P0013 "B" Camshaft Position Actuator Circuit/Open (Bank 1)

P0013 points to an electrical problem in the circuit controlling the “B” camshaft position actuator on Bank 1.

Unlike codes that say the camshaft timing is too advanced or too retarded, P0013 is primarily concerned with the actuator's control circuit.

That difference matters. The engine may have perfectly correct mechanical timing and still set P0013 because the ECM cannot properly control the VVT actuator.

What Is the ECM Detecting?

The engine control module uses an electrically controlled actuator to regulate the variable valve timing system.

When the ECM wants to change camshaft timing, it sends a control signal to the actuator, commonly referred to as a VVT solenoid or oil control valve.

With P0013, the ECM has detected an open or otherwise abnormal electrical path in that actuator circuit.

An open circuit means that electrical current cannot travel through the intended path.

For example, the problem could be caused by:

• A broken wire

• A disconnected connector

• A damaged terminal

• A failed actuator coil

• A blown fuse or missing power supply

• A problem in the control circuit

• An ECM driver fault

So P0013 is not simply saying that the camshaft is in the wrong position.

It is saying that the ECM is having a problem with the electrical circuit used to control the actuator.

What Does “B” Mean?

The “B” camshaft designation is manufacturer-dependent.

On many engines, B is associated with the exhaust camshaft, while A is often associated with the intake camshaft. However, this convention is not universal.

Bank 1 is the cylinder bank containing cylinder number 1.

The exact actuator represented by P0013 should therefore be identified from the manufacturer's wiring diagram and service information rather than assumed from the code description alone.

Why an Open Circuit Happens

A P0013 diagnosis often becomes much easier once the wiring is physically inspected.

Broken wiring

Engine wiring is exposed to heat, vibration, oil, and movement. A wire can break internally even when its insulation appears intact.

Disconnected connector

If the VVT actuator connector is not fully seated, the ECM may detect an open circuit.

This is particularly worth checking if the code appeared after recent engine work.

Damaged connector terminals

A terminal can be bent, pushed backward, corroded, or lose its tension inside the connector.

The connector may look normal from the outside while making poor electrical contact.

Faulty VVT actuator

The actuator contains an electrical coil. If that coil is internally open or otherwise outside the manufacturer's specification, P0013 can result.

Power supply problem

Depending on the engine design, the actuator may receive power through a shared circuit and be controlled by the ECM on the other side.

A fuse, relay, power feed, or common wiring fault can therefore affect the actuator.

Short or damaged control circuit

Although the code specifically mentions an open circuit, wiring damage can create several types of abnormal electrical conditions and should be tested according to the manufacturer's wiring diagram.

ECM control-driver problem

The ECM is responsible for controlling the actuator. An internal driver fault is possible, but it should generally be considered only after the actuator and wiring have been proven good.

P0013 Is Different From a Camshaft Timing Code

This distinction is particularly useful when diagnosing VVT faults.

A code such as P0014 describes a camshaft that is detected as being too advanced.

P0013, however, points toward the actuator's electrical circuit.

The two problems can sometimes occur together.

For example, an open VVT actuator circuit can prevent the ECM from controlling the camshaft properly. The resulting VVT behavior may then produce additional camshaft timing or performance codes.

But seeing P0013 does not automatically mean that the timing chain has jumped.

Symptoms You May Experience

The engine may continue to run, but the symptoms depend on how the particular VVT system behaves without actuator control.

Possible symptoms include:

• Check Engine Light

• Rough idle

• Hesitation

• Poor acceleration

• Reduced engine performance

• Increased fuel consumption

• Difficult starting

• Engine stalling

• Reduced torque

• Poor throttle response

Some engines may show very few noticeable symptoms because the camshaft remains in a default position when the VVT system cannot be controlled.

Where to Start the Diagnosis

P0013 is a good example of why electrical testing should come before replacing mechanical engine components.

Begin with a complete scan

Check all current, pending, and stored DTCs.

If additional VVT, camshaft, crankshaft, voltage, or communication codes are present, they may reveal a common cause.

Look at the freeze-frame data

Check the engine speed, coolant temperature, engine load, and other available parameters from when P0013 was recorded.

