P0023
B Camshaft Position - Actuator Circuit (Bank 2)P0023 is a generic OBD-II powertrain diagnostic trouble code: B Camshaft Position - Actuator Circuit (Bank 2). It is logged by the engine control unit when the ckp/cmp monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.
What P0023 means
P0023 — "B" Camshaft Position Actuator Circuit/Open (Bank 2) — is stored when the ECM detects an open circuit, short, or out-of-range electrical condition on the oil control valve (OCV) that drives the Bank 2 exhaust ("B") camshaft phaser. In most dual-overhead-cam engine architectures, the "B" designation refers to the exhaust camshaft, while Bank 2 is the cylinder bank that does not contain cylinder #1. The OCV is a PWM-driven solenoid that meters engine oil to advance or retard the camshaft phaser.
This is the Bank 2 mirror of P0020. The ECM typically detects the fault by monitoring the OCV drive current or the feedback voltage; an open winding, broken wire, or corroded connector removes the electrical load and the ECM logs the circuit-open condition. Unlike a timing performance code (P0025), P0023 is a pure circuit fault — the ECM cannot even attempt to actuate the phaser.
On vehicles with variable valve timing (VVT/CVVT/VCT), a disabled exhaust phaser causes the camshaft to sit at its mechanical default position. This degrades combustion efficiency, increases emissions, and can cause a rough idle or reduced power, but rarely causes immediate engine damage unless the phaser is also mechanically stuck and causing a timing jump.
Common causes
Most-frequently reported root causes when P0023 is logged.
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1
Open coil winding inside the Bank 2 exhaust OCV solenoid (most common electrical failure mode).
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2
Broken, chafed, or corroded wiring between the ECM and the Bank 2 exhaust OCV connector.
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3
Corroded or pushed-back pins at the OCV connector causing an intermittent or permanent open circuit.
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4
Failed ECM/PCM output driver for the Bank 2 exhaust OCV channel.
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5
Damaged connector from oil contamination or heat exposure near the camshaft cover.
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6
Short to ground in the OCV supply wire causing the ECM driver to detect an abnormal circuit state.
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7
Aftermarket or incorrect replacement OCV with incompatible resistance installed.
Symptoms drivers notice
How to diagnose P0023
A typical diagnostic flow when this code is present.
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1
Retrieve all stored codes; note any P0024/P0025 companions that would indicate a mechanical phaser issue alongside the circuit fault.
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2
Visually inspect the Bank 2 exhaust OCV connector, wiring, and nearby harness for oil contamination, corrosion, chafing, or heat damage.
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3
Measure OCV solenoid resistance across its two terminals; compare to specification (typically 6–12 Ω depending on manufacturer) — OL (infinite) confirms an open coil.
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4
With the ignition ON and the OCV disconnected, check the supply voltage at the connector; absence of voltage indicates an open in the harness or blown fuse.
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5
Check wire continuity from the OCV connector back to the ECM pin with a multimeter — a break indicates a harness repair is needed.
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6
Clear the code, perform a warm idle and road test, and monitor live VVT actuator position data to confirm the phaser responds.
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7
If the circuit tests good but the code returns, suspect an internal ECM driver fault.
Related powertrain codes
- P000A — A Camshaft Position Slow Response Bank 1
- P000B — B Camshaft Position Slow Response Bank 1
- P000C — A Camshaft Position Slow Response Bank 2
- P000D — B Camshaft Position Slow Response Bank 2
- P0010 — A Camshaft Position Actuator Circuit (Bank 1)
- P0011 — A Camshaft Position - Timing Over-Advanced or System Performance (Bank 1)
Frequently asked questions
What is the "B" camshaft on most engines?
The SAE J1979 standard defines "B" as the second camshaft in a bank, which in the majority of DOHC engines corresponds to the exhaust camshaft. Some manufacturers use different conventions, so always verify with the specific engine's service manual.
Is P0023 the same fault as P0020?
P0020 covers the same "B" camshaft actuator circuit fault but on Bank 1 (the bank containing cylinder #1). P0023 is the Bank 2 equivalent; the diagnosis and repair procedures are identical but performed on the opposite cylinder bank.
Can low oil level cause P0023?
Low oil level alone is unlikely to set a circuit code like P0023, which is specifically an electrical open/short fault. However, low oil pressure can cause a companion timing performance code. If P0023 is present, investigate the electrical circuit first.
Can I drive with P0023?
Short-distance driving is generally possible as the engine will run, but performance and fuel economy will be degraded. Prolonged operation with a stuck phaser can increase emissions and, in rare cases, accelerate wear if the phaser becomes mechanically seized.
Disabling P0023 in software
RaceTune can permanently disable P0023 — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.
Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.
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