Code
P001A
Generic
P — Powertrain
A Camshaft Profile Actuator A Control Circuit/Open Bank 1
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UK: 23
EN: 703
RU: 21
AI status
Completed
Completed
100%
Causes
- Open circuit in camshaft actuator control wiring
- Short to ground or short to battery in the control harness
- Faulty camshaft actuator (solenoid/valve)
- Poor or corroded connector/pin contact at actuator or PCM
- Blown fuse or faulty relay supplying the actuator circuit
- Faulty PCM (less common) or internal driver failure
Symptoms
- Malfunction Indicator Lamp (MIL) / Check Engine Light ON
- Rough idle, hesitation or reduced power
- Increased emissions or failed emissions test
- Possible engine misfire or loss of low-end torque
- Limp mode or reduced engine performance on some vehicles
- Irregular cam timing on scan tool/live data
What to check
- Read freeze frame and live data with a scan tool; verify code and conditions
- Visually inspect actuator connector, wiring harness, and PCM harness for damage, corrosion, or water
- Verify fuses and relays related to cam phaser/solenoid power
- Backprobe actuator connector and check for battery feed and control signal
- Measure actuator coil resistance and compare to specification
- Check continuity between actuator connector and PCM control pin; look for shorts to ground/battery
Signal parameters
- Battery supply at actuator power pin: ~12 V (Key ON, Engine OFF)
- Control wire (PCM output) voltage: varies 0–12 V depending on driver state; may be PWM
- Actuator coil resistance: typically ~5–35 ohms (manufacturer-specific) — consult service data
- Expected PWM frequency: often 50–500 Hz (varies by vehicle); duty cycle varies with commanded cam phase
- No continuity (open) or near-zero ohms (short) indicates fault relative to expected coil resistance
Diagnostic algorithm
- Retrieve all stored codes and freeze-frame data with a scan tool. Note engine conditions when the code set.
- Perform a visual inspection of the camshaft actuator harness and connectors on Bank 1 for damage, corrosion, or loosened pins.
- Check relevant fuses/relays. Restore any blown/failed items and retest.
- Backprobe the actuator connector (with connector mated) and measure: battery feed pin for 12 V (Key ON), control pin for voltage/PWM while cranking/running. Compare to expected.
- With ignition OFF, unplug the actuator and measure coil resistance across actuator terminals. Compare to spec. Infinite/very high = open coil; near-zero = short.
- Check continuity between actuator connector control pin and the PCM control pin. Verify no short to ground or battery along the harness.
- If wiring and connector checks are good but intermittent symptoms persist, wiggle-test wiring while monitoring the signal to replicate intermittent open/short.
- If possible, bench-test the actuator by applying battery power briefly (respecting polarity and duty limits) to confirm movement/sound. Do not exceed duty cycle ratings.
- If actuator is confirmed good and wiring/connector checks show proper voltages/continuity, suspect PCM driver failure — verify with manufacturer procedures before replacing PCM.
- After repair (repair/replace actuator, repair wiring, replace fuse/relay, or PCM per procedure), clear codes and perform road/test to ensure code does not return.
Likely causes
- Broken or disconnected wire at the camshaft actuator connector
- High resistance/poor contact at connector due to corrosion or bent pins
- Actuator coil open (high/∞ resistance) or internal short
- Power feed fuse or relay open (no battery supply to actuator)
- Short to battery (constant 12V) or short to ground on the control lead
- PCM driver transistor failed (if wiring and actuator test good)
Fault status
Status
Electrical fault detected in Bank 1 camshaft actuator A control circuit (open/short/abnormal signal).
Repair difficulty: Medium
Diagnostic time: 0.8-2.0 hours
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