P2B38

Code

Generic P — Powertrain

A Camshaft Profile Actuator B Control Circuit High Bank 2

Brand: Generic

Type: P — Powertrain

Views: UK: 21 EN: 28 RU: 22

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Page language: EN

Causes

Short to battery (12 V) on the actuator control circuit
Open or shorted wiring or connector (corrosion, damaged insulation, pin pushed out)
Faulty camshaft profile actuator (VVT solenoid/OCV) with internal electrical fault
Poor ground or power supply to the PCM or actuator
Blown fuse or faulty relay supplying the VVT circuit
Contaminated or hydraulically stuck actuator/OCV causing abnormal electrical behavior

Symptoms

Malfunction Indicator Lamp (MIL) illuminated
Reduced engine performance or torque (limp-home mode)
Rough idle, hesitation, or misfire under some conditions
Poor fuel economy
Erratic cam timing behavior, possible valve timing related noises
Possible difficulty starting or rough cold operation

What to check

Read and record freeze frame data and stored freeze frame parameters
Check for additional related DTCs (other camshaft/circuit codes, low oil pressure codes)
Visually inspect wiring harness and connector at Bank 2 Camshaft Profile Actuator B for damage, corrosion, or loose pins
Check battery voltage and fuses/relays for the cam phasing/VVT system
Backprobe actuator connector and measure voltage while commanding the actuator with a scan tool
Measure coil/solenoid resistance at the actuator connector (engine off) and compare to specification

Signal parameters

Typical idle/off: command driver low (0 V) when de-energized, exact behavior depends on vehicle
When commanded: PCM supplies a switched/PWM ground or 12 V source; expected PWM frequency typically ~50–500 Hz (manufacturer-specific)
Expected control circuit voltage range: ~0–12 V depending on command; persistent near-battery voltage indicates a short to 12 V
Typical VVT solenoid coil resistance: commonly 5–40 ohms (vehicle-specific). High/low values indicate open/short
Current draw when activated: typically hundreds of milliamps; abnormally high current suggests internal short or hydraulic jam

Diagnostic algorithm

Verify code and capture freeze frame. Note ignition on engine off (KOEO) and running (KOER) data.
Inspect harness/connector at Bank 2 Camshaft Profile Actuator B for physical damage, corrosion, or oil contamination. Repair any damage.
Check related fuses/relays and main power/ground circuits for the PCM and VVT system.
With ignition off, disconnect the actuator and measure coil resistance between the control and ground/power pins. Compare to spec. Infinite or very low resistance indicates open or short.
Reconnect and backprobe the control circuit. With key on/engine running, command the actuator ON/OFF using a scan tool and observe voltage. A steady battery voltage on the control lead when it should be low indicates a short to power.
Use an oscilloscope (if available) to confirm PWM waveform shape and frequency from the PCM while commanding the actuator. Look for abnormal amplitude or missing signal.
If wiring and connector are good but readings remain abnormal, swap the actuator with the same bank/position (if interchangeable) to see if the code follows the actuator.
If actuator swap does not change the result, suspect PCM driver fault. Before replacing PCM, confirm wiring continuity to PCM and verify PCM grounds and power supplies.
After repairs or component replacement, clear codes and perform a road test to verify the code does not return.

Likely causes

Faulty VVT solenoid (Camshaft Profile Actuator B) with internal short/high leakage
Wiring shorted to battery voltage in harness near bank 2 actuator
Corroded/loose connector or pin at the actuator causing intermittent high readings
Clogged or mechanically stuck oil control valve producing abnormal driver load
Damaged insulation or chafed harness contacting a 12 V source

Fault status

⚠️ Status

PCM detected a high-voltage condition on the Camshaft Profile Actuator B control circuit (Bank 2). Circuit voltage exceeded the expected threshold while commanded, triggering DTC P2B38.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-2.5 hours