generic. To properly test the system, follow the manufacturer’s given diagnostic flow chart.

Before starting, you should consult the factory wiring schematics to determine which wires are which.

For many different vehicles, Autozone provides free online repair manuals, while ALLDATA offers single vehicle subscriptions.

Test the Camshaft Position Sensor

Permanent magnet sensors or Hall Effect sensors make up the majority of camshaft position sensors.

There are three wires that connect to a Hall Effect sensor: reference, signal, and ground.

A permanent magnet sensor, on the other hand, will only have two wires: ground and signal.

Hall Effect Sensor

The signal return wire should be identified. Then, utilise a back-probe test lead to connect a digital multimeter (DMM) to it.

Turn the DMM to the DC volts setting and connect the black metre lead to chassis ground.

Crank the engine, you should notice a fluctuating reading on the metre if the sensor is working properly. If not, the sensor needs to be changed because it is defective.

Permanent Magnet Sensor

Connect a DMM to the sensor terminals after removing the sensor connector. Crank  the engine after setting the DMM to AC voltage.

A reading with fluctuating voltage should be visible. If not, the sensor needs to be changed because it is defective.

Test the Sensor Circuit

Follow the instructions listed below to test the sensor circuit.

Hall Effect Sensor

Start by inspecting the circuit’s ground side. To do this, attach a DMM (set to DC volts) to the connector’s harness side between the battery positive terminal and the sensor ground terminal.

You should achieve a reading of approximately 12 volts if the ground is good.

Connect a DMM (set to volts) between the battery negative terminal and the sensor reference terminal on the harness side of the connector to test the 5-volt reference side of the circuit.

Switch on the car’s ignition. A measurement of roughly 5 volts should be shown.

Both of these tests must provide satisfactory results; otherwise, the circuit will need to be identified and fixed.

Permanent Magnet Sensor

Verify the circuit’s ground connection. Connect a DMM (set to DC volts) between the positive terminal of the battery and the sensor ground connection on the connector’s harness side to do this.

You should obtain a reading of approximately 12 volts if the ground is good. If not, a diagnosis and repair of the circuit will be required.

Test the Oil Control Solenoid

Remove the connector for the solenoid. In order to measure the solenoid’s internal resistance, use a digital multimeter set to ohms.

Connect the multimeter between the solenoid ground terminal and the solenoid B+ terminal to do this. Compare the resistance measurement to the requirements of factory repairs.

The solenoid needs to be replaced if the multimeter shows a reading that is outside of limits (OL) or out of specification, which indicates an open circuit.

Removing the solenoid will allow you to visually check the screen for metal shavings.

Check the Oil Control Solenoid Circuit

  • Check Power Side: Remove the solenoid connector. With the vehicle ignition on, use a digital multimeter (set to DC volts) to check for power at the solenoid (typically about 12 volts). To do this, connect the negative meter lead to battery negative terminal and the positive meter lead to the solenoid B+ terminal on harness side of the connector. The meter should read about 12 volts. If not, the circuit will need to be diagnosed and repaired.
  • Check Ground Side: Remove the solenoid connector. With the vehicle ignition on, use a digital multimeter (set to DC volts) to check for ground. To do this, connect the positive meter lead to battery positive terminal and the negative meter lead to the solenoid ground terminal on harness side of the connector. Command the solenoid on with an OEM equivalent scan tool. The meter should read about 12 volts. If not, the circuit will need to be diagnosed and repaired.

Check the Timing Chain & VVT actuators

If everything is in order up to this stage, the timing chain, or VVT actuators may be in fault.

In order to access the timing chain and actuators, remove the required parts. Look for excessive movement, broken guides, or tensioners in the chain.

Look for visible damage (such as worn teeth) on the actuators.

How to Fix

Once this code has been correctly diagnosed, you could try the following fixes to see if this resolves the issue.

  • Repair any faulty wiring or connectors that are shorted, open, or loose
  • Fill engine oil to the levels advised by the manufacturer
  • Repair or replace the oil pump if it is faulty or broken
  • Repair or replace the camshaft position sensor if it is broken or ineffective
  • Repair or replace a camshaft position actuator that is broken or ineffective
  • Repair or replace the camshaft adjustment valve if it is broken or ineffective
  • Repair or replace a faulty or damaged ECM
  • Clear all codes, put the car through its paces, then rescan to see if any codes reoccur

Additional Notes

There are so many different problems that could be causing your vehicle to generate a P000B code.

Engine timing problems need specialised equipment to test the engine timing and correctly reset the timing when all repairs are finished.

  • Andy Lewin

    Andy Lewin is a senior mechanic, ASE qualified master technician, and an experienced automotive engineer.He's passionate about serving the automotive community with the highest-quality and trustworthy information on all things automotive. He loves to write about car repairs, maintenance, car modifications and tuning, faults, and much more.

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