P2B33

Code

Generic P — Powertrain

A Camshaft Profile Actuator B Control Circuit/Open Bank 1

Brand: Generic

Type: P — Powertrain

Views: UK: 23 EN: 41 RU: 22

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Page language: EN

Causes

Open or damaged wiring to the camshaft profile actuator B (Bank 1)
Poor electrical connection at actuator connector (corrosion, push-out pins)
Failed camshaft profile/variable timing actuator (solenoid)
Short to ground or short to battery in actuator control circuit
Faulty ECM or driver transistor (less common)
Inadequate engine oil pressure or contaminated thick oil causing actuator mechanical failure

Symptoms

Malfunction Indicator Lamp (MIL) illuminated
Reduced engine performance or hesitation on acceleration
Rough idle or poor running at some RPMs
Degraded fuel economy
Possible valve timing related noises or engine misbehavior
Faults reappear after clearing codes if underlying issue not fixed

What to check

Retrieve freeze frame data and all stored/related DTCs with a scan tool
Visual inspection of actuator connector and wiring for damage, corrosion, pin push-out, or oil intrusion
Verify battery voltage and good engine ground
Check engine oil level and condition (dirty/thick oil can affect actuator)
Check fuses and power supply circuits for the ECM/actuator
Attempt actuator command using a capable scan tool (active test) and observe response

Signal parameters

Supply voltage: ~battery voltage (key ON) present at the power feed to the actuator when fused (verify with meter)
Control signal: PWM from ECM — duty cycle varies with commanded timing (requires scope or advanced scan tool)
Typical coil resistance: usually low ohms (typical range 5–30 Ω) — consult vehicle specs before condemning
Expected behavior when commanded: measurable PWM/voltage change at pin and corresponding actuator movement or oil pressure response

Diagnostic algorithm

Connect a scan tool, record freeze frame, and note any related camshaft timing or oil pressure codes. Do not assume this single code is the only fault.
Perform a visual inspection: disconnect harness connector at actuator, check pins for corrosion, bending, or oil contamination, and inspect wiring along the loom for chafe or breaks.
With ignition OFF, measure resistance of the actuator coil between its control and ground pins. Compare to manufacturer spec — a very high/OL reading suggests open coil; a short to battery/ground suggests internal short.
With ignition ON (engine OFF), verify battery voltage present at the actuator power feed (if separate). Backprobe the control pin while commanding the actuator with the scan tool; observe voltage/PWM change. If no change, suspect open wiring or ECM driver.
Check grounds and continuity: verify continuity from the actuator ground to engine ground/ECM ground and check for resistance or intermittent connection.
If wiring and connector OK but actuator does not respond, substitute a known-good actuator (if available) or bench-test the actuator to confirm failure.
If actuator and wiring appear good, verify ECM supply and driver output — measure control signal with an oscilloscope while commanding; an absent or fixed voltage indicates ECM driver fault. Consider harness connector wiring harness repair before replacing ECM.
Repair or replace failed component(s), clear codes, and perform a road test and re-check for return of fault. If intermittent, perform wiggle tests and monitor live data during operation.
Safety note: avoid shorting pins when probing; follow vehicle manufacturer service procedures and disconnect battery when performing repairs that could short circuits.