This can help determine whether the fault occurs continuously or only under certain conditions.

Identify the exact actuator

Confirm the Bank 1 “B” actuator using the vehicle's service information.

Do not assume that every manufacturer uses “B” to mean the exhaust camshaft.

Inspect the connector

Check the actuator connector for:

• Loose terminals

• Corrosion

• Oil contamination

• Water intrusion

• Bent pins

• Broken locking mechanisms

• Terminals pushed back into the housing

Follow the wiring

Trace the actuator wiring back through the engine harness.

Look for melted insulation, rubbed-through wires, broken conductors, previous repairs, and areas where the harness contacts hot or moving components.

Testing the Actuator

Once the physical inspection is complete, the actuator itself should be tested according to the manufacturer's specifications.

Depending on the system, the technician may measure:

• Coil resistance

• Power supply

• Control voltage

• Continuity

• Short to ground

• Short to voltage

• Voltage drop

• Current draw

There is no universal resistance value that can be applied to every VVT actuator.

A resistance measurement should be compared with the specification for that particular engine.

Also, a coil that has an acceptable resistance does not necessarily prove that the actuator is mechanically clean and functional.

Why Voltage Testing Alone Can Be Misleading

Finding voltage at a connector does not always prove that the circuit can carry the required current.

A corroded connection may show apparently normal voltage with little electrical load but develop a significant voltage drop when the actuator is operating.

For difficult intermittent faults, a technician may therefore need to perform loaded circuit testing or voltage-drop testing rather than relying solely on a basic multimeter voltage check.

Could Engine Oil Cause P0013?

Oil can certainly cause VVT operating problems, but it is important to distinguish a VVT performance problem from an actuator circuit fault.

Dirty oil or restricted oil passages can prevent the camshaft actuator from operating correctly.

However, if the actual problem is a broken electrical wire or an open actuator coil, changing the engine oil will not repair the circuit.

Oil condition becomes particularly important if P0013 is accompanied by other VVT performance or camshaft timing codes.

Does P0013 Mean the Timing Chain Is Bad?

No.

A timing chain problem is not the first thing indicated by this particular code.

P0013 is centered on the electrical circuit controlling the camshaft actuator.

A timing-chain problem may cause other camshaft correlation or timing-related codes, but replacing the chain solely because P0013 is present is generally not justified without additional evidence.

Can the Camshaft Position Sensor Cause P0013?

The camshaft position sensor and the VVT actuator perform different jobs.

The sensor tells the ECM where the camshaft is.

The actuator is used by the ECM to change camshaft timing.

Therefore, a P0013 diagnosis should initially focus on the actuator circuit rather than automatically replacing the camshaft position sensor.

If other camshaft signal or correlation codes are present, then the sensor and its wiring should also be investigated.

A Practical Diagnostic Example

Imagine a vehicle comes into a workshop with P0013.

The technician replaces the VVT solenoid immediately, clears the code, and it returns.

A wiring inspection then reveals that the harness has been rubbing against a metal bracket and one conductor has broken internally.

The new solenoid was never the problem.

This is why P0013 is best approached as a circuit diagnosis, not a parts-replacement exercise.

Is P0013 Serious?

P0013 is generally not an immediate indication of catastrophic engine failure, but it should still be diagnosed.

If the VVT system cannot operate correctly, the engine may experience poor performance, increased fuel consumption, starting problems, or unstable operation.

The situation deserves more urgent attention if the vehicle develops:

• Severe power loss

• Repeated stalling

• Significant misfires

• Difficult starting

• Abnormal timing-system noise

• A flashing Check Engine Light

The Key to Fixing P0013

The most important thing to remember is that P0013 is an electrical actuator-circuit fault.

The correct repair may be as simple as repairing a damaged wire or connector. It may also involve replacing a defective VVT actuator, repairing its power supply, or, much less commonly, addressing an ECM control problem.

A logical diagnostic order is:

Identify the correct actuator → inspect connector and wiring → verify power and ground/control circuits → test actuator resistance and operation → check related VVT conditions → investigate ECM control only after the rest of the circuit has been proven good.

That approach keeps the diagnosis focused on what P0013 is actually reporting instead of assuming that the camshaft, timing chain, or sensor must be replaced.