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P0025: "B" Camshaft Position - Timing Over-Retarded (Bank 2)

Severity: Medium Arrange diagnosis promptly and avoid heavy loads. Stop the engine for timing-chain rattle, an oil-pressure warning, severe roughness, or a flashing check engine light; towing is safer than risking a timing failure.

What does P0025 mean?

The exhaust cam on bank 2 stays too far behind its expected timing target. Unlike the circuit fault P0023, this monitor evaluates achieved cam timing. Poor oil supply, a sticking control valve or phaser, and incorrect base timing can all prevent the cam from advancing to the requested position.

Generic OBD-II definition: "B" Camshaft Position - Timing Over-Retarded (Bank 2). Confirm applicability in your vehicle service information.

Common causes

  • Low, contaminated, or incorrect-viscosity engine oil
  • Sticking VVT oil-control valve or cam phaser
  • Incorrect belt/chain timing or worn timing components

Symptoms

  • Uneven idle
  • Poor acceleration
  • Check engine light and reduced fuel economy

Diagnostic focus

Use bank 2 exhaust actual-angle data during a commanded timing test. A slow-moving cam may indicate restricted oil flow; a fixed offset may require a mechanical timing check.

Can I keep driving with P0025?

Severity: Medium Arrange diagnosis promptly and avoid heavy loads. Stop the engine for timing-chain rattle, an oil-pressure warning, severe roughness, or a flashing check engine light; towing is safer than risking a timing failure.

If the check engine light is flashing or the car runs badly, stop driving and have it checked.

Typical fixes

  • Verify oil level and the required viscosity
  • Check commanded versus actual cam angle with a capable scan tool
  • Test the oil-control valve and check mechanical timing if the mismatch remains

Related codes

P0011
"A" Camshaft Position - Timing Over-Advanced or System Performance (Bank 1)P0012
"A" Camshaft Position - Timing Over-Retarded (Bank 1)P0014
"B" Camshaft Position - Timing Over-Advanced or System Performance (Bank 1)P0015
"B" Camshaft Position - Timing Over-Retarded (Bank 1)P0020
"A" Camshaft Position Actuator Circuit (Bank 2)P0021
"A" Camshaft Position - Timing Over-Advanced or System Performance (Bank 2)

Sources & review

Definitions and diagnostic background checked 2026-11-06. Generic guidance, not a substitute for the service procedure for your exact year, engine, and transmission.