Code
P001B
Generic
P — Powertrain
A Camshaft Profile Actuator A Control Circuit Low Bank 1
Views:
UK: 20
EN: 34
RU: 26
AI status
Completed
Completed
100%
Causes
- Open or shorted wiring in the actuator control circuit (short to ground)
- Poor or corroded connector at the camshaft actuator/solenoid
- Failed camshaft profile actuator / VVT solenoid
- Low engine oil pressure, clogged oil passages, or contaminated oil preventing actuator movement
- Mechanical failure of the actuator or cam phaser
- Faulty ECM or internal driver failure
Symptoms
- MIL/Check Engine Light illuminated
- Rough idle or unstable idle speed
- Reduced engine power or poor acceleration
- Increased fuel consumption and emissions
- Unusual engine noise from the timing area (rattle)
- Hard starting or delayed cam timing response
What to check
- Read and record freeze frame data and related DTCs with a scan tool
- Verify oil level, condition, and correct viscosity
- Visually inspect actuator/solenoid connector and wiring for damage, corrosion, or loose pins
- Check for additional cam/phase or crank/cam correlation codes
- Perform a wiggle test on wiring while monitoring live data for intermittent changes
- Consult service information/TSBs for vehicle-specific quirks
Signal parameters
- Control signal type: PWM from ECM (pulse-width modulation) or switched ground depending on design
- Typical coil resistance: commonly ~6–20 ohms (varies by vehicle) — check OEM spec
- Control voltage when inactive: ~0–12 V depending on circuit design; when driven may be pulsed to ground or pulsed to supply
- Expected PWM duty cycle: 0–100% commanded by ECM; frequency typically in the tens to low hundreds Hz (vehicle-specific)
- Battery voltage at harness during cranking/running: ~11–14.5 V (no excessive drop)
- Continuity: near 0 ohms to ground only when ECM commands (otherwise open except for sensor/coil internal resistance)
Diagnostic algorithm
- Verify DTC and capture freeze frame. Note engine temperature, throttle position, and RPM when fault set.
- Visually inspect harness and connector at camshaft actuator for corrosion, bent pins, or oil contamination. Repair any obvious issues.
- Check engine oil level and condition; correct level and change oil if contaminated. Replace with correct viscosity if needed.
- With ignition off, measure resistance of the VVT actuator/solenoid between its control pin and ground and compare to OEM spec. Replace if out of range.
- Back-probe the actuator connector with a multimeter or oscilloscope. Start engine or crank and observe control signal: verify presence of PWM or switching, proper amplitude (near battery voltage or ground pulses) and no constant low voltage.
- Check for short to ground or short to battery on the control wire: disconnect actuator and measure for continuity to ground/power. Repair wiring as required.
- Apply bench or fused 12 V to the actuator (follow manufacturer procedure) to verify mechanical movement (if safe to do so).
- If wiring and actuator test good but no proper control signal from ECM, check ECM power/grounds, fuses, and relays. If ECM driver suspected, confirm with manufacturer procedures before replacement.
- Clear codes and test drive to confirm repair. Monitor for reoccurrence and verify cam timing/engine performance.
- Note: follow vehicle-specific service information and safety procedures when applying power or performing mechanical checks.
Likely causes
- Faulty VVT actuator / oil control valve (most likely)
- Connector corrosion or poor pin contact at the solenoid
- Wiring short to ground in the control circuit
- Low oil pressure or blocked oil passage to the actuator
- ECM output driver fault (less common)
Fault status
Status
Camshaft profile actuator A control circuit low (Bank 1) — low voltage or short detected on VVT actuator control circuit; actuator response insufficient.
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
Similar codes
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email